In the treatment of hematological malignancies, the significance of achieving molecular complete remissions rather than a clinical complete remission has become increasingly apparent, as relapse is considered to be related to the presence and extent of residual, persistent malignant cells. Progress in the use of alemtuzumab (MabCampath™) to eradicate minimal residual disease in chronic lymphocytic leukemia (CLL) has positive implications for patients, particularly prior to stem cell transplantation. Another beneficial aspect of monoclonal antibody therapy under active investigation is the ability of alemtuzumab to repeatedly produce or maintain responses. Subcutaneous administration of alemtuzumab is now emerging as a key advancement in the treatment of CLL. A phase II trial of subcutaneous alemtuzumab has demonstrated an 87% response rate in 38 previously untreated patients, with a reduction in intravenous administration-related rigors, as well as the elimination of nausea, dyspnea, diarrhea, and hypotension, frequently seen following intravenous administration of alemtuzumab. This trial demonstrates the advantages for safety, cost, flexibility, and convenience offered by subcutaneous administration of alemtuzumab. Finally, encouraging results with the combination of alemtuzumab and fludarabine, which demonstrate eradication of malignant cells in patients who are resistant to either agent alone, open the way for such combinations to produce durable responses even in refractory disease.