This is a multicenter, phase 1b-2 trial. The phase 1b part of the trial is open label and aims to determine the recommended Phase 2 dose (RP2D) of onapristone and elacestrant when administered together. The Phase 2 part of the trial will evaluate the efficacy and safety of this combination in patients with ER+/PgR+/HER2- advanced/metastatic breast cancer after prior therapy with a CDK4/6 inhibitor.
This is a multicenter, Phase 1b-2 study of elacestrant in combination with onapristone in patients with advanced/metastatic ER+/PgR+/HER2- breast cancer.