ZN-c3 for the Treatment of Metastatic Triple-Negative Breast Cancer and Advanced Ovarian Cancer

Inclusion Criteria: * Participant must provide written informed consent before any study-specific procedures or interventions are performed * Participants aged \>= 18 years * Participants with biopsy proven metastatic TNBC defined as: * Estrogen receptor (ER) \< 10%, progesterone receptor (PR) \< 10% * HER2 non-amplified by College of American Pathologists (CAP) guidelines * Participants with biopsy proven advanced ovarian cancer (including primary peritoneal and fallopian tube cancers) * Prior PARP inhibitor therapy allowed * Participants must have at least one measurable site of disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) version (v) 1.1 that is amendable to biopsy * Participants must have received at least one standard of care line of therapy in the recurrent setting * Eastern Cooperative Oncology Group (ECOG) performance status (PS) =\< 2 * Prior treatment related toxicities resolved to =\< grade 1 (except neuropathy, alopecia or skin pigmentation) * Absolute neutrophil count (ANC) \>= 1.5 x 10\^9/L; excluding measurements obtained within 7 days after daily administration of filgrastim/sargramostim or within 3 weeks after administration of pegfilgrastim * Platelet count \>= 100 x 10\^9/L; excluding measurements obtained within 3 days after transfusion of platelets * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) =\< 3 × upper limit of normal (ULN). If liver function abnormalities are due to underlying liver metast…