The US Food and Drug Administration (FDA) has declined to approve Shin Nippon Biomedical Laboratories (SNBL) subsidiary Satsuma Pharmaceuticals’ investigational product STS101 (dihydroergotamine nasal powder) for acute migraine treatment in adults.

STS101 is designed to be an easy-to-use and portable treatment option for migraine patients, incorporating the company’s advanced powder formulation of dihydroergotamine delivered through a nasal device.

Satsuma submitted a new drug application (NDA) for STS101 to the FDA in March 2023.

The regulator issued a complete response letter to the company’s NDA, citing chemistry, manufacturing and controls issues as the primary reasons for its decision.

Satsuma has announced its intention to consult with the FDA to determine possible timing for a resubmission of the application.

The CRL did not raise any issues linked to the clinical data package submitted for STS101 or seek further clinical trials for the product’s approval.

The FDA based its NDA review of STS101 on the findings from two key clinical studies: a Phase I pharmacokinetic trial and the ASCEND Phase III open-label, long-term safety trial.

Data from these trials indicated that STS101 allows for quick absorption and attains high dihydroergotamine plasma concentrations and long-lasting plasma levels.

The asset also demonstrated safety and tolerability in individuals experiencing migraines.

Satsuma Pharmaceuticals president and CEO Dr Ryoichi Nagata stated: “We remain committed to working expeditiously with the FDA to complete the review for STS101 as soon as possible.”

SNBL subsequently signed a definitive agreement for the acquisition of Satsuma for $0.91 in cash per share plus a non-tradeable contingent value right (CVR) of up to $5.77 per share.

Based on the potential sale, licence or any other monetisation events linked to STS101, SNBL agreed to make the CVR payment.