Today, Biogen announced that the U.S. Food and Drug Administration (FDA) has delayed the approval with a Complete Response Letter (CRL) for the supplemental New Drug Application (sNDA) for the high-dose regimen of nusinersen (SPINRAZA) for people living with spinal muscular atrophy (SMA).
The CRL requests updates to the technical information included in the Chemistry Manufacturing and Controls (CMC) module. Importantly, the FDA did not identify any deficiencies in the clinical data for the high-dose regimen.
Biogen plans to resubmit the application promptly using readily available information and is working closely with regulatory authorities worldwide to advance this high-dose option, which was recently approved in Japan and is under review by the European Medicines Agency (EMA) and other global regulators.
While this update is unexpected, the clinical data supporting the high-dose regimen remains strong. Cure SMA will continue to monitor the process and share updates with the community as Biogen works toward approval.