TRC253 is a novel, orally bioavailable small molecule discovered and developed by Janssen that is a potent, high affinity competitive inhibitor of the androgen receptor (AR). TRC253 is also a pan-inhibitor of multiple AR mutations, including the F876L mutation, and is under development for the treatment of men with prostate cancer. The AR F876L mutation results in an alteration in the ligand binding domain that confers resistance to current AR inhibitors. TRACON expects to initiate clinical development for the product candidate in the first half of 2017.
Activation of the AR is crucial for the growth of prostate cancer at all stages of the disease. Therapies targeting the AR have demonstrated clinical efficacy by extending time to disease progression, and in some cases, the survival of patients with metastatic castration-resistant prostate cancer. However, resistance to these agents is often observed and several molecular mechanisms of resistance have been identified, including amplification, overexpression or mutation of the AR.
TRC253 is intended to address resistance mechanisms to current AR inhibitors by specifically targeting mutations in the AR ligand binding domain. TRC253 also potently inhibits signalling through the wild type AR. These susceptible AR mutations have been identified using circulating tumor DNA assays, potentially allowing for selected patient biomarker-directed therapy.