FEDERAL COURT OF AUSTRALIA
Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth [2011] FCAFC 132
IN THE FEDERAL COURT OF AUSTRALIA | |
SIGMA PHARMACEUTICALS (AUSTRALIA) PTY LTD ACN 004 118 594 Appellant | |
AND: | First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
DATE OF ORDER: | |
WHERE MADE: |
THE COURT ORDERS THAT:
1. The parties are to submit proposed agreed orders or, if there is no agreement, each party should submit proposed orders, accompanied if desired by submissions of no more than 3 pages, within 7 days.
Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1603 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | ALPHAPHARM PTY LIMITED ACN 002 359 739 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
JUDGES: | BENNETT, NICHOLAS AND YATES JJ |
DATE OF ORDER: | 28 october 2011 |
WHERE MADE: | SYDNEY |
THE COURT ORDERS THAT:
1. The parties are to submit proposed agreed orders or, if there is no agreement, each party should submit proposed orders, accompanied if desired by submissions of no more than 3 pages, within 7 days.
Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1644 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | GENERIC HEALTH PTY LTD ACN 110 617 859 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
JUDGES: | BENNETT, NICHOLAS AND YATES JJ |
DATE OF ORDER: | 28 october 2011 |
WHERE MADE: | SYDNEY |
THE COURT ORDERS THAT:
1. The parties are to submit proposed agreed orders or, if there is no agreement, each party should submit proposed orders, accompanied if desired by submissions of no more than 3 pages, within 7 days.
Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1533 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | SIGMA PHARMACEUTICALS (AUSTRALIA) PTY LTD ACN 004 118 594 Appellant
|
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent
|
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1603 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | ALPHAPHARM PTY LIMITED ACN 002 359 739 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent
|
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1644 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | GENERIC HEALTH PTY LTD ACN 110 617 859 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
JUDGES: | BENNETT, NICHOLAS AND YATES JJ |
DATE: | 28 october 2011 |
PLACE: | SYDNEY |
REASONS FOR JUDGMENT
BENNETT J
1 The patent the subject of this appeal is Australian Patent No AU 2003259586 and is entitled ‘Extended Release Formulation’ (the Patent). It was filed on 30 October 2003, amended on 20 December 2006 and granted to the respondents (together Wyeth) on 11 May 2007. The Patent contains 28 method claims relating to the administration of the compound venlafaxine hydrochloride, which is used in the treatment of depression. An earlier patent for the compound venlafaxine hydrochloride expired on 6 December 2008.
2 Wyeth claims that the earliest priority date for the Patent is 25 March 1996, based on United States Patent Application No 60/014,006 (the Priority Document). The Patent is a divisional of Australian Patent Application No 65442/00 which was filed on 10 October 2000 (the Parent Application), which itself is a divisional of Australian Patent Application No 16400/97 filed on 20 March 1997 (the Grandparent Application). The Grandparent Application claims priority from the Priority Document.
3 Amendments were made to the Patent on 20 December 2006 (the 2006 Amendments). I will refer to the contents of the Patent prior to the 2006 Amendments as the Original Patent and following the 2006 Amendments as the Amended Patent.
4 The appellants, Sigma Pharmaceuticals (Australia) Pty Ltd (Sigma), Alphapharm Pty Limited (Alphapharm) and Generic Health Pty Ltd (General Health) are generic pharmaceutical companies which have obtained registration of extended release (ER) formulations of venlafaxine hydrochloride on the Australian Register of Therapeutic Goods for products known as Evelexa XR, Enlafax-XR and “generichealth XR” respectively.
5 The primary judge found that the appellants had not established any ground under s 138(3) of the Patents Act 1990 (Cth) (the Act) to justify revocation of the Patent. Her Honour concluded that the appellants had threatened to infringe claims 1, 4, 5, 8, 9, 10, 15, 16 and 27 of the Amended Patent (at [632]).
6 A number of issues were raised in the appeal. In summary, they are:
whether the Priority Document affords fair basis for claims 1 to 17 and 27 of the Amended Patent (external fair basis). If not, Wyeth is not entitled to claim an earlier priority date based on the Priority Document, which, as the parties agree, would result in the relevant claims of the Amended Patent being revoked for lack of novelty; and
whether certain claims of the Amended Patent are fairly based on the specification of the Amended Patent pursuant to s 40(3) of the Act (internal fair basis);
whether the specification of the Amended Patent sufficiently describes the invention pursuant to s 40(2)(a) of the Act;
whether certain claims of the Amended Patent lack clarity pursuant to s 40(3) of the Act;
whether the invention of the Amended Patent was obvious pursuant to ss 7(2) and (3) of the Act;
whether certain statements made by Wyeth make the Amended Patent liable to be revoked for false suggestion or misrepresentation pursuant to s 138(3)(d) of the Act;
whether Wyeth is entitled to the invention pursuant to s 15(1) of the Act; and
whether Alphapharm has infringed the Amended Patent.
7 Each of the appellants addressed their notices of appeal and their submissions to different of these grounds. Rather than specify which submission was advanced by or adopted by each of the appellants, I shall refer to Sigma, Alphapharm and Generic Health as the appellants.
8 It is instructive to turn first to a characterisation of the inventions disclosed in the Priority Document and in the Amended Patent.
The Priority Document
9 It is necessary to summarise the content of the Priority Document. The title of the invention as set out in the Priority Document is “[ER] Formulation”. The abstract of the invention, again entitled “[ER] Formulation”, relates to a 24 hour ER dosage formulation which provides better control of blood plasma levels than conventional tablet formulations and further provides a lower incidence of nausea and vomiting than conventional tablets.
10 Under the heading “Background of the invention”, it is stated that:
ER drug formulations are conventionally produced as compressed tablets by hydrogel tablet technology. When the production of tablets is not feasible, it is conventional in the drug industry to prepare encapsulated drug formulations which provide extended or sustained release properties. Dosage forms are formulated and transformed into spheroids using standard spheronisation equipment. The spheroids, after drying, may then be film-coated to retard dissolution.
Gelatin capsules are filled with the film-coated spheroids in the quantity needed to obtain the desired therapeutic effect.
A cited US patent discloses a sustained release pharmaceutical composition of a hard gelatin capsule filled with film-coated spheroids where the film coating is composed of ethyl cellulose optionally with hydroxypropyl methylcellulose (HPMC).
Venlafaxine is a drug used in the treatment of depression. Venlafaxine hydrochloride is administered in compressed tablet form in doses ranging from 75 to 350 mg per day, in divided doses two or three times a day. In therapeutic dosing with tablets, rapid dissolution results in a rapid increase in blood plasma levels followed by a decrease in blood plasma levels over several hours as the active compound is eliminated or metabolised, until sub-therapeutic plasma levels are approached about 12 hours following administration. This requires additional dosing with the drug, which has the side effects of nausea and vomiting.
11 Under the heading “Brief description of the Invention”, the invention is described in summary as follows (emphasis added):
An ER encapsulated formulation containing venlafaxine as the active drug component provides in a single dose a therapeutic blood serum level over a 24 hour period.
Through administration of the venlafaxine formulation of this invention, there is provided a method for obtaining a flattened drug plasma concentration to time profile, affording a tighter plasma therapeutic range control than can be obtained with multiple daily dosing.
In other words, this invention provides a method for eliminating the sharp peaks and troughs (hills and valleys) in blood plasma drug levels induced by multiple daily dosing with conventional immediate release (IR) tablets.
The plasma levels of venlafaxine hydrochloride rise after administration of the ER formulations of the invention for between five to about eight hours (optimally about six hours) and then begin to fall for the remainder of the 24 hour period, maintaining at least a threshold therapeutic level of the drug during the entire 24 hour period.
In contrast, the conventional IR venlafaxine hydrochloride tablets give peak blood plasma levels in two to four hours.
Hence, in accordance with the use aspect of this invention, there is provided a method for moderating plural blood plasma peaks and valleys of multiple daily tablet dosing with administration of a one-a-day ER formulation of venlafaxine hydrochloride.
The use of the one-a-day formulations of this invention reduces the level of nausea and incidence of emesis that attend the administration of multiple day dosing.
In clinical trials of the ER formulation, the probability of developing nausea in the course of the trials was greatly reduced after the first week. Venlafaxine’s ER formulation showed a statistically significant improvement over conventional tablets.
Thus, in accordance with this use aspect of the invention, there is provided a method for reducing the level of nausea and incidence of emesis which comprises dosing a patient in need of treatment with venlafaxine hydrochloride with an ER formulation once a day in a therapeutically effective amount.
12 This brief description describes the invention as an ER encapsulated formulation containing venlafaxine hydrochloride. The use of that formulation, unlike conventional formulations, provides a therapeutic blood serum level of venlafaxine hydrochloride over a 24 hour period enabling a one-a-day dose and reduced side effects. The use of that formulation provides a method of treatment once a day with reduced side effects.
13 The “Detailed Description of the Invention” as set out in the specification can be summarised as follows (emphasis added):
Polymorphic forms of velafaxine hydrochloride may be used in the formulations of the invention. The ER formulations comprise venlafaxine hydrochloride, microcrystalline cellulose and HPMC.
The level of coating can be changed as desired. Other equivalents of ethyl cellulose and HPMC, having the same chemical and physical characteristics as the named proprietary products, may be substituted without changing the inventive concept.
It was completely unexpected that an ER formulation could be obtained. Numerous attempts to produce ER tablets by hydrogel technology proved to be fruitless, which is attributable to the extreme water solubility of the hydrochloride of venlafaxine. Typically, tablets prepared as hydrogel sustained release formulations gave 40–50% dissolution at two hours, 60–70% dissolution at four hours and 85–100% dissolution at eight hours.
Unsuccessful attempts at spheroid formulations are described.
Examples are said to illustrate the solution to the problem of preparation of the ER drug containing formulations of this invention.
The examples are of different levels of coating. Additional film coating gives the desired dissolution profile.
The capsules of the invention are filled to provide an amount of venlafaxine hydrochloride equivalent to that presently used in tablet form and also up to about 150 mg venlafaxine hydrochloride.
Table 2 shows the plasma level of venlafaxine hydrochloride versus time for an IR tablet administered every 12 hours; two ER capsules administered simultaneously every 24 hours; and one 150 mg ER capsule administered once every 24 hours in human male subjects who were already receiving venlafaxine according to the dosage protocol. The table reports that the plasma levels of the two 75 mg ER capsules and the one 150 mg ER capsule provided similar blood levels and that the plasma level after 24 hours for either ER regimen is very similar to that provided by two IR 75 mg tablets administered at 12 hour intervals. Further, the plasma levels with the ER formulation do not increase to the peak levels obtained with the conventional IR tablets given at 12 hour intervals.
Table 3 reports plasma blood levels for males having no prior venlafaxine blood level. The peak blood plasma concentration with the ER capsules was seen at about six hours; whereas the 50 mg IR tablet had a peak blood plasma concentration at four hours.
The tables are not presented as examples of a broader method unlimited by formulation.
Thus the desired dissolution rate of sustained release dosage form of venlafaxine hydrochloride, impossible to achieve with hydrogel tablet technology, has been achieved with the film coated spheroid compositions of this invention.
The claims
14 All of the claims refer to an encapsulated ER formulation of venlafaxine hydrochloride. In summary:
Claim 1 is:
An encapsulated, [ER] formulation of venlafaxine hydrochloride comprising a hard gelatin capsule containing a therapeutically effective amount of spheroids comprised of venlafaxine hydrochloride, microcrystalline cellulose and [HPMC] coated with ethyl cellulose and [HPMC].
[emphasis added]
Claims 2 to 5 are dependent on claim 1.
Claim 6 is to a film coating which is composed of, relevantly, ethyl cellulose and HPMC.
Claim 7 is to an ER formulation for once daily administration comprising spheroids containing, relevantly, venlafaxine hydrochloride, microcrystalline cellulose and HPMC and a coating of ethyl cellulose and HPMC sufficient to give those coated spheroids a dissolution profile which gives the desired release rate over a 24 hour period.
Claim 8 is dependent on claim 7.
Claim 9 is to:
A method for providing a therapeutic blood concentration of venlafaxine over a twenty four hour period with diminished incidences of nausea and emesis which comprises administering orally to a patient in need thereof, an encapsulated, [ER] formulation that provides a peak blood plasma level of venlafaxine in from about four to eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
[emphasis added]
Claim 10 is to:
A method for eliminating the troughs and peaks of drug concentration in a patients [sic] blood plasma attending the therapeutic metabolism of plural daily doses of which comprises administering orally to a patient in need thereof, an encapsulated, [ER] formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
The invention as described and claimed in the Priority Document
The primary judgment
15 The primary judge concluded at [165] that:
(a) The Priority Document disclosed two inventions, ‘an encapsulated formulation’ and ‘a method for obtaining a certain drug to plasma relationship over time yielding a “tighter plasma therapeutic control” than multiple daily dosing’, eliminating the sharp peaks and troughs in blood plasma level induced by multiple daily dosing and thereby reducing the level of nausea and the incidence of emesis that attended multiple daily dosing.
(b) When the Priority Document is read as a whole, the method disclosed is not confined to the particular encapsulated formulations which are disclosed in the Priority Document.
16 The appellants challenge these findings and submit that the only invention described in the Priority Document is the encapsulated formulation.
Consideration
17 The essential integers of claims 1 to 5 include:
an encapsulated ER formulation of venlafaxine hydrochloride;
a hard gelatin capsule containing a therapeutically effective amount of spheroids comprised of venlafaxine hydrochloride, microcrystalline cellulose and HPMC, with the spheroids being coated with a composition of ethyl cellulose and HPMC.
18 Claim 6 is to a particular film coating composition which includes, as an essential integer, HPMC.
19 Claims 7 and 8 are each to an ER formulation of venlafaxine hydrochloride for once daily administration. The essential integers include spheroids containing, inter alia, HPMC and a coating containing, inter alia, HPMC.
20 Claims 9 and 10 are method claims. The essential integers of claim 9 are:
a method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with diminished incidences of nausea and emesis;
administering orally to a patient an encapsulated ER formulation;
the formulation provides a peak blood plasma level of venlafaxine in from about four to about eight hours.
21 The essential integers of claim 10 are:
a method for eliminating the troughs and peaks of drug concentration in a patient’s blood plasma;
attending a therapeutic metabolism of plural daily doses;
the administration of an encapsulated ER formulation;
that provides a peak blood plasma level of venlafaxine in from about four to about eight hours.
22 While claims 9 and 10 do not expressly specify the nature of the formulation, in each case the formulation is in an encapsulated ER form.
23 An issue before the Court in considering the invention of the Priority Document is whether the Priority Document, in particular claims 9 and 10, includes a method for using any ER formulation, including hydrogel tablets.
24 The Priority Document describes the conventional approaches to ER drug formulations. They are conventionally produced as compressed tablets by hydrogel tablet technology and, when the production of tablets is not feasible, it is conventional to prepare encapsulated drug formulations which provide extended or sustained released properties. Venlafaxine and venlafaxine hydrochloride were both known. However, the hydrochloride of venlafaxine was extremely water soluble. IR dose formulations were known but produced side effects and could not be utilised because the compressed tablets produced by that technology were either physically unstable or dissolved too rapidly in solution studies.
25 The body of the specification of the Priority Document is explicit. It states that it was completely unexpected that an ER formulation containing venlafaxine hydrochloride could be obtained because of its extreme water solubility. The specification states that numerous attempts to produce ER tablets by known hydrogel technology proved to be “fruitless”. That is, conventional hydrogel tablet technology could not be utilised. This created a need for a different ER formulation of venlafaxine hydrochloride.
26 The invention was the preparation of spheroid formulations to provide an ER drug containing venlafaxine hydrochloride. The starting point for the invention, that is, the background against which the invention and inventive step were presented in the Priority Document, was a known compound with known characteristics, known therapeutic effect, known side effects, an inability to use existing known hydrogel tablet technology and a desire to develop a formulation that overcame the side effects. A formulation was obtained using a different methodology. There was no suggestion in the specification or in the claims of the Priority Document that the patentee overcame the problem with the use of hydrogel tablet technology. That technology formed no part of the invention. The solution to an ER formulation was to use a different style of formulation altogether; a spheroid formulation.
27 Read as a whole, it is clear that the Priority Document does not describe an invention or inventive step that includes hydrogel tablet technology. Indeed, the basis proffered for the invention is the stated impossibility of obtaining a formulation by such conventional technology. The invention is a successful formulation, overcoming the lack of utility of previous unsuccessful formulations, including those of hydrogel tablet technology. The statements of the patentee circumscribing the invention cannot be ignored in understanding what the invention is. The description of the invention in the specification and the description of how to achieve it are the consideration for and basis of the claimed monopoly.
