RAPT Therapeutics, a San Francisco-based pharmaceutical company, said Feb. 20 that two of its clinical trials are on pause because of one patient's liver failure.
The FDA placed the clinical hold on two phase 2 studies of zelnecirnon, which was being tested for eczema and asthma. The serious adverse event happened in a participant of the eczema trial.
RAPT said the cause is unknown but "has been characterized as potentially related to zelnecirnon," according to a news release. Enrollment of new participants and administration of the drug has been halted in both clinical trials.
About 350 patients have been enrolled in RAPT's trials for zelnecirnon, and liver toxicity has not been observed with anyone else. The company said it is investigating the matter.