The Food and Drug Administration has approved sarilumab (Kevzara), a human monoclonal antibody against the interleukin-6 receptor, for the treatment of adult patients with rheumatoid arthritis (RA), the manufacturer Regeneron Pharmaceuticals announced May 22.
Interleukin-6 is an important factor in RA, as excess amounts of IL-6 build up in the body and contribute to RA-associated inflammation. Sarilumab has been shown to bind to and reduce IL-6R signaling, and is intended for people who have shown inadequate response to or are intolerant to conventional synthetic disease-modifying antirheumatic drugs (DMARDs).
FDA approval of sarilumab was based on results from two phase III clinical trials. In the MOBILITY study , 66% of patients who received 200 mg sarilumab plus methotrexate achieved an American College of Rheumatology 20 level of improvement after 24 weeks, compared with 33% of patients who received placebo plus methotrexate. In the TARGET study , 61% of patients who received 200 mg sarilumab plus a nonbiologic DMARD achieved an ACR20 response after 24 weeks, compared with 34% of patients who received placebo plus a nonbiologic DMARD.
“Not all currently available treatments work in all patients, and some patients may spend years cycling through different treatments without achieving their treatment goals. Sarilumab works differently from the most commonly used biologics, such as those in the anti-TNF [tumor necrosis factor] class, and is a welcome new option for patients and their physicians,” Alan Kivitz, MD , an investigator in sarilumab clinical trials and a rheumatologist in group practice in Duncansville, Pa., said in Regeneron’s announcement .
The recommended dosage of sarilumab is 200 mg once every 2 weeks given as a subcutaneous injection, which can be self-administered. The dosage can be reduced from 200 mg to 150 mg once every 2 weeks, as needed, to help manage certain laboratory abnormalities (neutropenia, thrombocytopenia, and liver enzyme elevations). Significant adverse events associated with sarilumab include weakening of the immune system, changes in certain laboratory tests, perforation in the stomach or intestines, increased risk of cancer, and serious allergic reaction.
