CAMPATH-1H is a human immunoglobulin G1 (IgG1) anti-CD52 monoclonal antibody (MAb) that binds to nearly all B-cell and T-cell lymphomas. We report here the results of a multicenter phase II trial of CAMPATH-1H in patients with advanced, low-grade non-Hodgkin's lymphoma (NHL) who were previously treated with chemotherapy.

Fifty patients who had relapsed (n=25) after or were resistant (n = 25) to chemotherapy were treated with CAMPATH-1H 30 mg administered as a 2-hour intravenous (i.v.) infusion three times weekly for a maximum period of 12 weeks.

Six patients (14%) with B-cell lymphomas achieved a partial remission (PR). Patients with mycosis fungoides appeared to respond more frequently (50%; four of eight patients, which included two complete remissions [CRs]). Lymphoma cells were rapidly eliminated from blood in 16 of 17 patients (94%). CR in the bone marrow was obtained in 32% of the patients. Lymphoma skin lesions disappeared completely in four of 10 patients and partial regression was obtained in three patients. Lymphadenopathy and splenomegaly were normalized in only 5% and 15% of patients, respectively. Lymphopenia (< 0.5 x 10(9)/L) occurred in all patients. World Health Organization (WHO) grade IV neutropenia occurred in 14 patients (28%). Opportunistic infections were diagnosed in seven patients and nine patients had bacterial septicemia. Death related to infectious complications occurred in three patients.

CAMPATH-1H had a significant but limited activity in patients with advanced, heavily pretreated NHL. The most pronounced effects were noted in the blood and bone marrow and in patients with mycosis fungoides. The risk for serious infectious complications needs to be considered for severely ill patients who are evaluated for CAMPATH-1H treatment.