Valeant Int'l SRL v. Watson Pharms. Inc.

Decision Date08 November 2011
Docket NumberCase No. 10-20526-CIV-MORENO
CourtU.S. District Court — Southern District of Florida
PartiesVALEANT INTERNATIONAL (BARBADOS) SRL, Plaintiff, v. WATSON PHARMACEUTICALS, INC., WATSON LABORATORIES, INC— FLORIDA, and WATSON PHARMA, INC. Defendants.
AMENDED MEMORANDUM OPINION

The prior opinion was incomplete and is thus stricken and replaced with the following Order:

This action was filed by Valeant International (Barbados) SRL ("Valeant") against Watson Pharmaceuticals, Inc., Watson Laboratories, Inc.—Florida, and Watson Pharma, Inc. (collectively, "Watson"), alleging patent infringement. Valeant is the owner of several patents related to the drug known as Aplenzin®. Watson seeks to market the generic equivalent of that drug. Watson has conceded infringement but asserts as an affirmative defense that Valeant's asserted patents are invalid.

Aplenzin® is an antidepressant that contains bupropion hydrobromide as the active ingredient. Valeant owns four patents related to Aplenzin®: U.S. Patent Nos. 7,569,610, 7,563,823, 7,649,019, and 7,553,992 (collectively, "the patents-in-suit"). Each of the patents-in-suit contains several claims. In order to streamline the issues for trial, the parties agreed to try this case only with respect to five representative claims in the patents, with the resolution of theissues concerning those claims being dispositive as to all of the previously asserted claims as between the parties. The representative claims of the patents-in-suit are: (1) Claim 3 of the '610 patent; (2) Claim 9 of the '823 patent; (3) Claim 10 of the '823 patent; (4) Claim 2 of the '019 patent; and (5) Claim 1 of the '992 patent. The representative claims relate to controlled release and once-a-day formulations of bupropion hydrobromide, methods of treating depression with those formulations, and a specific crystalline form of bupropion hydrobromide.

The Court has jurisdiction over the parties and the subject matter pursuant to 28 U.S.C. § 1338(a). Additionally, venue is appropriate under 28 U.S.C. §§ 1391 and 1400(b). Neither jurisdiction nor venue is contested by the parties. The Court conducted a bench trial from June 21, 2011 to June 28, 2011. This Memorandum Opinion constitutes the Court's findings of fact and conclusions of law on the issues raised during trial. Ultimately, the Court finds that Watson has failed to prove by clear and convincing evidence that Valeant's asserted patent claims are invalid, and accordingly, grants judgment in favor of Valeant.

I. BACKGROUND

Bupropion was invented by Nariman Mehta in 1969 as a method of treating depression and was subsequently patented by Mehta in 1974 in U.S. Patent No. 3,819,706 (the "Mehta patent"). (Def. Ex. 135.) While the Mehta patent mentions a number of bupropion salts, it does not specifically mention bupropion hydrobromide. (Pl. Ex. 96 ¶¶53-54; Trial Tr. 437:25-438:11.) Bupropion has been sold since the 1980s as the bupropion hydrochloride salt, under the brand name Wellbutrin®. (Pl. Ex. 98 ¶18; Def. Ex. 602 at 10.) Today, both branded and generic versions of bupropion hydrochloride are on the market, including generic versions sold by Watson. (Pl. Ex. 94 at 86.)

Since the early 1980s, however, it was known that bupropion hydrochloride had stability problems when combined with pharmaceutical excipients. (Def. Ex. 128 at 20556-57; Def. Ex. 602 at 18-19.) Between 1984 and 2004 many attempts were made to improve the stability of bupropion hydrochloride formulations. (Trial Tr. 66:18-68:25; 301:10-303:16; Pl. Ex. 94 at 38.) One of the first such attempts was a 1984 patent application by Billinghurst where he tested several different bupropion salts to see if any had improved stability relative to the hydrochloride salt. (Def. Ex. 128; Pl. Ex. 94 at 38; Def. Ex. 379 at 40832.) Among the salts Billinghurst tested were a number of mineral acids1 , all of which were found to be unstable. (Trial Tr. 473:22-474:11.) As was the case in the Mehta patent, the hydrobromide salt was neither mentioned nor tested. (Trial Tr. 66:18-67:15.) Only the maleate salt, which is an organic carboxylic acid salt, was found to have improved stability. (Def. Ex. 602 at 18-19; Trial Tr. 434:21-436:10.) Due to toxicology concerns, however, it could never be formulated into a commercial product. (Def. Ex. 128 at 20557; Trial Tr. 435:10-23; Maes Dep. 130:20-131:24.) During the twenty years following Billinghurst's failed attempt to find an alternative salt with improved stability over bupropion hydrochloride, no new efforts were made to find a different bupropion salt; instead, other means were explored to improve stability of bupropion hydrochloride formulations, several of which were subsequently patented. (Trial Tr. 66:18-68:25; Def. Ex. 602 at 18-19.)

