Inclusion Criteria:

1. Cytologically and/or histologically confirmed small-cell lung cancer with
extensive-stage disease.

2. Measurable or evaluable disease.

3. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1.

4. Adequate bone marrow function, as defined by: absolute neutrophil count (ANC)
>1,500/µL; platelets >100,000/µL; hemoglobin >=9.0 g/dL.

5. Normal organ function, defined as follows: aspartate aminotransferase (AST) and
alanine aminotransferase (ALT) <=2.5 × the upper limit of normal (ULN), or AST and
ALT <=5 × the ULN if liver function abnormalities are due to underlying malignancy;
total serum bilirubin <=1.5 × the ULN; serum creatinine <=1.5 × the ULN.

6. Resolution of all acute toxic effects of prior therapy or surgical procedures to
grade <=1.

7. Women of childbearing potential and men with partners of childbearing potential must
agree to use a form of birth control that is acceptable to their physician to prevent
pregnancy during treatment.

8. Patients must be informed of the investigational nature of this study and sign an
informed consent form.

9. Patients who have treated brain metastases >=4 weeks out (with surgery and/or
radiation therapy) and who have no evidence of central nervous system (CNS)
progression. Steroid use should be discontinued before study treatment begins.

Exclusion Criteria:

1. Patients who are pregnant or breastfeeding.

2. Patients may not have received other agents (either investigational or marketed)
which act by anti-angiogenic mechanisms. Angiogenesis inhibitors include (but are
not limited to): thalidomide, sorafenib, bevacizumab.

3. Patients who have had previous chemotherapy or radiation therapy for extensive-stage
disease will be excluded. Palliative radiation (e.g., for bone disease) or radiation
for cranial metastasis is acceptable if the patient has recovered from any adverse
effects.

4. Previous treatment with sunitinib.

5. Myocardial infarction, severe or unstable angina, coronary/peripheral artery bypass
graft, congestive heart failure (CHF), cerebrovascular accident (including transient
ischemic attack), or pulmonary embolism within 6 months prior to study initiation.

6. Ongoing cardiac dysrhythmias of National Cancer Institute (NCI) Common Terminology
Criteria for Adverse Events (CTCAE) grade >=2, atrial fibrillation of any grade, or
prolongation of the QTc interval to >450 msec (for males) or >470 msec (for females).

7. Uncontrolled hypertension (i.e., blood pressure >150 mm Hg that cannot be controlled
with standard anti-hypertensive agents).

8. Active brain metastasis. (Patients who had brain metastases treated with radiation
or surgery and have no evidence of progressive brain metastases at least 4 weeks
later are eligible).

9. Patients who have had major surgical procedure, open biopsy, or significant traumatic
injury with 28 days (4 weeks) of study initiation.