Pliant Therapeutics Discontinues Late-Stage IPF Trial Due to Safety Concerns

Pliant Therapeutics, a California-based biotech company, has announced the discontinuation of its phase 2b/3 trial for bexotegrast, its lead candidate for the treatment of idiopathic pulmonary fibrosis (IPF). The decision comes after a safety review revealed an increased rate of adverse events in patients receiving the experimental therapy compared to those on placebo.

Trial Termination and Safety Signals

The BEACON-IPF trial, which was evaluating bexotegrast, an oral small molecule dual selective inhibitor of αvβ6 and αvβ1 integrins, has been halted following recommendations from an independent safety committee and an external expert panel. The study, which had an estimated enrollment of 350 patients and was expected to read out in mid-2026, was terminated after a mean exposure duration of approximately 17 weeks.

Pliant reported that the percentage of IPF-related adverse events among patients receiving bexotegrast (at doses of either 160-mg or 320-mg) was about 10%, compared to less than 3% in the placebo group. This imbalance of at least 7% higher rate of adverse events in the treatment arms prompted the company to discontinue the trial.

Impact on Pliant Therapeutics and Future Plans

The news of the trial discontinuation has had a significant impact on Pliant's stock, which dropped by 49% from $3.10 per share to $1.60 by 11 a.m. ET on the day of the announcement. Despite this setback, the company remains cautiously optimistic about the potential of bexotegrast.

Pliant has stated that early evidence of efficacy on the main endpoint—forced vital capacity—was observed in the trial. The company is now planning to analyze the complete dataset from the BEACON-IPF study to determine the next steps for bexotegrast. Depending on the full findings, Pliant may consider launching other phase 2b studies with lower doses in pulmonary fibrosis and potentially explore other indications, such as liver disease.

Regulatory Status and Future Outlook

Bexotegrast, Pliant's most clinically advanced asset, has received fast track and orphan drug designations from the FDA for both IPF and primary sclerosing cholangitis (PSC). These designations highlight the potential importance of the drug in addressing unmet medical needs.

As the company regroups from this setback, the pharmaceutical industry will be watching closely to see how Pliant navigates the challenges of drug development in the complex field of fibrotic diseases. The outcome of the full data analysis and Pliant's subsequent decisions will be crucial in determining the future of bexotegrast and the company's pipeline.