IP Law Daily Watson Labs failed to prove obviousness of erectile dysfunction treatment drug patent claims
Thursday, April 28, 2016

Watson Labs failed to prove obviousness of erectile dysfunction treatment drug patent claims

By Linda O’Brien, J.D., LL.M.

In an action by pharmaceutical company Bayer against competitor Watson Laboratories over its alleged infringement of Bayer’s patent covering certain formulations of erectile dysfunction treatment drug STAXYN®, the patent was not invalid due to obviousness, the federal district court in Wilmington, Delaware has ruled (Bayer Pharma AG v. Watson Laboratories, Inc., April 27, 2016, Sleet, G.).

U.S. Patent No. 8,613,950 (“the ’950 patent”) entitled “Pharmaceutical Forms with Improved Pharmacokinetic Properties” was issued in December 2013. The application for the ’950 patent claims priority to a German patent application that was filed in March 2005. Bayer AG is the assignee of the patent. Bayer asserted claims 9 and 11 of the patent, which cover particular orally disintegrating tablet formulations of vardenafil hydrochloride trihydrate. Vardenafil hydrochloride trihydrate is the active ingredient in STAXYN®, the brand drug marketed by Bayer for the treatment of erectile dysfunction.

In 2012, Watson Laboratories, a subsidiary of Actavis, Inc., submitted an Abbreviated New Drug Application (ANDA) to the FDA seeking approval to sell a generic version of STAXYN®. In 2014, Bayer filed suit against Watson, alleging infringement of the ’950 patent. Watson responded by filing a counterclaim for declaratory judgment of the noninfringement and invalidity of the ’950 patent. Following a bench trial, the parties stipulated to infringement of the ’950 patent. The remaining issue before the court was Watson’s defense of obviousness.

The court found that Watson failed to show by clear and convincing evidence that the patent-in-suit was obvious in light of the prior act. A person of ordinary skill in the art with respect to the ’950 patent would be a pharmaceutical scientist who would rely on other disciplines, such as analytical chemistry and clinical pharmacokineticists, with experience in formulation of pharmaceutical dosage forms, the court explained.

Watson’s argument that ODT formulations of erectile dysfunction drugs was obvious in light of prior art was rejected. Watson’s expert testified that literature reported that Pfizer was working on an ODT formulation for its brand drug Viagra in 1998. The court noted that, Bayer’s expert persuasively testified that, although the project was announced in 1998, Pfizer had not brought the product to market in March 2005 when Bayer filed its patent application. Moreover, even if a person of ordinary skill would have chosen to make a vardenafil ODT, that person would not have made an immediate release ODT due to vardenafil’s bitter taste.

The court also rejected Watson’s contention that a person of ordinary skill would have been motivated to make an ODT of vardenafil. The prior art would not motivate a person of ordinary skill to reformulate vardenafil into a different dosage form because ODTs were only marginally easier for patients to swallow. Furthermore, the court concluded, Bayer presented evidence that Watson copied the claimed invention and its drug STAXYN® produced increased oral bioavailability—which is evidence of non-obviousness.

The case is No. 1:12-cv-00517-GMS.

Attorneys: Jack B. Blumenfeld (Morris, Nichols, Arsht & Tunnell LLP) for Bayer Pharma AG, Bayer Intellectual Property GMBH and Bayer Healthcare Pharmaceuticals Inc. David A. Bilson (Phillips, Goldman, McLaughlin & Hall, P.A.) for Watson Laboratories Inc., Actavis Inc. and Actavis Pharma Inc.

Companies: Bayer Pharma AG; Bayer Intellectual Property GmbH; Bayer Healthcare Pharmaceuticals, Inc.; Watson Laboratories, Inc.; Actavis, Inc.; Actavis Pharma, Inc.

MainStory: TopStory Patent DelawareNews

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