Gilead's new liver drug succeeds in phase 3 trial

Gilead Sciences recently shared promising interim results from its ongoing phase 3 clinical trial for seladelpar, a novel treatment for primary biliary cholangitis (PBC). This investigational drug was a key component of Gilead's $4.3 billion acquisition of CymaBay Therapeutics just a few months ago. Seladelpar is a pioneering oral PPAR-delta agonist, which plays a critical role in regulating metabolic and liver disease pathways by impacting genes associated with bile acid synthesis, inflammation, fibrosis, and lipid metabolism.

The phase 3 ASSURE study is an open-label trial that includes 174 adult patients diagnosed with PBC who either did not respond adequately to or could not tolerate ursodeoxycholic acid, a standard liver disease medication. Over the course of 12 months, 70% of the participants achieved the composite response endpoint. Furthermore, 37% of these patients reached normalization of alkaline phosphatase (ALP), a significant marker of liver health, with an average ALP reduction of 44%. Additional improvements were noted in other liver injury biomarkers, such as a 9% reduction in total bilirubin, a 36% decrease in gamma-glutamyl transferase, and a 25% drop in alanine aminotransferase. Importantly, seladelpar was generally well-tolerated, and no serious adverse events related to the treatment were reported.

PBC is a chronic inflammatory liver condition that primarily affects women. It is characterized by cholestasis and the buildup of toxic bile acids, which cause liver inflammation and damage to the bile ducts. Patients with PBC often experience severe symptoms like pruritus and fatigue, with the disease's progression increasing the risk of liver-related death.

Seladelpar's new drug application (NDA) for treating PBC is currently under priority review by the U.S. Food and Drug Administration (FDA), with a decision anticipated by August 2024. The drug is also under review by the UK's Medicines and Healthcare products Regulatory Agency (MHRA) and the European Medicines Agency (EMA). If approved, seladelpar could potentially generate sales of $1.9 billion by 2029, according to data from LSEG.

In summary, the interim results of the phase 3 study for seladelpar are encouraging, demonstrating significant efficacy and tolerability in treating patients with PBC. Gilead Sciences is optimistic about the future of this drug, which could represent a significant advancement in the treatment of this chronic liver disease.