A randomized controlled multicenter study comparing recombinant interleukin 2 (rIL-2) in conjunction with recombinant interferon alpha (IFN-α) versus no immunotherapy for patients with malignant lymphoma postautologous stem cell transplantation

We have earlier shown an advantage in overall survival for malignant lympnoma (ML) patients wno received combined Interleukin-2 (rIL-2) and interferon alpha (IFN-α) immunotherapy after autologous stem cell transplantation (AutoSCT) in comparison with historic controls. On the basis of these results, we initiated a control prospective randomized multicenter 2-arm study, comparing the same combined immunotherapy treatment versus control for patients with malignant lymphoma after AutoSCT. One hundred nine patients were included in this study. After AutoSCT, patients were randomized either to the treatment group or to the control group. Patients in the treatment group received daily subcutaneous injections of rIL-2 6 × 10 6 IU/m 2 /d for 5 consecutive days followed by 2-weeks rest period. Subsequently, they were treated daily with rIL-2 6 × 10 6 IU/m 2 /d combined with INF-α 3 x 10 6 U/d for 5 consecutive days per week for 4 consecutive weeks. After 4 weeks of rest, IFN-α 3 x 10 6 U was administered for the next 6 months 3 times per week. Patients in the control group were followed up at the outpatient clinic. There was a significant enhancement of survival (P = 0.05) and a clear trend in disease-free survival in favor of NHL patients receiving post-AutoSCT immunotherapy, in comparison with the control group. Eighty-nine percent of patients with NHL treated with immunotherapy were alive and 64% were disease free. In the control group, 66% of patients survived and 46% were disease free. Among the HL patients no significant differences were observed regarding survival, disease-free survival, and relapse rate. No serious toxicity events were observed. These results suggest that outpatient administered immunotherapy with IFN-α and rIL-2 is relatively well tolerated and may intensify remission in NHL patients, but not HL patients after AutoSCT.