Purdue Pharma L.P., v. Mylan Pharms. Inc.

Whether it were a question of fact not properly determined on the pleadings if claims of subsequent patent were sufficiently different from the claims of previously litigated patents to overcome collateral estoppel issues.

April 26, 2017

GENERICally Speaking

Case Name: Purdue Pharma L.P., v. Mylan Pharms. Inc., 15-1155-RGA-SRF, 2017 U.S. Dist. LEXIS 28460 (D. Del. Mar. 1, 2017) (Fallon, M.J.) 

Drug Product and Patent(s)-in-Suit: OxyContin® (oxycodone hydrochloride); U.S. Patent No. 9,073,933 (“the ’933 patent”)

Nature of the Case and Issue(s) Presented: Purdue manufactured and marketed extended-release pain medication under the trade name of OxyContin. The ’933 patent claimed a pure form of oxycodone hydrochloride. Defendants, seeking to manufacture a generic version of the drug, filed an ANDA on November 2, 2015. Plaintiffs responded by filing the present suit, alleging patent infringement. Defendants then moved to dismiss the case for failure to state a claim on the basis that plaintiffs were collaterally estopped due to another related litigation. The court disagreed, and recommended denial of defendants’ motion to dismiss.

Why Purdue Prevailed: The court’s denial was premised on defendants’ failure to demonstrate that the claims of the previously litigated patents were substantially identical to the claims of the ’933 patent, which had not been litigated. The claims of the ’933 patent specifically required the presence of 8α,14-dihydroxy-7, 8-dihydrocodeine (“8α”). In contrast, the previously litigated patents all disclosed formulations of low alpha, beta unsaturated ketones (“ABUKs”) and did not necessarily require the presence of the 8α molecule. Further, the low-ABUK patents did not cite a particular percentage composition of oxycodone hydrochloride, whereas the ’933 patent required that the composition consist of at least 95% oxycodone hydrochloride. Finally, one of the claims of the ’933 also limited the amount of 14-hydroxycodeinone in the composition to less than 5 ppm. No similar limitation existed in the claims of the low-ABUK patents. The court reasoned that it was a fact issue that could not be determined based on the pleadings whether these differences in the claims were enough to overcome any issues of estoppel. Thus, the court recommended denial of the motion to dismiss.

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