California-based late-stage biopharmaceutical company DURECT Corporation (Nasdaq: DRRX) announced on Wednesday the design of its upcoming registrational Phase 3 trial of larsucosterol for the treatment of patients with severe alcohol-associated hepatitis (AH).

The proposed Phase 3 trial design includes feedback from the Type B meeting held with the US Food and Drug Administration (FDA) under the Breakthrough Therapy designation. The randomised, double-blind, placebo-controlled, multi-centre study in the United States is intended to assess the safety and efficacy of larsucosterol for the treatment of patients with severe AH.

A 90-day survival endpoint will be the primary outcome measure. The Phase 3 trial is proposed to enrol around 200 patients, randomised in a 1:1 ratio across two arms, larsucosterol (30 mg) or placebo, which will be added to the current standard of care, with or without methylprednisolone capsules at the investigators' discretion. Patients enrolled in the trial will be followed for up to 180 days to collect additional safety and outcomes data.

James E Brown, DVM, DURECT president and CEO, said: "We believe the primary endpoint of 90-day survival is clinically meaningful and provides the greatest probability of success based on the AHFIRM data. In the completed AHFIRM trial, larsucosterol showed the ability to reduce mortality in AH patients compared to standard of care, particularly in the US, where we observed nearly 60% lower mortality at 90-days in both the 30 mg and 90 mg dose groups. We look forward to initiating the Phase 3 trial as soon as possible, subject to obtaining sufficient funds, which should enable us to report topline data within two years of trial initiation. The FDA also agreed that a single Phase 3 trial would be sufficient to support a New Drug Application (NDA).

"Larsucosterol's Breakthrough Therapy designation for the treatment of AH gives us the opportunity to file an NDA as a rolling submission. As we continue to advance our development programme for larsucosterol in AH, we look forward to additional discussions with the FDA under this designation."