The goal of this study is to determine the progression-free survival rate in patients with extensive-stage small cell lung cancer who had achieved complete response, partial response, or stable disease with their previous platinum chemotherapy regimen, such as cisplatin or carboplatin in combination with etoposide or irinotecan. In addition, the safety and effectiveness of sunitinib will also be evaluated.

Despite a high initial response rate, all patients with extensive-stage small cell lung cancer treated with standard chemotherapy will develop disease progression, usually within one year of initial treatment. Therefore, prolonging progression-free survival in this disease is meaningful for clinical trials exploring agents such as sunitinib. Sunitinib is a drug that inhibits the biological pathway responsible for the growth and spread of cancer cells. For this reason, we believe that sunitinib maintenance therapy will delay or prevent recurrence and prolong survival.

The goal of this study is to determine the progression-free survival rate in patients with extensive-stage small cell lung cancer who had achieved complete response, partial response, or stable disease with their previous platinum chemotherapy regimen, such as cisplatin or carboplatin in combination with etoposide or irinotecan. In addition, the safety and effectiveness of sunitinib will also be evaluated.

Inclusion Criteria:

• Histologically or cytologically confirmed extensive-stage SCLC. Extensive-stage is defined as disease that extends beyond one hemithorax and regional lymph nodes (ipsilateral or contralateral hilar, mediastinal, or supraclavicular lymph nodes), or with cytologically positive pleural effusion.
• Patients who have completed platinum-based chemotherapy and demonstrated a complete response, partial response, or stable disease can be registered on the trial. A maximum of 4 cycles of induction chemotherapy is allowed. Patients must begin therapy within 28-42 days after day 1 of the 4th cycle of induction therapy and within 28 days of scans demonstrating stable disease or better. Prior palliative radiation therapy will be allowed as long as radiation was completed at least 1 week before starting protocol therapy.
• Resolution of all acute toxic effects of prior chemotherapy or radiotherapy or surgical procedures to NCI CTCAE Version 3.0 grade 1.
• Age * 18 years with Southwest Oncology Group (SWOG) performance status of 0,1 or 2 (Appendix 2).
• Adequate organ function as evidenced by the laboratory values listed in the protocol

Exclusion Criteria:

• Symptomatic or untreated brain or leptomeningeal metastases. Treated patients should be neurologically stable for at least 2 weeks after completion of appropriate therapy without the use of steroids. Patients currently on steroids are ineligible.
• More than 4 cycles of induction chemotherapy. Patients will be eligible for if they have completed at least 2 cycles of platinum-based induction chemotherapy and they have exhibited a complete or partial response to therapy. Patients who have received less than 4 cycles of induction chemotherapy and have less than a partial response will not be eligible.
• NCI CTCAE grade 3 hemorrhage within 4 weeks of starting the study treatment.
• History of gross hemoptysis due to lung cancer.
• Previous or concurrent malignancies, with the exception of adequately treated squamous cell or basal cell carcinoma of the skin, in situ carcinoma of the cervix, or any other malignancy treated and in clinical remission for more than 3 years.
• Major surgery or within 4 weeks of starting study treatment.
• Any history of the following within the 6 months prior to study drug administration: myocardial infarction, severe/unstable angina, coronary/peripheral artery bypass graft, symptomatic congestive heart failure (CHF), cerebrovascular accident or transient ischemic attack, or pulmonary embolism.
• Ongoing cardiac dysrhythmias
• Hypertension that cannot be controlled by medications
• Pre-existing thyroid abnormality with thyroid function that cannot be maintained in the normal range with medication.
• Therapeutic anticoagulation with warfarin or heparin.
• Serious concomitant medical illness, including, but not limited to, uncontrolled angina, myocardial infarction and/or stroke within 3 months, or HIV infection.
• Acute or chronic liver disease
• History of dementia, active psychiatric disorder or any other condition, considered by the treating physician to impair the patient's ability to take oral pills on a daily basis or comply with the protocol requirements.
• Pregnant or lactating females.
• Use of agents with proarrhythmic potential is not permitted during the study.

Lung cancer patients who are greater than or equal to 18 years old, who have had a response or maintained stable disease after undergoing no more that 4 cycles with platinum with etoposide chemotherapy

Participants were evaluated for toxicity if they received sunitinib maintenance therapy (at least one dose) from onset of this therapy until the participant ended participation.

Treatment was held for Participants with grade 4 hematologic or grade 3-4 non-hematologic toxicities until resolution to grade 2 or less. Treatment was then restarted at a dose of 3.75 mg. A second dose reduction to 25 mg was permitted. Treatment discontinued for a third dose reduction or life-threatening, irreversible or unacceptable toxicity.

The trial was to be terminated at stage 1 if less than, or equal to, 8 patients were progression free at 4 months. The PFS rate did not reach the threshold required for study continuation and, therefore, the study was discontinued early.