HTL0039732

HTL0039732 is an orally available small molecule drug developed as a selective antagonist of the E-type prostanoid receptor 4 (EP4), which is activated by prostaglandin E2 (PGE2). In cancer, elevated PGE2 signaling through EP4 can suppress immune activity in the tumor microenvironment, allowing cancer cells to evade immune detection. By blocking EP4, HTL0039732 aims to relieve this immunosuppression and enhance anti-tumor immune responses. The drug is being investigated both as a monotherapy and in combination with other immunotherapies such as atezolizumab (a PD-L1 inhibitor) for the treatment of advanced solid tumors, including those that are typically less responsive to current immunotherapies like microsatellite stable colorectal, gastroesophageal, head and neck, and castrate-resistant prostate cancers[1][5][7].