Temozolomide With or Without Veliparib in Treating Patients With Relapsed or Refractory Small Cell Lung Cancer

PRIMARY OBJECTIVES: I. To demonstrate an improvement in progression free survival (PFS) at four months in patients with relapsed sensitive or refractory small cell lung cancer (SCLC) receiving ABT-888 (veliparib) and temozolomide compared to placebo and temozolomide. SECONDARY OBJECTIVES: I. Determine the objective response rate (ORR) (based on Response Evaluation Criteria in Solid Tumors \[RECIST\] 1.1 criteria) in both arms of the study: ABT-888 and temozolomide and placebo and temozolomide. II. Determine the overall survival (OS) of patients in both arms of the study. III. Determine the ORR, PFS and OS of ABT-888 and temozolomide and placebo and temozolomide, in the following patient groups: sensitive disease vs. refractory disease; second-line treatment vs. third-line treatment; brain metastases vs. no brain metastases. IV. Determine the safety and tolerability of ABT-888 and temozolomide in patients with SCLC. TERTIARY OBJECTIVES: I. Evaluate available tumor samples for methylated O6-methylguanine-DNA methyltransferase (MGMT) promoter by the EpiTyper assay, as well as MGMT expression by immunohistochemistry and determine if these correlate with PFS, ORR, and OS. II. Evaluate available tumor samples for poly (ADP ribose) polymerase (PARP)-1, breast cancer 1 (BRCA-1) and RAD51 recombinase (RAD51) expression by immunohistochemistry and determine if they correlate with PFS, ORR, and OS. III. Evaluate available tumor samples for messenger ribonucleic acid (mRNA) BRCA-1 expression and determine if it correlates PFS, ORR, and OS. IV. Evaluate available tumor samples for phosphatase and tensin homolog (PTEN) expression by immunohistochemistry and determine if it correlates PFS, ORR, and OS. V. Identify and enumerate circulating tumor cells (CTCs) using the Cell Search System in these patients with SCLC at baseline and at the time of repeat imaging. VI. Correlate the number of CTCs with PFS and OS at each time point. VII. Correlate the change in CTCs with radiographic response. VIII. Correlate the number of CTCs at baseline with patient characteristics (disease burden, location of metastases, progression at existing sites or new sites of disease). IX. Evaluate gamma H2A histone family, member X (H2AX)-positive CTCs using the CellSearch. X. Assess the percentage increase in DNA fragments during treatment and correlate with outcome in each of the treatment groups. XI. Evaluate plasma markers for apoptosis and angiogenesis. XII. Assess changes in plasma markers for apoptosis and angiogenesis, including caspase-cleaved cytokeratin 18 fragment (M30), soluble cytokeratin 18 (M65), pro-gastrin-releasing peptide (pro-GRP), soluble vascular endothelial growth factor (sVEGF), sVEGF receptor 2 (sVEGFR2), and soluble v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (sKIT), and correlate these markers with outcome in the two treatment arms. OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM I: Patients receive veliparib orally (PO) twice daily (BID) on days 1-7 and temozolomide PO on days 1-5. ARM II: Patients receive placebo PO BID on days 1-7 and temozolomide as in Arm I. In both arms, courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 8-12 weeks.