Purpose

This randomized phase I/II trial studies the side effects and best dose of veliparib when given together with or without cisplatin and etoposide and to see how well they work in treating patients with extensive stage small cell lung cancer or large cell neuroendocrine non-small cell lung cancer that has spread to other parts of the body. Drugs used in chemotherapy, such as cisplatin and etoposide, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Veliparib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving cisplatin and etoposide with or without veliparib may work better in treating patients with extensive stage small cell lung cancer or metastatic large cell neuroendocrine non-small cell lung cancer.