Treatment of low-grade non-Hodgkin's lymphoma by cytoreductive chemotherapy with prednimustine/mitoxantrone followed by interferon alpha-2b maintenance: results of a clinical phase II study.

In a clinical phase II study, the antitumor activity of the recently introduced combination of prednimustine and mitoxantrone (PmM) was evaluated in 17 patients with advanced low-grade non-Hodgkin's lymphoma after failure with or relapse after standard chemotherapy. The PmM regimen consisted of prednimustine 100 mg/m2/d orally on days 1 to 5, and mitoxantrone 8 mg/m2/d intravenously on days 1 and 2, giving a total dose of 16 mg/m2. Treatment was repeated every 4 to 6 weeks to a maximum of 6 cycles. Patients achieving complete remission (CR) or partial remission (PR) received two additional courses for consolidation, followed by interferon (IFN) alpha-2b 5 x 10(6) U subcutaneously three times a week until progression or relapse. Twelve of the 17 patients (71%) responded (CR, 4 and PR, 8). Side effects consisted mainly of neutropenia, which required dose reduction in 48% of treatment cycles. All 12 responders subsequently received IFN alpha-2b maintenance treatment. At present, remission duration ranges from 4.5+ to 17.5+ months (median 14.5 months). In comparison to unmaintained first remission prior to receiving PmM/IFN alpha-2b, a clear tendency towards a longer period of freedom from progression emerged in the 12 patients receiving IFN alpha-2b maintenance treatment during a second PR or CR. These data indicate a high antitumor activity of PmM in low-grade non-Hodgkin's lymphoma and suggest a beneficial effect of IFN alpha-2b maintenance. Present findings, however, will require confirmation in future investigations.