28 The problem prior to the invention of the Priority Document was that IR formulations of venlafaxine in multiple daily doses gave unwanted side effects. Wyeth’s case is that the solution that it invented was the appreciation that the answer to the problem was a formulation that provided a therapeutic level of venlafaxine over a 24 hour period and an ER formulation with the prescribed plasma profile.
29 The continuous release of venlafaxine in lesser but still therapeutic levels did not cause the side effects of an IR formulation. That approach was conventional and was not asserted as part of the invention. Further, if that was the idea, it had to be put into effect and it was formulation dependent. Not all formulations would achieve the required delivery and the Priority Document does not assert otherwise.
30 Wyeth points to the claims of the Priority Document. Eight of those claims relate to the particular formulation. Independent claims 9 and 10 are, standing alone, to a method unrestricted to formulation, other than a requirement that it be an encapsulated ER formulation containing venlafaxine hydrochloride as the active ingredient. The consistory clause or parts of the specification of the Priority Document said by Wyeth to provide the basis for these claims refer to a method using ‘an [ER] formulation of venlafaxine hydrochloride once a day in a therapeutically effective amount’. However this is the continuation of a sentence that commences ‘in accordance with this use aspect of the invention’; that is, the method of claims 9 and 10 is linked to the use of the invention, the invention being the formulation described. In context, the formulation is not unlimited.
31 It simply cannot be said that, properly construed, claims 9 and 10 of the Priority Document encompass a hydrogel tablet formulation. The claims are read as part of the specification as a whole; if there were any ambiguity or uncertainty on the part of the skilled reader as to the scope of ‘an encapsulated [ER] formulation’, a reading of the specification would make it clear that it did not extend to hydrogel tablet formulations. A construction of these claims to encompass any formulation of venlafaxine hydrochloride would result in these claims not being fairly based on the specification of the Priority Document.
32 However, the fact that it could be said that the unlimited claims 9 and 10 are not fairly based on the body of the specification of the Priority Document does not necessarily answer Wyeth’s contention that the unrestricted claim is present and therefore disclosed sufficiently to provide external fair basis for the equivalent unrestricted claim in the Amended Patent and, accordingly, provide the basis for the earlier claimed priority date, to which I will turn below. The question for present purposes is what the disclosure of those claims was. If, in context, they are read, or would have been read, as restricted to the formulation described in the Priority Document and claimed in claims 1 to 8, the disclosure of those claims is of the use of the formulation of the invention.
33 In my view, the latter is the case. A skilled reader reading the whole of the Priority Document would be left in no doubt that the methods of claims 9 and 10 refer to the use of an encapsulated, ER formulation. In order to know how to work the method of those claims, the reader would have to turn to the body of the specification which provides that formulation. Otherwise, claims 9 and 10 would be to a goal and not to a patentable invention that is a manner of manufacture and useful and where sufficient instruction is given to enable the skilled worker to work the claimed method.
34 On reading the whole of the document, the skilled reader would understand the formulation of those claims to be the formulation of the invention and not unrestricted except for the requirement that it be encapsulated and an ER formulation. Both the specification of the Priority Document and the description of the methods subsequently claimed in claims 9 and 10 make it clear that the method is ‘through administration of the venlafaxine formulation of this invention’. In the words of the specification, the method is ‘the use aspect of this invention’, the invention being the formulation. The formulation achieved is central to the invention and it is the administration of the formulation that achieves the results as set out in the method. The method is dependent on the formulation. It is not a separate and independent invention. This is supported by the information in the specification which provides the blood plasma levels of the new formulation and discloses a direct relationship between the particular formulation disclosed and the particular blood plasma levels achieved. That is, the disclosure of the specific formulation yielding the specific plasma profile (the first invention of the Priority Document found by the primary judge) is not a disclosure of a general method where the administration of any ER oral dosage form would have the same therapeutic effect and plasma profile (the second invention of the Priority Document found by the primary judge).
35 When the Priority Document is read as a whole, not only are the methods of claims 9 and 10 limited to the administration of the encapsulated ER formulation, but they are also limited to the encapsulated ER formulation of claims 1 to 8. What was new and inventive was not a method for eliminating troughs and peaks of drug concentration with an ER formulation but of providing the ER formulation of venlafaxine hydrochloride, a drug which was, according to the inventors, difficult to formulate by conventional hydrogel tablet technology.
the amended patent
36 The Original Patent is, as relevant to the appeal, the same as the Priority Document, save for:
the abstract of the Original Patent describes the invention as ‘an encapsulated, [ER] formulation of venlafaxine hydrochloride comprising a hard gelatin capsule containing a therapeutically effective amount of spheroids comprised of venlafaxine hydrochloride, microcrystallised cellulose and [HPMC], the spheroids being coated with ethyl cellulose and [HPMC]’; and
the application of the Original Patent says that it is a divisional of the Parent Application which is in turn a divisional of the Grandparent Application and that ‘the entire disclosure of both these early applications is incorporated herein by reference’.
These changes to the Original Patent have been retained in the Amended Patent.
37 The background of the invention in the Amended Patent has not been changed from the Priority Document and the Original Patent save for:
a statement to the effect that the discussion of the background of the invention is included to explain the context of the invention; and
a statement that it is not to be taken as an admission that any of the material referred to was published, known, or part of common general knowledge in Australia as at the priority date of any of the claims.
The 2006 Amendments
Deletions
38 The following subject matter in the Priority Document/Original Patent was deleted:
The statement that what is provided, in accordance with the invention, is an ER encapsulated formulation.
The statement that, through administration of the venlafaxine formulation of the invention there is provided a method of obtaining a flattened drug plasma concentration to time profile, thereby affording a tighter plasma therapeutic range control than can be obtained with multiple daily dosing.
A reference to the fact that the use of the one-a-day formulation of the invention reduces by adaptation the level of nausea and incidence of emesis that attended the administration of multiple daily dosing and that in accordance with this use aspect of the invention there is a method of reducing the level of nausea and incidence of emesis attending the administration of venlafaxine hydrochloride.
The statement that the ER formulations of the invention are comprised of venlafaxine hydrochloride in admixture with microcrystalline cellulose and HPMC.
The unequivocal statement that preferably the spheroid formulations of the invention contain stated percentages of venlafaxine hydrochloride, microcrystalline cellulose and HPMC.
The statement that it was completely unexpected that an ER formulation containing venlafaxine hydrochloride could be obtained because it proved to be extremely water soluble.
39 There has been substantial alteration to the “brief description of the invention”. The reference to an ER encapsulated formulation that provides a therapeutic blood serum level over a 24 hour period has been deleted. The references to the flattened drug plasma concentration time profile and the moderation of the plural blood plasma peaks and valleys have been deleted. Also deleted is the statement that the use of the ‘one-a-day venlafaxine hydrochloride formulations of the invention’ reduces the level of nausea and incidence of emesis that attend the administration of multiple daily dosing.
Additions
40 The changes to the body of the specification include the addition of statements that the invention is no longer simply the formulation described, which is now only one example of a broader invention. For example, a number of references to the formulation of the invention have been deleted and replaced by broad consistory statements, for new claims, each to a method.
41 The brief description of the invention now commences with the statement that, in accordance with the invention, there is provided the claimed method. Further embodiments are described:
A method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilisation of multiple daily dosing of venlafaxine hydrochloride, which comprises the claimed method.
A method of reducing the level of nausea and emesis in a patient in need of venlafaxine by the claimed method.
A method for treating depression – including by the claimed method.
A method for providing a therapeutic blood plasma concentration of venlafaxine hydrochloride over a 24 hour period with a stated peak blood plasma concentration of no more than 150 ng/ml.
A method of moderating the plural blood plasma peaks and valleys by administering venlafaxine hydrochloride over a 24 hour period with a peak blood plasma level of no more than 150 ng/ml.
A method of reducing the level of nausea in a patient in need of venlafaxine by the administration of venlafaxine hydrochloride over a 24 hour period with a peak blood plasma level of no more than 150 ng/ml.
A method for treating depression at the dosage level (defined above).
A method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period by administering orally a single daily dosing formulation with a specified dissolution profile.
A method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilisation of multiple daily dosing of venlafaxine hydrochloride which comprises administering orally a single daily dosing formulation having the stated dissolution profile. Added by a further amendment on 11 January 2007 is a further feature that the daily dosing formulation provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period.
Similarly, a method of reducing the level of nausea and the incidence of emesis with the specified profile.
A method for treating depression by the stated profile.
42 The formulations of venlafaxine hydrochloride are, after the 2006 Amendments, only examples and embodiments of examples. One example is an ER formulation that is administered as a single daily dosing formulation. One embodiment of the invention is the use of that example in the claimed method or minor variations of the claimed method. ER formulations previously described as beads or spheroids are described in the Amended Patent as “coated beads”. Where in the Priority Document and the Original Patent the statement was made that the drug containing the formulation is coated with a mixture of ethylcellulose and HPMC to provide the desired level of coating, that wording is now described merely as one embodiment. A further change has been to specify that, instead of the ER spheroid formulations of the invention “comprising” stated percentages of venlafaxine hydrochloride, microcrystalline cellulose and HPMC, the coated spheroid core of the ER formulation “preferably comprise” those percentages.
43 The statement in the Priority Document that:
It was completely unexpected that an [ER] formulation containing venlafaxine hydrochloride could be obtained because the hydrochloride of venlafaxine proved to be extremely water soluble. Numerous attempts to produce [ER] tablets by hydrogel technology proved to be fruitless because the compressed tablets were either physically unstable (poor compressibility or capping problems) or dissolved too rapidly in dissolution studies.
has been replaced in the Amended Patent with:
It was completely unexpected that a single daily dosing formulation containing venlafaxine hydrochloride for use in the methods of the invention could be obtained because the hydrochloride of venlafaxine proved to be extremely water soluble. Numerous attempts to produce single daily dosing, [ER] or tablets by hydrogel technology proved to be fruitless because the compressed tablets were either physically unstable (poor compressibility or capping problems) or dissolved too rapidly in dissolution studies.
[emphasis added]
The claims
44 There has been substantial alteration to the claims of the Original Patent by the 2006 Amendments and some further minor alteration by amendments made in 2007 (the 2007 Amendments). Claims 1 to 8 of the Original Patent have been deleted. Claim 1 of the Amended Patent is now a method of treatment claim, untrammelled by reference to any specific kind of formulation of venlafaxine. Claim 1 of the Amended Patent is the previous claim 9 of the Original Patent and the Priority Document amended to remove references to diminished incidences of nausea and emesis and substituting ‘a single daily dosing formulation of venlafaxine hydrochloride’ for ‘an encapsulated [ER] formulation’. Claim 1 of the Amended Patent is to:
A method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
45 The remaining claims of the Amended Patent reflect the amended consistory clauses added by the 2006 Amendments. All references to “encapsulated” ER formulations in claims 9 and 10 of the Original Patent (which were the same as claims 9 and 10 of the Priority Document) have been removed in the claims of the Amended Patent. None of the added claims refer to an encapsulated ER formulation. They refer to ‘a single daily dosing formulation of venlafaxine hydrochloride’ that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with a specified peak blood plasma level.
46 The reference to a spheroid core first appears in claim 18, which has been modified from claim 1 of the Priority Document and the Original Patent to be a claim not to a formulation but to a method according to one of the preceding claims wherein the formulation contains a therapeutically effective amount of spheroid core, the spheroid core being coated with a coating comprising ethyl cellulose and HPMC.
47 Claim 27, the final claim, is to:
A method according to any one of the preceding claims wherein the formulation is an encapsulated formulation.
This is the only claim that limits the formulation to an encapsulated formulation.
48 The 2007 Amendments insert into various of the claims the requirement that the single daily dosage formulation of venlafaxine hydrochloride provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period.
The invention of the Amended Patent
49 It is necessary to turn to the Amended Patent to understand the invention there described. To ascertain the invention of the Amended Patent, I am assisted by the way in which the patentee describes:
• the invention;
• what is said about the problem faced by the patentee; and
• the advance over matters previously known.
50 The invention of the Amended Patent is said to be a method. What was in the forefront of the description of the invention in the Priority Document, that is, a formulation for treating depression and the elimination of the side effects of nausea and emesis, is now relegated to the role of further embodiments.
51 The appellants submit that the formulation is central to the operation of the method and that the “method” is a description of the result of administering a single daily dosing of venlafaxine.
52 Wyeth says that it has developed a new method of treatment which depends on the parameters of the blood plasma profile achieved. Wyeth characterises the invention of the Amended Patent as ‘a method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride, characterised by certain parameters’. Those parameters include a Tmax and a Cmax.
53 Wyeth submits that the claimed method represents a new result or thing, obtained by a new application of principle as in Shave v HV McKay-Massey Harris Pty Ltd (1935) 52 CLR 701 at 709 and Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (2004) 217 CLR 274 (Lockwood (No 1)) at [59]. Accordingly, Wyeth submits, the inventor may claim all the alternative means by which the thing or result may be achieved. Wyeth emphasises that the Amended Patent does not disclaim that the method achieved is one of “general application”.
54 Wyeth cites part of the brief description of the invention as supporting the claimed general ER formulation:
In accordance with this invention, there is provided a method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
However, that passage must be read in the context of the Amended Patent as a whole.
55 The first sentence of the “Background of the Invention” in the Amended Patent says:
[ER] drug formulations are conventionally produced as compressed tablets by hydrogel tablet technology.
56 There follows an explanation of the conventional preparation of sustained or ER forms. It is stated that it is conventional to prepare encapsulated drug formulations which provide extended or sustained release properties where the production of tablets is, as here, not feasible. One way is to form spheroids using standard techniques, which may be coated to retard dissolution. Gelatin capsules are filled with the film-coated spheroids ‘in the quantity needed to obtain the desired therapeutic effect’. This can include a means of releasing the drug at different rates. The Amended Patent discusses the unwanted side effects with two or three doses a day of venlafaxine tablets accompanied by a rapid increase in blood plasma levels of the drug after administration followed by a decrease in blood plasma to sub-therapeutic levels. It is in this context that the Amended Patent turns to a brief description of the invention, saying that what is provided is an ER formulation which provides, in a single dose, a therapeutic blood serum level over a 24 hour period. It is this invention that is said ‘to provide a method for eliminating’ the uneven blood plasma drug levels of multiple dosing. Again, as in the Priority Document and the Original Patent, the Amended Patent states that ‘in accordance with the use aspects of the invention’ a method is provided for moderating the plural blood plasma levels of multiple dosing.
57 The specification includes a description of the invention as a method. It states that the method of the invention is that of claim 1, the broadest claim.
58 The invention does not, however, disclose a new “principle” or a new application of principle. The principle of the invention is to achieve an ER formulation which was, as the Amended Patent states, a conventional means of formulation of a compound that was difficult to formulate. A plasma profile that provides a therapeutic level of a drug over a 24 hour period was not a new principle. There is no explanation in the Amended Patent of how the side effects were diminished but that result followed the elimination of the troughs and peaks as a result of the plasma profile achieved with the specific formulation described.
59 The invention is not the discovery of a new method with any formulation. The method disclosed is the use of the invention, the ER formulation. There is no asserted invention in the measurement of blood plasma levels after administration of the drug. There is no asserted invention in the idea of a sustained release formulation delivering a therapeutic plasma level of the drug over 24 hours. They are the parameters by which the success of the formulation is measured. They are the parameters of the method which is the goal: a therapeutic dosage, measured by the plasma level of the drug, delivered over 24 hours. The goal is not the patentable invention. The invention is the means of achieving the goal.
60 Wyeth submits that the utility of the method turns on the parameters of the profile achieved, but that confuses the measurements or parameters by which a successful ER formulation may be assessed with the disclosure of the formulation which can achieve those outcomes. It is equivalent to saying ‘I claim all methods of transporting man to the moon that will overcome the earth’s gravitational pull, travel at X km/h and achieve an orbit around the moon’ with the disclosure of one particular rocket that does so. It confuses the goal with the means of achieving the goal.
61 The plasma profile, exemplified for the specific formulation described in the Amended Patent, is, in its application to any ER formulation, a “wish list”. It tells the reader that the desired invention is a formulation of venlafaxine that is formulated to achieve an ER of a therapeutic dosage. However, it does not tell the reader how to do so, or what the formulations are other than the specified formulation. The Amended Patent says that it is providing the method, which achieves the desired outcome ‘through administration of the venlafaxine formulation of this invention’, not through some sort of recognition of the parameters that can be measured when the formulation is used. The method may be characterised by the outcome of the blood plasma profile but that is in the context of the desirable blood plasma profile of a successful formulation. It is the use of the disclosed formulation that achieves the method, with an outcome of the desirable therapeutic amounts of venlafaxine over a 24 hour period without undesirable side effects. The method is at all times linked to the nature of the formulation. That is the description of the invention, read as a whole.
62 Evidence from Professor Charman, Wyeth’s expert witness at the trial, that, in his view, a formulation using hydrogel technology was not in fact impossible and that a formulation that achieved the plasma profile of the invented formulation would be useful in the method of the Amended Patent is not relevant to the description of the invention.
