Regeneron Pharmaceuticals, Inc. (REGN) and partner Sanofi (SNY) announced that the FDA has approved a label expansion of the arthritis drug Kevzara (sarilumab).The drug is now approved in the United States for the treatment of patients weighing 63 kilograms or more with active polyarticular juvenile idiopathic arthritis (pJIA).The FDA approval is supported by evidence from adequate and well-controlled studies and pharmacokinetic data from adults with rheumatoid arthritis as well as a pharmacokinetic, pharma ...