Interferon alfa 2b as maintenance therapy in poor risk diffuse large B-cell lymphoma in complete remission after intensive CHOP-BLEO regimens

Abstract

Objectives: We conducted a randomized clinical trial to evaluate the role of interferon alfa 2b (IFN) as maintenance therapy in patients with diffuse large B-cell lymphoma with high or high-intermediate clinical risk on complete remission (CR) after CHOP-BLEO regimens. Methods: Patients were initially treated with CHOP-BLEO regimens (which include increased doses of cyclophosphamide and epirubicine, instead of doxorubicin). If the patients achieved CR they were randomly assigned to receive either maintenance therapy with IFN 5.0 MU, three times at week by 1 yr, or no treatment (control group). Results: Two hundred and twenty-three patients were considered as candidates for the study. They were of high (80%) or high-intermediate (20%) clinical risk; additionaly most patients had poor prognostic factors such as high levels of beta 2 microglobulin, lactic dehydrogenase levels, bulky disease (defined as a tumor mass > 10 cm) or multiple extranodal involvement. In an intent-to-treat analysis all patients were evaluable to efficacy and toxicity. Median follow-up was 45 months, the estimated 5-yr overall survival and event-free survival (EFS) for patients who received IFN were 71% (95% confidence interval (CI): 61-83%) and 57% (95% CI: 39-69%), respectively, values which were not statistically different from the control group: 69% (95% CI: 63-79%) and 54% (95% CI: 37-63%), respectively (p = 0.2). Toxicity was mild. Conclusions: These results suggest that IFN used as maintenance therapy at these doses and schedules is not useful in aggressive malignant lymphoma when more intensive chemotherapy has been employed during induction treatment. Nevertheless, follow-up is too short, and long-term follow-up would be necessary in order to draw definitive conclusions. Probably, an multicenter study is necessary to define the role of IFN as maintenance therapy in this patient setting.