Maintenance Therapy with Interferon Alfa 2b Improves Outcome in Aggressive Malignant Lymphoma

To assess the efficacy and toxicity of interferon alfa 2b (IFN) as maintenance therapy in patients with malignant lymphoma on complete response after conventional chemotherapy we start a randomized clinical trial. One hundred and seventy patients were randomized to received either IFN 5.0 MU three time at week by one year or no further treatment, as control group. At a median follow-up of 9.0 years (range 4.3 to 11 years) median freedom from relapse (FFR) has not been reached in patients who received IFN, it is statistically significant to patients in control group with a median FFR of 60 months (p <.001). Actuarial curves show that at 10-years, 58 patients (66%, 95% confidence interval (CI) 53% to 79%) remain in first remission, statistical different to control group 33 patients (40%, 95% Cl: 33% to 57%) (p <.001). Event free survival (EFS) shown that a 10-years 63 patients (71%, 95% CI: 59% to 81%) are alive free of disease in the IFN arm compared to only 38 patients (45%, 95% CI: 37% to 57%) in the control group (p <.001). Toxicity was mild, 81 patients received the planned doses of IFN on time and 6 patients had transitory delay secondary to hematological toxicity (grade 1 or 2) and completed the treatment on 13 months. No late side effects has been observed. After a long term follow-up we confirm that IFN used as maintenance therapy improves outcome in patients with aggressive malignant lymphoma who were in complete remission after conventional chemotherapy without excessive toxicity. We feld that IFN will be consider in controlled clinical trials to define the role of this therapeutic option.