Regeneron, Sanofi hit a trio of goals in first PhIII test of rheumatoid arthritis drug

Sanofi ($SNY) has experienced a series of internal setbacks on the R&D front in recent months, but its close partnership with Regeneron ($REGN) is still paying off with promising late-stage data. Friday morning, the companies reported that two doses of the anti-IL-6R blocker sarilumab easily beat out a placebo in the first of a string of Phase III studies for rheumatoid arthritis.

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 the drug also passed co-primary endpoints for an improvement in physical function and inhibition in structural bone damage after a year of therapy.

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. Two years ago, Regeneron green-lighted the late-stage program from RA 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, which delivered the first positive results weeks ago.

Those advances have helped take some of the sting out of Sanofi's setbacks on the cancer front, with back-to-back failures for its top two oncology programs in recent months. Regeneron and Sanofi developed the cancer drug Zaltrap but found only weak demand for the therapy, which had to be discounted after the price triggered a backlash among some prominent oncologists.

"Irreversible joint damage can be a consequence for patients suffering from rheumatoid arthritis, and this is accompanied by reduced physical function in these patients," said Tanya Momtahen, sarilumab global project head at Sanofi. "This remains a major concern for rheumatoid arthritis patients.  We are encouraged by these Phase III results and the impact sarilumab demonstrated on inhibition of progression of structural damage assessed radiographically in this study."  

- here's the press release