Sanofi said the FDA’s recent rejection of its potential blockbuster MS treatment was “unexpected” and that the agency raised questions too late to make changes. The company "observed evolving perspectives within the FDA review team with new considerations introduced late in the review cycle," a Sanofi spokesperson told Endpoints
News via email. After multiple, earlier meetings with the agency, questions "regarding patient population definitions emerged only during the review, post study completion, when adjustments were no longer feasible," the spokesperson said. The FDA published the complete response letter this week for tolebrutinib, a BTK inhibitor, in
non-relapsing secondary progressive MS in adults. In the letter, issued late last year, the regulator raised safety questions about the drug, as well as questions about post-hoc analyses and its mechanism of action. |