∙ The main inclusion criteria include but are not limited to the following:

• Cohort A:

‣ Has a diagnosis of hormone receptor positive/Human Epidermal Growth Factor Receptor 2 negative (HR+/HER2-) invasive breast carcinoma that is either locally advanced disease not amenable to resection with curative intent (herein called unresectable) or metastatic disease not treatable with curative intent.

⁃ Has experienced disease progression on or after at least 1 prior endocrine-based therapy in the metastatic setting.

• Cohort B:

‣ Has histologically confirmed high-grade epithelial (including high-grade serous or predominantly serous, high-grade endometrioid, malignant mixed Müllerian tumors \[carcinosarcoma\], or clear cell) ovarian, fallopian tube, or primary peritoneal carcinoma.

⁃ Has received between 4 to 8 cycles of platinum-based doublet chemotherapy in third-line (3L) setting for ovarian cancer.

• Cohort C:

‣ Histologically confirmed diagnosis of primary advanced or recurrent low-grade endometrioid carcinoma (eg, Federation of Gynecology and Obstetrics \[FIGO\] Grade 1/2, or well/moderately differentiated).

⁃ Treatment naïve or has received up to 1 prior line of platinum-based therapy in either the advanced/metastatic OR adjuvant/neoadjuvant setting.

• All Cohorts :

‣ Participants who have AEs due to previous anticancer therapies must have recovered to ≤Grade 1 or baseline.

⁃ Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on antiretroviral therapy.

⁃ Participants who are Hepatitis B surface antigen positive are eligible if they have received Hepatitis B virus (HBV) antiviral therapy for at least 4 weeks, and have undetectable HBV viral load.

⁃ Participants with a history of Hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable.