Study Assessing the Efficacy and Safety of Alpelisib Plus Fulvestrant in Men and Postmenopausal Women With Advanced Breast Cancer Which Progressed on or After Aromatase Inhibitor Treatment.

Open to people ages 18 years and up

• If female, patient is postmenopausal
• Patient has identified PIK3CA status
• Patients may be:
• relapsed with documented evidence of progression while on (neo) adjuvant endocrine therapy or within 12 months from completion of (neo)adjuvant endocrine therapy with no treatment for metastatic disease;
• relapsed with documented evidence of progression more than 12 months from completion of (neo)adjuvant endocrine therapy and then subsequently; progressed with documented evidence of progression while on or after only one line of endocrine therapy for metastatic disease;
• newly diagnosed advanced breast cancer, then relapsed with documented evidence of progression while on or after only one line of endocrine therapy
• Patient has recurrence or progression of disease during or after AI therapy (i.e.

letrozole, anastrozole, exemestane).

• Patient has a histologically and/or cytologically confirmed diagnosis of estrogen-receptor positive breast cancer by local laboratory and has HER2 negative breast cancer
• Patient has either measurable disease per RECIST 1.1 criteria OR at least one predominantly lytic bone lesion must be present
• Patient has adequate bone marrow function

• Patient with symptomatic visceral disease or any disease burden that makes the patient ineligible for endocrine therapy per the investigator's best judgment
• Patient has received prior treatment with chemotherapy (except for neoadjuvant/ adjuvant chemotherapy), fulvestrant, any PI3K, mTOR or AKT inhibitor (pre-treatment with CDK4/6 inhibitors is allowed)
• Patient with inflammatory breast cancer at screening
• Patients with Child pugh score B or C
• Patients with an established diagnosis of diabetes mellitus type I or not controlled type II
• Patient has Eastern Cooperative Oncology Group (ECOG) performance status 2 or more
• Patient with CNS involvement unless he/she is at least 4 weeks from prior therapy completion to starting the study treatment and has stable CNS tumor at time of screening and not receiving steroids and/or enzyme inducing ant-epileptic medications for brain metastases
• Patient has participated in a prior investigational study within 30 days prior to enrollment or within 5 half-lives of the investigational product, whichever is longer
• Patient has a history of acute pancreatitis within 1 year of screening or a past medical history of chronic pancreatitis
• Patient who relapsed with documented evidence of progression more than 12 months from completion of (neo)adjuvant endocrine therapy with no treatment for metastatic disease

Other protocol-defined inclusion/esclusion criteria may apply.