Sanofi and Regeneron announced that in the SARIL-RA-MOBILITY Phase 3 clinical trial, sarilumab in combination with methotrexate (MTX) improved disease signs and symptoms as well as physical function, and inhibited progression of joint damage in adult patients with active rheumatoid arthritis (RA) who were inadequate responders to MTX therapy.
Sarilumab (REGN88/SAR153191) is the first fully-human monoclonal antibody directed against the IL-6 receptor (IL-6R) that blocks the binding of IL-6 to its receptor and interrupts the resultant cytokine-mediated inflammatory signaling. Sarilumab was developed using Regeneron’s VelocImmune antibody technology.
The 52-week trial enrolled approximately 1,200 patients with active, moderate-to-severe rheumatoid arthritis, and who were inadequate responders to MTX therapy. Patients were randomized to either the sarilumab 200mg, sarilumab 150mg, or placebo group, all in combination with MTX and dosed every other week.
Both sarilumab groups showed clinically relevant and statistically significant improvements compared to the placebo group in all three co-primary endpoints (P<0.0001). Improvement in signs and symptoms of RA at 24 weeks, as measured by the American College of Rheumatology score of 20% improvement (ACR20) was 66%, 58%, and 33% in the sarilumab 200mg, sarilumab 150mg, and placebo groups respectively, all in combination with MTX.
Inhibition of progression of structural damage at Week 52, as measured by the change in the modified Van der Heijde total Sharp score (mTSS) was 0.25, 0.90, and 2.78 in the sarilumab 200mg, sarilumab 150mg, and placebo groups respectively, all in combination with MTX. The group receiving 200mg dose of sarilumab + MTX had a reduction of approximately 90% in the radiographic progression assessed by the mTSS compared to the radiographic progression with placebo + MTX at Week 52.