Sanofi and Regeneron’s Kevzara has been cleared in the US to treat moderately to severely active rheumatoid arthritis (RA) in adult patients.

The decision allows physicians to prescribe the drug for patients who have had an inadequate response or intolerance to one or more disease modifying antirheumatic drugs (DMARDs), such as methotrexate.

RA is a chronic inflammatory autoimmune disease that attacks the tissues of the joints, causing inflammation, pain, and eventually joint damage and disability, affecting around 1.3 million people in the US alone.

Kevzara (sarilumab) is a human monoclonal antibody that binds to the interleukin-6 receptor (IL-6R), and has been shown to inhibit IL-6R mediated signalling. In excess and over time, IL-6 can contribute to the inflammation associated with RA.

Approval was based on data from around 2,900 adults with moderately to severely active RA who had an inadequate response to previous treatment regimens, which showed that the drug induced statistically significant, clinically-meaningful improvements in patients with the disease.

The most common side effects were found to be neutropenia, increased ALT, injection site erythema, upper respiratory-tract infections, and urinary tract infections.

"In the clinical trial program, sarilumab demonstrated statistically significant, clinically-meaningful improvements in adult patients with rheumatoid arthritis by reducing signs and symptoms, improving physical function, and resulting in significantly less radiographic progression of structural damage of RA," said Alan Kivitz, founder and medical director of the Altoona Center for Clinical Research and Altoona Arthritis and Osteoporosis Center, and an investigator in the global SARIL-RA clinical program for sarilumab.

"This is important because 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 class, and is a welcome new option for patients and their physicians."

The Wholesale Acquisition Cost (WAC) of Kevzara is $39,000/year, which is around 30 percent lower than that for the two most widely used TNF-alpha inhibitors, the firms noted.

The European Medicines Agency Committee for Medicinal Products for Human Use backed the drug’s approval for RA in April, with a final decision expected in the coming months.