B-cell chronic lymphocytic leukemia (B-CLL) is conventionally incurable lymphoproliferative disease. Modern chemotherapy can effectively affect disease course and survival in only small proportion of patients. Monoclonal antibodies represent new category of anticancer drugs that mediate cell death utilizing several mechanism different from classical chemotherapy including direct pro-apoptotic effect, complement – mediated cytotoxicity and antibodydependent cellular cytotoxicity. Alemtuzumab (anti-CD52) and rituximab (anti-CD20) are currently widely used monoclonal antibodies in B-CLL. Alemtuzumab is approved for the treatment of relapsing and resistant patients and recent pilot reports demonstrate its activity in eliminating the minimal residual disease. Rituximab have synergistic anti-leukemic effect with fludarabine and cyclophosphamide and this combination will probably become gold standard in the first-line treatment of B-CLL.

        Key words: B-cell chronic lymphocytic leukemia, monoclonal antibodies, rituximab, alemtuzumab, residual disease