Sanofi, Regeneron add positive PhIII data on key RA drug

Sanofi ($SNY) and its close development partner Regeneron ($REGN) added some positive year-long results to the promising Phase III rheumatoid arthritis data that they've been gathering on sarilumab, an antibody that is billed as one of the pharma giant's top late-stage drug prospects.

As reported last fall, the two doses in the study improved patient ratings on the signs and symptoms of the disease after 24 weeks of treatment for 66% of the patients in the 200 mg arm and 58% in the 150 mg dose arm, compared with 33% in the placebo arm.  And now investigators say that after 52 weeks the response rates were 54%, 59%, and 32% for sarilumab 150 mg, sarilumab 200 mg, and placebo groups, respectively.

For the secondary endpoint: "Sarilumab combined with MTX demonstrated statistically significantly greater effect than MTX alone in achieving a major clinical response, defined as reducing signs and symptoms of RA by 70% or more, as measured by improvement of the American College of Rheumatology score (ACR70 response), for at least 24 consecutive weeks. These results were 13%, 15% and 3% in the sarilumab 150 mg, sarilumab 200 mg, and placebo groups, respectively (p<0.0001)."

There are 6 ongoing studies for the Phase III program.

Sarilumab (REGN88/SAR153191) is billed as the first IL-6 drug in studies. Regeneron--which has been reaping a fortune from Eylea--used its own in-house tech to develop the antibody, which blocks IL-6 from binding to its receptor, interrupting a cascade of events that trigger rheumatoid arthritis. Regeneron green-lighted the late-stage program for RA more than two years ago but reported that a Phase II study for ankylosing spondylitis had failed.

The partnership on sarilumab is one of a string of pacts that closely bind the pharma giant to the Tarrytown, NY-based biotech, which has enjoyed a stellar R&D record in recent years. The collaboration includes dupilumab (REGN668), an IL-4 receptor treatment for allergic asthma and atopic dermatitis, as well as the blockbuster PCSK9 tie-up for alirocumab.

- here's the release