New Drug Exclusivity Not Impacted By Impurities In Compound, Court Finds In Loss For Sandoz

DC Circuit Court upholds FDA’s grant of new chemical entity exclusivity to Sanofi’s multiple sclerosis drug Aubagio (teriflunomide) even though the agency had previously approved teriflunomide as an impurity in Sanofi’s Arava (leflunomide). FDA reviews known impurities in drugs only to assess their impact on safety and efficacy, not to approve them, court says.