RAPT Thera ends zelnecirnon program after FDA worries

RAPT Therapeutics (Nasdaq: RAPT) has announced the termination of its zelnecirnon program following regulatory concerns around safety.

The company had been testing the oral CCR4 inhibitor in two Phase II trials, targeting asthma and atopic dermatitis (AD). The US Food and Drug Administration placed both trials on hold in February after a serious adverse event involving liver failure in a patient in the AD study, which necessitated a transplant.

RAPT shares lost almost half their value in early trading following the news. The setback follows a tough year for the company, which had already seen its stock take a hit in February when the FDA issued the clinical hold.