Quantitative molecular evaluation of minimal residual disease in patients with chronic lymphocytic leukemia: efficacy of in vivo purging by alemtuzumab (Campath-1H).
Although novel therapies for chronic lymphocytic leukemia have resulted in higher hematologic response rates, the complete eradication of disease rarely occurs. Alemtuzumab (Campath-1H) seems to be extremely effective in this role in pretreated patients. The authors used a molecular semiquantitative polymerase chain reaction (PCR) method to assess the ability of alemtuzumab to induce PCR negativity in eight patients pretreated with fludarabine. IgH rearrangement was coamplified with a housekeeping gene and fluorescent PCR products were analyzed on a DNA automatic sequencer. Each patient was evaluated at diagnosis, after fludarabine, and after Campath-1H. The median interval between the last therapy course with fludarabine and the start of Campath-1H was 14 weeks. Patients received subcutaneous doses up to 10 mg, three times a week, for 12 weeks, with a median dose of 190 mg. After six cycles with fludarabine, only one patient (12.5%) achieved molecular remission, and in three other patients IgH levels decreased by 0.5 to 1 log. At the beginning of Campath-1H administration, all patients were PCR positive, including the one previously found to be negative. At the end of treatment, five patients achieved molecular remission (62.5%), four of them within 1 month after the end of therapy. Seventy-two percent of responses, with 43% of complete responses, were documented on bone marrow smears. A significant reduction of lymph node and spleen diameters was noted in 50% and 33% of patients, respectively. Four patients showed grade 2 skin reaction at the site of the subcutaneous injection and grade 1 or 2 fever. Two patients developed neutropenia (grade 2 and 3) and two hemolytic episodes. Three patients showed cytomegalovirus and one herpes zoster and Epstein-Barr virus reactivation. These results show that Campath-1H represents an efficacious in vivo purging tool with a safe profile.
Department of Oncology, Transplant and Advances in Medicine, Section of Hematology, University of Pisa, Pisa, Italy.
Sara
S
Galimberti
Giulia
G
Cervetti
Nadia
N
Cecconi
Rita
R
Fazzi
Simone
S
Pacini
Francesca
F
Guerrini
Chiara
C
Manetti
Francesco
F
Caracciolo
Mario
M
Petrini
D000328:Adult; D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000009:adverse effects / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy*; D008297:Male; D018365:Neoplasm, Residual; D016133:Polymerase Chain Reaction; D016896:Treatment Outcome; D014740:Vidarabine / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D000074323:Alemtuzumab; D014740:Vidarabine; C024352:fludarabine