Inclusion Criteria:

          -  Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1

          -  A life expectancy of at least 3 months

          -  Have disease that is measurable as according to RECIST v1.1

          -  Have sufficient archival formalin-fixed paraffin-embedded (FFPE) tumor tissue
             available for planned analyses

          -  For Part 1, have a histologically confirmed diagnosis of ovarian or endometrial
             cancer, and have received at least one line of prior therapy for metastatic disease

          -  For Part 2 ONLY, have disease that can be safely biopsied

          -  For Part 2 ONLY, have a deleterious germline or somatic breast cancer susceptibility
             gene 1 (BRCA1) or BRCA2 mutation or tumors that are wild-type BRCA but show high
             levels of loss of heterozygosity (LOH) (tBRCAwt/LOHhigh) signature

          -  For Part 2 Cohort 1 (ovarian cancer), high-grade serous or Grade 3 endometrioid
             epithelial ovarian, fallopian tube, or primary peritoneal cancer (PPC)

          -  For Part 2 Cohort 1, have received at least one and no more than two lines of prior
             platinum-containing therapy and progressed after the most recent platinum therapy in a
             platinum-sensitive timeframe

          -  For Part 2 ONLY, Cohort 1, have a CA125 measurement that is greater than 2 times the
             upper limit of normal (ULN)

          -  For Part 2 Cohort 2 (TNBC), metastatic, histologically confirmed estrogen receptor
             (ER)-negative, progesterone receptor-negative, and HER2-negative adenocarcinoma of the
             breast per local laboratory assessment

          -  For Part 2 Cohort 2, radiologic/objective evidence of recurrence or disease
             progression after one line of chemotherapy for TNBC in the metastatic setting

          -  Have adequate organ function

        Exclusion Criteria:

          -  History of prior malignancy except a) curatively treated non-melanoma skin cancer, b)
             solid tumor treated curatively more than 3 years ago without evidence of recurrence,
             c) For Cohort 1 (ovarian cancer): breast cancer with no evidence of disease or
             inactive for at least 3 years, and d) synchronous endometrial cancer (Stage 1A) with
             ovarian cancer

          -  Treatment with chemotherapy, radiation, hormones (except corticosteroids and megestrol
             acetate), or other anticancer therapies less than or equal to (<=) 14 days prior to
             first dose of study treatment

          -  Preexisting duodenal stent and/or any gastrointestinal disorder or defect that would,
             in the opinion of the investigator, interfere with absorption of rucaparib

          -  Symptomatic and/or untreated central nervous system metastases

          -  Prior treatment with any poly adenosine diphosphate-ribose polymerase (PARP) inhibitor