Alpelisib Plus Olaparib in Platinum-resistant/Refractory, High-grade Serous Ovarian Cancer, With no Germline BRCA Mutation Detected

Key Inclusion Criteria:

* Participant has histologically confirmed diagnosis of high-grade serous or high-grade endometrioid ovarian cancer, fallopian tube cancer, or primary peritoneal cancer
* Measurable disease, i.e., at least one measurable lesion per RECIST 1.1 criteria (a lesion at a previously irradiated site may only be counted as a target lesion if there is clear sign of progression since the irradiation)
* If no measurable disease is present, the disease should be assessable by Gynecologic Cancer Intergroup criteria (GCIC) for CA-125
* Participant has no germline BRCA1/2 mutation as determined by an FDA-approved assay
* Participant has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
* Participant has platinum-resistant (progression within one to six months after completing platinum-based therapy) or platinum refractory disease (progression during treatment or within 4 weeks after the last dose), where platinum-based therapy is not an option, according to the GCIG 5th Ovarian Cancer Consensus Conference definitions (Wilson et al 2016). The platinum-based chemotherapy regimen does not necessarily need to be the last regimen the participant received prior to study entry
* Participant must have received at least one but no more than three prior systemic treatment regimens and for whom single-agent chemotherapy is appropriate as the next line of treatment
* Participant has received prior bevacizumab or is not eligible to receive bevacizumab due to medical reasons.

Key Exclusion Criteria:

* Participant has received prior treatment with any PI3K, mTOR or AKT inhibitor
* Participant is concurrently using other anti-cancer therapy
* Participant is in a state of small or large bowel obstruction or has other impairment of gastrointestinal (GI) function or GI disease
* Participant has had surgery within 14 days prior to starting study drug or has not recovered from major adverse effects
* Participant has not recovered from all toxicities related to prior anticancer therapies to baseline or NCI CTCAE Version 4.03 Grade ≤1. Exception to this criterion: participants with any grade of alopecia are allowed to enter the study
* Participant has an established diagnosis of diabetes mellitus type I or uncontrolled type II based on fasting plasma glucose and HbA1c
* Participants with liver impairment and Child Pugh score B or C
* Participant has received radiotherapy ≤ 4 weeks or limited field radiation for palliation ≤ 2 weeks prior to randomization, and who has not recovered to baseline, grade 1 or better from related adverse effects of such therapy (with the exception of alopecia)
* Participant has a known hypersensitivity to any of the study drugs or excipients
* Participant has a history of myelodysplastic syndrome or acute myeloid leukemia, or presents clinical and/ or laboratory features suggestive thereof.

Other inclusion/exclusion criteria may apply