Rapt Therapeutics terminates zelnecirnon program following clinical hold

RAPT Therapeutics (RAPT) announced it is terminating its zelnecirnon program. Zelnecirnon was being evaluated in two randomized, placebo-controlled Phase 2 clinical trials in asthma and atopic dermatitis, and both trials were placed on clinical hold by the U.S. Food and Drug Administration in February 2024 due to a serious adverse event of liver injury requiring transplant in one patient in the AD trial. No liver toxicity nor other treatment-related SAEs were reported in any other trial participant. The company subsequently closed both studies before completing the planned enrollment. Following feedback recently received from the FDA, the company has stopped its zelnecirnon program. “In light of the agency’s feedback, we do not see a viable path forward for zelnecirnon, although we continue to believe that CCR4 remains an exciting target with the potential to provide a safe, oral therapeutic option across a number of inflammatory diseases,” commented Brian Wong, M.D., Ph.D., President and CEO of RAPT. “We plan to continue advancing our next generation CCR4 compounds with improved safety margins for inflammatory disease and expect to identify a new candidate in the first half of 2025. Additionally, we continue to actively pursue in-licensing opportunities for clinical-stage assets.”