Fair Basis
General
63 A patent, conventionally drafted, records the background to the invention, generally describing a problem in the art, realised or unrealised by others. It explains how the inventor solved the problem and what he, she or they found. It then sets out the extent of the monopoly claimed for the invention described. It is necessary to read the whole of the patent to understand what the invention is. In order to gain the monopoly sought, the patent must satisfy the statutory tests in the Act. Some tests are directed to the way in which the patent is drafted, others to the right of the patentee to the claimed monopoly. A patent that satisfies the drafting requirements, for example where claims are fairly based on the description in the body of the specification, may still be liable for revocation, for example for want of novelty, lack of utility, the absence of an inventive step in “the journey” to the invention as outlined in the patent, or lack of sufficient description of the invention.
64 Section 40(3) of the Act provides that the claims of a patent must be fairly based on the matter described in the specification. The test for determining whether a claim is fairly based is determined by the application of the principles set out in Lockwood (No 1) at [69]. Section 40(3) requires a ‘real and reasonably clear disclosure’ of what is claimed. The invention must be broadly described in the body of the specification and not travel beyond the matter disclosed. As the High Court emphasised in Lockwood (No 1), s 40(3) does not involve an analysis of the inventor’s rights to the invention but whether, as a matter of drafting, the claims can be said to reflect what is disclosed or stated in the body of the specification.
65 The same principles apply to a determination of external fair basis (Inverness Medical Switzerland GmbH v MDS Diagnostics Pty Ltd (2010) 85 IPR 525 at [142]); the claims must be fairly based on matter disclosed in a parent patent or a priority document. If the patentee asserts an earlier priority date than the filing date of the patent, by reason of the filing of an earlier patent or document in Australia or overseas, the claims of the patent must be supported by the description of the invention in the earlier patent or document. If the patentee changes the claims, the priority date of the claims may be deferred to the date that those changes were made.
66 In essence, even if an amended patent itself complies with the drafting rules, for example by amendments to add information to the specification to provide support for amended claims, a patentee cannot set forth one basis for and description of the invention to obtain an early priority date and then change the basis and the characterisation and description of the invention while keeping the same earlier priority date.
External fair basis
67 Section 114(1) of the Act provides:
Where a claim of a complete specification claims matter that was in substance disclosed as a result of amending the specification, the priority date of the claim must be determined under the regulations.
68 Regulation 3.14 of the Patent Regulations 1991 (Cth) (the Regulations) relevantly provides:
If subsection 114(1) of the Act applies to a claim of a specification, the priority date of the claim is:
…
(b) in any other case – the date of filing of the statement of proposed amendments that resulted in the disclosure referred to in subsection 114 (1) of the Act.
69 If, as contended by the appellants, claims 1 to 17 and 27 of the Amended Patent claim matter that was ‘in substance disclosed’ as a result of the 2006 Amendments, the priority date of each claim of the Amended Patent is determined under s 114 of the Act and reg 3.14(b) of the Regulations. The priority date of the claim would then be the date of filing of the statement of amendments, 20 December 2006.
70 The principles to be applied are not in dispute in the appeal. The primary judge held at [154] that the test for ‘in substance disclosed’ for the purposes of s 114 is essentially the same as that for fair basis under s 40(3). Therefore, as the primary judge stated, the issue for determination for the purpose of the priority date of the Amended Patent is whether the claims of the Amended Patent are in substance disclosed in the Priority Document.
71 The key issue is the description and characterisation of the invention disclosed in the Priority Document, which I have already discussed above.
The primary judgment
72 Her Honour found at [165] that the relevant claims of the Amended Patent were disclosed in the Priority Document. This was based on her Honour’s conclusion that the Priority Document disclosed the two inventions of:
an encapsulated formulation; and
a method for obtaining a certain drug to plasma relationship over time.
73 Her Honour said that when the Priority Document is read as a whole, the method there disclosed was not confined to the particular encapsulated formulations, embodiments or examples disclosed. In coming to that conclusion, her Honour discounted the references to the inventor’s failed efforts to prepare a hydrogel tablet formulation and to the fact that claims 9 and 10 of the Priority Document, which claimed a method, were themselves restricted to a method comprising the administering of ‘an encapsulated, [ER] formulation’.
Consideration
74 Based on my consideration of the invention of the Priority Document above, if Wyeth relies on the whole of the Priority Document for external fair basis, the claims of the Amended Patent are wider than the invention there disclosed which, as I found above and as is claimed in claims 1 to 8 of the Priority Document, is limited to the ER formulation described in the body of that specification. The claimed methods of the Amended Patent are not so limited. The subject matter of each of claims 1 to 17 and 27 of the Amended Patent is not fairly based on the matter disclosed in the Priority Document and those claims claim matter in substance disclosed as a result of the 2006 Amendments.
75 If the claims of the Amended Patent are to a method that includes the administration of a formulation utilising hydrogel technology, they travel beyond the disclosure of the Priority Document and are not fairly based. The description of the invention in the Priority Document is of the specific formulation as claimed in claims 1 to 8 of that document. As I found above, the invention of the Priority Document does not include a formulation based on hydrogel tablet technology. The claims of the Amended Patent, which include such formulations, are thereby not fairly based.
76 Wyeth relies on claims 9 and 10 of the Priority Document, standing alone, to provide fair basis for claims 1 to 17 and 27 of the Amended Patent. Claims 1 to 17 of the Amended Patent are each to any ‘single daily dosing formulation of venlafaxine hydrochloride’ whether encapsulated or not. Claim 27 is to a method according to any of the preceding claims ‘wherein the formulation is an encapsulated formulation’.
77 Claims 9 and 10 cannot be read in isolation to provide fair basis for these claims. The invention described in the specification of the Priority Document also circumscribes a proper construction of claims 9 and 10. As described earlier in these reasons, that is not any formulation or any encapsulated formulation but the formulation or encapsulated formulation of the invention of the Priority Document.
78 There is no dispute that regard must be had to the whole of the Priority Document, including the claims. This involves an assessment of statements in the Priority Document in context. There is no dispute that the comparison must be conducted as a matter of substance. However, Wyeth submits that, by analogy with the fair basing of a complete patent specification on a provisional specification, ‘a development along the same line of thought which constitutes or underlies the invention described in the earlier document’ may be regarded as fairly based on matter disclosed in the earlier document (Delnorth Pty Ltd v Dura-Post (Aust) Pty Ltd (2008) 78 IPR 463 at [20] per Gyles J, citing Stauffer Chemical Co’s Application [1977] RPC 33 at 54). Those observations cannot, however, derogate from the requirement that the earlier document must in substance disclose the claimed invention. Even if that invention were further developed in the later document, it must be the same invention. Additionally, a disclaimer of the scope of the invention described in the earlier document cannot be disregarded in assessing the external fair basis of the subsequent claim on that earlier document.
79 The necessity of putting stray phrases, parts of sentences or parts of paragraphs into the context of the whole of the Priority Document answers many of Wyeth’s submissions on external fair basis. It is correct that, as Wyeth submits, there is a reference in the specification of the Priority Document to the provision of an ER encapsulated formulation containing venlafaxine hydrochloride, unlimited by reference in that sentence to the particular spheroid formulation the subject of the later examples. However, the beginning of that sentence is ‘in accordance with this invention’ an ER formulation is provided. The next sentence commences with ‘through administration of the venlafaxine formulation of this invention, there is provided a method’. The Priority Document does not assert that it provides a method unrestricted to the formulation described. To the contrary, it asserts that some formulations, such as a hydrogel formulation, have not worked.
80 Claims 1 to 17 and 27 of the Amended Patent are not fairly based on the Priority Document. They claim matter that was in substance disclosed as a result of the 2006 Amendments. Accordingly, the priority date of the Amended Patent is deferred to 20 December 2006.
81 As agreed, as at that date, the relevant claims of the Amended Patent lacked novelty and are liable to be revoked.
82 The alternative basis advanced for the determination of the priority date is through the application of reg 3.12 of the Regulations which also deals with the priority date of a claim. Regulation 3.12 relevantly provides:
(1) Subject to regulations 3.13 and 3.14 and subregulation (2), the priority date of a claim of a specification is the earliest of the following dates:
(a) the date of filing of the specification;
(b) if the claim is fairly based on matter disclosed in 1 or more priority documents, the date of filing the priority document in which the matter was first disclosed;
(c) if the specification is a complete specification filed in respect of a divisional application under Section 79B of the Act and the claim is fairly based on matter disclosed in the specification referred to in paragraph 79B(1)(a) of the Act – the date mentioned in subregulation (2C); …
(2C) The date for a specification to which paragraph 3.12 (1) (c) applies is the date that would have been the priority date of the claim if it had been included in the specification referred to in paragraph 79B (1) (a) of the Act.
83 Accordingly, the Amended Patent would take the date of filing of the Original Patent unless the claims are fairly based such that:
a claim of the Original Patent is fairly based on matter disclosed in the specification of the Grandparent Application (see regs 3.12(1)(c) and 3.12(2C) of the Regulations); and
a claim of the Grandparent Application is fairly based on matter disclosed in the Priority Document (see reg 3.12(1)(b) of the Regulations);
then, the priority date of the amended claim would be the date of filing of the Original Patent, that is, 30 October 2003.
84 However, reg 3.12 is subject to reg 3.14 of the Regulations. It follows that the claims of the Amended Patent as filed in the statement of proposed amendments only take the date of the Original Patent and thereby of the Priority Document if they are in substance disclosed in the Original Patent and, it follows, in the Priority Document. In this case, the result is the same as that obtained by a direct application of reg 3.14. The priority date is, again, the date of filing of the statement of amendments, 20 December 2006.
85 I agree with Yates J that it is unnecessary to consider further the interaction between s 114 of the Act and regs 3.14(b), 3.12(1)(a) and 3.12(1)(b) for the purposes of this appeal.
86 It follows that the appellants have been successful in their appeal and it is not necessary to consider the remaining grounds. I will, however, consider some further aspects and indicate, shortly, my conclusions.
Internal fair basis
87 The primary judge’s characterisation of the invention of the Amended Patent, as a method of treatment by administration of any formulation of venlafaxine hydrochloride that achieved the required profile, led to the conclusion that claims 1 to 17 and 27 of the Amended Patent were fairly based on the description of the invention in the specification of the Amended Patent.
88 If the assessment of internal fair basis were a mere comparison of the claims and specification of the Amended Patent as a matter of drafting, it can be said that there is a disclosure by the consistory clause inserted into the specification to mirror and support the claims as a matter of drafting of words. To that extent, there is internal fair basis. That, in essence, was the approach of the primary judge, accepting Wyeth’s submissions on the principles in Lockwood (No 1).
89 However, Lockwood (No 1) does not set down a superficial test based solely on the presence or absence of words. The High Court emphasised that s 40(3) does not concern the question of the merits of or entitlement to the claimed invention; it concerns the question of drafting and a single comparison of the claims with the disclosures of the specification. However, the High Court also stated at [99]:
[T]he correct position is that a claim based on what has been cast in the form of a consistory clause is not fairly based if other parts of the matter in the specification show that the invention is narrower than that consistory clause. The inquiry is into what the body of the specification read as a whole discloses as the invention. An assertion by the inventor in a consistory clause of that of which the invention consists does not compel the conclusion by the court that the claims are fairly based nor is the assertion determinative of the identity of the invention. The consistory clause is to be considered by the court with the rest of the specification.
90 That is, it is not simply a matter of matching a consistory clause or other stray phrases with a claim. It is a question of comparing the invention claimed with the invention disclosed. Frequently, indeed most often, there is no real difference; sometimes there is.
91 Fair basis requires a ‘real and reasonably clear disclosure’ in the body of the specification of what is claimed (Lockwood (No 1) at [69]). If the consistory clause is not consistent with the description of the invention in the body of the specification considered as a whole, or is wider than that invention, the mere insertion of a statement mirroring the claim does not, of itself, provide fair basis for the claim. If the consistory clause must be understood in a particular way to be consistent with the rest of the specification, and if so understood it does not describe the invention claimed, there is no fair basis (Lockwood (No 1) at [99]).
92 The specification states that the priority documents are incorporated by reference, in their totality, which includes the description of the invention that I have already discussed. This should not be ignored in a determination of the invention of the specification as a whole. I agree generally with the consequences of this as set out in the reasons of Yates J.
93 Further, the characterisation of the invention of the Amended Patent as a method of treatment by result led her Honour to conclude at [209] that the claims were fairly based despite the method including the administration of a formulation utilising hydrogel technology. The primary judge concluded that the method as claimed in the Amended Patent is not limited to a particular formulation, nor limited to exclude the use of hydrogel tablet technology. Her Honour seemed to rely on the fact that there was no stated limitation in the specification of the formulation of the claims to exclude a formulation using hydrogel tablet technology (at [209]). The primary judge said that once she characterised the invention as the method, the appellants’ contended lack of internal fair basis for a formulation utilising hydrogel technology failed.
94 The specification of the Amended Patent repeatedly states that the invention is a method and also states that the formulation is for use in the method of the invention. Although there remain references to the solution to the problem of preparation of an ER formulation being the ‘formulations of this invention’, for the purposes of internal fair basis, it can be said that there is fair basis for claims to a method, generally as set out. However, the specification still contains the statement that ‘attempts to produce single daily dosing, [ER] or tablets by hydrogel technology proved to be fruitless’ and that the success of an ER formulation, which was at least part of the inventive step and of the invention, was in the context that an ER dosage form of venlafaxine hydrochloride was ‘impossible to achieve with hydrogel tablet technology’.
95 It follows that claims 1 to 17 and claim 27 (to the extent that it is dependent on claims 1 to 17), which encompass a formulation of venlafaxine hydrochloride which includes a formulation achieved using hydrogel tablet technology, travel beyond and are not fairly based on the disclosures of the specification.
The spheroid core formulation
96 The appellants further contend that the specification of the Amended Patent is limited to an invention comprising a particular spheroid composition and that, therefore, the claims of the Amended Patent, which claim more than that particular formulation, are not fairly based.
97 Her Honour rejected the argument that the claims lack fair basis because they extend beyond the use of the particular spheroid formulation disclosed and/or the particular blood plasma profile appearing in Tables 2 and 3 of the specification. Her Honour held at [195] that those tables provided mere descriptions of the shape of the plasma concentration curve resulting from the administration of the particular formulation and concluded that it cannot be said that the specification does not disclose that other formulations may also be used to achieve the therapeutic blood plasma concentration in the claims. The primary judge held at [197] that neither the particular formulation described, the particular embodiments described, the failed attempts using hydrogel tablet technology described, nor the solution found to enable the preparation of the spheroids, confined the general method claimed.
98 Wyeth accepts that the Amended Patent describes the preparation of a particular formulation, the spheroid formulation. However, it says that while the preparation of a single daily dosing formulation was a necessary step in the development of the claimed method and provides an example of one type of single daily dosing formulation that may be used in the claimed method, the utility does not depend on the nature of the particular formulation used but on the parameters of the blood plasma profile achieved. Further, it contends, the Tmax and Cmax are not confined to those exemplified. That, Wyeth says, entitles it to claim the method by reference to those parameters, unlimited to the particular formulation.
99 That is directly contradicted by the statements in the specification that formulations produced by hydrogel tablet technology were impossible to achieve. The appellants also point to the following evidence of Professor Charman, that the blood plasma profile from one dose form cannot be predicted across to another dose form, which was quoted by the primary judge at [194]:
To accept different plasma profiles from different types of formulations is a whole another [sic] situation because it requires different releases, where it is released, what is the rate of release, so it is a lot more complicated… In terms of predictability of different dose forms, I am not comfortable as to how one would make those predictions…
100 Wyeth has not established fair basis by reason of the description of a new principle, or a principle, of general application.
Depression
101 The appellants further contend that to the extent that the word “therapeutic” as used in the claims means ‘therapeutic in therapies other than depression’ the relevant claims travel beyond, and are not fairly based upon, the specification of the Amended Patent.
102 Her Honour’s characterisation of the invention of the Amended Patent formed the basis for the conclusion at [226] that the treatment of depression was only one embodiment of the invention, which meant that the general claim, unrestricted by clinical action, was fairly based. This was despite her Honour’s earlier finding at [187]-[188] that the phrase “therapeutic blood plasma concentration” meant:
The blood plasma concentration-time profile of venlafaxine arising from the administration of a single daily dosing formulation of venlafaxine hydrochloride that has been shown to be therapeutically effective when studied in a population of depressed patients.
[emphasis added]
103 There are difficulties with Wyeth’s submission that there is no limitation to the use of the formulation to the treatment of depression. It is difficult to see how the skilled reader is given information as to the therapeutic level of venlafaxine for unnamed disorders, or how he or she is to assess ‘a person in need of venlafaxine’. The only condition to which reference is made in the Amended Patent is depression.
