16 November 2010

Australian Federal Court Blocks Generic EFFEXOR-XR

Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth Australia Pty Ltd [2010] FCA 1211 (8 November 2010)

Validity – whether claims entitled to priority date of original US application – whether description is sufficient – whether claims are clear and fairly based on description – whether claims are novel –  whether claims are inventive – whether patent obtained by false suggestion or misrepresentation – entitlement – whether patentee gained title to the invention from all inventors – effect of omission of co-inventors' names from application – infringement – whether generic pharmaceuticals would infringe patent

An Australian Federal Court judge has upheld a patent covering the "extended release" formulation of Wyeth's antidepressant drug EFFEXOR (venlafaxine hydrochloride), marketed as EFFEXOR-XR, barring generic manufacturers Sigma Pharmaceuticals (Australia) Pty Ltd, Alphapharm Pty Ltd and Generic Health Pty Ltd from "importing, marketing, taking orders for, selling, supplying, and offering to supply" their own versions of the drug in Australia.

Each of the three generic pharmaceutical companies has obtained registration of extended release formulations of venlafaxine hydrochloride on the Australian Register of Therapeutic Goods.  Sigma's product is known as Evelexa XR, Alphapharm's as Enlafax-XR and Generic Health's as "generichealth XR".

The extended release formulation of venlafaxine hydrochloride is the subject of Australian Patent No. 2003259586 ("the XR patent"), which was granted on 11 May 2007.  The basic compound, venlafaxine hydrochloride, was the subject of Australian Patent No. 567524, which expired on 6 December 2008.

Sigma, Alphapharm and Generic Health (collectively "the generic manufacturers") all sought revocation of the XR patent, so that they would be free to market their generic products in Australia.  Wyeth contended that by doing so they would be infringing claims 1, 4, 5, 8, 9, 10, 15, 16 and 27 of the XR patent, and sought orders restraining all three companies from bringing the generic drugs to the Australian marketplace.

Justice Jagot dismissed the generic manufacturers' invalidity claims, and granted Wyeth the restraining orders that it sought.


The generic manufacturers' invalidity case was based on a number of distinct grounds, including:
  1. that by virtue of amendments made on 20 December 2006, the claims of the XR patent are not entitled to the priority date of United States Patent Application No 60/14006, filed on 25 March 1996, and are invalid in view of the sale of EFFEXOR-XR in Australia since 1999;
  2. that the invention claimed in claims 1 to 17 (and 27 insofar as it is dependent upon those claims) of the XR patent does not disclose a manner of manufacture and is not inventive;
  3. that the amended form of the XR patent was obtained upon the making of false representations to the Commissioner of Patents, which materially contributed to the grant;
  4. that Wyeth was not entitled to the XR patent because (based on declarations filed by Wyeth in each of Canada and the United States) there were three additional inventors of the claimed invention, not named in the Australian application;
  5. that the claims of the XR patent lack clarity and therefore do not claim an invention; and
  6. that the claims are not fairly based on the disclosure in the US priority document, nor the body of the specification, irrespective of the priority date determined.
 The judge was unpersuaded by any of the generic manufacturers' arguments, and upheld all claims of the XR patent.  A full discussion of the lengthy reasoning in the decision is impractical, however it is worthwhile to highlight a few salient points.

Incorporation by Reference

The amendments made on 20 December 2006 included the deletion of certain passages included in the original US priority application, as well as in prior divisional parent and grandparent applications of the XR patent.  However, the disclosure in the patent incorporates the contents of the parent and grandparent specifications in their entirety, by reference.

Justice Jagot confirmed the effectiveness of incorporation by reference in this manner, finding in particular that the deletion of passages duplicating content from the referenced documents does not create any inference that the patentee had "eschewed the deleted part of the description of the invention" ([146]-[151]).


The decision confirms that, under the Australian law as it currently stands, the requirement for sufficiency of description equates with asking whether or not the addressee of the specification is enabled to produce something within each claim without new inventions or additions or prolonged study of matters presenting initial difficulty.  A single embodiment falling somewhere within the scope of each claim will suffice.  There is no requirement (as under US or European laws, for example) that the claims be enabled substantially across their entire scope ([227]-[238]).

Claiming by Reference to Result

It is well established that a claim defining the scope of the patent monopoly by reference to a result to be achieved is not impermissible, so long as the boundaries of the monopoly remain sufficiently well-defined.

In this case, the claims of the XR patent make reference to achieving a blood plasma concentration of the drug having a therapeutic effect, which the generic manufacturers said amounted to a circular definition.  The court disagreed, agreeing with Wyeth that the skilled person would clearly know that performing a method incorporating all of the other specified integers of the claims would infringe, unless no therapeutic effect was achieved.  As Wyeth put it, "[i]t is axiomatic that no person would aim for such a result" ([239]-[241]).

"Obvious to Try"

Regular readers of this blog will be aware that the recent approval of an "obvious to try" test for inventive step in the Australian Examiners Manual has become something of a Patentology hobby horse.  As we have argued previously, it is our opinion that "obvious to try" does not form part of the current law in Australia, and that it is wrong to conflate this with the question of whether the path from the prior to a claimed invention comprises only "matters of routine."  (See previous articles Australian Patent Office Embraces "Obvious to Try", Federal Court Again Rejects "Obvious to Try" and IP Australia Gets Tougher on Patent Applicants.)

This decision again supports our views on this issue, citing at [252] the observation of Lindgren J in Alphapharm Pty Ltd v H Lundbeck A/S [2008] FCA 559 (at [180]) that the High Court has "insisted on the two elements: (1) being led as a matter of routine to the desired result; and (2) having a reasonable expectation of achieving that result", and at [255] that "[i]t is wrong to characterise the variation of all parameters or the trying of all choices until one proves successful as being obvious, where the prior art did not point to it" (referring again to Alphapharm v Lundbeck at [283]).


The evidence suggested that while only one inventor (Ms Sherman) was named in the XR patent application, there were, in fact, three further co-inventors (Messrs Clark, Lamer and White).

While the failure to correctly identify all inventors may have adverse consequences in some jurisdictions (such as the US), in Australia the only relevant consideration is whether or not the patentee was entitled to the grant of the patent, eg by derivation of title from all inventors.

In this case, Wyeth's evidence established that all of the potential co-inventors were employees of Ayerst Laboratories Incorporated, which was a wholly owned subsidiary of American Home Products Corporation.  Following a merger and name changes, the employees and the rights to their inventions accrued to Wyeth.  The court found that there was no credible evidence or argument to suggest that Wyeth was not entitled to the patent, or that it had at any point falsely represented its entitlement to the grant of a patent ([554] and [587]-[590]).


Although the generic manufacturers denied infringement, it appears that there was little support in their evidence for this defence.  The court appears to have had little difficulty in reaching a conclusion that the proposed generic products would infringe the XR patent ([620]-[631]).


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