Inclusion Criteria for Dose Escalation Cohort:

          1. Men and women, 18 years or older

          2. Understand and voluntarily sign informed consent prior to any study-related
             assessments or procedures are conducted and are able adhere to the study visit
             schedule and other protocol requirements.

          3. Solid tumors with one or more of the following DNA repair defects:

             a. BRCA1, BRCA2, ATM, BARD1, BRIP1, CDK12, CHEK2, FANCA, NBN, PALB2, RAD51, RAD51B,
             RAD51C, RAD51D, RAD54L (validated from archival tumor tissue or germ line testing from
             any Clinical Laboratory Improvement Amendments (CLIA) approved lab). This testing
             should occur prior to study consent or enrollment.

          4. Presence of at least one lesion with measurable disease as defined by Response
             Evaluation Criteria in Solid Tumors (RECIST) version 1.1 criteria for response
             assessment

          5. Advanced solid tumor malignancy without curative options

          6. Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 1.

          7. Adequate organ function:

               1. Absolute neutrophil count (ANC) ≥ 1.5 X 109/L

               2. Hemoglobin (Hgb) ≥9g/dL; (last transfusion cannot be within 7 days of trial
                  initiation)

               3. Platelets (plt) ≥ 100 x 109/L

               4. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 x Upper
                  Limit Normal (ULN), <5x in patients with known liver metastases

               5. Serum total bilirubin ≤ 1.5 x ULN

               6. Creatinine<1.5 x ULN or estimated Glomerular filtration rate (GFR) ≥ 50ml/min by
                  Cockcroft-Gault
                  (http://www.mdcalc.com/creatinine-clearance-cockcroft-gault-equation/)

          8. The effects of rucaparib on the developing fetus are unknown. Therefore a. Given the
             results of the embryo-fetal development study, in which rucaparib was embryotoxic at
             all doses administered, females of childbearing potential and their male partners are
             advised to practice a highly effective method of contraception during treatment with
             rucaparib and for 1 month following the last dose for females and 4 months following
             the last dose for males. A woman is considered to be of childbearing potential unless
             one of the following applies: i. Is considered to be permanently sterile. Permanent
             sterilization methods include hysterectomy, bilateral salpingectomy and bilateral
             oophorectomy.

             ii. Is postmenopausal, defined as no menses for 12 months without an alternative
             medical cause. A high follicle-stimulating hormone (FSH) level consistently in the
             postmenopausal range (30 milli-international units per millilitre (mIU/mL) or higher)
             may be used to confirm a postmenopausal state in women not using hormonal
             contraception or hormonal replacement therapy; however, in the absence of 12 months of
             amenorrhea, a single FSH measurement is insufficient to confirm a postmenopausal
             state.

             b. Highly effective contraception is considered to be a method with a < 1% per year
             failure rate. Recommendations for highly effective contraception while taking
             rucaparib include: i. Ongoing use of injectable or implantable progesterone ii.
             Placement of an intrauterine device or intrauterine system iii. Bilateral tubal
             occlusion iv. Complete (as opposed to periodic) abstinence v. Male sterilization, with
             appropriate post-vasectomy documentation of absence of sperm in ejaculate

             Additional Inclusion Criteria for Dose Expansion Cohort

          9. Mandatory biopsy on study entry, if the lesion can be biopsied with acceptable
             clinical risk (as judged by the investigator)

         10. PARP inhibitor (PARPi) naïve or prior exposure to PARPi therapy (varies depending on
             Arm 1 and Arm 2)

               1. Patients in Arm 1 (single agent rucaparib followed by combination upon
                  progression) must be PARPi naïve. Prior irinotecan is allowed

               2. Patients in Arm 2 (combination) must have been treated with and progressed on a
                  PARPi previously. Prior irinotecan is allowed.

        Exclusion Criteria for Dose Escalation Cohort:

          1. Any significant medical condition, laboratory abnormalities, which places the subject
             at unacceptable risk if he/she were to participate in the study at clinician's
             discretion and not otherwise stated below.

          2. Allergic reaction to single-agent rucaparib or irinotecan.

          3. Myelodysplastic features on peripheral blood smear

          4. Prior allergic reaction or known intolerance to irinotecan

          5. Known Gilbert's disease

          6. Poorly controlled or symptomatic central nervous system (CNS) metastases or
             carcinomatous meningitis

        Note: Patients with previously treated brain metastases may participate, 2 weeks after
        gamma knife (or equivalent) or 4 weeks after Whole Brain Radiotherapy (WBRT), provided they
        are stable (without evidence of progression by imaging and have not been using steroids for
        at least 7 days prior to study treatment.

        8. Pregnancy and breast feeding

        9. Inability to comply with study procedures or willingness to use adequate birth control

        Additional Exclusion Criteria for Dose Expansion Cohort

        10. PARP inhibitors (PARPi) naïve or prior exposure to PARPi therapy

          1. Patients in Arm 1 of the Dose Expansion cohort cannot have prior exposure to PARPi
             therapy.

          2. Patients in Arm 2 of the Dose Expansion cohort cannot be PARPi naïve.