104 Apart from claims 4, 8 and 14, the claims of the Amended Patent are not limited to the treatment of depression and there is no specific restriction or limitation in the specification to depression. The fact that the drug is used in the treatment of depression is part of the background to the invention but this is not in itself a reason why, in the claim for a formulation of venlafaxine to deliver a therapeutic dose to a patient in need of it, the claim should be read down for lack of fair basis in the absence of evidence from a person of skill in the art that the results with the described formulation are not relevant to the use of venlafaxine for another disorder. However, there is also no basis by which to link the described plasma levels, reflecting the therapeutic dosage for the treatment of depression, with any other disorder. Nor is there any basis for extending the treatment of one disorder to any other disorder, even another form of social anxiety disorder.
105 The primary judge accepted that “therapeutically effective” was linked to the medical condition for which it was required to achieve therapeutic effectiveness. References to venlafaxine are only as a treatment for depression. The only reference to a therapeutic blood concentration is a therapeutic dosage for a patient with depression. To the extent that the claims are not limited to therapeutic effectiveness in patients suffering from depression, they are not fairly based.
106 The claims of the Amended Patent are not fairly based on the specification as required by s 40(3) of the Act.
SUFFICIENCY OF DESCRIPTION
107 Section 40(2)(a) of the Act states: ‘A complete specification must describe the invention fully, including the best method known to the applicant of performing the invention.’ A failure to comply with s 40(2)(a) makes a patent liable to be revoked pursuant to s 138(3)(f) of the Act. The test for sufficiency has been formulated by the High Court in Kimberly-Clark Australia Pty Ltd v Arico Trading International Pty Ltd (2001) 207 CLR 1 at [25] as follows:
The question is, will the disclosure enable the addressee of the specification to produce something within each claim without new inventions or additions or prolonged study of matters presenting initial difficulty?
108 This was endorsed in Lockwood (No 1) at [60], in which the High Court also held that for the purposes of s 40(2)(a) it is not necessary for the inventor to disclose all of the alternative means of performing the invention.
109 I agree with Yates J, generally for the reasons he gave, that the primary judge did not err in rejecting the appellants’ contention that the specification does not comply with s 40(2)(a) of the Act.
False suggestion
110 Pursuant to s 138(3)(d) of the Act, the Court may revoke a patent that was obtained by a false suggestion or misrepresentation. Alphapharm points to the statement in the specification that declared that ‘the desired dissolution rate of a sustained release dosage form of venlafaxine [was] impossible to achieve with hydrogel tablet technology’ (the “impossibility” statement) and the statement that the stated basis for the ‘completely unexpected’ outcome of obtaining a single daily dosing formulation of venlafaxine hydrochloride for use in the methods of the invention set up a problem that was overcome by the development of the spheroid formulations described in the specification (the “completely unexpected” statement). Alphapharm submits that this problem did not exist because, as a matter of fact, it was not impossible to achieve an ER formulation of venlafaxine hydrochloride using hydrogel tablet technology. Alphapharm contends that the Amended Patent is liable to be revoked because the “impossibility” statement and the “completely unexpected” statement were material to the grant of the Patent.
111 The primary judge found that the skilled addressee would have understood the “impossibility” statement and the “completely unexpected” statement to reflect the position of the inventor only and that these statements were not to be taken as an objective statement of impossibility (at [531]). The effect of her Honour’s finding was that these statements were not material to the grant of the Patent, as the person skilled in the art would have known that hydrogel tablet technology was not impossible. Her Honour relied on Professor Charman’s evidence as support for that interpretation of the “completely unexpected” statement (at [532]). Wyeth relies on the evidence of Professor Charman to the effect that he did not read the Patent specification as meaning that it was impossible to obtain a formulation using hydrogel technology.
112 A patent may state that the experimental method for isolating a compound is X when the skilled reader knows that there is a better method. That does not affect the statement made that X was used. Such evidence, that a skilled reader does not accept a statement in the Priority Document of impossibility of a formulation, does not affect the disclosure of the specification. “Impossible” is not a term of art (Ranbaxy Australia Pty Ltd v Warner-Lambert Co LLC (2008) 77 IPR 449 at [96]). The specification stated clearly that hydrogel formulation was impossible.
113 Nevertheless, a statement in a patent that a step was impossible does not amount to a false suggestion simply because it can later be demonstrated that it was not impossible. A statement that a course of inquiry or experimentation was fruitless does not amount to a false suggestion just because it can later be shown that the course of inquiry or experimentation would bear fruit. If the specification stated that it was impossible to formulate venlafaxine hydrochloride using hydrogel technology, the fact that it was later shown to be possible does not demonstrate false suggestion. There is no suggestion that the statement was false to the knowledge of the inventors or of Wyeth prior to grant.
114 There was no evidence from the Commissioner or any of his delegates. That is relevant to questions of materiality but certainly not decisive. There have been a number of recent cases in this Court where a claim for revocation based upon a false suggestion or misrepresentation has succeeded even though the Commissioner did not take up any such position: see, in particular, W M Wrigley Jr Company v Cadbury Schweppes Pty Ltd (2005) 66 IPR 298 and Ranbaxy. However, there is no basis for concluding that the statements relied upon, even if they amounted to a false suggestion within the meaning of s 138(3)(d) of the Act, were material to the grant of the Patent.
115 The appellants have not demonstrated a false suggestion that was material to the grant of the Patent.
CLARITY
116 Another issue before the Court is whether, as the appellants contend, the relevant claims of the Amended Patent are lacking in clarity pursuant to s 40(3) of the Act on the basis of the term ‘therapeutic blood plasma concentration’. Her Honour rejected the submission that the term should be construed as meaning a specific level of venlafaxine in the blood, accepting that the unanimous expert evidence indicated that the skilled addressee at the priority date would have known that there is no point-to-point relationship between levels of venlafaxine in the blood (at [240]).
117 That conclusion has not been shown to be in error.
OBVIOUSNESS/INVENTIVE STEP
118 The test for whether an invention is obvious is set out in ss 7(2) and (3) of the Act.
119 Despite stating that the problem-solution approach was inapposite in the circumstances, the primary judge found at [488] that it was far from obvious that the solution to the “problem” of the IR formulation was a method of treatment involving the single daily dosing formulation claimed in the Amended Patent. Her Honour accepted Wyeth’s submission that the appellants ‘did not ask the appropriate hypothetical question... [which was] whether a method of treating depression by oral administration of a single daily dosing of venlafaxine hydrochloride which provides a therapeutic blood plasma concentration of venlafaxine over 24 hours with a peak plasma concentration in from about 4 to 8 hours is obvious’ (at [489]).
120 Her Honour found at [266] that much of the evidence of the appellants’ witnesses ‘was affected by a number of circumstances material to their conclusions that would not have existed at the priority date’. The primary judge observed that ‘each of these experts, when giving their opinions, knew that the matter related to a disputed patent and thus would have been aware that at least one person had successfully prepared an [ER] formulation of venlafaxine hydrochloride at the priority date’, which meant that the experts were approaching their task with the assumed knowledge that an ER formulation could be prepared. This knowledge, her Honour said, was available only with hindsight despite the experts’ best efforts to put themselves in the position in which they would have been as at 25 March 1996 (at [319]).
121 The primary judge identified specific difficulties with the expert evidence at [320]–[323] and [328]–[331] and concluded at [327] that the evidence was not to be disregarded but that the weight of the evidence was affected.
122 The appellants urge a reconsideration of her Honour’s approach to obviousness and inventive step. Inter alia, this includes what they describe as a finding that mere knowledge of the existence of a patent and thus of a successful ER formulation of venlafaxine hydrochloride was sufficient to taint the experts’ conclusions with hindsight (at [319]). Although it is apparent that this factor alone was not the reason for her Honour’s conclusion not to rely on that evidence, it is worth making some brief comments on this.
123 The primary judge’s reasoning on the issue of obviousness was focussed on her characterisation of the invention. Her Honour carefully noted at [326] the observations of the Full Court in Fresenius Medical Care Australia Pty Ltd v Gambro Pty Ltd (2005) 224 ALR 168 at [175], where it was pointed out that there are many factors affecting the weight to be given to the evidence of experts concerning the obviousness of an invention as at an earlier time. That passage, which states the correct approach, was applied by the primary judge. Her Honour did not discount the expert evidence simply because the relevant experts knew of the existence of a patent or knew that there was a successful ER formulation. That alone is no reason to discount or reject expert evidence. It may be the case that an expert is fully aware of the patent and of the invention prior to being retained to provide his or her opinion. Again, that factor alone is not necessarily a reason to discount or reject the evidence. The primary judge recorded the evidence and the opinions and discussed various factors that affected her assessment of the weight of the evidence and of the conclusions drawn by the experts. The appellants have not demonstrated an error of principle in this approach taken by the primary judge.
124 The appellants challenge the primary judge’s findings and conclusion on obviousness. I have concluded that the claims are invalid for lack of novelty by reason of the deferred priority date and that they fail to comply with s 40(3) of the Act. I have characterised the invention differently to the characterisation by the primary judge. My view is that the problem-solution approach would have been apposite and helpful in the assessment of inventive step (Apotex Pty Ltd v Sanofi-Aventis (2009) 82 IPR 416). However, in the circumstances, it is not necessary or practicable to undertake a full consideration of the obviousness of what the primary judge considered to be the invention.
Issues of Inventorship: False Suggestion and Entitlement
125 The appellants contend that the invention of the Patent had additional co-inventors apart from the named inventor. Accordingly, the appellants submit that the Patent is liable to be revoked on the bases that:
• Wyeth is not entitled to the Patent by reason only of its assignment from the named inventor as a result of the operation of ss 15(1) and 138(3)(a) of the Act; and
• this constituted a false suggestion in obtaining the Patent pursuant to s 138(3)(d) of the Act.
126 I agree with Yates J, substantially for the reasons that he gave, that no error has been demonstrated in the primary judge’s approach to determining the false suggestion entitlement issue. I also agree with his Honour, substantially for the reasons that he gave, that the primary judge did not err in rejecting the contention that Wyeth was not entitled to the Patent.
Infringement
127 The claims said to be infringed are of the Amended Patent. As discussed above, the Amended Patent does not contain the same claims to the formulation as the Original Patent.
128 In the alternative to its submissions on fair basis, Alphapharm contends that the words ‘a single daily dosing formulation of venlafaxine hydrochloride’ should be construed in the claim as a ‘single daily dosing formulation (not utilising hydrogel tablet technology)’, with the consequence that the appellants’ products, which utilise hydrogel tablet technology, would not infringe the Amended Patent.
129 The primary judge said that the reference in the claim to a ‘single daily dosing formulation of venlafaxine hydrochloride’ is not unclear. Her Honour declined to read down the words by reference to the specification as that would import an impermissible gloss on the claims (at [621]). This was based upon her Honour’s finding that the specification disclosed that the invention is the method and that the particular formulation described in the specification is but one embodiment of that method which, her Honour said at [622], ‘in contrast to the inventor’s attempts to use hydrogel tablet technology, proved practical for use in the method of the invention’.
130 The primary judge discussed whether or not the appellants’ formulations were properly within the description of ‘hydrogel tablet technology’ but concluded at [628] that, whatever else it might be, Alphapharm’s Enlafax–XR formulation is not a sustained release tablet using the conventional technology described under the heading “Background of the invention”. It does not seem to be in dispute that the product comes within that claim by reference to the blood plasma profile that is part of one of the essential integers of the claim. Whether or not Enlafax-XR comes within the description in the “Background of the invention” as hydrogel tablet technology, the relevant claims as drafted do not contain the asserted limitation.
131 It follows that, if the relevant claims of the Amended Patent were valid, which they are not, Enlafax-XR would infringe the Patent.
CONCLUSION
132 Claims 1 to 17 and 27 of the Amended Patent are invalid for the reasons I have given. It follows that the appeal should be allowed. The parties should submit proposed agreed orders or, if there is no agreement, each party should submit proposed orders, accompanied if desired by submissions of no more than 3 pages, within 7 days.
I certify that the preceding one hundred and thirty-two (132) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Bennett. |
Associate:
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1533 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | SIGMA PHARMACEUTICALS (AUSTRALIA) PTY LTD ACN 004 118 594 Appellant
|
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent
|
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1603 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | ALPHAPHARM PTY LIMITED ACN 002 359 739 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1644 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | GENERIC HEALTH PTY LTD ACN 110 617 859 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
JUDGES: | BENNETT, NICHOLAS AND YATES jj |
DATE: | 28 OCTOBER 2011 |
PLACE: | SYDNEY |
REASONS FOR JUDGMENT
NICHOLAS J
Background
133 I have had the advantage of reading the reasons for judgment of Bennett J and Yates J. I generally agree with their reasons and I also agree with the orders they propose. However, I wish to explain in my own terms why I do not think the relevant claims are entitled to a priority date of 25 March 1996 and why they are not fairly based on matter described in the specification. For the purpose of doing so I shall use the definitions adopted by Bennett J to identify parties and relevant documents.
The Priority Document
134 The Priority Document is entitled “Extended Release Formulation”. The specification embarks upon its description of the background to the invention with a discussion of extended release drug formulations.
135 The specification then explains that such formulations are conventionally produced as compressed tablets by hydrogel tablet technology. When the tablets made by compounding the active ingredient with various cellulose ethers are introduced to the digestive system, the latter gradually leach away, making the active ingredient available for the absorption by the body. These formulations are referred to as “extended” or “sustained” release formulations. The specification explains that where the production of tablets is not feasible, it is conventional in the drug industry to prepare encapsulated formulations which provide extended release properties. This is achieved by mixing the active ingredient with binding agents from which an extrudable cylindrical mass is created which is then chopped into small lengths that are then transformed into spheroids. These are then film coated (if so desired) to varying degrees to retard dissolution of the active ingredient at different rates in order to obtain the desired therapeutic effect. Gelatin capsules can then be filled with the film coated spheroids.
136 The specification then explains that venlafaxine is an important drug used in the treatment of depression. Venlafaxine hydrochloride is administered to adults in compressed tablet form in doses ranging from 75 to 350 mg/day in divided doses two or three times a day. The specification explains that rapid dissolution of venlafaxine results in a rapid increase in blood plasma levels of the drug shortly after dosing followed by a decrease in those levels over several hours until sub-therapeutic levels are approached after twelve hours. It is these fluctuations in the blood plasma levels of the drug that give rise to the need for multiple dosing. However, nausea is said to be a common side effect of the multiple dosing.
137 There follows what is entitled “Brief Description of the Invention” which is the part of the Priority Document that describes the invention in the broadest terms. It states:
In accordance with this invention, there is provided an extended release (ER), encapsulated formulation containing venlafaxine hydrochloride as the active drug component, which provides in a single dose, a therapeutic blood serum level over a twenty four hour period.
Through administration of the venlafaxine formulation of this invention, there is provided a method for obtaining a flattened drug plasma concentration to time profile, thereby affording a tighter plasma therapeutic range control than can be obtained with multiple daily dosing. In other words, this invention provides a method for eliminating the sharp peaks and troughs (hills and valleys) in blood plasma drug levels induced by multiple daily dosing with conventional immediate release venlafaxine hydrochloride tablets. In essence, the plasma levels of venlafaxine hydrochloride rise, after administration of the extended release formulations of this invention, for between about five to about eight hours (optimally about six hours) and then begin to fall through a protracted, substantially linear decrease from the peak plasma level for the remainder of the twenty four hour period, maintaining at least a threshold therapeutic level of the drug during the entire twenty-four [hour] period. In contrast, the conventional immediate release venlafaxine hydrochloride tablets give peak blood plasma levels in 2 to 4 hours. Hence, in accordance with the use aspect of this invention, there is provided a method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily tablet dosing with venlafaxine hydrochloride which comprises administering to a patient in need of treatment with venlafaxine hydrochloride, a one-a-day, extended release formulation of venlafaxine hydrochloride.
The use of the one-a-day venlafaxine hydrochloride formulations of this invention reduces by adaptation, the level of nausea and incidence of emesis that attend the administration of multiple daily dosing. In clinical trials of venlafaxine hydrochloride ER, the probability of developing nausea in the course of the trials was greatly reduced after the first week. Venlafaxine ER showed a statistically significant improvement over conventional venlafaxine hydrochloride tablets in two eight-week and one 12 week clinical studies. Thus, in accordance with this use aspect of the invention there is provided a method for reducing the level of nausea and incidence of emesis attending the administration of venlafaxine hydrochloride which comprises dosing a patient in need of treatment with venlafaxine hydrochloride with an extended release formulation of venlafaxine hydrochloride once a day in a therapeutically effective amount.
