The U.S. Food and Drug Administration has lifted its full clinical hold on Protagonist Therapeutics’ clinical studies of rusfertide. The clinical hold was announced on September 17 after the company reported observation of benign and malignant subcutaneous skin tumors in a 26-week rasH2 transgenic mouse model study.
Rusfertide is a subcutaneous hepcidin-mimetic that helps reduce iron availability and decrease erythropoiesis. Protagonist Therapeutics has been testing rusfertide in phase II studies for the treatment of polycythemia vera and hereditary hemochromatosis. According to the FDA, the biotech company may fully resume trials after providing individual patient clinical safety reports.
A press release from Protagonist Therapeutics indicated that the company “is working with the FDA and will be prepared to make all appropriate updates to clinical study documents and determine the next steps in consultation with the FDA. In particular, we will provide additional clinical safety reports, update the investigator brochures and patient informed consent forms, and make necessary modifications to study protocols. Dosing of patients in all ongoing clinical trials with rusfertide will be put on hold, and study investigators have been contacted to facilitate patient notification.”