WASHINGTON, DC—The IL-6Rα–targeting human monoclonal antibody (mAb) sarilumab offers durable responses against rheumatoid arthritis (RA), according to an analysis of 3-year clinical and radiographic outcomes and safety for patients from the MOBILITY open-label extension study, EXTEND (NCT01146652), presented at the 2016 ACR/ARHP Annual Meeting.

“Active treatment with sarilumab 200mg every 2 weeks resulted in durable clinical response and stabilization of radiographic progression at 3 years, irrespective of prior treatment,” reported lead study author Désirée van der Heijde, MD, PhD, of Leiden University Medical Center in Leiden, Netherlands. 

However, the initial sarilumab 200mg group “showed the most favorable outcomes,” Dr. van der Heijde noted.

A total of 901 patients participated in EXTEND. “At year 3, after all patients had received open-label sarilumab for 2 years, percentages of patients achieving DAS28-CRP <2.6 or clinical disease activity index (CDAI) ≤2.8 were similar in patients originally treated with either dose of sarilumab or placebo,” Dr. van der Heijde said. “Improvements were maintained within each group from year 2 to year 3.”

After switching to active treatment in EXTEND, study authors observed a slowed progression of structural damage despite which group patients were initially randomized to in MOBILITY. 

Adverse events (AEs) “were consistent with the anticipated effects of IL-6 inhibition and the known safety profile of sarilumab,” Dr. van der Heijde reported. Treatment-emergent AEs (TEAEs) occurred in 89.7% of patients, and the most common of these were neutropenia (19.4%), increased alanine aminotransferase (13.0%), and upper respiratory tract infections (12.7%).

“Infections were the most frequently reported serious AE (4.2/100 patient-years),” Dr. van der Heijde said.

Dr. van der Heijde and coauthors disclosed financial support from AbbVie, Amgen, Astellas, AstraZeneca, Bristol-Myers Squibb, Boeringer Ingelheim, Celgene, Daiichi, Eli-Lilly, Galapagos, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi-Aventis, and UCB.