138 What is described in this passage is an extended release, encapsulated formulation containing venlafaxine hydrochloride as the active ingredient and a method of obtaining a particular drug plasma concentration to time profile. Significantly, however, the method so described is said to be obtained “[t]hrough the administration of the venlafaxine formulation of this invention.” Similarly, the description of the variations in plasma levels of venlafaxine occurring over a twenty four hour period are also said to be obtained after administration of the extended release formulation of this invention.
139 The general description of the invention is followed by a detailed description. After referring to the two forms of venlafaxine hydrochloride isolated and characterised to date, the detailed description continues:
The extended release formulations of this invention are comprised of [venlafaxine] hydrochloride in admixture with microcrystalline cellulose and hydroxpropylmethylcellulose. Formed [as] beads or spheroids, the drug containing formulation is coated with a mixture of ethyl cellulose and hydroxypropylmethyl cellulose to provide the desired level of coating, generally from about two to about twelve percent on a weight/weight basis of final product or more preferably from about five to about ten percent (w/w), with best results obtained at from about 6 to about 8 percent (w/w).
Thus, the specification contains a very clear statement that the formulations of the invention are comprised of venlafaxine hydrochloride in admixture with microcrystalline cellulose (MC) and hydroxpropylmethylcellulose (HPMC), formed into beads or spheroids, and coated with ethyl cellulose (EC) and more HPMC.
140 After further describing the ingredients and methods used to make the spheroids and the coatings the following statement appears:
It was completely unexpected that an extended release formulation containing venlafaxine hydrochloride could be obtained because the hydrochloride of venlafaxine proved to be extremely water soluble. Numerous attempts to produce extended release tablets by hydrogel technology proved to be fruitless because the compressed tablets were either physically unstable (poor compressibility or capping problems) or dissolved too rapidly in dissolution studies. Typically, the tablets prepared as hydrogel sustained release formulations gave 40-50% dissolution at 2 hrs, 60-70% dissolution at 4 hrs and 85-100% dissolution at 8 hrs.
And later:
Thus, the desired dissolution rate of a sustained release dosage form of venlafaxine hydrochloride, impossible to achieve with hydrogel tablet technology, has been achieved with the film-coated spheroid compositions of this invention.
141 Each of the claims 1 to 8 of the Priority Document is to an encapsulated extended release formulation of venlafaxine hydrochloride that comprises encapsulated spheroids made from venlafaxine hydrochloride, MC and HPMC coated with EC and HPMC. However, claims 9 and 10 are as follows:
9. A method for providing a therapeutic blood plasma concentration of venlafaxine over a twenty four hour period with diminished incidences of nausea and emesis which comprises administering orally to a patient in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
10. A method for eliminating the troughs and peaks of drug concentration in a patients blood plasma attending the therapeutic metabolism of plural daily doses of which comprises administering orally to a patent in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
Each of these claims is for a method that provides, among other things, a peak blood plasma concentration of venlafaxine in from about four to eight hours. And each of them involves the administration of an encapsulated, extended release formulation containing venlafaxine hydrochloride.
The Amended Patent
142 The Amended Patent is also entitled “Extended Release Formulation” and, except for some minor and immaterial differences, the background to the invention is precisely the same as that contained in the Priority Document. However, substantial amendments have been made to the section entitled “Brief Description of the Invention”. The brief description states:
In accordance with this invention, there is provided a method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
This statement is followed by a series of references to various embodiments of the invention that are in the nature of consistory clauses the language of which mirrors subsequent claims. These are followed by a description of what are referred to as examples of the invention. The specification states:
In an example of the invention, the formulation of venlafaxine hydrochloride is an extended release formulation that is administered as a single daily dosing formulation. In one embodiment, the single daily dosing formulation when used in the method of the invention will provide a peak blood plasma level of venlafaxine from 5-8 hours after administration, most preferably, about 6 hours after administration.
In one embodiment, the venlafaxine hydrochloride formulation for use in the methods of this invention is comprised of venlafaxine hydrochloride … in admixture with microcrystalline cellulose and hydroxypropylmethylcellulose.
As an example, the extended release formulations are formed as coated beads or spheroids. In one embodiment, the drug containing formulation is coated with a mixture of ethyl cellulose and hydroxypropylmethylcellulose to provide the desired level of coating ...
143 The 2006 Amendments introduced new claims falling into two groups. The first, claims 1 to 17 and claim 27 (insofar as it is dependent on claims 1 to 17), are method of treatment claims that are not limited to methods utilising a formulation made from spheroid core comprising venlafaxine hydrochloride, MC and HPMC. The second, claims 18 to 28, are confined to treatments utilising a formulation made from spheroid core comprising venlafaxine hydrochloride, MC and HPMC.
144 The statements in the Priority Document concerning what was “completely unexpected” and what was “impossible to achieve” also appear in the Amended Patent except that in the Amended Patent the first of these statements refers to “a single daily dosing formulation” instead of “an extended release formulation”.
145 Claims 1 to 4 are as follows:
1. A method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
2. A method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily dosing with venlafaxine hydrochloride, which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
3. A method of reducing the level of nausea and the incidence of emesis in a patient in need of venlafaxine which comprises administering orally to said patient, a single daily dosing formulation of venlafaxine hydrochloride that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period and a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
4. A method for treating depression in a patient in need of such treatment, which comprises administering orally to said patient, a single daily dosing formulation of venlafaxine hydrochloride that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration.
146 Claims 5 to 8 mirror the language of claims 1 to 4 except that, rather than referring to “a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration”, each of these claims refers to “a peak blood plasma level of no more than 150 ng/ml”. Claim 9 is dependent upon claims 1 to 4 and limits the blood plasma level of venlafaxine for the purposes of those claims to 150 ng/ml. Claim 10 is dependent on claims 5 to 7. It provides that the blood plasma level of venlafaxine for the purposes of claim 5 to 7 will be achieved in from about 4 to 8 hours. Claims 11 to 14 also mirror claims 1 to 4 but rather than specifying peak blood plasma levels they instead specify various dissolution profiles. Claims 15 to 17 are dependent claims about which I need not say more. Claim 18 is not in issue but is worthy of mention in that it is another dependent claim which confines the method of treatment the subject of the preceding claims to the use of a formulation comprising spheroids made of venlafaxine hydrochloride, MC and HPMC coated with EC and HPMC. Claim 27, which is in issue, is to “[a] method according to any one of the preceding claims wherein the formulation is an encapsulated formulation.”
Priority Date/External Fair Basis
147 Each of the relevant claims, being claims 1 to 17 and 27 of the Amended Patent, was introduced by the 2006 Amendments. The appellants submitted that the primary judge erred in failing to find that the relevant claims were not fairly based on the Priority Document. The respondents concede that if that submission is accepted then it follows that the appeals must be allowed and that each of the relevant claims must be revoked. Before considering this submission further it is necessary to refer to the statutory context in which it arises.
148 The Amended Patent is the result of a divisional application made under s 79B(1) upon the Parent Application which was itself a divisional application founded upon the Grandparent Application. This is of significance because the Regulations make specific provision for determining the priority date of a claim based upon matter disclosed in a specification filed under s 79B(1) of the Act. Section 79B(1) provides:
(1) If a complete patent application for a patent is made (but has not lapsed or been refused or withdrawn), the applicant may, in accordance with the regulations, make a further complete application for a patent for an invention:
(a) disclosed in the specification filed in respect of the first mentioned application; and
(b) where the first mentioned application is for a standard patent and at least 3 months have elapsed since the publication of a notice of acceptance of the relevant patent request and specification in the Official Journal—falling within the scope of the claims of the accepted specification.
149 Each of the claims of the Amended Patent must have its own priority date determined in accordance with the relevant provisions of the Act and the Regulations. To that end there are two relevant sets of provisions. The first set relates to the priority dates of claims generally including, in particular, the priority dates of claims of a patent resulting from an application under s 79B(1) of the Act. The second relates to the priority date of claims to matter that was in substance disclosed as a result of an amendment to a specification.
150 The position with respect to priority dates generally is dealt with in s 43(2) of the Act. Relevantly, the priority date of a claim is the date of the filing of the specification or, where the Regulations provide for the determination of a different date, the date determined under the Regulations. Regulation 3.12 relevantly provides:
(1) Subject to regulations 3.13 and 3.14 and subregulation (2), the priority date of a claim of a specification is the earliest of the following dates:
(a) the date of filing of the specification;
(b) if the claim is fairly based on matter disclosed in 1 or more priority documents, the date of filing the priority document in which the matter was first disclosed;
(c) if the specification is a complete specification filed in respect of a divisional application under section 79B of the Act and the claim is fairly based on matter disclosed in the specification referred to in paragraph 79B (1) (a) of the Act — the date mentioned in subregulation (2C);
…
(2) For the purposes of paragraph (1) (b):
(a) if the application that relates to the specification containing the claim is a complete application — a provisional application that is associated with that complete application in accordance with section 38 of the Act is a priority document; and
(b) if the application that relates to the specification containing the claim is a Convention application, a document of any of the following kinds is a priority document:
(i) a basic application that is related to the Convention application;
(ii) a specification, or another document filed in respect of, and at the same time as, a basic application that is related to that Convention application; or
(iii) a specification in respect of a basic application that is related to that Convention application, being a specification that was filed after the basic application was made;
…
…
(2C) The date for a specification to which paragraph 3.12 (1) (c) applies is the date that would have been the priority date of the claim if it had been included in the specification referred to in paragraph 79B (1) (a) of the Act.
…
151 The relevant effect of these provisions is as follows. Subject to reg 3.14, if a claim of the Amended Patent is fairly based on matter disclosed in the Parent Application then the claim will have the priority date to which it would have been entitled if it had been included in the Parent Application. However, since the Parent Application is itself a divisional application based upon the Grandparent Application, the priority date of the claim also depends upon what priority date it would have had it if had been included in the Grandparent Application. The Grandparent Application, which was not a divisional application, claimed priority of 25 March 1996 – the earliest available priority date – based upon the filing of the Priority Document. So if a claim of the Amended Patent is to have the earliest available priority date, it must be fairly based on the matter disclosed in each of the Parent Application, the Grandparent Application and the Priority Document.
152 As to amendment or, more specifically, any disclosure by amendment, s 114(1) of the Act provides that where a claim of a complete specification claims matter that was in substance disclosed as a result of amending the specification, the priority date of the claim must be determined under the Regulations. The regulation made for that purpose is reg 3.14 which relevantly provides that the priority date of a claim to which s 114(1) applies is the date of the filing of the proposed statement of amendments which resulted in the disclosure occasioned by the amendment to the specification. As I have mentioned, reg 3.12 is expressed to apply subject to reg 3.14. So the logical starting point in determining the priority date of the claims of the Amended Patent is therefore s 114(1) and reg 3.14.
153 Section 114 and reg 3.14 are directed to a consideration of the matter disclosed by the specification as it stood immediately prior to the relevant amendment. This has significance in the present case because the amendments made not only introduced new matter but also excluded existing matter. In fact, the matter excluded included a great deal of matter said to be incorporated by reference including the entirety of the Parent Application and the Grandparent Application. Thus, one way or another, all of the disclosures of the Priority Document were already present at the time of the 2006 amendments. The question is whether these disclosures provide a sufficient basis for the new claims introduced by the 2006 Amendments or whether such claims are for matter that was in substance disclosed as a result of the 2006 Amendments. The priority date of any claim to matter that was in substance disclosed as a result of the 2006 Amendments will be 20 December 2006 which is, as is conceded by the respondents, fatal to validity.
154 Subject to a number of minor differences not relevant for present purposes, prior to its amendment by the 2006 Amendments the Amended Patent was in virtually identical terms to the Priority Document. Hence, the question arising under s 114 and reg 3.14 may be addressed, in a practical sense, by asking whether the new claims introduced by the 2006 Amendments were to matter not disclosed in the Priority Document.
155 Wyeth relied upon the primary judge’s analysis of the Priority Document. Her Honour identified the relevant question as being whether there was a real and reasonably clear disclosure of the claims of the Amended Patent in the Priority Document. In support of that approach the primary judge cited Lockwood Security Products Pty Limited v Doric Products Pty Ltd (No 1) (2004) 217 CLR 274 at [69]. In that case the High Court was concerned with a question of internal fair basis, that is to say, whether the claims of the patent in issue were fairly based on the matter described in the specification. Nevertheless, the same test is in my view applicable here, the question being whether there was a real and reasonably clear disclosure of the invention claimed in the Amended Patent in the Priority Document. However, there was a debate before us as to what role, if any, claims 9 or 10 of the Priority Document should play in answering that question.
156 The primary judge found that when read as a whole, the Priority Document disclosed two different inventions, the first being an encapsulated formulation, and the second being, in her Honour’s words, “a method for obtaining a certain drug to plasma relationship over time yielding a tighter plasma therapeutic range control than multiple daily dosing, eliminating the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing and thereby reducing the level of nausea and incidence of emesis that attend multiple daily dosing.” Having referred to Wyeth’s submissions, her Honour said (at para [165]):
This is not a case where claims 9 and 10 are unrelated to the disclosure in the US priority document. The US priority document discloses two inventions. The first is an encapsulated formulation. The second is a method for obtaining a certain drug to plasma relationship over time yielding a “tighter plasma therapeutic range control” than multiple daily dosing, eliminating the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing and thereby reducing the level of nausea and incidence of emesis that attend multiple daily dosing. The method involves providing in a single dose a therapeutic blood serum level of venlafaxine hydrochloride over a 24 hour period, with plasma levels rising for between about five to eight hours after administration of the formulation (optimally about six hours) and then beginning to fall through a protracted substantially linear decrease from the peak plasma level whilst maintaining a threshold therapeutic level over the entire twenty four hour period. The references to the inventor’s failed efforts to prepare a hydrogel tablet formulation and to an encapsulated formulation in claims 9 and 10 do not eliminate the disclosure in the US priority document of this method of treatment. When the US priority document is read as a whole, the method disclosed is not confined to the particular encapsulated formulations (or embodiments or examples) which are also disclosed. The claims of the patent are in substance disclosed in or fairly based on the US priority document. The amendments made in December 2006 cannot and do not alter this fact of disclosure.
The role of claims 9 and 10 of the Priority Document was not addressed by the primary judge because, as I read her Honour’s reasons, she considered that the body of the specification provided the necessary disclosure. Indeed, on her Honour’s interpretation of the Priority Document, the disclosure went beyond what was claimed in claims 9 and 10, at least in the sense that those claims are, as her Honour noted, limited to methods of treatment involving the use of “encapsulated” formulations containing venlafaxine hydrochloride.
157 I do not agree that the invention as defined by various claims of the Amended Patent was the subject of a real or reasonably clear disclosure in the Priority Document. Numerous claims introduced by the 2006 Amendments travel beyond the disclosure of the Priority Document. In my view it is quite apparent that none of the claims for methods of treatment which involve the use of formulations that are not encapsulated are properly based upon any real or reasonably clear disclosure in the Priority Document. Although there is a dependent claim which incorporates a limitation of this kind, the primary judge upheld the validity of all the claims of the Amended Patent including those which did not incorporate any such limitation. With due respect to the primary judge, I consider that she has construed the Priority Document too broadly.
158 By the time the reader of the Priority Document gets to the claims 9 and 10, there is already much to indicate that the invention disclosed is limited to a particular formulation and a method of treatment involving the administration of that formulation.
159 First, the discussion of the background to the invention explains the context of the invention. In particular it identifies various problems associated with venlafaxine hydrochloride in the compressed tablet formulation presently administered to adults. The discussion raises the question (at least by clear implication) of how to provide those in need of venlafaxine hydrochloride with a single daily dosing of the drug in lieu of two or three times a day dosing so as to avoid the pronounced fluctuations in blood plasma concentrations and the common side effects associated with a multiple dosing regime. The solution proposed is a new formulation the use of which is said to eliminate or reduce both the fluctuations in blood plasma concentrations and the side effects associated with the multiple dosing regime.
160 Secondly, there is the repeated reference to “formulations of this invention” occurring throughout the Priority Document. The brief description of the invention describes an encapsulated formulation. The whole of the brief description is confined to production and administration of that formulation. So too is the detailed description of the invention. It describes the invention as being made from a mixture including MC and HPMC which is formed into spheroids coated with CE and more HPMC. While various options are discussed, there is no suggestion that the formulation might not be made from spheroids formed with a mixture including MC and HPMC. On the contrary, the whole of the description suggests that these are essential features of the formulation of the invention.
161 Thirdly, nowhere in the detailed description of the invention is there any mention of the possibility that the methods disclosed might include those which involve the administration of a formulation different to “the formulation of this invention”. In saying this I am not suggesting that the disclosure of the Priority Document is confined to a specific formulation corresponding in every detail to the embodiments described in the detailed description. The Priority Document makes clear that various equivalents may be substituted for some of the ingredients used in the particular examples that are described. But nowhere is it stated or implied that the methods of the invention might be employed through the use of a completely different formulation such as might be produced using hydrogel tablet technology.
