Abstract
BACKGROUND
The objective of this study was to investigate the efficacy and safety of alemtuzumab, the humanized antiβCD52 monoclonal antibody, in patients with Bβcell chronic lymphocytic leukemia and residual disease after chemotherapy.
METHODS
Fortyβone patients received alemtuzumab 3 times weekly for 4 weeks. The first 24 patients received 10 mg per dose, and the next 17 patients received 30 mg. All patients received infection prophylaxis during therapy and for 2 months after treatment.
RESULTS
The overall response rate was 46%, including 39% of patients who received the 10 mg dose and responded versus 56% of the patients who received the 30 mg dose. The major reason for failure to respond was the presence of adenopathy. Residual bone marrow disease cleared in most patients, and 11 of 29 patients (38%) achieved a molecular disease remission. The median time to disease progression had not been reached in responders with a median followβup of 18 months. Six patients remained in disease remission between 24β38 months after therapy. Infusionβrelated events were common with the initial doses, but all such events were NCI Common Toxicity Criteria Grade 1β2. Infections were reported to occur in 15 patients (37%), and 9 of these infections were reactivation of cytomegalovirus. Three patients developed EpsteinβBarr virus positive, large cell lymphoma. Two patients had spontaneous resolution of the lymphoma and, in one patient, the lymphoma resolved after treatment with cidofovir and immunoglobulin.
CONCLUSIONS
Alemtuzumab produced significant responses in patients with residual disease after chemotherapy. Bone marrow disease was eradicated more frequently than lymph node disease, and molecular disease remissions were achieved. A randomized trial comparing alemtuzumab with observation after chemotherapy is indicated. Cancer 2003;98:2657β63. Β© 2003 American Cancer Society.