A Study Evaluating the Efficacy and Safety of Biomarker-Driven Therapies in Patients With Persistent or Recurrent Rare Epithelial Ovarian Tumors

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