Study of PIK3CA Mutations and Effectiveness and Tolerability Outcomes of Alpelisib in Real-world

Inclusion Criteria:

PART A:

1. Males (≥18 years of age), post-menopausal* females or pre-menopausal** females withovarian ablation (as per physician decision).

2. Patients with confirmed diagnosis of ABC/MBC (locoregionally recurrent not amenableto curative therapy or metastatic)

3. Patient with histologically and/or cytologically confirmed diagnosis of HR-positive (ER+ and/or PgR+), as well as HER2-negative breast cancer by local laboratory (HER2-by Immunohistochemistry [IHC], for borderline2+ Fluorescence In Situ Hybridization [FISH])

4. A separate signed patient ICF for Part A of the study must be obtained prior to anydata collection and sample shipment to the central designated laboratory

5. Patient's tumor tissue (archival or fresh) is available to be sent to a centrallaboratory for PIK3CA testing. In case, tissue sample (archival or fresh) is notavailable or feasible, liquid biopsy may be allowed.

PART B:

1. Males (≥18 years of age), post-menopausal* females or pre-menopausal** females withovarian ablation (as per physician decision).

2. Patients with confirmed diagnosis of ABC/MBC (locoregionally recurrent not amenableto curative therapy or metastatic) - for direct enrollment patients into Part B ofthe study.

3. Patient with histologically and/or cytologically confirmed diagnosis of HR-positive (ER+ and/or PgR+), as well as HER2-negative breast cancer by local laboratory (HER2-by Immunohistochemistry [IHC], for borderline2+ Fluorescence In Situ Hybridization [FISH]) - for direct enrollment patients into Part B of the study.

4. Participants with confirmed positive PIK3CA mutation status prior to study entry.

5. A separate signed ICF for Part B of the study must be obtained by all the patients,prior to any data collection, irrespective of patients who are being enrolled fromPart A of the study or who are being enrolled directly into Part B of the study.

6. Physician decision to treat patients with alpelisib plus fulvestrant, according tothe prescribing label and the local practicing guidelines.

7. Patient should be alpelisib treatment naïve.

Exclusion Criteria:

PART A:

1. Prior or current enrollment in any interventional clinical trial for ABC/MBC.

Part

PART B:

1. Patients' who had prior or current exposure to alpelisib or had prior or currentexposure to any other PIK3CA inhibitor should be excluded.

2. Known hypersensitivity to alpelisib or fulvestrant, or to any of the excipients ofalpelisib or fulvestrant.

3. Participant with type I or uncontrolled type II diabetes mellitus (HbA1c >7, [as perADA/ACP guidelines 2020]).

4. Participant has a history of severe cutaneous reactions likeStevens-Johnson-Syndrome (SJS), Erythema Multiforme (EM), Toxic Epidermal Necrolysis (TEN), or Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS).

5. Participant has documented pneumonitis/interstitial lung disease which is active andrequiring treatment.

6. Participant with unresolved osteonecrosis of the jaw.

7. Participant reports history of acute pancreatitis within 1 year of screening or pastmedical history of chronic pancreatitis, major surgery, any relevant medicalcondition, gastrointestinal (GI) condition preventing absorption, Child Pugh score Bor C etc.