Efficacy and Safety of Ribociclib in Pre- and Postmenopausal Chinese Women With HR Positive, HER2-negative, Advanced Breast Cancer.

Inclusion Criteria: * Patient has a histologically and/or cytologically confirmed diagnosis of estrogen receptor (ER) positive and/or progesterone receptor positive breast cancer by local laboratory (based on most recently analyzed biopsy). * Patient has HER2-negative breast cancer (based on most recently analyzed biopsy) defined as a negative in situ hybridization test or an Immunohistochemistry (IHC) status of 0, 1+ or 2+. If IHC is 2+, a negative in situ hybridization (FISH, CISH, or SISH) test is required by local laboratory testing. * Patient must have either: * Measurable disease, i.e., at least 1 measurable lesion as per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria (a lesion at a previously irradiated site may only be counted as a target lesion if there is a clear sign of progression since the irradiation). OR * If no measurable disease is present, then at least 1 predominantly lytic bone lesion must be present (patients with no measurable disease and only 1 predominantly lytic bone lesion that has been previously irradiated are eligible if there is documented evidence of disease progression of the bone lesion after irradiation). * Patient has ECOG performance status 0 or 1. For premenopausal cohort: * Patient is an adult, female ≥ 18 years old and \< 60 years old at the time of informed consent and has signed informed consent before any trial related activities are conducted and according to local guidelines. * Confirmed negative serum pr…