Participants who had the below specified histologically confirmed malignancies that had progressed to the advanced or metastatic stage:
- In Part A, the participants must have had an advanced malignancy, including but not limited to high-grade serous cancer of the ovary, fallopian tube, or peritoneum, triple negative breast cancer, small cell lung cancer (SCLC), primary peritoneal cancer, and any tumor likely to harbor DNA damage repair deficiencies susceptible to treatment with a PARP inhibitor or likely to be responsive to a PD-1 blocker.
- In Part B, the participants recruited to 1 of the 8 expansion arms must have had advanced solid tumors of the following types:
Arm 1: Participants with relapsed, platinum-sensitive high-grade epithelial, non-mucinous, ovarian cancer, fallopian tube, or primary peritoneal cancer (EOC) must have met the following criteria:
i. Must have had at least 2 prior platinum-containing treatments in any treatment setting.
ii. Must have had platinum-sensitive recurrent disease and must not have progressed (by Response Evaluation Criteria in Solid Tumors [RECIST] v1.1 criteria) within 6 months of the completion of the last platinum-containing line of treatment.
• Note: Participants may have received additional non-platinum-based chemotherapy for recurrence after prior last platinum-containing regimen if the criteria for platinum sensitivity were met.
iii. Arm 1a: Participants with relapsed, platinum-sensitive high-grade EOC with either known deleterious or suspected deleterious germline or somatic breast cancer susceptibility gene 1/2 (BRCA1/2) mutations or with homologous recombination deficiency (HRD).
• If HRD or BRCA1/2 mutation status from archival tissue was unknown or had not been previously evaluated, then the archival tissue must have undergone tissue screening using a validated diagnostic test to determine eligibility. If the diagnostic test result was BRCA1/2 or HRD positive, the participant was eligible for enrollment in Arm 1a.
iv. Arm 1b: Participants with relapsed, platinum-sensitive high grade EOC who otherwise met the above criteria and were without known germline or somatic BRCA1/2 mutations and without HRD mutation.
Arm 2: Participants with triple negative breast cancer must have met the following criteria:
i. 0-1 prior platinum-containing treatment in any treatment setting.
• Note: participants could have received additional therapy after the last platinum-containing line of treatment if the other eligibility criteria were met.
ii. Participants who received at least 1 prior treatment but not more than 3 prior lines of treatment in the advanced or metastatic setting.
iii. Known deleterious or suspected deleterious germline or somatic BRCA1/2 mutations or with documented HRD.
• If HRD or BRCA1/2 mutation status from archival tissue was unknown or had not been previously evaluated, then the archival tissue must have undergone tissue screening using a validated diagnostic test to determine eligibility. If the diagnostic test result was HRD positive, then the participant was eligible for enrollment in Arm 2.
• If archival tissue was not available and the participant submitted a fresh tumor biopsy, then the diagnostic test needed to demonstrate somatic BRCA1/2 mutation or HRD positivity.
Arm 3: Participants with metastatic castration-resistant prostate cancer, including but not limited to mutations in homologous recombination (HR) pathways and/or defined by HRD algorithms, and must have met the following criteria:
i. May be either chemotherapy-naïve, but must have received prior abiraterone acetate and/or enzalutamide treatment, or have previously had no more than 2 taxane-based chemotherapy lines of treatment, including docetaxel and carbazitaxel. If docetaxel was used more than once, this was considered as 1 line of treatment.
ii. At least 2 weeks since the completion of prior flutamide, bicalutamide, and nilutimide, or enzalutamide and abiraterone treatment.
iii. Documented prostate cancer with one of the following:
- Surgically or medically castrated. The testosterone levels did not need to be checked if the participant had undergone surgical castration for > 4 months. Participants receiving chemical castration should have had testosterone levels checked at baseline and confirmed to be in the castrate levels (< 0.5 ng/mL or 1.735 nM). In all cases, the luteinizing hormone-releasing hormone antagonist/agonist was to be continued in these participants.
- Participants with only non-measurable bone lesions must have had disease progression based on Prostate Cancer Clinical Trials Working Group with 2 or more new lesions or have had prostate-specific antigen progression before enrolment.
iv. Known deleterious or suspected deleterious germline or somatic BRCA1/2 mutations or with documented HRD.
- If HRD or BRCA1/2 mutation status from archival tissue was unknown or had not been previously evaluated, then the archival tissue must have undergone tissue screening using a validated diagnostic test to determine eligibility. If the diagnostic test result was HRD positive, then the participant was be eligible for enrollment in Arm 3.
- If archival tissue was not available and the participant summitted a fresh tumor biopsy, then the diagnostic test needed to demonstrate somatic BRCA1/2 mutation or HRD positivity.
Arm 4: Participants with extensive-stage disease SCLC must have met the following criteria:
i. Received at least 1 and not more than 2 prior lines of treatment; ii. At least 1 prior line of treatment must have contained a platinum agent
Arm 5: Participants with human epidermal growth factor receptor-2 (HER2)-negative gastric or gastroesophageal junction cancer must have met the following criteria:
i. May have received at least 1 and not more than 2 prior lines of treatment
Arm 6: Participants with locally advanced or metastatic urothelial (muscle-invasive bladder, ureter, urethra, or renal pelvis) cancer must have met the following criteria:
i. Received at least 1 and not more than 2 prior lines of treatment in the advanced or metastatic disease setting; ii. At least 1 prior line of treatment must have contained a platinum agent
Arm 7: Participants with advanced or metastatic pancreatic adenocarcinoma must have met the following criteria:
i. Received at least 1 but not more than 2 lines of treatment in either an advanced or metastatic setting; ii. At least 1 prior treatment for advanced or metastatic disease must have contained a platinum agent; iii. Participants with known deleterious germline or somatic BRCA1/2 mutation could be considered for the study even if platinum naïve.
Arm 8: (Note: Closed to enrollment) Participants with advanced or metastatic recurrent non-ovarian gynecological cancers (endometrial cancer, cancer of the cervix and participants with tumors known to be mismatch repair deficient or HRD positive) must have met the following criteria:
i. Participants with a complete response, partial response, or stable disease from at least 1 prior platinum-containing treatment in any treatment setting; ii. The Sponsor medical monitor would approve tumor types for Arm 8 prior to screening.
• Note: Excluded tumor types included participants with bone or soft tissue sarcoma; central nervous system (CNS) malignancies; colorectal cancer (except microsatellite instability-high colorectal cancer is permitted); cutaneous or ocular melanoma; hematologic malignancies; HER2-negative breast cancer without BRCA mutation; mesothelioma, papillary, follicular, medullary or Hürthle cell thyroid cancer; unknown primary malignancy.