Alpha-interferon as maintenance drug after initial fludarabine therapy for patients with chronic lymphocytic leukemia and low-grade non-Hodgkin's lymphoma

BACKGROUND: Fludarabine monophosphate (FLU) is an adenine nucleoside analogue with promising therapeutic activity in lymphoproliferative disorders. In addition, the effectiveness of alpha-interferon (alpha-IFN) in low-grade non-Hodgkin's lymphoma (LG-NHL) and B-cell chronic lymphocytic leukemia (B-CLL) has been demonstrated in several clinical trials. METHODS: In a phase II study of 45 patients with B-CLL and 28 with LG-NHL, we used FLU as second and third-line chemotherapy. Dosages of 25 mg/m2 were given in 30-minute infusions for 5 consecutive days. Treatment was repeated every 28 days depending on patients' clinical status for a maximum of 6 cycles. Entrance in the human lymphoblastoid alpha-IFN maintenance portion of the study depended on response to initial FLU. Following randomization we administered alpha-IFN, or no therapy at all, to patients who obtained a complete or a partial response after FLU therapy. The alpha-IFN dose was 3 x 10(6) U three times per week until disease progression. RESULTS: Twenty-one B-CLL patients achieved major responses, as did 17 of those with LG-NHL. Twenty-four of the former group and 11 of the latter failed to respond or obtained only a minor response. The 38 patients who responded well and entered the second part of the trial showed significant prolongation of remission duration with maintenance alpha-IFN. CONCLUSIONS: In consideration of its significant activity, the role of FLU in the management of lymphoproliferative disorders needs to be evaluated further; at the same time, this preliminary analysis seems to indicate that maintenance alpha-IFN may extend remission duration in B-CLL and LG-NHL.