Shin Nippon Biomedical Laboratories Ltd. announced that its wholly-owned US subsidiary, Satsuma Pharmaceuticals Inc. received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) in response to the Satsuma's New Drug Application (NDA) for STS101 (dihydroergotamine nasal powder). STS101 is an investigational product for the acute treatment of migraine with or without aura in adults. The FDA indicated in the CRL that it has completed its review of the NDA and determined that it cannot be approved in its present form.

The principal reasons described in the CRL relate to chemistry, manufacturing, and controls (CMC) considerations. Satsuma intends to provide potential timing for a resubmission following consultation with the FDA. The CRL did not indicate any concerns about the clinical data package in the NDA, and the FDA did not request any new clinical trials to support the approval of STS101.

STS101 is a proprietary drug device investigational product incorporating both Satsuma's advanced nasal powder formulation of dihydroergotamine (DHE) administered via its unique nasal delivery device. The product is designed to provide patients and easy-to-use and easy-to-carry treatment option. The FDA's review for STS101 was based on two clinical studies (Phase 1 PK trial and ASCEND Phase 3 open-label, long-term safety trial), which demonstrated fast absorption, rapid achievement of high DHE plasma concentrations, and sustained DHE plasma levels over time as well as safety and tolerability in subjects with migraine.