Combination therapy with irinotecan (CPT-11), mitoxantrone, and dexamethasone in relapsed or refractory non-Hodgkin's lymphoma: a pilot study.

Irinotecan hydrochloride (CPT-11) is a topoisomerase I inhibitor with a broad antitumor spectrum. In the present study, we combined CPT-1 and mitoxantrone (MIT) with dexamethasone because the effect elicited by this combination was additive or better in a preclinical study. This study was performed to determine the efficacy and toxicities of this combination. Thirty-two patients were evaluable. CPT-11 combined with MIT achieved a complete remission in 11 patients (34.4%) and a partial remission in 9 patients (28.1%). The median follow-up period was 20 months. The 4-year survival rate was 31.8% (95% confidence intervals: 11.2-64.6%), and the 3-year event-free survival rate was 16.1% (95% confidence intervals: 8.2-24.6%). Grade 3 or higher hematological toxicity included neutropenia in 96.9%, anemia in 3.1%, and thrombocytopenia in 15.6%. Grades 1, 2, and 3 nonhematological toxicity included diarrhea in one patient, nausea/vomiting in five patients, and hematuria in one patient, respectively. CPT-11 combined with MIT was safe even for elderly patients and was effective even in patients who had received pretreatment with doxorubicin. In addition, this regimen can be used on an outpatient basis. This combination should be tested further to determine the optimum doses and administration schedule.