Cisplatin and Etoposide With or Without Veliparib in Treating Patients With Extensive Stage Small Cell Lung Cancer or Metastatic Large Cell Neuroendocrine Non-Small Cell Lung Cancer

Inclusion Criteria:

• Women must not be pregnant or breastfeeding

• All females of childbearing potential must have a blood test within 2 weeks prior to registration to rule out pregnancy

  • A female of childbearing potential is any woman, regardless of sexual orientation or whether they have undergone tubal ligation, who meets the following criteria: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months)
• Women of childbearing potential and sexually active males must be strongly advised to use an accepted and effective method of contraception

• Patients must have histologically or cytologically confirmed:

  • Extensive stage small cell lung cancer (SCLC) (Phase I and II)

    • The extensive disease SCLC classification for this protocol includes all patients with disease sites not defined as limited stage

      • Limited-stage disease category includes patients with disease restricted to one hemithorax with regional lymph node metastases, including hilar, ipsilateral and contralateral mediastinal, and/or ipsilateral supraclavicular nodes
      • Extensive-disease patients are defined as those patients with extrathoracic metastatic disease, malignant pleural effusion, or bilateral or contralateral supraclavicular adenopathy
  • Stage IV (M1a or M1b according to American Joint Committee on Cancer [AJCC] Staging Manual, 7th edition) large cell neuroendocrine non-small cell lung cancer (NSCLC) (Phase I only)
  • Small cell carcinoma of unknown primary or extrapulmonary origin and must be a candidate for systemic therapy (phase I only)
• Patients must have measurable or non-measurable disease based on Response Evaluation Criteria in Solid Tumors(RECIST) 1.1; baseline measurements and evaluations of all sites of disease must be obtained =< 4 weeks prior to registration (phase I)
• Patients must have measurable disease based on RECIST 1.1; baseline measurements and evaluations of all sites of disease must be obtained =< 4 weeks prior to registration (phase II)
• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
• Absolute neutrophil count >= 1,500/mm^3
• Platelets >= 100,000/mm^3
• Leukocytes >= 3,000/mm^3
• Hemoglobin >= 9 g/dL
• Total bilirubin =< 1.5 times institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]) and alanine aminotransferase (ALT) (serum glutamic pyruvate transaminase[SGPT]) =< 3 times institutional ULN (=< 5 times if liver function test [LFT] elevations due to known liver metastases)
• Creatinine =< 1.5 X ULN OR creatinine clearance >= 60 mL/min/1.73 m^2 for patients with creatinine levels > 1.5 x ULN
• Patients with central nervous system (CNS) metastases or a history of CNS metastases are ineligible
• Patients cannot have had prior chemotherapy or biologic therapy for SCLC (phase I and II) or large cell neuroendocrine NSCLC (phase I only), or small cell carcinoma of unknown primary or extrapulmonary origin (phase I only)
• Patients receiving prior radiation cannot register within 7 days after completion of radiation, and must have resolved adverse events attributed to radiation to =< grade 1; no previous irradiation to the only site of measurable or evaluable disease, unless that site had subsequent evidence of progression
• Patients may not be receiving any other investigational agents while on study
• Patients must NOT have active seizure(s) or history of seizure(s)
• Patients must NOT have history of allergic reactions attributed to compounds of similar chemical or biologic composition to veliparib or other agents used in the study
• Patients must NOT have uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, uncontrolled cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Human immunodeficiency virus (HIV)-positive patients on combination antiretroviral therapy are ineligible
• Patient must be able to swallow pills