Arrowhead Pharmaceuticals Sues Ionis Pharmaceuticals Over Patent Dispute

Arrowhead Pharmaceuticals has sued Ionis Pharmaceuticals in a Delaware District Court over a patent dispute related to its lead candidate, plozasiran. The lawsuit seeks a declaratory judgment determining the validity of Ionis' U.S. Patent No. 11,477,579, which Ionis claims covers the same technology as Arrowhead's product. Arrowhead's lawsuit does not seek monetary compensation.

Arrowhead Pharmaceuticals has filed a lawsuit against Ionis Pharmaceuticals in the U.S. District Court for the District of Delaware. The suit seeks a declaratory judgment determining the validity of Ionis' U.S. Patent No. 11,477,579, which Ionis claims covers the same technology as Arrowhead's investigational drug plozasiran Arrowhead battles Ionis over patent dispute tied to RNAi candidate that could rival Tryngolza^[1].

Arrowhead's lawsuit does not seek monetary compensation but rather a declaratory decree establishing that the patent is invalid and not infringed by the manufacture, use, sale, or offer for sale of plozasiran. The company's President and CEO, Christopher Anzalone, stated that the lawsuit is aimed at protecting the interests of patients with familial chylomicronemia syndrome (FCS), a severe and rare disease characterized by extremely high triglyceride levels Arrowhead Pharmaceuticals Files Complaint for Declaratory Judgment Against Ionis Pharmaceuticals^[2].

Plozasiran is a first-in-class investigational RNA interference (RNAi) therapeutic designed to reduce the production of apolipoprotein C-III (APOC3), a key regulator of triglyceride metabolism. The drug has been granted Breakthrough Therapy Designation, Orphan Drug Designation, and Fast Track Designation by the U.S. Food and Drug Administration (FDA) for the treatment of FCS Arrowhead Pharmaceuticals Files Complaint for Declaratory Judgment Against Ionis Pharmaceuticals^[2].

Ionis Pharmaceuticals has previously claimed that its patent No. 9,593,333 would be infringed if plozasiran were to be marketed. However, Arrowhead maintains that its patents covering plozasiran are based entirely on work developed internally and that Ionis had no contribution to the development of the drug Arrowhead battles Ionis over patent dispute tied to RNAi candidate that could rival Tryngolza^[1].

The lawsuit is a significant development in the ongoing competition between Arrowhead and Ionis for the treatment of FCS. If Arrowhead's candidate gains FDA approval, it will face competition from Ionis' Tryngolza, which was approved for FCS in December 2024 Arrowhead battles Ionis over patent dispute tied to RNAi candidate that could rival Tryngolza^[1].