Humanized CD52 monoclonal antibody Campath-1H as first-line treatment in chronic lymphocytic leukaemia.

The humanized CD52 monoclonal antibody Campath-1H was used as first-line therapy in nine patients with progressive chronic lymphocytic leukaemia (CLL). Intravenous (n = 5) or subcutaneous (n = 4) injections (up to 30 mg/inj.) were given three times a week for a maximum of 18 weeks. Three patients achieved a complete remission (CR) and five patients a partial remission (PR) (response rate 89%). CLL cells were cleared from blood in all patients and from the bone marrow in seven patients. The response duration time was 8 + -24+ months. Adverse events were mild except for one patient who developed CMV pneumonitis. All patients developed lymphocytopenia (B and T cells) but other haematological toxicities were negligible. Campath-1H is a highly effective and well-tolerated agent in patients with previously untreated CLL and further studies are warranted.