This study will evaluate the efficacy and safety of multiple biomarker-selected treatments in patients with persistent or recurrent rare epithelial ovarian, fallopian tube, or primary peritoneal tumors. Enrollment will take place in two phases: a preliminary phase followed by a potential expansion phase.

Inclusion Criteria:

• Persistent or recurrent EOC that meets the following criteria: Histologically confirmed non-high-grade serous, non-high-grade endometrioid epithelial ovarian, fallopian tube, or primary peritoneal cancer, including but not limited to low-grade serous ovarian carcinoma, clear cell carcinoma, mucinous carcinoma, carcinosarcoma, undifferentiated carcinoma, seromucinous carcinoma, malignant Brenner tumors, Grades 1 or 2 endometrioid carcinoma, mesonephric-like adenocarcinoma and small cell carcinoma of the ovary, hypercalcemic type (SCCOHT). Disease that is not amenable to curative surgery
• Measurable disease (at least one target lesion) according to RECIST v1.1
• Previous treatment with one to four lines of therapy, at least one of which was platinum-based. Hormonal therapy does not count as a line of therapy.
• Platinum-resistant disease, defined as disease progression during or within 6 months of last platinum therapy, with the following exception: Participants with primary platinum-refractory disease are excluded.
• Submission of a representative tumor specimen that is suitable for next-generation sequencing (NGS) testing and estrogen receptor immunohistochemistry (ER IHC) to determine treatment arm assignment and for central pathology review.
• Submission of the local pathology report and, if available, any associated stained slides that supported the local diagnosis of the histology (to be used for central pathology review)
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
• Adequate hematologic and end-organ function
• For women of childbearing potential: agreement to remain abstinent or use contraception, and agreement to refrain from donating eggs (if applicable)
• In addition to the general inclusion criteria above, participants must meet all of the arm-specific inclusion criteria for the respective arm

General Exclusion Criteria:

• Pregnant or breastfeeding, or intending to become pregnant or breastfeed during the study
• Primary platinum-refractory disease, defined as progression during or within 4 weeks after the last dose of the first-line platinum treatment
• Histologic diagnosis of high-grade serous or high-grade endometrioid ovarian, fallopian tube, or primary peritoneal cancer
• Current diagnosis of solely borderline epithelial ovarian tumor
• Current diagnosis of non-epithelial ovarian tumors
• Current diagnosis of synchronous primary endometrial cancer
• Prior history of primary endometrial cancer, with the following exception: a prior diagnosis of primary endometrial cancer is permitted if it meets all of the following conditions: Stage IA, no lymphovascular invasion, International Federation of Gynecology and Obstetrics Grade 1 or 2, not a high-grade subtype.
• Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures
• Symptomatic, untreated, or actively progressing CNS metastases
• Severe infection within 4 weeks prior to initiation of study treatment
• Treatment with chemotherapy, radiotherapy, antibody therapy or other immunotherapy, gene therapy, vaccine therapy, or investigational therapy within 28 days prior to initiation of study treatment
• Treatment with hormonal therapy within 14 days prior to initiation of study treatment
• In addition to the general exclusion criteria above, participants can not meet any of the arm-specific exclusion criteria for the respective arm

For eligible studies, qualified researchers may request access to individual patient level clinical data. See Roche's commitment to transparency of clinical study information here: https://go.roche.com/data\_sharing