Rapt Therapeutics is terminating its clinical programs for zelnecirnon, an oral immunology drug being evaluated in asthma and atopic dermatitis, following recent feedback from the FDA.
Zelnecirnon is an orally-administered small molecule CCR4 antagonist that blocks the recruitment of inflammatory immune cells, known as Th2 cells, which are clinically implicated in a range of inflammatory disorders.
Back in February, the agency put a clinical hold on two phase 2 trials of the San Fran-based company's lead asset due to a serious adverse event of liver injury requiring transplant in one patient in the atopic dermatitis trial. Rapt subsequently closed both studies before completing the planned enrollment.
“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,” said Rapt CEO Brian Wong.
Instead, Rapt plans to advance its next generation CCR4 compounds with improved safety margins for inflammatory disease and expects to identify a new candidate in the first half of 2025.