The purpose of this study is to determine the maximum tolerated dose of veliparib (ABT-888)and to establish the recommended Phase 2 dose of veliparib (ABT-888) when administered in combination with carboplatin and gemcitabine in subjects with advanced solid tumors.

Inclusion Criteria:

• Histologically or cytologically confirmed solid tumors that are metastatic or unrespectable for which carboplatin/gemcitabine is a treatment option.
• Eastern Cooperative Group performance score of 0 to 2.
• Adequate hematologic, hepatic and renal function
• Subject has received up to 2 DNA damaging or cytotoxic regimens in the past five years

Exclusion Criteria:

• Subject has received any anti-cancer therapy including chemotherapy, immunotherapy, radiotherapy, biologic or any investigational therapy within 28 days prior to study administration.
• Subjects with known history of brain metastases and primary CNS tumors.
• Hypersensitivity reactions to platinum compounds or gemcitabine.
• Clinically significant and uncontrolled major medical conditions
• Active malignancy within the past 5 years except for any cancer in situ cured or non-melanoma carcinoma of the skin.