A Study of Oral Sapacitabine and Oral Seliciclib in Patients With Advanced Solid Tumors

Inclusion Criteria: * Incurable advanced solid tumors that are no longer responding to conventional therapy or for which no effective therapy exists; at the RD of Part 1, an extension cohort up to 20 patients with metastatic breast cancer who are known to be BRCA mutation carriers will be enrolled. * Age 18 years or older * ECOG 0-2 * Life expectancy ≥ 3 months * Evaluable disease * Adequate bone marrow function * Adequate renal function * Adequate liver function * At least 3 weeks from prior systemic treatments including investigational anti-cancer therapy, radiation therapy; and have recovered from prior toxicities * Able to swallow capsules * At least 3 weeks from major surgery * Agree to practice effective contraception * Ability to understand and willingness to sign the informed consent form Exclusion Criteria: * Previously untreated CNS metastases or progressive CNS metastases * Currently receiving radiotherapy, biological therapy, or any other investigational agents * Uncontrolled intercurrent illness including * Pregnant or lactating women * Known to be HIV-positive * A history of active hepatitis B and/or hepatitis C infection