162 None of this is surprising considering the background to the invention as explained in the section of the Priority Document devoted to that topic and the subsequent account of the problems experienced by the inventors when attempting to use hydrogel tablet technology. It is represented that the inventors moved to an encapsulated formulation using film coated spheroids because the use of hydrogel tablet technology was not feasible.
163 Sigma submitted that in considering the scope of the disclosure of the Priority Document claims 9 and 10 should be disregarded because, as I understood the submission, they were not fairly based. But the question before us does not depend on whether or not those claims are fairly based. There is no reason why they or any other claims of the Priority Document should not be considered for the purpose of ascertaining what is disclosed by the Priority Document when read as a whole. Claims 9 and 10 are part of an entire document said to make a particular disclosure. However, read in context, those claims refer to methods of achieving certain concentrations and profiles which employ “an encapsulated extended release formulation” which I take to be the formulation of the invention as more fully described in the specification.
164 The primary judge did not place any reliance upon claims 9 and 10 of the Priority Document but remarked that the references in those claims to an encapsulated formulation “do not alter the fact that a method is disclosed.” However, when the Priority Document is read as a whole, the method disclosed is limited to one which makes use of an encapsulated formulation. The language of claims 9 and 10 of the Priority Document is consistent with this particular limitation being an essential feature of the invention described.
165 In my opinion the invention disclosed by the Priority Document is an encapsulated extended release formulation of venlafaxine hydrochloride which can be used to eliminate the sharp peaks and troughs in blood plasma levels associated with multiple daily dosing regimes and some of their common side effects. What is described in the Priority Document is essentially a formulation, with the methods of treatment described being confined to those which make use of that formulation. The formulation and the method of treatment are not different inventions but different forms or aspects of the same invention.
166 Thus, in the brief description of the invention, reference is made to “the use aspect of this invention” suggesting, consistently with my reading of the whole of the description, that there is in substance a single invention disclosed in the Priority Document consisting of an encapsulated formulation which may be used in the treatment of depression. There is no suggestion in the description of the invention or the claims in the Priority Document that any method of treatment the subject of the invention might involve the use of a non-encapsulated formulation.
167 None of claims 1 to 17 of the Amended Patent is confined to a method of treatment involving the administration of encapsulated formulations. Accordingly, I do not think those claims are fairly based on the Priority Document. Each of claims 1 to 17 is therefore invalid.
168 Claim 27 is dependent on (inter alia) each of claims 1 to 17 and introduces an additional requirement that the formulation referred to in each such claim be encapsulated. However, claim 27, when read in conjunction with any of claims 1 to 17, is not confined to a formulation made from spheroids formed with a mixture including MC and HPMC. Again, I do not think that claim 27, when read with any of claims 1 to 17, is fairly based on the Priority Document. Each of the methods of treatment described in the Priority Document involves the administration of what is referred to throughout as “the formulation of the invention” or “the film-coated spheroid compositions of this invention” comprising, among other things, spheroids made from a mixture including venlafaxine hydrochloride MC and HPMC. It follows that claim 27, insofar as it is dependent on any of claims 1 to 17, is not fairly based.
Internal Fair Basis
169 A consistory clause may provide a fair basis for a claim which mirrors its language but not if there are other matters disclosed in the specification which show that the invention is narrower than the consistory clause suggests. The High Court said in Doric at [99]:
… the correct position is that a claim based on what has been cast in the form of a consistory clause is not fairly based if other parts of the matter in the specification show that the invention is narrower than that consistory clause. The inquiry is into what the body of the specification read as a whole discloses as the invention [Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at 612-613]. An assertion by the inventor in a consistory clause of that of which the invention consists does not compel the conclusion by the court that the claims are fairly based nor is the assertion determinative of the identity of the invention. The consistory clause is to be considered by the court with the rest of the specification.
170 Wyeth relied upon the consistory clauses introduced by the 2006 Amendments as providing fair basis for claims 1 to 17 and claim 27. In my opinion, the consistory clauses do not do so because they do not reflect the description of the invention contained in the specification when read as a whole.
171 I agree with Wyeth that claims 1 to 17 of the Amended Patent cover methods of treatment that involve the administration of formulations containing venlafaxine hydrochloride produced through the use of hydrogel tablet technology. I do not think it is possible to read those claims down so to exclude from their scope methods of treatment that utilise such formulations. This is significant because, in my view, the specification contains what is tantamount to a disclaimer of hydrogel tablet technology. In particular, it makes clear that the advantages of the invention cannot be obtained by using hydrogel tablet technology and that the addressee wishing to prepare an extended release formulation of venlafaxine hydrochloride for administration to those in need of that drug should not attempt to use that technology for that purpose.
172 Dr Marshall and Professor Charman agreed that, as at the priority date, the skilled addressee would not have considered it impossible to achieve an extended release formulation of venlafaxine hydrochloride. But the fact that they might disagree with what is said in the specification is not relevant to its proper construction.
173 In my view, the specification, read as a whole, makes clear that the invention described does not encompass the use of any formulation of venlafaxine hydrochloride produced by hydrogel tablet technology. Since claims 1 to 17 of the Amended Patent encompass methods of treatment that utilise formulations produced by hydrogel tablet technology, each of claims 1 to 17 is too broad and not fairly based upon matter described in the specification. Accordingly, claims 1 to 17 are also invalid on the ground that they do not comply with the requirements of s 40(3) of the Act.
174 The position with respect to claim 27, in so far as it is dependent on claims 1 to 17, is slightly different because it does not include within its scope methods of treatment that utilise formulations produced by hydrogel tablet technology.
175 Since it is the Amended Patent which must be construed for the purpose of determining any questions of internal fair basis, one would ordinarily undertake that exercise without regard to the terms of any priority document. But the position here is somewhat unusual in that the entire disclosure of the Parent Application and the Grandparent Application is incorporated by reference. Each of these reproduce the whole of the Priority Document. What is even more unusual about the way in which these prior disclosures have been incorporated is that the reader is not given any instruction or guidance as to what use he or she is expected to make of them.
176 I agree with Wyeth that the Amended Patent should be read as though these prior disclosures were set out in their entirety. When this is done, it is in my opinion apparent that the invention described is for a method of treatment calling for the administration of an encapsulated formulation of venlafaxine hydrochloride comprising film coated spheroid compositions made from a mixture of venlafaxine hydrochloride, MC and HPMC.
177 There is no doubt that the consistory clauses describe the methods of the invention much more broadly than this. However, by the time the reader gets to the consistory clauses a great deal of information has already been imparted to show that the methods of the invention are as I have described.
178 Wyeth submitted that the specification disclosed a method for achieving a specified plasma concentration profile and drug dissolution profile that was found to be efficacious, but with reduced nausea and vomiting. It submitted that while those plasma concentration and drug dissolution profiles may be achieved by the administration of the formulations described in the specification, they might just as well be achieved by the use of different formulations of venlafaxine hydrochloride. Wyeth submitted that by achieving the specified profiles with reduced nausea and vomiting the inventors had arrived at a new result by a new application of principle thereby entitling them to claim all the alternative means by which that result could be achieved: see Shave v H V McKay Massey Harris Pty Ltd (1935) 52 CLR 701 at 709 per Rich, Dixon, Evatt and McTiernan JJ.
179 Wyeth’s arguments were substantially based upon evidence given by Professor Charman as to his understanding of the Amended Patent. He said that the Amended Patent “teaches that a unique plasma profile of venlafaxine leads to the reported beneficial clinical profile (including improvements in side effects)”. In support of this interpretation of the specification he pointed to the profiles reported in tables 2 and 3 of the Amended Patent. His evidence was relied upon by Wyeth and by the primary judge in support of the conclusion that the method taught by the Amended Patent is not limited to the use of any particular venlafaxine hydrochloride formulation.
180 The profiles reported in tables 2 and 3 of the specification are the profiles achieved using what are referred to as the film coated spheroid formulations of the invention. While tables 2 and 3 describe profiles achieved using those formulations, they do not disclose anything at all about the profiles that might be achieved using other formulations. The evidence established that it would have been understood by the skilled addressee as at 25 March 1996 that it was not possible to predict what profile any other formulation of venlafaxine hydrochloride would have based upon anything contained in the Amended Patent. So I do not think tables 2 and 3 provide any basis for inferring that the methods of the invention, as disclosed by a reading of the specification as a whole, are not limited to the use of the film coated spheroid compositions described in the specification.
181 In the result, I do not think the specification when read as a whole – including all that is incorporated by reference – provides a fair basis for claim 27 insofar as it is dependent on claims 1 to 17. It follows that claim 27 is also invalid on the ground that it does not comply with the requirements of s 40(3) of the Act.
I certify that the preceding forty-nine (49) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Nicholas. |
Associate:
Dated: 28 October 2011
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1533 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | SIGMA PHARMACEUTICALS (AUSTRALIA) PTY LTD ACN 004 118 594 Appellant
|
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent
|
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1603 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | ALPHAPHARM PTY LIMITED ACN 002 359 739 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
IN THE FEDERAL COURT OF AUSTRALIA | |
NEW SOUTH WALES DISTRICT REGISTRY | |
GENERAL DIVISION | NSD 1644 of 2010 |
ON APPEAL FROM THE FEDERAL COURT OF AUSTRALIA |
BETWEEN: | GENERIC HEALTH PTY LTD ACN 110 617 859 Appellant |
AND: | WYETH First Respondent WYETH AUSTRALIA PTY LIMITED ACN 000 296 211 Second Respondent |
JUDGES: | BENNETT, NICHOLAS AND YATES JJ |
DATE: | 28 OCTOBER 2011 |
PLACE: | SYDNEY |
REASONS FOR JUDGMENT
YATES J
182 I have had the considerable advantage of reading in draft the reasons for judgment prepared by Bennett J.
183 I agree with Bennett J that claims 1 to 17 and 27 (when dependent on claims 1 to 17) of the Patent have the deferred priority date of 20 December 2006, with the consequence that the claims are not novel. In this connection, Wyeth has accepted that, if the deferred priority date is the correct priority date of those claims, they will have been anticipated by the sale of its own ER form of venlafaxine hydrochloride, EFEXOR XR, in Australia from 1999.
184 I wish to add, however, some observations of my own, reflecting more particularly my reasons for this outcome. For ease of reference, I will use the abbreviations adopted by Bennett J.
The Priority date of the claims
The Priority Document
185 In her reasons for judgment, Bennett J has described the disclosures in the Priority Document, which I gratefully adopt.
186 On reading the Priority Document it is clear, in my view, that Wyeth, as the patent applicant, is disclosing, to the person skilled in the art, the invention of a particular ER formulation of venlafaxine hydrochloride which has, as its essential features, spheroids comprised of venlafaxine hydrochloride, microcrystalline cellulose and HPMC, coated with ethyl cellulose and HPMC. These essential features are adopted as essential features of the encapsulated formulations and compositions claimed in claims 1 to 8 of the Priority Document.
187 The disclosed context for this claimed invention is that venlafaxine (in the form of its acid addition salts) is an important drug used for the treatment of depression. As such, it is administered to human adults as compressed tablets containing venlafaxine hydrochloride in doses ranging from 75 to 350 mg/day. These are divided doses, administered two or three times a day. The reason for this dosing regimen is that this formulation exhibits rapid dissolution, resulting in a rapid increase in blood plasma levels of the active ingredient, venlafaxine hydrochloride, shortly after administration, followed by a decrease in these blood plasma levels over time, leading to “sub-therapeutic” plasma levels of the active ingredient after about 12 hours.
188 It is clear that the reference in the Priority Document to “sub-therapeutic plasma levels” is to the therapeutic efficacy of venlafaxine hydrochloride administered in this formulation for the treatment of depression. It is not suggested that doses of venlafaxine hydrochloride from 75 to 350 mg/day would have therapeutic efficacy for any other indication. Indeed, no other indication is disclosed that would be suitable for treatment by venlafaxine, regardless of dosage or dose form. The consequence of this conventional dosage regimen is that, in the treatment of depression, about 45% of patients experience nausea, with vomiting (emesis) occurring in about 17% of patients.
189 The Priority Document makes clear that a benefit of this invention is that, when administered, it provides “a method for obtaining a flattened drug plasma concentration to time profile”. In other words, the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing with venlafaxine hydrochloride tablets, in accordance with the conventional regimen described, are eliminated. Thus, by using the “one-a-day venlafaxine hydrochloride formulations of this invention”, the level of nausea and incidence of emesis are reduced, compared with “the plural daily dosing regimen” using venlafaxine hydrochloride tablets.
190 It is clear that the reference to the “one-a-day formulations of the invention” is to the extended release spheroid formulation in which the spheroids comprise venlafaxine hydrochloride, microcrystalline cellulose and HPMC, and in which the spheroids are coated with ethyl cellulose and HPMC. The use of the plural “formulations” simply denotes that various embodiments of the formulation will have these essential features. Some of these are exemplified in the Priority Document.
191 The Priority Document makes a number of additional, important disclosures.
192 First, the Priority Document discloses that it was “completely unexpected” that an extended release formulation containing venlafaxine hydrochloride could be obtained. This is because the hydrochloride of venlafaxine proved to be extremely water soluble.
193 Secondly, the Priority Document discloses that, despite numerous attempts, the production of ER tablets by hydrogel tablet technology proved to be “fruitless”. This is because the compressed tablets were either physically unstable or dissolved too rapidly in dissolution studies. This led Wyeth to conclude, and thus to disclose in the Priority Document, that it was “impossible to achieve with hydrogel tablet technology” a formulation that had the desired dissolution rate of a sustained release dosage form of venlafaxine hydrochloride. However, the desired dissolution rate had been achieved “with the film-coated spheroid compositions of this invention”. Once again, it is clear that this reference is to the formulation having the essential features to which I have referred.
194 The Priority Document refers to a “use aspect of this invention”, being “a method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily tablet dosing with venlafaxine hydrochloride”. However, both the language of this statement, and the particular context in which it is made, leave no doubt, in my view, that this method is achieved “through administration of the venlafaxine formulation of this invention”, not any formulation of venlafaxine hydrochloride that does not have, as its essential features, spheroids comprised of venlafaxine hydrochloride, microcrystalline cellulose and HPMC, coated with ethyl cellulose and HPMC. The method is thus formulation-dependent and referable only to the inventor’s particular ER spheroid formulation of venlafaxine hydrochloride.
195 In short, what is relevantly disclosed is the described formulation and the use of the described formulation, not any formulation, to achieve certain outcomes (the diminution of nausea and emesis and the elimination of peaks and troughs of drug concentration in blood plasma). When the Priority Document records the blood plasma levels of venlafaxine over time in comparing IR tablets with ER capsules, it is clear that the results for ER capsules have been obtained from an analysis of ER capsules containing spheroids of venlafaxine hydrochloride having the essential features to which I have referred. There is nothing in the Priority Document to suggest that these results are not formulation-dependent. In particular, the Priority Document does not disclose that these results will be the same as, or predictive of, the results that would be obtained by using any ER formulation of venlafaxine hydrochloride, including any other encapsulated ER formulation, in the same studies.
196 My conclusions are based on a reading of the text of the Priority Document, giving it meaning according to the language and syntax adopted by its author. Although such a document must be read through the eyes of the person skilled in the art, the parties did not suggest that, in the respects to which I have referred, the person skilled in the art would read the Priority Document in a way that did not give its text its ordinary and plain English meaning. There was some debate on appeal about how the person skilled in the art would understand the expressions “subject” and “patient” where used with reference to Tables 2 and 3 of the Priority Document. In my view it is not necessary to resolve that debate because it does not affect in any material way the scope or content of the disclosures to which I have referred.
The Amended Patent
197 In her reasons for judgment, Bennett J has fully described the various deletions and additions, and other amendments, made to the Original Patent (which, in relevant respects, is accepted to be indistinguishable from the Priority Document, the Grandparent Application and the Parent Application) which are reflected in what is now the Amended Patent.
198 As Bennett J has demonstrated in her reasons for judgment, the 2006 Amendments made a substantial alteration to the description of the invention in the Original Patent. The invention is no longer described as being the specific ER spheroid formulation or the use of that formulation in providing a method for moderating “the plural blood plasma peaks and valleys” attending multiple daily dosing with venlafaxine hydrochloride, thereby reducing the level of nausea and incidence of emesis as side effects of that dosing regimen. Rather, the invention is described as a series of methods (namely, a method of providing a therapeutic blood plasma concentration of venlafaxine hydrochloride over a 24 hour period; a method of moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily dosing with venlafaxine hydrochloride; a method of reducing the level of nausea and the incidence of emesis in a patient in need of venlafaxine; and a method of treating depression in a patient in need of such treatment), involving “a single daily dosing formulation of venlafaxine hydrochloride”.
