Anchen Pharmaceuticals, Inc.

Company overview. Anchen Pharmaceuticals, Inc. is a California corporation headquartered at 9601 Jeronimo Road, Irvine, California. It was founded in 2002 by Chih-Ming Chen (a co-founder of Andrx Corp.) as a privately held specialty pharmaceutical developer; some databases list a 2004 incorporation date. In November 2011, Par Pharmaceutical Companies (then NYSE: PRX) acquired Anchen for $410 million. Par was itself acquired by Endo International plc in 2015, and Anchen operates as a wholly owned Endo subsidiary (held through Anchen Incorporated). Endo and Anchen entities filed for Chapter 11 in 2022 and Endo emerged as a private company in 2024. Anchen reported roughly 200–220 employees and more than 72,000 sq ft of Irvine manufacturing/warehouse space at the time of the 2011 acquisition; current headcount and revenue are not publicly disclosed.

Products / operations. Anchen is an operating generics developer and manufacturer, not an NPE. It focuses on extended-release and other "niche," higher-barrier generic products and filed abbreviated new drug applications (ANDAs) with FDA paragraph IV certifications. At acquisition it had five marketed products — including generic Wellbutrin XL (bupropion ER) and a generic Cipro — 27 ANDAs on file (five considered first-to-file) and about 26 products in development. Later FDA approvals include clonidine hydrochloride extended-release tablets (2013). It also has/had parallel development and manufacturing operations in Taiwan.

Patent-litigation posture. The tracked data show Anchen as a defendant only (0 plaintiff cases, 1 defendant case): a classic operating-company profile. The single tracked suit is a Hatch-Waxman ANDA action filed by a brand manufacturer, not an NPE assertion. The venue is the District of Delaware — the dominant venue for ANDA/paragraph IV litigation — not a plaintiff-friendly NPE district such as the Eastern District of Texas.

Notable case. Merck Sharp & Dohme Corp. v. Anchen Pharmaceuticals, Inc. et al., No. 1:19-cv-00311 (D. Del., filed Feb. 13, 2019), named Anchen and Par Pharmaceutical as defendants and was consolidated into In re Sitagliptin Patent Litigation, MDL No. 19-2902. Merck asserted U.S. Patent 7,326,708 (sitagliptin phosphate salt, listed for Janumet XR) against Anchen's ANDA No. 204144. A consent judgment and injunction were entered in March 2021. Anchen has historically faced similar paragraph IV suits from brand owners, including Abbott (Zemplar) and AstraZeneca (quetiapine ER).