28 October 2016 - Sanofi and Regeneron Pharmaceuticals today announced the U.S. FDA issued a complete response letter regarding the biologics license application for sarilumab, an investigational interleukin-6 receptor antibody for the treatment of adult patients with moderately to severely active rheumatoid arthritis.

The complete response letter refers to certain deficiencies identified during a routine good manufacturing practice inspection of the Sanofi Le Trait facility where sarilumab is filled and finished, one of the last steps in the manufacturing process. Satisfactory resolution of these deficiencies is required before the application can be approved. Sanofi submitted a comprehensive corrective action plan to the FDA and is implementing the corrective actions specified in that plan. Sanofi is working closely with the FDA towards a timely resolution that addresses these concerns. 

The complete response letter does not identify any concerns relating to the safety or efficacy of sarilumab.

Read Sanofi press release