Valeant Pharms Int’l, Inc. v. Mylan Pharms Inc.

Case Name: Valeant Pharms Int’l, Inc. v. Mylan Pharms Inc., No. 2018-2097, 2020 WL 1698591 (Fed. Cir. April 8, 2020) (Circuit Judges Lourie, Reyna, and Hughes presiding; Opinion by Lourie, J.) (Appeal from D.N.J., Chesler, J.)

Drug Product and Patent(s)-in-Suit: Relistor® (methylnaltrexone); U.S. Patent No. 8,552,025 (“the ’025 patent”)

Nature of the Case and Issue(s) Presented: Plaintiffs sued Mylan alleging infringement of the ’025 patent based on the filing of Mylan’s ANDA seeking approval to make and sell a generic version of Relistor. Asserted claim 8 of the ’025 patent claims a methylnaltrexone solution with a pH between 3.0 and 4.0 that is stable for 24 months. Methylnaltrexone is an opioid antagonist. Mylan ultimately conceded that its proposed generic product would infringe claim 8 of the ’025 patent, but argued that claim 8 was obvious over similar prior-art preparations.

Valeant moved for summary judgment that claim 8 was not obvious and the district court granted the motion. Mylan argued that claim 8 would have been obvious in view of three references that disclosed formulations of naloxone or naltrexone, in further view of two treatises on pharmaceutical formulation. According to Mylan, a POSA would have arrived at the formulation of claim 8 through routine optimization of pH. Further, the three primary references Mylan cited taught pH ranges for naltrexone and naloxone solutions that overlapped with the “about 3 to about 4” range of claim 8. Mylan argued that even though those references did not disclose methylnaltrexone solutions, the references still established a prima facie case of obviousness because the compounds were structurally and functionally similar to each other. Mylan further argued that the pH range of claim 8 would have been obvious to try.

The district court granted Valeant’s motion. First, it held that overlapping ranges could establish a prima facie case of obviousness only if the only difference between the prior-art disclosure and the claim were the “range or value of a particular variable.” Here, there was another difference, namely that the art did not teach the claimed compound. Second, the district court rejected Mylan’s obvious-to-try argument. Mylan argued that the pH range of 3 to 4 was just one range in a finite number of options from 3 to 7. The district court disagreed, stating that it was basic math that the number of ranges falling between two numbers was infinite, not finite. The district court further rejected Mylan’s reliance on a prior-art reference and testimony of two experts that stated adjusting pH could improve stability. The district court was not persuaded that adjusting the pH would be the first thing a POSA would consider to improve stability. Mylan appealed, and the Federal Circuit reversed and remanded.

Why Mylan Prevailed: The Federal Circuit reversed the district court’s finding of non-obviousness, agreeing instead with Mylan that the record supported a prima facie case of obviousness. The Federal Circuit noted that in its precedent it recognized that “a prima facie case of obviousness typically exists when the ranges of a claimed composition overlap the ranges disclosed in the prior art.” In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003). Thus, overlapping ranges are sufficient to establish prima facie obviousness, shifting the burden to the patentee to show that the invention would not have been obvious. Additionally, the Federal Circuit recognized that it had previously held that a prima facie case of obviousness for chemical compound claims “frequently turns on the structural similarities and difference between the compounds claimed and those in the prior art.” Daiichi Sankyo Co. v. Matrix Labs., Ltd., 619 F.3d 1346, 1352 (Fed. Cir. 2010). A POSA can expect that compounds with common properties are likely to share other related properties as well, including optimal formulation for long-term stability. The Federal Circuit held that the prior art established that naltrexone, naloxone, and methylnaltrexone shared “remarkably similar structures” and all functioned as opioid antagonists. Because of these functional and structural similarities, and because the prior art taught pH ranges that overlapped the range of claim 8, Mylan had raised a prima facie case of obviousness sufficient to survive summary judgment.

The Federal Circuit also addressed Mylan’s argument that there were factual disputes that should have precluded summary judgment. Specifically, Mylan was concerned with the district court’s obvious-to-try analysis. The Federal Circuit agreed that the district court erred here as well. First, the Federal Circuit disagreed that there was an infinite number of pH ranges to try because the record established that pH was reported with only one figure behind the decimal point. Additionally, the Federal Circuit held that there was no requirement that for a variable to be obvious to try, it must be the first variable a POSA would alter.