Line design
Vasostrict® (vasopressin)
GENERICally Speaking

Case Name: Par Pharmaceutical Inc. v. Eagle Pharmaceuticals Inc., No. 18-0823-CFC-JLH, 2021 WL 3886418 (D. Del. Aug. 31, 2021) (Connolly, J.) 

Drug Product and Patent(s)-in-Suit: Vasostrict® (vasopressin); U.S. Patents Nos. 9,744,209 (“the ’209 patent”) and 9,750,785 (“the ’785 patent”)

Nature of Case and Issue(s) Presented: Vasostrict is used to treat shock in patients whose blood vessels suddenly relax. The patents-in-suit claimed vasopressin compositions and methods of increasing blood pressure using such compositions. The patents-in-suit required that the vasopressin compositions have a pH between 3.7 and 3.9. Eagle’s ANDA specification indicated a pH between 3.4 and 3.6. Initial batches of Eagle’s generic product were found to have varying pH levels, but later batches showed a pH of 3.64 (which rounds down to 3.6). Moreover, Eagle committed to an optimized manufacturing process in its ANDA to stay within the 3.4 – 3.6 range. Par alleged that Eagle’s generic product infringed the patents-in-suit by having a pH between 3.7 and 3.9. Par argued that two facts compelled a finding of infringement: (i) Eagle’s product had a “drift problem” in that when refrigerated its pH tended to rise; and (ii) Eagle’s product had pH values up to 3.64 and if those products were to drift upward by 0.01 pH units they would infringe. After a 3-day jury trial, the court found that Eagle’s product did not infringe the claims of the patents-in-suit.

Why Eagle Prevailed: The court found Eagle’s product did not have a drift problem. While there were variances in pH in earlier batches, in later batches the pH of Eagle’s product was within the range claimed in Eagle’s ANDA. Moreover, Par offered no evidence to negate the fact that Eagle would not use its optimized manufacturing process, which prevented the alleged upward drift in pH. Further, the court found that Eagle’s ANDA pH specifications defined its proposed generic product in a manner that directly addressed the issue of infringement, and therefore the ANDA “controls the infringement inquiry” and required a judgment of non-infringement. Par failed to establish by a preponderance of the evidence that Eagle would distribute a generic product that did not meet the 3.4-3.6 stability pH specification in its ANDA; and therefore, necessarily, Par failed to prove by a preponderance of the evidence that Eagle’s ANDA product would infringe the 3.7-3.9 pH limitation in the asserted claims. At most, Par proved at trial that if Eagle were not bound by its ANDA pH specification and its representation to use its optimized process then Eagle could use a different manufacturing process that could result in a drug product with a pH that would meet the pH limitation in the asserted claims. The court noted that proof of that possibility was insufficient to sustain a finding of infringement under Section 271(e)(2).

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