Ribociclib and Bicalutamide in AR+ TNBC

This is a non-randomized, single arm, open label study of the combination of bicalutamide with ribociclib in subjects with advanced AR+ TNBC. Prior to enrollment on the phase II cohort, a phase I run-in study will be performed to ensure safety and tolerability of the combination of bicalutamide and ribociclib in subjects with advanced AR+ TNBC. In both the phase I and phase II portions of the study, subjects will receive bicalutamide 150 mg orally, once daily, continuously on Day 1 to Day 28. Each cycle of treatment is 28 days. In the phase I portion of the study, cohorts of subjects will receive ribociclib in escalated doses orally, once daily in a 28 day cycle. For the phase II portion, the RP2D dose of ribociclib will be based on the phase I run-in. In the phase II cohort, a two week lead-in of bicalutamide monotherapy will occur before cycle 1 combination therapy (Day -14 to day -1). Then ribociclib will be added on day 1 of cycle 1. This lead-in will be for CTC androgen receptor analysis.