RATIONALE: Monoclonal antibodies, such as alemtuzumab, can block cancer growth in different ways. Some block the ability of cancer cells to grow and spread. Others find cancer cells and help kill them or carry cancer-killing substances to them.

PURPOSE: This phase II trial is studying how well giving alemtuzumab by injection works in treating patients with advanced chronic lymphocytic leukemia that did not respond to previous fludarabine.

OBJECTIVES:

• Compare the safety and efficacy of subcutaneous alemtuzumab vs intravenous alemtuzumab in patients with fludarabine-refractory advanced chronic lymphocytic leukemia.
• Determine the response in patients with high-risk genetic abnormalities (unmutated immunoglobulin variable heavy-chain [IgVH] status, del [17p], del [11q]) treated with subcutaneous alemtuzumab after progression on fludarabine.

OUTLINE: This is a multicenter study.

Patients receive alemtuzumab IV once, followed 1 week later by alemtuzumab subcutaneously once weekly for up to 12 weeks.

PROJECTED ACCRUAL: A total of 100 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Confirmed diagnosis of previously treated advanced chronic lymphocytic leukemia (CLL)

  • Fludarabine-refractory disease
  • Requires treatment

PATIENT CHARACTERISTICS:

• Life expectancy more than 6 months
• ECOG 0-2
• No severe organ dysfunction
• No other concomitant or previous neoplasms
• No autoimmune hemolytic anemia or thrombocytopenia

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Up to 5 prior chemotherapy regimens allowed