Pliant Therapeutics has commenced participant enrolment in the Phase IIa INTEGRIS-PSC trial of bexotegrast (PLN-74809) at 320mg doses in primary sclerosing cholangitis (PSC) patients.

The latest move follows a positive independent safety review by the Data Safety Monitoring Board (DSMB).

The placebo-controlled, double-blind, randomised, dose-ranging trial has been designed for assessing the safety, tolerability, and pharmacokinetics (PK) of PLN-74809 in the indicated patients.

It will assess 40mg to 320mg doses of bexotegrast, given daily, in approximately 112 PSC patients.

Earlier this month, the bexotegrast independent DSMB held a meeting to review the safety data from all participants enrolled in the trial to date once the 40mg, 80mg, and 160mg dose groups were enrolled.

The DSMB recommended that the trial should be continued without any changes. This enabled the start of participant enrolment for the 320mg dose group.

The company stated that the start of the 320mg dose group coincides with the authorisation from the Food and Drug Administration (FDA) for assessing long-term dosing of bexotegrast in PSC patients, who will receive the treatment for at least 24 weeks and up to 48 weeks.

Pliant Therapeutics chief medical officer Éric Lefebvre said: “We are pleased to see the continued favourable safety and tolerability profile exhibited by bexotegrast, allowing us to evaluate a higher dose at a longer treatment duration in patients with PSC.

“We recognise the high unmet medical need in PSC, as there are no FDA approved therapies for the indication, and look forward to sharing 12-week interim data from our Phase IIa trial in the third quarter.”

The company stated that the INTEGRIS-PSC trial is also assessing the exploratory pharmacodynamic endpoints, including fibrosis biomarkers, such as changes in alkaline phosphatase (ALP), liver imaging, enhanced liver fibrosis (ELF) score, and PRO-C3.

It expects to receive the 12-week data from the trial’s 40mg, 80mg, and 160mg dose groups in the third quarter of this year.