Despite the various attempts to improve the stability of bupropion hydrochloride formulations, the shelf life of commercial bupropion hydrochloride tablets has remained short, with once-a-day formulations having never achieved a shelf life longer than eighteen months. (Trial Tr. 299:23-300:4.) Thus, in 2003, Valeant (then Biovail) set out to address the longstanding stability issues with bupropion hydrochloride formulations. (Trial Tr. 298:20-299:20; 303:17-22; 380:16-21.) While Valeant tried a number of different approaches, it ultimately decided to revisit what Billinghurst had attempted but failed to discover in 1984—a new bupropion salt that could be formulated into a commercial product with an extended shelf life. (Trial Tr. 303:14-22.) The goal of this new salt project was to extend the shelf life of Wellbutrin® without negatively impacting any of its other properties. (Trial Tr. 307:5-8.)

The first step in the project was to figure out what salts of bupropion could even be made. (Maes Dep. Tr. 64:15-16.) Because Valeant was not specialized in manufacturing new salts, it sought the assistance of an Italian chemical company known as Chemi S.p.A. ("Chemi"). (Maes Dep. Tr. 64:15-65:6.) Valeant and Chemi spent several months attempting to make new salts, many of which failed to result in a testable product. (Def. Ex. 95; Def. Ex. 98.) Their selection of salts was largely an empirical process, because it was difficult to predict exactly which salt would be the best. (Maes Dep. 84:2-6; 170:23-171:13.)

In 2004 the inventors from Valeant and Chemi made bupropion hydrobromide. They discovered that bupropion hydrobromide exists in many forms, both amorphous and crystalline. (Def. Ex. 604 at 10; Pl. Ex. 96 at 15; Trial Tr. 643:16-25; 671:2-15.) Among these forms was the very stable crystalline compound—Form I bupropion hydrobromide—covered by Claim 1 of the '992 patent. (Trial Tr. 224:16-225:8.) The inventors also tested bupropion hydrobromide and discovered that bupropion hydrobromide in a controlled-release formulation produces a much more stable product relative to corresponding bupropion hydrochloride formulations. (Trial Tr. 311:18-312:8; Pl. Ex. 95 at 015319, 154331.) They also discovered that bupropion hydrobromide once-a-day tablets can be formulated at all the recommended daily dosages, even the highest dosage, which had never been accomplished with bupropion hydrochloride. (Trial Tr. 312:25-316:13; Pl. Ex. 98 ¶34.)

As a result of this research project, Valeant was able to develop Aplenzin®, a once-a-day bupropion hydrobromide tablet covered by the patents-in-suit. The effective filing date of the patents-in-suit is June 27, 2005. Valeant launched Aplenzin® in April 2009. Less than a year later Watson sought FDA approval to market a generic version of Aplenzin®, which Watson has conceded infringes the patents-in-suit. Therefore, the sole issue for trial was whether each of the asserted claims in the four patents-in-suit is invalid.

II. DISCUSSION

"A patent shall be presumed valid.'" 35 U.S.C. § 282. By statute, the patents-in-suit "have a strong presumption of validity in infringement proceedings." Al-Site Corp. v. VSI Int'l, Inc., 174 F.3d 1308, 1323 (Fed. Cir. 1999). This presumption of validity applies independently to each claim within a patent, even if other claims within the patent are held invalid. 35 U.S.C. § 282. Accordingly, Watson must prove invalidity for each asserted claim.

To overcome the presumption of validity, the challenger has the burden of proving by clear and convincing evidence that the patent is invalid. Microsoft Corp. v. i4i Ltd. Partnership, 131 S. Ct. 2238, 2242 (2011). Clear and convincing evidence is evidence that places in the fact finder "an abiding conviction that the truth of [the] factual contentions [is] highly probable." Colorado v. New Mexico, 467 U.S. 310, 316 (1984) (internal quotations omitted). "[I]f the fact trier of the issue is left uncertain, the party with the burden loses." Tech. Licensing Corp. v. Videotek, Inc., 545 F.3d 1316, 1327 (Fed. Cir. 2008). This burden "is constant and remains throughout the suit on the challenger" and "does not shift at any time to the patent owner." TP Labs., Inc. v. Prof'l Positioners. Inc., 724 F.2d 965. 971 (Fed. Cir. 1984). Moreover, when the Patent Office has considered the prior art during prosecution of the patents, the burden on the challenger to establish invalidity is even heavier. Glaxo Ltd. v. Apotex, Inc., 376 F.3d 1339,1348 (Fed. Cir. 2004); Impax Labs., Inc. v. Aventis Pharms., Inc., 468 F.3d 1366, 1378 (Fed. Cir. 2006).

Here, Watson challenges the validity of the five representative patent claims on the basis that they are (1) anticipated by the prior art; and/or (2) obvious in view of the prior art. The Court will address each argument in turn.

A. Anticipation

Watson contends that Claim 3 of the "610 patent and Claim 1 of the '992 patent are invalid for anticipation under 35 U.S.C. § 102(b).2 Generally speaking, "[a]nticipation means that the claimed invention was previously known, and that all of the elements and limitations of the claims are described in a single prior art reference." Hakim v. Cannon...

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