United States Court of Appeals for the Federal Circuit ______________________

ALLERGAN USA, INC., ALLERGAN HOLDINGS UNLIMITED CO., ALLERGAN PHARMACEUTICALS INTERNATIONAL LTD., JANSSEN PHARMACEUTICA NV, EDEN BIODESIGN, LLC, Plaintiffs-Appellants

v.

MSN LABORATORIES PRIVATE LTD., MSN PHARMACEUTICALS, INC., SUN PHARMACEUTICAL INDUSTRIES LIMITED, Defendants-Appellees ______________________

2024-1061 ______________________

Appeal from the United States District Court for the District of Delaware in Nos. 1:19-cv-01727-RGA, 1:20-cv- 01479-RGA, 1:21-cv-01064-RGA, 1:21-cv-01065-RGA, Judge Richard G. Andrews. ______________________

Decided: August 13, 2024 ______________________

ERIC WILLIAM DITTMANN, Paul Hastings LLP, New York, NY, argued for plaintiffs-appellants. Also repre- sented by PETER E. CONWAY, MELANIE R. RUPERT; STEPHEN BLAKE KINNAIRD, Washington, DC; JAMES YI LI, LISA BARONS PENSABENE, HASSEN A. SAYEED, O’Melveny & Case: 24-1061 Document: 37 Page: 2 Filed: 08/13/2024

2 ALLERGAN USA, INC. v. MSN LABORATORIES PRIVATE LTD.

Myers LLP, New York, NY.

CHARLES B. KLEIN, Winston & Strawn LLP, Washing- ton, DC, argued for defendant-appellee Sun Pharmaceuti- cal Industries Limited. Also represented by JOVIAL WONG; EIMERIC REIG-PLESSIS, San Francisco, CA.

RONALD M. DAIGNAULT, Daignault Iyer LLP, Vienna, VA, for defendants-appellees MSN Laboratories Private Ltd., MSN Pharmaceuticals, Inc. Also represented by RICHARD JUANG, TEDD W. VAN BUSKIRK. ______________________

Before LOURIE, DYK, and REYNA, Circuit Judges. Opinion for the court filed by Circuit Judge LOURIE. Opinion concurring-in-part and dissenting-in-part filed by Circuit Judge DYK. LOURIE, Circuit Judge. Allergan USA, Inc., Allergan Holdings Unlimited Co., Allergan Pharmaceuticals International Ltd., Janssen Pharmaceutica NV (“Janssen”), and Eden Biodesign, LLC (collectively, “Allergan”) appeal from the final judgment of the United States District Court for the District of Dela- ware. Following a three-day bench trial, the district court determined that claim 40 of U.S. Patent 7,741,356 (“the ’356 patent”), asserted against Sun Pharmaceutical Indus- tries Limited (“Sun”), is invalid under the doctrine of obvi- ousness-type double patenting. Allergan USA, Inc. v. MSN Lab’ys Priv. Ltd., 694 F. Supp. 3d 511, 541 (D. Del. 2023) (“Decision”). The district court also determined that the claims of U.S. Patents 11,007,179 (“the ’179 patent”), 11,090,291 (“the ’291 patent”), 11,160,792 (“the ’792 pa- tent”), and 11,311,516 (“the ’516 patent”) asserted against Case: 24-1061 Document: 37 Page: 3 Filed: 08/13/2024

ALLERGAN USA, INC. v. MSN LABORATORIES PRIVATE LTD. 3

Sun are invalid under 35 U.S.C. § 112 for lack of written description. Id. at 529. 1 For the following reasons, we reverse the district court’s determination that asserted claim 40 of the ’356 pa- tent is invalid for obviousness-type double patenting. We also reverse its determination that the asserted claims of the ’179, ’291, ’792, and ’516 patents lack written descrip- tion. BACKGROUND I In 2015, the U.S. Food and Drug Administration (“FDA”) approved the New Drug Application (“NDA”) for eluxadoline tablets, which Allergan markets and sells un- der the brand name Viberzi®. Eluxadoline is a mu- and kappa-opioid agonist and a delta-opioid antagonist that mitigates the symptoms of irritable bowel syndrome with diarrhea, i.e., IBS-D. The drug compound and composi- tions thereof are protected by a number of patents, includ- ing each of those asserted here, which were timely listed