RPT193, an oral, second-generation CCR4 inhibitor from RAPT Therapeutics, is in Ph. II clinical trials (400 mg QD) to treat atopic dermatitis (AD) and asthma. CCR4 has been a long outstanding therapeutic target for treating inflammatory diseases, but despite many efforts, no molecule inhibiting this receptor has progressed beyond Ph. I for these indications.
RPT193’s story is interesting as it’s an example of a zwitterionic drug that is orally available, and is a great example of a small molecule that could compete in immunology with biologics including but not limited to dupilumab, mepolizumab, and tezepelumab.