Low accrual rate

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

PURPOSE: This phase II trial is studying the side effects and how well sorafenib works in treating patients with metastatic or unresectable kidney cancer.

OBJECTIVES:

Primary

• Evaluate the safety and toxicity of dose escalating sorafenib tosylate in patients with metastatic or unresectable renal cell carcinoma.

Secondary

• Determine tumor response in these patients.
• Determine time to progression in these patients.
• Determine overall survival of these patients.

Tertiary

• Collect data on angiogenesis inhibition induced by sorafenib tosylate.
• Collect data on immunomodulatory effects of sorafenib tosylate.

OUTLINE: This is an open-label study.

Patients receive oral sorafenib tosylate twice daily on days 1-28. Treatment repeats every 4 weeks for at least 2 courses in the absence of disease progression or unacceptable toxicity.

Patients receive escalating doses of sorafenib tosylate (in the absence of grade 3 or 4 dose-limiting toxicity) until a pre-determined dose is reached.

Blood and urine samples are collected at baseline and periodically during study for VEGF level determination. Blood samples are analyzed for T4/T8, NK, CD25+, and Fox p3 by flow cytometry. Tumor tissue blocks or unstained slides are obtained for chemistry staining of VEGF.

DISEASE CHARACTERISTICS:

Inclusion Criteria:

• Histologically or cytologically confirmed renal cell carcinoma (RCC)

  • Must have a component of conventional clear cell RCC
  • Predominant clear cell component ≥ 75%

• Metastatic or unresectable disease (Measurable disease is defined as any lesion that can be accurately measured in at least one dimension (longest diameter to be recorded) as ≥ 20 mm by conventional techniques or ≥ 10 mm by spiral CT scan or MRI)

• Measurable or nonmeasurable disease, includes any of the following:

  • Small lesions, longest diameter < 20 mm by conventional techniques or < 10 mm by spiral CT scan
  • Bone lesions
  • Leptomeningeal disease
  • Ascites
  • Pleural/pericardial effusion
  • Lymphangitis cutis/pulmonitis
  • Abdominal masses that are not confirmed and followed by imaging techniques
  • Cystic lesions
  • Irradiated lesions, unless progression is documented after radiotherapy

• Paraffin RCC tissue blocks or unstained slides must be obtained for future chemistry staining of VEGF

• Karnofsky performance status 70-100%

• Fertile patients must use effective contraception (hormonal and/or barrier method) during and for 3 months after completion of study treatment

• Granulocyte count ≥ 1,500/µL

• Platelet count ≥ 100,000/µL

• AST/ALT ≤ 2.5 times upper limit of normal (ULN)

• Alkaline phosphatase ≤ 2.5 times ULN

• Serum bilirubin ≤ 1.5 times ULN

• Protein ≤ 1+ by urinalysis

• Creatinine ≤ 1.5 times ULN

• At least 4 weeks since prior major surgery and/or radiotherapy and recovered

• Prior palliative radiotherapy for metastatic lesion(s) allowed provided there is at least one measurable and/or evaluable lesion(s) that has not been irradiated

• More than 4 weeks since prior and no other concurrent anticancer therapy

• Concurrent continuation of bisphosphonates allowed for bone metastases prophylaxis

Exclusion Criteria:

• Patients with true papillary, sarcomatoid features without any clear cell component, chromophobe, oncocytoma, collecting duct tumors, or transitional cell carcinoma are not eligible

• No evidence of CNS metastases

• No imaging (MRI or CT scan of the brain) abnormality indicative of CNS metastases within past 42 days

• Not pregnant or nursing (negative pregnancy test)

• No ongoing hemoptysis

• No cerebrovascular accident within the past 12 months

• No peripheral vascular disease with claudication while walking less than 1 block

• No history of clinically significant bleeding

• No deep venous thrombosis or pulmonary embolus within the past year

• No significant cardiovascular disease, defined as NYHA class II-IV congestive heart failure, angina pectoris requiring nitrate therapy, or myocardial infarction within the past 6 months

• No uncontrolled hypertension, defined as systolic BP > 160 mm Hg and/or diastolic BP > 90 mm Hg while on medication

• No preexisting thyroid abnormality whose thyroid function cannot be maintained in the normal range by medication

• No uncontrolled psychiatric disorder

• No delayed healing of wounds, ulcers, and/or bone fractures

• No currently active second malignancy except nonmelanoma skin cancer (patients are not considered to have a 'currently active' malignancy if they have completed anticancer therapy and are considered by their physician to be at less than 30% risk of relapse)

• No more than one prior systemic therapy for RCC

• No prior vascular endothelial growth factor receptor agents

• No concurrent systemic corticosteroid therapy (except replacement therapy for adrenal insufficiency)

  o Topical and/or inhaled steroids allowed

• No concurrent full-dose oral or parenteral anticoagulation

  o Low-dose warfarin (1 mg) for maintenance of catheter patency or daily prophylactic aspirin allowed

• No concurrent Hypericum perforatum (St. John's wort)

• No concurrent ketoconazole, itraconazole, ritonavir, rifampin, or products containing grapefruit juice

• No concurrent hormonal therapy or chemotherapy o Concurrent hormones administered for non-disease related conditions (e.g., insulin for diabetes) allowed

Adverse events and serious adverse events will be collected and reported on the forms beginning with the first dose of investigational product and continuing through the end of the study. (approximately 4 months)