Temozolomide is a drug used to treat brain cancer. It has shown some activity against small cell lung cancer and is being evaluated as a potential treatment for this disease. ABT-888 (veliparib) is an investigational drug that kills cancer cells by blocking a protein called PARP, thereby preventing the repair of DNA or genetic damage in cancer cells and possibly making them more susceptible to anticancer drugs, such as temozolomide.
The purpose of this study is to evaluate the safety and effectiveness of temozolomide alone and with ABT-888 in patients with small cell lung cancer that has persisted despite, or has returned after, prior chemotherapy. Patients will be randomly assigned to receive temozolomide plus placebo or temozolomide plus ABT-888. Both medications are pills that are taken orally (by mouth).