Patent Dispute Erupts Between Arrowhead and Ionis Over Potential FCS Treatment

Arrowhead Pharmaceuticals has initiated legal action against Ionis Pharmaceuticals in a patent dispute concerning a promising investigational drug for familial chylomicronemia syndrome (FCS). The lawsuit, filed on September 10 in the U.S. District Court for the District of Delaware, seeks to invalidate Ionis' patent claims related to Arrowhead's plozasiran, an RNAi therapeutic currently under FDA review.

Battle Over FCS Treatment Market

Plozasiran, formerly known as ARO-APOC3, is designed to reduce the production of apolipoprotein C-III (APOC3) to lower triglycerides and restore lipid levels in patients with FCS. The drug has received breakthrough therapy, orphan drug, and fast track designations from the FDA, with a decision expected by November 18.

If approved, plozasiran would directly compete with Ionis' Tryngolza (olezarsen), which gained FDA approval for FCS treatment in December 2024. Tryngolza, an antisense oligonucleotide, was the first FDA-approved treatment for this rare metabolic condition and marked Ionis' debut in independent commercialization.

Legal Claims and Corporate Responses

Arrowhead's lawsuit challenges Ionis' assertion that the commercialization of plozasiran would infringe on Ionis' patent No. 9,593,333, titled "Modulation of apolipoprotein C-III (APOC3) expression in lipoprotein lipase deficient populations."

Christopher Anzalone, Ph.D., President and CEO of Arrowhead, stated, "Arrowhead has multiple issued U.S. patents that cover plozasiran for the treatment of patients with FCS based entirely on work developed internally at Arrowhead, which Ionis was not involved with and provided no contribution to whatsoever."

Anzalone further expressed concern over Ionis' actions, saying, "It is unfortunate and troubling that Ionis Pharmaceuticals is attempting to take action that clearly puts their corporate goals ahead of the needs of patients with familial chylomicronemia."

In response, an Ionis spokesperson affirmed the company's commitment to the FCS community and welcomed advancements that raise awareness and improve patients' lives. The spokesperson emphasized, "Importantly, we are not seeking to block the launch of this new therapy to patients. We are confident in our IP around FCS and will vigorously defend our patent position."

Implications for FCS Patients

FCS is a severe and rare genetic disorder characterized by extremely high triglyceride levels, which can lead to acute and potentially fatal pancreatitis, chronic abdominal pain, diabetes, hepatic steatosis, and cognitive issues. The introduction of new treatment options could significantly impact patient care and management of this challenging condition.

As the legal battle unfolds, both companies maintain their commitment to serving the FCS community. The outcome of this patent dispute could have far-reaching implications for the availability and accessibility of innovative treatments for patients with this rare metabolic disorder.