R-(-)-Gossypol Acetic Acid in Treating Patients With Recurrent Extensive-Stage Small Cell Lung Cancer

Inclusion Criteria: * Histologically or cytologically confirmed small cell lung cancer * Extensive stage disease * Recurrent disease * Measurable disease * Chemotherapy-sensitive disease, defined as: * No progression during first-line chemotherapy * No disease recurrence \< 2 months after completion of first-line chemotherapy * Must have received prior platinum-based chemotherapy * No symptomatic or progressive brain metastases * Patients with previously treated brain metastases who are clinically and radiographically stable or improved and have been off steroids ≥ 14 days are eligible * ECOG performance status 0-2 * Life expectancy \> 12 weeks * Leukocytes ≥ 3,000/μL * ANC ≥ 1,500/μL * Platelet count ≥ 100,000/μL * Total bilirubin \< 1.5 mg/dL * AST and ALT ≤ 2.5 times upper limit of normal * Serum creatinine ≤ 1.5 mg/dL OR creatinine clearance ≥ 60 mL/min * Hemoglobin \> 8 g/dL * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception before, during, and for 30 days after completion of study therapy * Able to take oral medications on a regular basis * Willing to provide blood samples for mandatory correlative studies * No condition that impairs the ability to swallow and retain R-(-)-gossypol tablets, including the following: * Gastrointestinal tract disease resulting in an inability to take oral medication or a requirement for IV alimentation * Active peptic ulcer disease * No malabsorption syndrome or disease significantly affecting gastrointestinal function * No ulcerative colitis, inflammatory bowel disease, or a partial or complete small bowel obstruction * No uncontrolled concurrent illness including, but not limited to, any of the following: * Ongoing or active infection * Symptomatic congestive heart failure * Unstable angina pectoris * Cardiac arrhythmia * Psychiatric illness or social situations that would limit compliance with study requirements * No symptomatic hypercalcemia \> grade 2 * No requirement for routine use of hematopoietic growth factors (including G-CSF, GM-CSF, or IL-11) or platelet transfusions to maintain ANC or platelet counts * No history of allergic reactions attributed to compounds of similar chemical or biologic composition to R-(-)-gossypol * No HIV positivity * Recovered from all prior therapy, including prior surgical procedures * No prior surgical procedures affecting absorption * No prior resection of the stomach or small bowel * No more than one prior chemotherapy regimen * No prior racemic gossypol or R-(-)-gossypol * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin C) * At least 4 weeks since prior radiotherapy, hormonal agents, or biologic response modifiers * At least 4 weeks since prior and no concurrent investigational agents or devices * No concurrent prophylactic hematopoietic growth factors (including filgrastim \[G-CSF\], sargramostim \[GM-CSF\], or interleukin-11 \[IL-11\]) during course one * No concurrent combination antiretroviral therapy for HIV-positive patients