Biologic Agents and Approaches in the Management of Patients with Lymphoma: A Critical Appraisal

The role of interferon as maintenance therapy in malignant lymphoma

Interferon (IFN) is a biologic response modifier that has been employed in the treatment of malignant lymphomas with various degrees of success. In patients with low-grade lymphomas, IFN alone induced complete remissions in 17-62% of the patients. When used in combination with chemotherapy, prolongation of remission duration and survival has been reported. The best results have been reported when IFN was used as maintenance therapy in patients with minimal residual disease or complete remission. When used as maintenance treatment toxicity was mild with less than 5% of the patients discontinuing IFN treatment, and late side-effects have not been reported. The results obtained with IFN in patients with intermediate and high-grade lymphomas are disappointing. Complete remissions were observed in less than 10% of the patients and duration of remission and survival did not exceed 12 months. In contrast, promising results have been reported when IFN was used as maintenance treatment following bone marrow transplantation. In conclusion, IFN should be considered as part of the therapeutic process in patients with low-grade lymphomas, and in particular as a maintenance treatment following induction chemotherapy.

Maintenance therapy with interferon alfa 2b in patients with diffuse large cell lymphoma

Forty-eight consecutive patients with diffuse large cell lymphoma (DLCL) in complete remission (CR) after conventional chemotherapy were enrolled in a prospective clinical trial. The maintenance therapy was a random either nothing or interferon alfa 2b (IFN) 5.0 MU three times a week for one year. The median duration of CR in the patients treated with IFN has not been reached. After five years 60% of patients remain in CR compared to the control group who had a median CR of 40 months (p < 0.001). Actuarial five-years survival in the IFN treated patients was 88% compared to 42% in the control group (p < 0.001). Maintenance therapy with IFN has been beneficial in patients with DLCL with improvement of duration of CR and survival without the excessive toxicity of most common third generation regimen chemotherapy. We felt that IFN could be explored in most controlled clinical trials in patients with DLCL in CR after conventional chemotherapy.