Fortress shares slide as NDA derailed by manufacturing issues

2 October 2025

US biopharma Fortress Biotech (Nasdaq: FBIO) saw its shares tumble by more than 30% Wednesday after the Florida firm revealed an update on its New Drug Application (NDA) for CUTX-101 (copper histidinate), intended to treat Menkes disease in pediatric patients.

Fortress and its majority-owned subsidiary, Cyprium Therapeutics, announced that the US Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) relating to the NDA.

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