Purpose: This multicenter phase II trial evaluated the efficacy and toxicity of the topoisomerase I inhibitor topotecan (TPT, 9-dimethylaminomethyl-10-hydroxycamptothecin) in patients with refractory or relapsing non-Hodgkin's lymphoma.
Patients and methods: Thirty-two patients with previously treated non-Hodgkin's lymphoma were accrued in this study from June 1992 to June 1997. Patients were eligible if they had measurable disease and had received two or less chemotherapy treatments for indolent lymphoma or no more than one treatment for aggressive lymphoma. Nineteen patients with aggressive lymphoma including seven with transformed indolent disease and 11 patients with indolent disease were treated. Two additional patients had both indolent and aggressive lymphoma in the bone marrow and lymph nodes at entrance into the study. Topotecan was administered as a 30-min infusion at a dose of 1.25 mg/m2 for five days and repeated at three week intervals.
Results: Thirty-two patients were evaluable for toxicity and 29 patients were evaluable for response. There were five objective responses including two complete remissions and three partial remissions (17%; CI 4-30%). Four of the five responders had aggressive disease and had been responsive to prior chemotherapy. The duration of remissions were short, lasting a median of 2 months (range 2-52 months). The major toxicity seen was myelosuppression with 28 of the 32 patients having grade three or greater granulocytopenia.
Conclusion: Topotecan given as a five day 30 min infusion at a dose of 1.25 mg/m2 has modest activity in previously treated non-Hodgkin's lymphoma as compared to other active agents.