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 (p=0.02, corrected for multiplicity, for the highest sarilumab dose regimen).
The most common adverse events (>5%) reported more frequently in active treatment arms included infections (non-serious), neutropenia, and liver function test abnormalities. The types and frequencies of adverse events were consistent with those previously reported with IL-6 inhibition. The incidence of serious adverse events among the five sarilumab treatment groups and placebo group were comparable.
Separately, Sarilumab failed to show statsig efficacy in a phase-2 trial in ankylosing spondylitis.
The companies need to decide which dose(s) of Sarilumab to advance to phase-3 in RA. If it makes it to market, Sarilumab will be a direct competitor of Roche’s Actemra; both drugs are mAbs that block the IL-6 receptor.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”