199 In the disclosure of these methods, the specific ER spheroid formulation of the Original Patent is given as a non-limiting example of an ER formulation that can be used. Having said this, the Amended Patent still incorporates, by reference, the entire disclosures of the Grandparent Application and the Parent Application (and hence the Original Patent) and, expressly, the disclosure that the production of an ER formulation of venlafaxine hydrochloride by hydrogel tablet technology had proved to be “fruitless” or “impossible to achieve”, either because the compressed tablets are physically unstable or because they dissolve too rapidly in dissolution studies to provide the desired dissolution rate of a sustained release dosage form of that active ingredient.
200 The apparent shift in the Amended Patent from the Original Patent, is from (a) a specific ER spheroid formulation and its use in a method or methods, to (b) a variety of methods involving the use of “a single daily dosing formulation of venlafaxine hydrochloride” with certain peak blood plasma levels (including over time) and/or a specific dissolution profile, of which the specific ER spheroid formulation is but an example.
201 The claims of the Amended Patent make clear that it is not essential to the alleged invention that this single daily dosing formulation be an ER formulation (save for claim 15) or an encapsulated formulation (save for claim 27).
202 Claim 18 of the Amended Patent claims a formulation of venlafaxine hydrochloride containing a “therapeutically effective amount of spheroid core” comprising venlafaxine hydrochloride, microcrystalline cellulose and HPMC, the spheroid core being coated with a coating comprising ethyl cellulose and HPMC (that is, the specific ER spheroid formulation disclosed in the Priority Document, and described as an example formulation in the specification of the Amended Patent). Claims 19 to 26 are expressed to be dependent, directly or indirectly, on claim 18.
203 In the present case, claim 18 and its immediately dependent claims are not engaged in the case for invalidity raised by the appellants or in the case for threatened infringement raised by Wyeth. Those claims can, therefore, be put to one side.
The determination of the priority date
204 The determination of the priority date of the relevant claims depends upon:
(a) the application of s 114 of the Act and reg 3.14(b) of the Regulations, or if those provisions are not applicable;
(b) the successive application of reg 3.12(1)(c) in respect of the Parent Application and Grandparent Application, and thereafter the application of reg 3.12(1)(b) in respect of the Priority Document, or, if those regulations cannot be satisfied, the application of reg 3.12(1)(a) of the Regulations.
205 If, by reason of the 2006 Amendments, a relevant claim of the Amended Patent claims matter that was in substance disclosed as a result of amending the specification (s 114), the priority date of that claim will be the date of filing of the statement of amendments that resulted in that disclosure (reg 3.14(b)), namely 20 December 2006.
206 If, by reason of the application of a fair basing analysis involving a consideration of the Parent Application, Grandparent Application and the Priority Document (regs 3.12(1)(b) and (c)), it is not established that a relevant claim is fairly based on matter disclosed in each of those documents (which the parties accept are relevantly the same for practical purposes), the priority date for the claim will be the filing date of the application for the Original Patent (reg 3.12(1)(a)), namely 30 October 2003.
207 In either case, the priority date of the claim would be after Wyeth’s sale in Australia of EFEXOR XR in 1999.
208 On appeal, the appellants’ submissions concentrated on how regs 3.12(1)(b) and (c) did not apply to the relevant claims of the Amended Patent in light of the disclosures in the Priority Document. Regulation 3.12(1), however, is expressed to be subject to reg 3.14. In the present case the correct starting point to determine the priority date is the question whether s 114 applies to one or more of the claims of the Amended Patent.
209 Furthermore, the appellants tended to treat the proper application of reg 3.12(1) as resulting in the deferred priority date of 20 December 2006, whereas, if their analysis is otherwise correct, the priority date would be, as I have indicated, the date of filing the application for the Original Patent, namely 30 October 2003.
210 The same approach, with its apparent conflation of regs 3.12(1) and 3.14(b), was apparently pressed on the primary judge: see Reasons [9] and [153]-[154]. It may be that this was because the parties had agreed that the test under s 114 (i.e. whether a claim of a complete specification claims “matter that was in substance disclosed” as a result of amending the specification) was “the same” as the test for determining whether a claim is fairly based on a specification as required by s 40(3) of the Act: Reasons [154]; cf ICI Chemicals & Polymers Ltd v The Lubrizol Corporation Inc (2000) 106 FCR 214 at [118] and the cases there cited.
211 Certainly on appeal, Wyeth advocated this approach. It submitted that reference to s 114 added nothing: if the relevant claims of the Amended Patent were fairly based on the Priority Document they would not claim matter in substance disclosed as a result of any amendment. However, this submission is only possible because of the parties’ acceptance that the specification of the Original Patent is relevantly the same as the specification of the Priority Document, for practical purposes.
212 In light of the way the parties conducted this aspect of the case before the primary judge, and on this appeal, the first question of present significance is: what matter is disclosed by the Priority Document? The answer to this question also answers the question of what is disclosed by the Original Patent.
213 The primary judge held that there were two inventions disclosed: an encapsulated formulation; and “a method for obtaining a certain drug to plasma relationship over time yielding a ‘tighter plasma therapeutic range control’ than multiple daily dosing, eliminating the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing and thereby reducing the level of nausea and incidence of emesis that attend multiple daily dosing”: Reasons [165].
214 In arriving at this conclusion, the primary judge was persuaded by Wyeth’s submission (repeated on appeal) that this conclusion is supported by the disclosures of claims 9 and 10 of the Priority Document. Those claims are as follows:
9. A method for providing a therapeutic blood plasma concentration of venlafaxine over a twenty four hour period with diminished incidences [sic] of nausea and emesis which comprises administering orally to a patient in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
10. A method for eliminating the troughs and peaks of drug concentration in a patients [sic] blood plasma attending the therapeutic metabolism of plural daily doses of which comprises administering orally to a patient in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
215 Wyeth submitted, and the primary judge accepted, that these claims disclose a method that is not limited to the use of any particular formulation and that the references in the Priority Document to the inventor’s failed efforts to prepare a hydrogel tablet formulation do not eliminate the independent disclosure of a method of treatment.
216 I am, with respect, unable to agree with that conclusion.
217 Although claims 9 and 10 of the Priority Document refer only to “an encapsulated, extended release formulation” containing venlafaxine hydrochloride as the active ingredient, without expressly referring to the specific ER spheroid formulation in the body of that document, in my view the words “extended release formulation” in those claims can only be really understood, in their context, as implicitly disclosing “the extended release formulations of this invention” in the detailed description of the invention, which have then been encapsulated. This description makes clear that the formulation is of “beads or spheroids” formed from an admixture of venlafaxine hydrochloride, microcrystalline cellulose and HPMC coated with a mixture of ethyl cellulose and HPMC, which is then encapsulated.
218 This is the widest description of the formulation given as “[Wyeth’s] solution to the problem of preparation of the extended release drug containing formulations of this invention”, that solution having been “completely unexpected”, and the problem having arisen from the fact that the hydrochloride of venlafaxine proved to be extremely water soluble, thereby rendering numerous attempts to produce ER tablets by hydrogel technology “fruitless” and “impossible to achieve”.
219 I am not persuaded that the Priority Document discloses, relevantly, anything more than the particular ER formulation, or more limited embodiments of it, including encapsulated embodiments, which was Wyeth’s solution to the disclosed problem, and the consequent use of that formulation, or more limited embodiments of it. It discloses no other encapsulated formulation as the method of providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with diminished incidence of nausea and emesis (claim 9) and as the method of eliminating the troughs and peaks of drug concentration in a patient’s blood plasma attending the therapeutic metabolism of plural daily doses of venlafaxine (claim 10).
220 Moreover, I am unable to read the Priority Document, and in particular claims 9 and 10, as disclosing methods that can be performed by use of a postulated ER formulation of venlafaxine hydrochloride that the patent applicant itself describes as “fruitless” and “impossible to achieve”. By implication, the Priority Document discloses that the performance of the methods using such a postulated formulation would also be “fruitless” and “impossible to achieve”.
221 For these reasons, I share Bennett J’s view that the primary judge erred in concluding that the second invention, as described by her Honour, was disclosed by the Priority Document.
222 The further questions that then arise are, first, do the relevant claims of the Amended Patent claim matter that was in substance disclosed as a result of amending the specification and, secondly, if necessary to be decided, are the relevant claims of the Amended Patent fairly based on matter disclosed in the Priority Document?
223 In my respectful view, the answer to the first of those questions is “yes” and the answer to the second of those questions is “no”.
224 Each of these questions directs attention to what is in fact claimed, relevantly, in the Amended Patent. The focus of attention is, therefore, claims 1 to 17, and claim 27 (when dependent on claims 1 to 17).
225 I have referred to the fact that the relevant claims are directed to methods involving “a single daily dosing formulation of venlafaxine hydrochloride”. Save for claims 15 (an ER formulation) and 27 (an encapsulated formulation), the formulation is not specified beyond the result to be achieved in terms of identified peak blood plasma levels and/or a specific dissolution profile.
226 Thus, aside from claims 15 and 27, what is now claimed in the Amended Patent, but not in substance disclosed in the Priority Document or the Original Patent, is that any single daily dosing formulation of venlafaxine hydrochloride that attains the specified results can be used in the claimed methods. This is how Wyeth asserts its monopoly rights. However, this development or advance was disclosed only by the 2006 Amendments.
227 It follows, in my view, that the priority date of claims 1 to 14, and claims 16 and 17 (when not dependent on claim 15), falls to be determined under s 114 of the Act and reg 3.14(b) of the Regulations. The same result ensues in relation to claim 15 (and claims 16 and 17 when dependent on claim 15) and claim 27 because, although these claims add the respective limitations of an ER formulation of venlafaxine hydrochloride which is encapsulated, neither claim is limited to the specific ER spheroid formulation of the Original Patent.
228 Thus, for this reason alone, claims 1 to 17 and 27 (when dependent on claims 1 to 17) have the deferred priority date of 20 December 2006.
229 Although it is unnecessary to determine the relevant priority date by reference to reg 3.12(1) of the Regulations, a similar result ensues because there is no real and reasonably clear disclosure in the Priority Document of any method that is not dependent on the use of the specific ER spheroid formulation.
230 As I have discussed, the Priority Document makes clear that what is provided is a specific formulation, and its more limited embodiments, that can then be used in a method to achieve particular outcomes. What is discussed, and thus what is provided, is a particular formulation solution to a particular formulation problem. The more general method claims of the Amended Patent, limited so far as formulation is concerned only to “a single daily dosing formulation of venlafaxine hydrochloride”, even as an ER formulation that is encapsulated, travel well beyond, and are not fairly based on, matter disclosed in the Priority Document.
231 Thus, if recourse to reg 3.12(1) were necessary, claims 1 to 17 and 27 (when dependent on claims 1 to 17) would have a priority date of 30 October 2003.
232 For these reasons, I am of the view that the primary judge erred in concluding that the relevant claims of the Amended Patent have a priority date of 25 March 1996.
Other challenges to validity
233 If claims 1 to 17 and 27 of the Amended Patent take the deferred priority date, or even the priority date of 30 October 2003, those claims will be invalid, for lack of novelty. It follows that the appeals should be allowed for that reason alone.
234 In those circumstances it is unnecessary to deal with the other grounds of invalidity advanced by the appellants. I propose, however, to briefly set out my conclusions on the fate of the appellants’ challenges with respect to those grounds. In stating these conclusions it is convenient, for simplicity of exposition, to treat all relevant challenges on appeal as having been made by all appellants.
Internal fair basis
235 The primary judge rejected the appellants’ contention that the relevant claims of the Amended Patent are not fairly based on the matter described in the specification: s 40(3) of the Act.
236 In my respectful view, the primary judge erred in her conclusion. My reasons for this view are influenced significantly by the features of the Amended Patent I discussed when dealing with the question of the correct priority date of the claims.
237 When the relevant claims refer to a single daily dosing formulation of venlafaxine hydrochloride, they include all such formulations having the result or results specified in the claims, and otherwise conforming to the limitations of the claims, including even an ER formulation produced as compressed tablets by hydrogel tablet technology, if such a formulation can be produced. I do not read the claims as implicitly limited to exclude such a formulation. Indeed, Wyeth did not contend for such a construction. To the contrary, it contended that it can claim, validly, all single daily dosing formulations of venlafaxine hydrochloride that achieve the results, and otherwise conform to the express limitations, of the claims.
238 Wyeth advanced two principal reasons to support this contention.
239 First, as a matter of textual comparison, Wyeth submitted that the relevant claims are supported by corresponding consistory clauses in the body of the specification. In this connection Wyeth submitted that there is nothing in the body of the specification that suggests that the description of the invention is narrower than the description in the consistory clauses.
240 Secondly, Wyeth submitted that, as a matter of principle, once it is recognised that the specification discloses a method, and enables one way of performing that method, it is entitled to claim all alternative means by which the method may be performed. In this connection, Wyeth sought to draw support from the statement of general principle in Shave v H.V. McKay Massey Harris Proprietary Limited (1935) 52 CLR 701 at 709, quoted with approval in Lockwood Security Products Pty Limited v Doric Products Pty Limited (2004) 217 CLR 274 at [59], to the effect that when, by a new application of principle, an inventor obtains a new result or thing, the inventor may claim all the alternative means by which the thing or result may be achieved.
241 In my view those submissions should not be accepted.
242 First, despite its deletions, additions and other amendments, the specification of the Amended Patent still incorporates, in the way that I have described above, the unambiguous statements that, so far as Wyeth is concerned, the search for an ER formulation produced by hydrogel tablet technology is “fruitless” and “impossible to achieve”. Once again, these statements cannot be ignored, although Wyeth sought to do so by appealing to evidence from Professor Charman and Dr Marshall to the effect that the relevant passages in the specification dealing with the attempts to use hydrogel tablet technology do not represent statements of absolute fact, beyond the inventor’s own endeavours. This evidence really diverts attention from the fact that the comparison for s 40(3) purposes is between the relevant claim and “the matter described in the specification”. An argument based on an appeal to an abstract, independent or objective truth, according to the understanding of an expert witness, rather than to the matter described in the specification, really misses the point.
243 A consideration of the entirety of the specification of the Amended Patent, with its express incorporation of the entire disclosures of the Grandparent Application and the Parent Application, and the retention of the text concerning the “fruitless” endeavours to produce an ER formulation by hydrogel tablet technology, which was “impossible to achieve”, shows that the consistory clauses do not reflect the description of the invention in the light of the specification as a whole: Lockwood at [87]; Atlantis Corporation Pty Ltd v Schindler (1997) 39 IPR 29 at 50.
244 Secondly, the statement of general principle in Shave does not mandate or permit a departure from a consideration of what is in fact disclosed, described and claimed in the patent specification for the purposes of applying s 40(3) of the Act.
245 As recourse to the judgment in Shave makes clear, the proper construction of the patent specification is all-important. At 709 Rich, Dixon, Evatt and McTiernan JJ observed:
In the present case the plaintiff’s specification contains no indication that he sought protection for the application of principle upon which the construction of his implement is based. Indeed it does not even appear from the specification that he appreciated the generality of the mechanical principles it brought together and the existence of variant means of applying them. He sought and secured simplicity of design and to this achievement his spindle contributed much. Whatever gains may be had by departing from his spindle, greater simplicity is not one of them. In our opinion his claim is for the mechanism he describes.
246 In that case, their Honours concluded that, although a principle was described in the specification, the inventor was not seeking to claim as his invention all alternative means by which a thing or result may be achieved. This conclusion resulted from the proper construction of the claims. The present case is somewhat different in that the immediate concern is: what is the matter described in the specification? Nevertheless, the approach referred to by their Honours is apposite.
247 In the present case it may be accepted that a new application of principle (although not necessarily an application of new principle) was involved in the invention as claimed. However, a method including an ER formulation of venlafaxine hydrochloride produced by hydrogel tablet technology is not part of the matter described in the body of the specification. Rather, it is matter that was effectively disclaimed in that part of the specification as being part of the invention. While the matter described in the body of the specification presages the possibility of workable formulations for use in the claimed methods other than the specific ER spheroid formulation exemplified, an ER formulation produced by hydrogel tablet technology is not one of them. Any principle described in the body of the specification is not an unqualified one so far as concerns the formulations that could be used in the methods of the claims.
248 Accordingly, the specification does not provide, by description, a basis for claiming any one of the methods performed by use of a single daily dosing formulation of venlafaxine hydrochloride produced by using hydrogel tablet technology.
249 I agree with Bennett J that, by seeking to claim methods which include such a formulation, Wyeth has travelled beyond the matter described in the specification. For that reason alone, claims 1 to 17 are not fairly based for the purposes of s 40(3) of the Act. The same result ensues for claim 27 (when dependent on claims 1 to 17). An encapsulated formulation is one that can comprise tablets contained within the capsule. Alphapharm’s ENLAFAX – XR product is of that kind: see Reasons [628]. Claim 27 would include a method involving the use of an encapsulated formulation where the capsule contents are produced by hydrogel tablet technology.
