Rapt Therapeutics announces clinical hold on studies evaluating zelnecirnon

RAPT Therapeutics announced that the U.S. Food and Drug Administration, FDA, has verbally notified the company that a clinical hold has been placed on the company’s Phase 2b trial of zelnecirnon, RPT193, in atopic dermatitis and its Phase 2a trial in asthma. The company expects to receive a formal clinical hold letter from the FDA. The clinical hold determination was based on a serious adverse event of liver failure in one patient in the atopic dermatitis trial, the cause of which is currently unknown but which has been characterized as potentially related to zelnecirnon. Dosing of zelnecirnon has been halted in both clinical trials, as has enrollment of new trial participants. The clinical hold does not apply to RAPT‘s ongoing trial of tivumecirnon, FLX475, in oncology.