• Number of patients achieving a CR, PR, or SD [ Designated as safety issue: No ]
• Number, type, and severity of adverse events [ Designated as safety issue: Yes ]
• Time to progression [ Designated as safety issue: No ]

• Number of patients achieving a CR, PR, or SD
• Number, type, and severity of adverse events
• Time to progression

RATIONALE: Biological therapies such as lenalidomide use different ways to stimulate the immune system and stop cancer cells from growing. Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. Combining lenalidomide with rituximab may kill more cancer cells.

PURPOSE: This phase II trial is studying the how well giving lenalidomide with or without rituximab works in treating patients with relapsed or refractory chronic lymphocytic leukemia.

OBJECTIVES:

Primary

• Determine the best cytostatic response rate (including complete response, partial response, or stable disease) in patients with relapsed or refractory chronic lymphocytic leukemia treated with lenalidomide (CC-5013).

Secondary

• Determine the cytostatic response rate in patients who progress on CC-5013 and are then treated with CC-5013 and rituximab.
• Determine the safety of these regimens in these patients.
• Determine time to progression in patients treated with these regimens.

OUTLINE: This is an open-label, non-randomized, pilot study.

Patients receive oral lenalidomide (CC-5013) once daily on days 1-21. Treatment repeats every 28 days for up to 12 courses in the absence of disease progression or unacceptable toxicity. Patients who achieve complete response (CR) receive 2 additional courses beyond CR.

Patients with disease progression receive oral CC-5013 once daily on days 1-21 and rituximab IV on days 1, 8, and 15 during the first treatment course and on days 1 and 15 of all subsequent courses. Treatment repeats every 28 days for up to 6 courses in the absence of further disease progression. Patients who achieve CR receive 2 additional courses beyond CR.

Patients are followed at 1 month and then every 3 months thereafter.

PROJECTED ACCRUAL: A total of 45 patients will be accrued for this study within 1.5 years.

• Biological: rituximab
• Drug: lenalidomide

DISEASE CHARACTERISTICS:

• Diagnosis of chronic lymphocytic leukemia (CLL) by flow cytometry

  • Relapsed or refractory disease

• Measurable disease, defined by 1 of the following criteria:

  • Absolute lymphocyte count ≥ 5,000/mm^3
  • Measurable lymphadenopathy or organomegaly
• Received ≥ 1 prior therapy for CLL

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• See Disease Characteristics
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 30,000/mm^3

Hepatic

• Bilirubin ≤ 1.5 mg/dL
• AST and ALT ≤ 2 times upper limit of normal (ULN) (5 times ULN if hepatic metastases are present)

Renal

• Creatinine ≤ 1.5 mg/dL

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective double-method (including barrier) contraception during and for 3 months after study participation
• No known hypersensitivity to thalidomide
• No erythema nodosum characterized by a desquamating rash after prior thalidomide or similar drug administration
• No known anaphylaxis or immunoglobulin E-mediated hypersensitivity to murine proteins
• No serious medical condition or laboratory abnormality that would preclude study participation
• No psychiatric illness that would preclude giving informed consent

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior lenalidomide (CC-5013)
• No concurrent thalidomide

Chemotherapy

• Not specified

Endocrine therapy

• Not specified

Radiotherapy

• No concurrent radiotherapy

Surgery

• Not specified

Other

• At least 4 weeks since prior therapy for CLL
• At least 28 days since prior experimental drug or therapy
• No other concurrent anticancer therapies
• No other concurrent investigational agents