Abemaciclib in Combination With Bicalutamide for Androgen Receptor-positive, HER2-negative Metastatic Breast Cancer

This is an open label multicenter, Phase IB/II Study of Abemaciclib in Combination with Bicalutamide for Androgen Receptor-positive, HER2-negative Metastatic Breast Cancer About 54-60 patients will be enrolled over the course of 36 months. Patients will be treated until disease progression. Study regimen is Abemaciclib with Bicalutamide Primary objective is to determine the dose-limiting toxicity (DLT) and recommended phase II dose for abemaciclib when administered in combination with bicalutamide and to determine the efficacy of the treatment secondary objective is to determine the safety and tolerability along with progression free survival. Given the suggestive pre-clinical data and the unique properties of abemaciclib, the researchers believe that abemaciclib is an ideal partner for bicalutamide in treatment of AR+ metastatic breast cancer. The study team hypothesize that the combination will demonstrate a further improved clinical benefit rate than either agent alone, including in those patients who have already been treated with prior endocrine therapies. Additionally, the study team believe that the convenience of an all-oral, continuous daily dosing schedule and the favorable side effect profile of both therapies with minimal overlapping or serious toxicities further supports this investigation.