Mass General - Division of Clinical Research

• Histologically or cytologically confirmed and documented locally-advanced, recurrent inoperable, or metastatic TNBC (ER < 1%, PgR < 1%, HER2 IHC 0, 1+, or 2+ with ISH negative for HER2 gene amplification) or ER-low, HER2-negative BC (ER and / or PgR 1% to 10%, HER2 IHC 0, 1+, or 2+ with ISH negative for HER2 gene amplification) per ASCO/CAP criteria, based on the most recently analyzed biopsy or other pathology specimen. - Patients with recurrent disease must have experienced disease relapse at least 6 months after finishing their last therapy with curative intent. - Patients with TNBC must be considered ineligible for 1L chemotherapy combination treatment with an anti-PD-1 or an anti-PD-L1 due to either one of the following criteria: i) Investigator-determined ineligibility based on PD-L1 negative disease determined and documented prior to trial screening as part of SoC; ii) Has experienced disease relapse between 6 to 12 months after the completion of (neo)adjuvant therapy with an anti-PD(L)1; iii) Has a severe auto-immune disease or other contraindication. - Patients with ER-low, HER2-negative BC must be ineligible, in the opinion of the Investigator, for endocrine therapy-based treatments. - No previous systemic therapy in the locally advanced, recurrent inoperable or metastatic setting (ie incurable setting). - Measurable disease by CT or MRI as per RECIST v1.1. - Other protocol-defined Inclusion/

apply.