[An early phase II study of CPT-11 (irinotecan hydrochloride) in patients with hematological malignancies]

An early phase II study of CPT-11 (irinotecan hydrochloride) was conducted in patients with hematological malignancies by 4 administration regimens in a cooperative study involving 13 institutes in Japan. The overall response rate was 23% (7/30) for non-Hodgkin's lymphoma, 33% (1/3) for Hodgkin's disease, 18% (2/11) for acute lymphoblastic leukemia and 7% (1/15) for acute myelogenous leukemia. One PR was also obtained in a patient with chronic myelogenous leukemia. Among responders, 6 relapsed and refractory malignant lymphomas (ML) and 2 relapsed and refractory acute leukemias (AL) were involved. The response rates in ML with the regimens B (40 mg/m2 for 5 days every 3-4 weeks) and C (40 mg/m2 for 3 days every weeks) were 31% (5/16) and 33% (3/9), respectively. The other regimens (regimen A, 200 mg/m2 once a day every 3-4 weeks and regimen D) resulted in no response. Responses in AL were only observed in regimen D (20 mg/m2 twice a day for 7 days every 3-4 weeks). Major toxicities were leukopenia (91%), nausea/vomiting (74%), diarrhea (73%) and anorexia (64%). The incidence of severe gastrointestinal symptoms was higher in regimen B than regimen C. Further studies are warranted to confirm the effectiveness and safety of CPT-11 against ML and AL. The recommended administration schedule was regimen C for ML and regimen D for AL.