Clinical Hold Imposed on Zelnecirnon Trials by RAPT Therapeutics

RAPT Therapeutics, a biopharmaceutical firm specializing in oral small molecule treatments for inflammatory diseases and cancer, has encountered a setback. The FDA has placed a clinical hold on the company's Phase 2b atopic dermatitis trial and Phase 2a asthma trial for their drug candidate, zelnecirnon (RPT193). This decision follows a report of liver failure in one patient involved in the dermatitis study, which is still under investigation for a definitive cause. As a precautionary measure, dosing and new patient enrollment for these trials have been suspended. However, the clinical hold does not impact the ongoing oncology trial for another drug, tivumecirnon (FLX475).

To date, around 350 individuals have participated in trials assessing zelnecirnon, including the two Phase 2 studies and an earlier Phase 1a/1b trial. Notably, no liver toxicity has been detected in any other participant, nor was it observed in preclinical studies. The patient who experienced the adverse event had a multifaceted medical background, including drug allergies, autoimmune conditions, herbal supplement use, and a recent COVID-19 infection.

RAPT's President and CEO, Brian Wong, emphasized the company's commitment to patient safety and their intent to collaborate with the FDA to address the issue promptly. The company plans to conduct a comprehensive investigation into the incident.

For further updates and discussion, RAPT will be hosting a webcast conference call on February 20, 2024, at 8:30 a.m. ET. Interested parties can join the call by pre-registering online to receive the necessary dial-in details and access the live webcast and audio recording on the RAPT Therapeutics website.

RAPT Therapeutics is dedicated to the development of highly selective small molecules that target key immune pathways in inflammatory and cancer diseases. The company has two main drug candidates, zelnecirnon and tivumecirnon, both designed to modulate the CCR4 receptor for treating inflammation and cancer, respectively. Additionally, RAPT is exploring other targets in the early stages of drug discovery.