Phase III trial of REGN 475 meets primary endpoint in pain from osteoarthritis of the knee or hip.- Regeneron + Teva.

Regeneron Pharmaceuticals and Teva Pharmaceutical announced positive topline results from a Phase III, randomized, double-blind, placebo-controlled study of REGN 475 (fasinumab) in patients with chronic pain from osteoarthritis (OA) of the knee or hip. At the week 16 primary efficacy analysis, the study met both co-primary endpoints and all key secondary endpoints. Fasinumab-treated patients experienced significantly less pain and significantly improved functional ability from baseline compared to placebo. After the primary efficacy assessment at week 16, patients continue on therapy for an additional 36 weeks, followed by a subsequent 20-week off study drug follow-up period for further safety assessment. Interim safety data indicate that fasinumab was generally well tolerated, with similar adverse events (AEs) as those observed in previous fasinumab trials. At week 16, treatment discontinuations due to AEs had occurred in 6% of the placebo group patients, 5% of the fasinumab 1 mg every eight weeks group patients and 6% of the fasinumab 1 mg every four weeks group patients.

The fasinumab safety program was designed to capture all arthropathies (joint damage), including those identified due to symptoms and those identified by regularly-scheduled radiographic monitoring, the first of which was scheduled at week 24. Among the approximately 65% of patients who had completed their first radiographic assessment, the placebo-adjusted rate of adjudicated arthropathies was approximately 2%. The majority of arthropathies were captured by the regularly-scheduled radiographic monitoring and involved isolated joint space narrowing, called RPOA-1 (rapid progressive OA type 1). No cases of osteonecrosis have been identified to date in this study. The companies plan to present detailed results at an upcoming medical congress.

Comment: Regeneron and Teva are currently enrolling patients with chronic pain caused by OA of the knee or hip in three Phase III clinical trials including one assessing fasinumab long-term safety and two trials comparing fasinumab to standard pain therapies. The safety and efficacy of fasinumab have not been fully evaluated by any regulatory authority.