Low dose alemtuzumab in patients with fludarabine-refractory chronic lymphocytic leukemia

Alemtuzumab has been shown to be effective in poor-prognosis chronic lymphocytic leukemia (CLL); treatment, however, has been associated with significant toxicity. With the aim of seeking better tolerability, we treated 39 patients with fludarabine-refractory CLL subcutaneous alemtuzumab 10 mg three times a week, for 18 weeks. In 18 randomly selected patients, after obtaining lymphocyte count reduction by 1 Log, the antibody was administered once weekly at the dose of 30 mg. Overall response rate was 44%, including 8% complete remissions. Median overall survival and progression free survival were 29.1 and 10.3 months, respectively. Treatment was well tolerated, severe non-CMV infection occurred in 7% of the patients. CMV reactivation was detected in 27% of the patients, with only one case of CMV disease. No deaths occurred during therapy. In conclusion, low-dose alemtuzumab shows a promising safety profile coupled with satisfactory effectiveness in this category of poor prognosis CLL patients.