DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed small cell carcinoma of the lung

  • Small cell and variant histology allowed
  • No mixed tumors (small and large cell)
  • No neuroendocrine tumors of the lung

• Must have received at least 4 courses of first-line combination chemotherapy as part of an induction regimen

  • No prior change in regimen due to disease progression

• Must have achieved a radiologically confirmed (i.e., CT scan, chest x-ray, or bone scan) complete response (CR) or partial response (PR) after prior chemotherapy with or without radiotherapy AND meets 1 of the following criteria:

  • No more than 28 days since prior chemotherapy
  • At least 7 and no more than 14 days since prior radiotherapy if administered after completion of prior chemotherapy*

• No CNS metastases

  • Asymptomatic patients with CNS metastases who received prior therapeutic cranial irradiation and are on stable, decreasing, or no steroids are eligible
  • No symptomatic lesions or evidence of necrosis or bleeding NOTE: *Randomization may take place up to 21 days after prior radiotherapy in the instance of severe esophagitis that precludes administration of oral medications

PATIENT CHARACTERISTICS:

Age

• Over 16

Performance status

• ECOG 0-2

Life expectancy

• At least 12 weeks

Hematopoietic

• Absolute granulocyte count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• No history of bleeding diathesis

Hepatic

• Bilirubin less than 1.5 times upper limit of normal (ULN)
• ALT less than 2.5 times ULN

Renal

• Creatinine less than 1.5 times ULN
• Calcium normal

Cardiovascular

• No prior ventricular arrhythmia that was symptomatic or required treatment (CTC grade 3), including any of the following:

  • Multifocal premature ventricular contractions
  • Bigeminy
  • Trigeminy
  • Ventricular tachycardia
• No prior QT prolongation with any medication
• No congenital long QT syndrome
• No QT and QTc (with Bazett's correction) that is unmeasurable or is 460 msec or higher on screening ECG
• No significant cardiac event, including symptomatic heart failure or angina, within the past 3 months or any cardiac disease that increases the risk for ventricular arrhythmia
• No ongoing chronic atrial fibrillation
• LVEF at least 45% by MUGA for patients with significant cardiac history (myocardial infarction, severe hypertension, or arrhythmia) OR who received prior doxorubicin greater than 450 mg/m^2

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• Potassium normal
• Magnesium normal
• No serious active infection
• No recent major bleeding
• No other concurrent serious underlying medical condition that would preclude study participation
• Willing and able to complete quality of life questionnaires in English or French

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior signal transduction inhibitors
• No prior angiogenesis inhibitors
• No concurrent anticancer biologic therapy or immunotherapy

Chemotherapy

• See Disease Characteristics
• Recovered from prior chemotherapy

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• Recovered from prior radiotherapy

• No concurrent anticancer radiotherapy

  • Concurrent low-dose, nonmyelosuppressive palliative radiotherapy allowed

Surgery

• More than 2 weeks since prior major surgery

Other

• More than 4 weeks since prior investigational drugs
• No prior epidermal growth factor receptor inhibitors
• No prior vascular endothelial growth factor receptor inhibitors

• No concurrent CYP3A4 inhibitors or inducers, including any of the following:

  • Verapamil
  • Rifampin
  • Phenytoin
  • Carbamazepine
  • Barbiturates
  • Hypericum perforatum (St. John's wort)
• No concurrent medication that affects QT/QTc and/or induces torsades de pointes
• No other concurrent anticancer cytotoxic therapy
• No other concurrent investigational drugs during and for 30 days after study participation

• No concurrent oral bisphosphonates (e.g., clodronate)

  • Concurrent IV bisphosphonates allowed
• No concurrent 5HT_3 antagonists