Pliant Therapeutics has reported preliminary results from the 320mg dose group of the INTEGRIS-IPF Phase IIa clinical trial of bexotegrast (PLN-74809) in idiopathic pulmonary fibrosis (IPF) patients.

The 12-week multinational, dose-ranging, randomised, double-blind, placebo-controlled trial has been designed to assess bexotegrast’s safety, tolerability, and pharmacokinetics in these patients.

In the trial, it was observed that the 320mg group met its primary and secondary endpoints and demonstrated that the therapy was well tolerated over the treatment period of 12 weeks, and displayed a favourable pharmacokinetic profile.

Exploratory efficacy endpoints of the trial evaluated changes in forced vital capacity (FVC), Quantitative Lung Fibrosis (QLF) imaging, and biomarkers.

Additionally, from baseline at all timepoints, bexotegrast at the given dose demonstrated a statistically significant mean FVC increase.

During the treatment period, it also showed a strong treatment effect on FVC percent predicted (FVCpp), QLF, and profibrotic biomarkers, compared to a placebo.

In the INTEGRIS-IPF Phase IIa trial, 119 patients with IPF were enrolled in 40mg, 80mg, 160mg, or 320mg doses, or a placebo, for 12 weeks, with a 3:1 randomisation ratio and stratification based on use of standard of care therapy.

Evaluation of PLN-74809’s safety and tolerability is the primary endpoint of the trial and the secondary endpoint is the assessment of its pharmacokinetics across a dose range.

The INTEGRIS-IPF trial’s exploratory efficacy endpoints measured changes in FVC, high-resolution CT (HRCT)-based QLF, and profibrotic biomarkers for 12 weeks.

The bexotegrast 320mg group also showed a mean FVC increase of +29.5ml relative to baseline during the period, versus a decline of 110.7 ml in the placebo group.

This resulted in a 140ml increase compared to a placebo.

Pliant Therapeutics chief medical officer Éric Lefebvre said: “Data from the INTEGRIS-IPF trial have far exceeded our expectations, supporting bexotegrast’s favourable safety profile and demonstrating a statistically significant treatment response on FVC at 320mg.

“Additionally, we are extremely encouraged to see a consistent dose response on FVC, QLF, and profibrotic biomarkers. We look forward to advancing bexotegrast into Phase IIb clinical development.”

Results from the trial in patients treated for a minimum of 24 weeks are expected in the second quarter of this year.

During the middle of this year, Pliant plans to commence a Phase IIb clinical trial of bexotegrast.