Helsinn Healthcare S.A. v. Dr. Reddy's Labs., Ltd.

Case Name:Helsinn Healthcare S.A. v. Dr. Reddy's Labs., Ltd., No. 12-2867 (MLC) (DEA), 2017 U.S. Dist. LEXIS 21477 (D.N.J. Feb. 14, 2017) (Cooper, J.)

Drug Product and Patent(s)-in-Suit: Aloxi® (palonosetron); U.S. Patents Nos. 7,947,724 (“the ’724 patent”), 8,729,094 (“the ’094 patent”), and 9,066,980 (“the ’980 patent”)

Nature of the Case and Issue(s) Presented:  Aloxi is indicated to treat chemotherapy-induced nausea and vomiting and consists of the active pharmaceutical ingredient palonosetron. Dr. Reddy’s (“DRL”) filed paragraph IV certifications pursuant to § 505(b)(2) against the patents-in-suit. DRL challenged 13 claims, three based on non-infringement and ten based on invalidity under 35 U.S.C. § 112.

Why Helsinn Prevailed: With respect to infringement, Helsinn prevailed because it showed that the sodium acetate trihydrate in DRL’s accused product is the claimed chelating agent. The court had previously construed the term “chelating agent” to mean “a multidentate ligand that can form a ring structure by reacting with a metal ion.” According to the court, a multidentate ligand is a molecule that has at least two atoms that can simultaneously make a bond with a metal ion. The court accepted Helsinn’s evidence, found in textbooks and the scientific literature, as evidence that sodium acetate trihydrate could, under various conditions, form at least two bonds with a metal ion. The court rejected DRL’s argument that Helsinn’s evidence did not demonstrate the required capability for bonding in the context of the accused liquid pharmaceutical preparation. To reject Helsinn’s evidence, the court said, would “essentially unravel our careful construction of the term ‘chelating agent.’” (The court noted that DRL had not filed a motion for reconsideration of its Markman order.)

Turning to the § 112 invalidity challenge, DRL asserted that three claims were not enabled. The issues revolved around the claimed 18- or 24-month stability. The court found that the patents’ guidance concerning selection of the API and its concentration, the optimal pH, the preferred chelating agent and its concentration, the preferred tonicifying agent and its concentration, and specific categories of excipient to use, gave adequate guidance to practice the claims without undue experimentation. Long-term testing, if required, does not require undue experimentation because that testing only involves repetition of known or commonly used techniques. DRL also argued that those same claims were not adequately described. In particular, DRL argued that the patents claim conceivably thousands of possible formulations, and a person of skill in the art would be unable to tell from reading the patents which would have the required shelf-lives. Nevertheless, the court found that the patent specification gave adequate guidance for choosing formulations that have a long shelf-life, and therefore, DRL’s arguments did not reach the required clear and convincing burden of proof.