Rituximab therapy of patients with B-cell chronic lymphocytic leukemia.
Rituximab (IDEC-C2B8) is a chimeric antibody that binds to the B-cell surface antigen CD20. Rituximab has significant activity in follicular non-Hodgkin lymphomas. Much less is known about the effects in chronic lymphocytic leukemia (CLL). We have initiated a phase II trial to evaluate the efficacy and safety of rituximab in patients with CD20+ pretreated CLL. To avoid the rituximab-associated toxicity, we restricted the tumor cell load, as measured by the number of circulating lymphocytes and the spleen size, in the first 2 cohorts of patients included in the study. Patients received 4 intravenous infusions of 375 mg/m2 once a week over a period of 1 month. Of the 28 patients evaluable for response, 7 patients showed a partial remission (National Cancer Institute criteria) lasting for a median of 20 weeks, with 1 patient still in remission after 71 weeks. Based on lymphocyte counts only, we found at least a 50% reduction of lymphocyte counts lasting for at least 4 weeks in 13 (45%) of 29 patients. Fifteen patients from 3 institutions were monitored for the immunophenotype profile of lymphocyte subsets. The number of CD5+CD20+ cells decreased significantly and remained low until day 28 after therapy. T-cell counts were not affected. With the exception of one rituximab-related death, adverse events in the remaining patients were mild. The results suggest that rituximab has clinical activity in pretreated patients with B-CLL. Toxicity is tolerable. Response duration after withdrawal of rituximab is rather short. Therefore, other modes of application and the combination with other agents need to be tested.
Huhn
D
D
Department of Medicine/Hematology and Oncology, Charité Campus Virchow-Klinikum, Humboldt Universität Berlin, Germany. dieter.parczany@charite.de
von Schilling
C
C
Wilhelm
M
M
Ho
A D
AD
Hallek
M
M
Kuse
R
R
Knauf
W
W
Riedel
U
U
Hinke
A
A
Srock
S
S
Serke
S
S
Peschel
C
C
Emmerich
B
B
D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20 / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000139:chemically induced; D018450:Disease Progression; D005260:Female; D005334:Fever / Q000139:chemically induced; D006801:Humans; D016130:Immunophenotyping; D007167:Immunotherapy; D007262:Infusions, Intravenous; D015993:Life Tables; D018655:Lymphocyte Count; D008224:Lymphoma, Follicular / Q000276:immunology / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000139:chemically induced; D012074:Remission Induction; D000069283:Rituximab; D016019:Survival Analysis
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D000069283:Rituximab