Positive results from sarilumab Phase 2b trial on RA, ankylosing spondylitis

Sanofi (EURONEXT: SAN and NYSE: SNY) and Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) announced results from Phase 2b trials in rheumatoid arthritis (RA) and ankylosing spondylitis (AS) with sarilumab (REGN88/SAR153191), a novel, high-affinity, subcutaneously administered, fully-human antibody targeting the interleukin-6 receptor (IL-6R).

The Phase 2b MOBILITY trial in rheumatoid arthritis demonstrated that patients treated with sarilumab in combination with a standard RA treatment, methotrexate (MTX), achieved a significant and clinically meaningful improvement in signs and symptoms of moderate-to-severe RA compared to patients treated with MTX alone.  The MOBILITY study is a 306-patient, dose-ranging, multi-national, randomized, multi-arm, double-blind, placebo-controlled study, that compared five different dose regimens of sarilumab in combination with MTX to placebo plus MTX.  The primary endpoint of the study was the proportion of patients achieving at least a 20% improvement in RA symptoms (ACR20) after 12 weeks.

In the MOBILITY trial, there was a dose response observed in patients receiving sarilumab in combination with MTX.  An ACR20 response after 12 weeks was seen in 49.0% of patients receiving the lowest sarilumab dose regimen and 72.0% of patients receiving the highest dose regimen compared to 46.2% of patients receiving placebo and MTX.

Sarilumab also demonstrated significant benefit compared to placebo in secondary endpoints, including ACR 50, ACR 70, and DAS 28 scores, additional measures of clinical activity used in RA trials.  

"Following these encouraging Phase 2b results in rheumatoid arthritis, the companies are currently discussing the dose(s) of sarilumab to advance into the Phase 3 portion of the MOBILITY  trial," said Elias Zerhouni, President, Global Research & Development, Sanofi.

"The MOBILITY results provide evidence that IL-6R blockade with sarilumab represents a promising new anti-inflammatory investigational therapy for reducing RA disease symptoms.  We are very pleased that the first of our novel VelocImmune^® derived antibodies is poised to enter Phase 3 development," said George D. Yancopoulos, M.D., Ph.D., Chief Scientific Officer of Regeneron and President of Regeneron Research Laboratories.

In the Phase 2b ALIGN trial in ankylosing spondylitis (AS), sarilumab did not demonstrate significant and clinically meaningful improvements in signs and symptoms of active AS compared to placebo in patients who had inadequate response to NSAIDs.  Sarilumab was generally well tolerated. The most common adverse events reported more frequently in active treatment arms included infections and neutropenia.