Mitoxantrone, prednisone, pentostatin and bleomycin for patients with indolent non-Hodgkin's lymphoma relapsed or unresponsive to previous treatments. Results of a phase II study conducted by the Gruppo Italiano per lo Studio dei Linfomi (GISL)

Background. Taking into account the promising results achieved with purine analogs in combination regimens in patients with indolent NHL, we designed a phase II study aimed at assessing the efficacy of Pentostatin in combination with Mitoxantrone, Prednisone and Bleomycin (MiPPeB). Patients and Methods. Thirty patients (18 males and 12 females) with relapsed or unresponsive indolent NHL were treated with MiPPeB. The treatment consisted of Pentostatin 5 mg/m2, on day 1 and 8, Mitoxantrone 10 mg/m2, on day 1, Bleomycin 8 mg/m2, on day 8, Prednisone 100 mg, on day 1 and 8; cycles were administered at 3 week intervals for a maximum of 6 cycles. In 5 patients we investigated the pharmacokinetics of Pentostatin and 2’-deoxyadenosine. Results. A median of 5 cycles (range 2-6) was administered. Ten Complete Remissions (CRs) and 8 Partial Remissions (PRs) were observed, with an overall (CR+PR) response rate of 60%. The median response duration was 38 months (95% CI: 28 to 48 months). The actuarial 3-year relapse free survival for 10 patients in CR was 57%. The 3-year overall and failure free survival rates were 71% and 23%, respectively. Toxicity was mainly hematological with grade 3-4 neutropenia in 37% and grade 3 thrombocytopenia in 7% of the cases. Conclusion. MiPPeB, as used in the present study, showed a promising activity with acceptable toxicity in patients with relapsed or unresponsive indolent NHL and resulted in durable remission.