Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed renal cell carcinoma (RCC)

- Advanced or unresectable RCC

- Measurable disease, defined as at least one lesion that can be accurately measured in
at least one dimension (longest diameter to be recorded) as ≥ 20 mm with conventional
techniques OR ≥ 10 mm with spiral CT scan

- No brain metastases

- Brain metastases that have been treated with either radiotherapy or surgery and
remain asymptomatic, with no active brain metastases, as shown by CT scan or
MRI, for ≥ 6 months are allowed

PATIENT CHARACTERISTICS:

- ECOG performance status (PS) 0-1 OR Karnofsky PS 70-100%

- Absolute neutrophil count ≥ 1,500/mm³

- Platelet count ≥ 100,000/mm³

- Creatinine ≤ 2.0 mg/dL

- Bilirubin ≤ 1.5 mg/dL

- AST and ALT ≤ 2.5 times upper limit of normal (ULN) (5 times ULN if hepatic
metastases are present)

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No other malignancies within the past 5 years, except for treated basal cell or
squamous cell carcinoma of the skin, carcinoma in situ of the cervix or breast,
localized prostate cancer, or superficial bladder cancer

- No history of allergic reactions attributed to compounds of similar chemical or
biological composition to lenalidomide or thalidomide

- No uncontrolled intercurrent illness including, but not limited to, any of the
following:

- Ongoing or active infection

- Symptomatic congestive heart failure

- Unstable angina pectoris

- Cardiac arrhythmia

- Psychiatric illness or social situation that would limit study compliance

- No hepatitis A, B, or C positivity

- No HIV positivity

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- No more than 1 prior systemic therapy for RCC (e.g., chemotherapy, hormonal therapy,
immunotherapy)

- At least 4 weeks since prior surgery, radiotherapy, hormonal therapy, chemotherapy,
or immunotherapy and recovered

- No prior lenalidomide

- No other concurrent anticancer agents or treatments

- No other concurrent investigational agents

- No concurrent sargramostim (GM-CSF), radiotherapy, or thalidomide