This is a multi-site, global, open-label study that includes a phase 1b evaluation of elacestrant in combination with abemaciclib in women and men with brain metastases from estrogen receptor (ER)-positive, human epidermal growth factor receptor-2 (HER-2) negative breast cancer. Phase 1b was designed to select the recommended phase 2 dose (RP2D) and is followed by an ongoing phase 2 evaluation of elacestrant in combination with abemaciclib in participants with active brain metastases from ER-positive, HER-2 negative breast cancer.
Participant has the signed informed consent form before any study-related activities according to local guidelines.
Women or men aged ≥18 years, at the time of informed consent signature.
Age ≥60 years
Age <60 years and amenorrhea for 12 or more months without an alternative cause) and follicle stimulating hormone and estradiol in postmenopausal ranges per local reference ranges
Immediate CNS-specific treatment is likely to be required, per the treating physician's assessment.
Participant has imminent organ failure and/or visceral crisis.
Participant has leptomeningeal metastases, defined as having positive cerebrospinal fluid (CSF) cytology or unequivocal radiologic and clinical evidence of leptomeningeal involvement. Note: Discrete dural metastases are permitted.
Breast cancer treatment-naïve participants (that is, not having received any systemic therapy) in the advanced/metastatic setting.