European regulators have agreed to review Regeneron and Sanofi's application to market the biologic sarilumab as a treatment for rheumatoid arthritis.

Sarilumab is an investigational, fully human monoclonal antibody directed against the IL-6 receptor that has been developed for the treatment of patients with active, moderate-to-severe forms of the condition.

The drug's application contains data from the global SARIL-RA Phase III programme involving more than 3,300 patients, the majority of whom were inadequate responders to previous treatment regimens such as disease-modifying anti-rheumatic drugs (DMARDs) or anti-tumour necrosis factor alpha (anti-TNFα).

Recently released data from the SARIL-RA-TARGET study showed "clinically relevant and statistically significant improvements" with the drug versus placebo on the co-primary endpoints of improving symptoms of the disease and physical function.

Improvement in signs and symptoms of RA at 24 weeks, as measured by the American College of Rheumatology score of 20 percent improvement (ACR20), were: 61 percent in the sarilumab 200mg group; 56 percent in the sarilumab 150mg group; and 34 percent in the placebo group, all in combination with DMARD therapy.

Sarilumab is also currently under review in the US, where a decision is expected by October 30.