An ANDA Specification that Directly Addresses Issues of Infringement Controls the Infringement Inquiry

PAR PHARMACEUTICAL, INC. V. EAGLE PHARMACETICALS, INC.

Before Moore, Prost, and Hughes. Appeal from the United States District Court for the District of Delaware.

Summary: An ANDA was held not to infringe asserted claims because the ANDA specifies pH ranges that fall outside of those recited in the asserted claims.

Par Pharmaceutical has two patents relating to Vasostrict, which is an injection product used to treat patients with critically low blood pressure. The claims of both patents require a composition having a pH between 3.65 and 3.94. In 2018, Eagle Pharmaceuticals filed an abbreviated new drug application (ANDA) to make and sell a generic version of Vasostrict. Eagle’s ANDA specifies a pH range between 3.35 and 3.64 when released for distribution and a pH range between 3.4 and 3.6 during the drug’s shelf life.

Par sued Eagle alleging that Eagle’s ANDA filing was an act of infringement under 35 U.S.C. § 271(e)(2). Par noted that Eagle’s ANDA seeks authority to release products for distribution with a pH just 0.01 beneath the claimed range, and contended “real-world” evidence shows the pH of Eagle’s drug increases over time.  Thus, Par argued, Eagle’s proposed product would inevitably drift upward into the claimed range. The district court disagreed, noting the ANDA requires Eagle’s product to maintain a pH between 3.4 and 3.6 during the drug’s shelf life. After a bench trial, the district court found no infringement under § 271(e). Par appealed.

The Federal Circuit affirmed. It noted that when an ANDA defines a proposed generic drug in a manner that directly addresses the issue of infringement, the ANDA controls the infringement inquiry. Here, the court held, the pH ranges in the ANDA “directly and unambiguously” address the pH range of Eagle’s proposed product. Because those pH ranges are outside the claimed range, the court affirmed the finding of no infringement.

Editor: Paul Stewart

Written by: Justin J. Gillett & Alistair J. McIntyre