250 For completeness, I also agree with Bennett J, substantially for the reasons given by her Honour, that, additionally, the relevant claims are not fairly based on the matter described in the specification of the Amended Patent to the extent that they are not limited to methods involving the treatment of depression: cf. claims 4, 8 and 14 where, for example, that limitation is provided.
Sufficiency
251 The primary judge rejected the appellants’ contention that the specification does not describe the invention fully, including the best method known to Wyeth of performing the invention: s 40(2)(a).
252 In my view, the primary judge did not err in her conclusion.
253 The main plank of the appellants’ challenge was that, given the apparent width of the relevant claims to include methods using a single daily dosing formulation of venlafaxine hydrochloride produced by hydrogel tablet technology, there is no description in the specification that would enable the performance of the claimed methods using such a formulation.
254 That proposition may be accepted. However, in my view, that acceptance does not lead to the conclusion that the Amended Patent is invalid for want of compliance with s 40(2)(a) of the Act.
255 The specification of the Amended Patent fully describes the invention that can be validly claimed. In so doing, the specification lays bare the fruitlessness and impossibility of Wyeth’s endeavours in seeking to achieve an ER formulation using hydrogel tablet technology. The specification, by the provision of examples, enables the claimed methods to be performed. Wyeth was not required by s 40(2)(a) of the Act to describe every formulation that might be used in the performance of those methods; nor was it required to describe a formulation that was found to be “fruitless” or “impossible to achieve”.
256 In my view the problem with the specification, for s 40 purposes, is not one of insufficiency of description, but one of impermissible claim width.
Clarity
257 The primary judge rejected the appellants’ contention that the relevant claims of the Amended Patent do not define the claimed invention clearly: see s 40(3). The appellants’ contention was directed to the phrase “therapeutic blood plasma concentration” where used in those claims.
258 Based on the argument developed on appeal, there seems to be no error suggested in the primary judge’s acceptance that the phrase should be given its ordinary English meaning as referring to a single daily dosing of a formulation of venlafaxine hydrochloride that achieves a blood plasma concentration of venlafaxine that is therapeutically effective. The import of the appellants’ submissions is that, so understood, the phrase is unclear: it does not provide a workable standard because there is no way of predicting in advance what the therapeutic concentration for a particular formulation will be, thereby enabling the person skilled in the art to avoid the possibility of infringement. In advancing these submissions the appellants did not suggest that the determination of the therapeutic efficacy of a given formulation of venlafaxine hydrochloride itself presents a challenge to the person skilled in the art.
259 In my view the appellants’ contention raises, in a conventional way, a criticism that can be made of many claims limited by result. As a general rule, however, such claims do not fail for lack of clarity simply because further steps must be taken by the person skilled in the art, in the nature of trial and error or routine testing not involving invention, in order to understand when the result will be achieved: No-Fume Ltd v Frank Pitchford & Co Ltd (1935) 52 RPC 231 at 238, 245-246 and 247-249. The necessity for, or extent of, the work required in that regard may point to the possibility of insufficient description, but no challenge to validity of that kind has been raised in this respect.
260 Like Bennett J, I am not persuaded that the appellants have shown that the primary judge erred in her conclusion.
False suggestion
261 The primary judge rejected the appellants’ contention that the statements in the Amended Patent that it was completely unexpected that an ER formulation could be achieved because of the fruitless attempts to obtain such a formulation by hydrogel tablet technology, and that it was impossible to achieve with hydrogel tablet technology a dosage form that achieved the desired dissolution rate, constituted a false suggestion or misrepresentation on which the Patent was obtained: see s 138(3)(e).
262 I agree with Bennett J, substantially for the reasons advanced by her Honour, that the appellants have not demonstrated a false suggestion that was material to the grant of the Patent.
Lack of inventive step
263 The primary judge rejected the appellants’ contention that the invention as claimed is not a patentable invention because it lacks an inventive step: see ss 18(1)(b)(ii) and 138(3)(b).
264 In coming to that conclusion the primary judge gave detailed consideration to a significant body of factual and scientific evidence, including opinion evidence, which had been adduced by the parties on that question. In undertaking that task the primary judge identified a significant number of complex factual issues that were necessary to be decided in the present case in order for her to reach a finding on the ultimate question of inventive step: see Reasons [264].
265 The primary judge’s reasons stand as ample testimony of the magnitude of that task and of the methodical way in which her Honour considered those issues: see Reasons [265]-[514]. A significant part of the argument on appeal was devoted to challenging the primary judge’s factual findings and conclusions that were made along the way to reaching her conclusion on that ultimate question, in an endeavour to identify appealable error.
266 The framework for considering whether an inventive step is involved in an invention is provided by s 18(1)(b)(ii) of the Act, assisted by ss 7(2) and (3) and the definitions of “prior art base” and “prior art information”. A question of comparison is involved. Section 18(1)(b)(ii) makes clear that the invention is the invention “so far as claimed in any claim”. It also makes clear that the invention, as claimed, must be compared with the “prior art base as it existed before the priority date of that claim”.
267 The primary judge’s consideration of the question of inventive step was undertaken by making a comparison of the invention, as claimed in each of the relevant claims, with the prior art base as it existed at 25 March 1996, based on her conclusion that Wyeth was entitled to rely on the date of filing of the Priority Document as the priority date for those claims. This included a consideration of what information comprised the prior art base at that time, including what knowledge was part of common general knowledge. This consideration also took place in a context where the primary judge had rejected the appellants’ contention that the relevant claims were not fairly based for the purposes of s 40(3) of the Act.
268 It is clear that the determination of the correct priority date is pivotal to the comparison required by s 18(1)(b)(ii) of the Act. If the correct priority date is not 25 March 1996, but the deferred priority date of 20 December 2006 (as, in my opinion, it is) or even 30 October 2003, it can be appreciated that the prior art base may be radically different from that considered by her Honour, especially where, as here, Wyeth’s own embodiment of the invention had been on the market for a number of years before the relevant priority date and would have been prior art information.
269 In my view there is no utility in the Full Court now proceeding to deal with this part of the case by reference to the incorrect priority date of 25 March 1996. To do so would not only be to ignore critical findings made in this appeal about the relevant priority date but also to engage in an essentially barren exercise given that, regardless of the priority date chosen, the relevant claims are not valid, for want of fair basis under s 40(3) of the Act.
Entitlement and false suggestion
270 The primary judge rejected the appellants’ contention that Wyeth’s failure to correctly nominate all inventors in its application for the Patent constituted a false suggestion or misrepresentation on which the Patent was obtained: see s 138(3)(e).
271 The primary judge also rejected the appellants’ contention that Wyeth was not entitled to the Patent: see s 138(3)(a).
272 It is convenient to deal with these two challenges to validity together.
273 As to the question of false suggestion or misrepresentation, there is no debate about the fact that Ms Sherman was shown, incorrectly, to be the only inventor on Wyeth’s application for the Patent. The primary judge found that Messrs Clark, Lamer and White were co-inventors with Ms Sherman. Her Honour also found that all these inventors were employees of Wyeth at all material times. In its patent application, Wyeth claimed to be the person entitled to the invention based on the assignment to it of the rights in and to the invention. The primary judge reasoned that the representation that Ms Sherman was the sole inventor could not have been material to the grant of the Patent because the only material representation was Wyeth’s entitlement as assignee of the invention, a question which the primary judge subsequently resolved in Wyeth’s favour: see Reasons [552] and [554].
274 In my view, no error has been demonstrated in the primary judge’s approach to determining this aspect of the appellants’ case on false suggestion and misrepresentation. I agree with the primary judge that the determination of this issue depends on whether the appellants could demonstrate that Wyeth was not entitled to the Patent in reliance on s 15(1) of the Act.
275 As to the question of entitlement, the evidence before the primary judge revealed that the inventors had each entered into a standard form invention and disclosure agreement with a subsidiary company, Ayerst Laboratories Inc (Ayerst), of American Home Products Corporation (American Home Products). Between 1996 and 2001 the inventors also executed a series of specific assignments of patent and other rights in the invention to American Home Products.
276 On 11 March 2002, American Home Products merged with one of its subsidiary companies, to become Wyeth.
277 Moreover, through a series of corporate reorganisations, Ayerst was merged with another company, the surviving corporation being a company ultimately named, as at 21 March 2002, Wyeth Pharmaceuticals Inc (Wyeth Pharmaceuticals). In December 2002, Wyeth Pharmaceuticals was merged into another Wyeth subsidiary company, with all the “estate, rights, privileges, immunities, powers and franchises of Wyeth Pharmaceuticals being vested in and held and enjoyed by” the Wyeth subsidiary company, the name of which was then changed to Wyeth Pharmaceuticals Inc. I include that company in the description “Wyeth Pharmaceuticals”.
278 Annual Reports lodged under United States securities legislation for the years 2001 to 2008 showed Wyeth Pharmaceuticals to be a wholly-owned subsidiary of Wyeth.
279 Part of the appellants’ case before the primary judge was that Wyeth had an evidentiary onus to establish its entitlement. The primary judge rejected that contention, correctly in my view. It was for the appellants to establish a lack of entitlement, not for Wyeth to prove its entitlement. That is not to say, however, that the appellants could not discharge that onus by reference to material that Wyeth itself had tendered on this issue.
280 In this connection the appellants did not seek to adduce their own evidence. Their initial challenge to Wyeth’s entitlement was based solely on the alleged false suggestion or misrepresentation arising from the fact that only Ms Sherman was shown on Wyeth’s original application for the Patent, not on the history or the effect of corporate reorganisations revealed by Wyeth’s evidence. However, in light of the evidence adduced by Wyeth, the appellants’ approach was to raise arguments directed to the sufficiency of that evidence or to what that evidence might otherwise show.
281 The highest that the appellants’ case rose on this issue at trial was that “the person most likely to be entitled to the invention claimed in the Patent is a company the corporate status of which is unclear, or in any event has not come forward in these proceedings”: see Reasons [572]. Why this should be so is not clear because the evidence before the primary judge either showed or supported the conclusion that American Home Products had been merged into the one surviving corporation that was Wyeth, and Ayerst, through a succession of mergers, had been merged in the surviving corporation that was Wyeth Pharmaceuticals. Furthermore, Wyeth Pharmaceuticals was a wholly-owned subsidiary of Wyeth.
282 The primary judge concluded that the appellants had not discharged their onus of establishing lack of entitlement in the face of the evidence of assignment of all rights in connection with the invention to Wyeth: see Reasons [588]. The evidence of assignment was constituted by the specific assignments by the inventors to Wyeth.
283 The primary judge went further and held that, in any event, the terms of the standard form invention and disclosure agreements were themselves sufficient to establish Wyeth’s entitlements to the invention. The primary judge held that clauses 4, 5 and 8 of those agreements provided “a workable scheme for the identification and vesting of all rights as identified in Wyeth’s subsidiary … in circumstances where Wyeth was the sole shareholder”: see Reasons [589].
284 Those clauses were as follows:
4.(a) AYERST and EMPLOYEE agree that all Confidential Information, including its uses and the ideas related to its advertisement and promotion, is AYERST’s sole property. Further, all the Confidential Information developed, improved, discovered, invented or conceived by EMPLOYEE, solely or in concert with others, during the term of his (or her) employment with AYERST, shall become AYERST’s sole property.
5. EMPLOYEE will immediately disclose and assign to AYERST his (or her) entire right and interest in and to (1) developments, improvements, discoveries and inventions related to Confidential Information; (2) any applications for patents that may be filed relating to Confidential Information, and (3) any letters patent that may issue relating to such Confidential Information. He (or she) will also promptly give all assistance possible, including signing of necessary documents, for the preparation and prosecution of any application for new, revised or reissued patents on the above, or divisional or corresponding foreign patent applications thereon, as may be requested by AYERST.
8. EMPLOYEE agrees that every part of this agreement applies to, inures to the benefit of, and is enforceable by any of the subsidiary, affiliate, associate, or successor companies of AYERST or its parent company, American Home Products Corporation. In addition, this Agreement shall insure [sic] to the benefit of and be binding upon EMPLOYEE, EMPLOYEE’S heirs, executors, and administrators.
285 Her Honour then concluded, in accordance with a submission advanced by Wyeth, that, by accepting the specific assignments made to it, and in applying for the Patent in its own name, Wyeth had signified its assent to that transaction on its own behalf and on behalf of its wholly-owned subsidiary Wyeth Pharmaceuticals. That assent was consistent with clause 8 of the standard form invention and disclosure agreement.
286 The substance of the appellants’ contentions on appeal, reflected in submissions made by Alphapharm, was that the primary judge had concluded (correctly, according to the appellants’ submissions) that the invention had been assigned to Ayerst by the standard form invention and disclosure agreements, but that her Honour erred by finding that: (a) those rights vested in the company called Wyeth Pharmaceuticals, following the merger in December 2002; and (b) Wyeth had established that there had been an assignment, disposition or alienation of those rights to it, based on the fact that it was the sole shareholder of Wyeth Pharmaceuticals. The appellants maintained the position that it was not sufficient for Wyeth to rely on the documents it had tendered; it had to go further and prove the legal effect of the documents it had tendered including, where relevant, the content of foreign law.
287 In my view the primary judge did not err in rejecting the appellants’ contention that Wyeth was not entitled to the Patent. It was not incumbent on Wyeth to positively prove its chain of title. It was entitled to apply for the Patent on an assertion as to its entitlement. That assertion of its entitlement was based on its status as “the assignee of the actual inventor”: see the Request for a Standard Patent and Notice of Entitlement lodged by Wyeth on 30 October 2003 and Reasons [541]. That claimed entitlement derives from s 15(1)(c) of the Act which, for its own purposes, treats an “invention” as a species of property. The position revealed on the face of the documents was consistent with Wyeth’s assertion as to its entitlement.
288 First, there were specific assignments to Wyeth of the rights in and to the invention by the inventors. Wyeth is entitled to rely on those documents for what they show on their face.
289 Secondly, in my view, clauses 4(a) and 5 of the standard form invention and disclosure agreement did not operate to immediately assign all rights in and to the invention to Ayerst. Rather, those clauses constituted a contractual obligation on the part of the inventor to give over inventions to Ayerst and to provide other assistance to Ayerst in applying for patents in respect of inventions. It follows that the standard form invention and disclosure agreements did not stand in the way of the specific assignments taking effect in favour of Wyeth, according to their terms. There is no evidence to suggest that Wyeth Pharmaceuticals or any other surviving Wyeth subsidiary company has asserted a superior right to Wyeth’s or could realistically do so over Wyeth’s objection.
290 In this connection, I am not satisfied that the primary judge did find (as the appellants contend) that the invention was assigned by the standard form invention and disclosure agreements. The primary judge found no more than that the standard form invention and disclosure agreements provided a “workable scheme” for the identification and vesting of rights, which her Honour then considered in the context of Wyeth itself taking direct assignments from the inventors in circumstances where, absent any evidence to the contrary, Wyeth Pharmaceuticals, as the successor of Ayerst and as Wyeth’s wholly-owned subsidiary, was subject to Wyeth’s corporate will and could be taken to have assented to such transfers to its parent company.
291 If the appellants wished to contend, contrary to what was shown on the face of the documents in evidence, that Wyeth Pharmaceuticals was not the successor of Ayerst or that Wyeth Pharmaceuticals was not a wholly-owned subsidiary of Wyeth (and, therefore, not subject to Wyeth’s corporate will), or that, say, Wyeth Pharmaceuticals had asserted and maintained a valid prior claim to ownership of the invention, or that, realistically, it could and would make such a claim, then it was for them to adduce evidence of the relevant facts, including proof of relevant foreign law if necessary: see s 7(3)(a) of the Foreign Corporations (Application of Laws) Act 1989 (Cth). That position was not achieved by the appellants contending that Wyeth had failed to discharge an onus which it did not bear or by pointing, argumentatively, to the possibility of other legal outcomes.
Infringement
292 The primary judge rejected Alphapharm’s contention that the use of its ENLAFAX XR formulation in the methods of the relevant claims would not infringe those claims because ENLAFAX XR “is hydrogel tablet technology within the meaning of the specification, and therefore does not infringe the claims”.
293 Acceptance of Alphapharm’s contention required acceptance of the related contention that the words “a single daily dosing formulation of venlafaxine hydrochloride” should be construed as meaning “a single daily dosing formulation of venlafaxine hydrochloride (not utilising hydrogel tablet technology)”.
294 For the reasons given above in relation to the issue of internal fair basing, the relevant claims do not bear the construction for which Alphapharm contends.
295 It follows, in my view, that the primary judge did not err in her conclusion. However, as I have also found, the impermissible breadth of the relevant claims stands as an independent reason why those claims are invalid.
disposition
296 The appeals should be allowed. I agree with the orders proposed by Bennett J.
I certify that the preceding one hundred and fifteen (115) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Yates. |
Associate:
Dated: 28 October 2011
