RATIONALE: Sorafenib may stop the growth of small cell lung cancer by blocking blood flow to the tumor and by blocking some of the enzymes needed for cell growth.

PURPOSE: This phase II trial is studying how well sorafenib works in treating patients with extensive stage small cell lung cancer.

• Response rate every 8 weeks during treatment
• Overall survival every 8 weeks during treatment
• Toxicity every 8 weeks during treatment

• Correlative markers related to response during courses 1 and 2

OBJECTIVES:

Primary

• Determine the efficacy of sorafenib, in terms of response rate (confirmed and unconfirmed, complete and partial), in patients with platinum-refractory or platinum-sensitive small cell lung cancer.

Secondary

• Determine the qualitative and quantitative toxic effects of this drug in these patients.
• Determine the overall survival of patients treated with this drug.

OUTLINE: This is a multicenter study. Patients are stratified according to platinum sensitivity status (platinum sensitive vs platinum refractory).

Patients receive oral sorafenib twice daily on days 1-28. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed every 3 months for up to 2 years from study entry.

PROJECTED ACCRUAL: A total of 40-80 patients (20-40 per stratum) will be accrued for this study within approximately 7-13 months.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed small cell lung cancer

  • Extensive stage with disease progression or recurrence after first-line therapy with either a cisplatin or carboplatin
  • Patients who received prior primary curative chemoradiotherapy for limited stage disease but who have experience subsequent recurrent disease* within the primary tumor site or previously irradiated field OR with distant metastases are eligible NOTE: *Patients with clinical evidence of recurrent disease do not require a confirmatory biopsy to be eligible

• Measurable disease by plain radiographs, CT scan, or MRI within the past 28 days

  • Measurable disease inside the prior radiotherapy field allowed provided the lesion is progressing by CT scan OR there is measurable disease outside of the prior radiotherapy field
  • Must have disease outside the area of prior surgical resection OR a new lesion must be present

• Must have received only 1 prior platinum-based regimen which contained either a cisplatin or carboplatin AND have the information necessary to be placed in 1 of the following groups:

  • Platinum-sensitive disease, defined as an initial response to platinum-based therapy and subsequent progression > 90 days after last platinum-based treatment
  • Platinum-refractory disease, defined as no response to platinum-based therapy, disease progression during platinum-based therapy, or disease progression ≤ 90 days after completion of platinum-based therapy
• Brain or leptomeningeal metastases by CT scan or MRI allowed provided the patient is asymptomatic, has no deficits on neurologic exam, and is not receiving corticosteroid therapy to control symptoms

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Zubrod 0-1

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• No bleeding diathesis

Hepatic

• Bilirubin ≤ 2 times upper limit of normal (ULN)
• Alkaline phosphatase ≤ 2 times ULN
• ALT or AST ≤ 2 times ULN
• PT OR INR AND PTT < 1.5 times ULN (except for patients on warfarin or heparin)

Renal

• Creatinine normal OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• No significant history of cardiac disease, including any of the following:

  • Uncontrolled hypertension
  • Unstable angina
  • Congestive heart failure
  • Myocardial infarction within the past 6 months
  • Cardiac ventricular arrhythmias requiring medication

Gastrointestinal

• No uncontrolled inflammatory gastrointestinal (GI) disease (e.g., Crohn's disease or ulcerative colitis)
• No intractable nausea or vomiting
• No GI tract disease resulting in an inability to take oral medication
• No malabsorption syndrome
• No requirement for IV alimentation
• Able to swallow pills and/or receive enteral medications via gastrostomy feeding tube

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• Willing to provide smoking history
• No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics
• At least 90 days since prior chemotherapy

Endocrine therapy

• See Disease Characteristics

• No concurrent systemic corticosteroids

  • Concurrent topical and/or inhaled steroids allowed

Radiotherapy

• See Disease Characteristics
• At least 3 weeks since prior radiotherapy and recovered
• No concurrent radiotherapy to measurable lesions

Surgery

• See Disease Characteristics
• At least 2 weeks since prior surgery (thoracic or other major surgery) and recovered
• No prior surgical procedures affecting absorption

Other

• Concurrent prophylactic or therapeutic anticoagulation treatment with warfarin or heparin allowed
• Concurrent nonenzyme-inducing anticonvulsants (e.g., Keppra^®) allowed for patients requiring anticonvulsants