Rare Malady Drug Goes From FDA Priority to Reject in Four Months

The rejection of Disc Medicine Inc.’s experimental compound for a rare and devastating disorder by the US Food and Drug Administration, just months after it received a voucher intended to speed US reviews for breakthrough treatments, is the latest example of the growing uncertainty at the nation’s top drug regulator.

On Friday, the development-stage drugmaker said the FDA rejected its application for bitopertin, a treatment for the rare genetic disorder erythropoietic protoporphyria, which causes severe sensitivity to light. It’s the latest medical product that’s been delayed or rejected by the agency based on questions about development plans that ...