The role of recombinant interferon alfa-2a in the therapy of cutaneous T-cell lymphomas.

Maximally tolerated doses of interferon alfa-2a, 50 X 10(6) U/m2 administered intramuscularly (IM) 3 times weekly, were given to 20 patients with advanced stages of cutaneous T-cell lymphoma (CTCL) to determine the efficacy and toxicity of this therapy. All patients were heavily pretreated and had failed standard therapies. Objective remissions were noted in 45% of the patients, including two patients who achieved complete remissions and seven patients who had partial remissions. The median duration of response was 5.5 months, with responses lasting a minimum of 3 months and a maximum of more than 3 years. Responses in excess of 2 years occurred in three of the nine responding patients. These results were achieved with moderate toxicities. The dose-limiting toxicity was a flu-like syndrome consisting of malaise, anorexia, weight loss, and falling performance status. Toxicity was observed in all patients but was always alleviated by dose reduction. Patients with indolent B-cell non-Hodgkin's lymphoma who received the same therapy had a similar objective response rate (54%) and showed the same toxicities. These trials were followed by an ongoing trial using the same dose of interferon in a different schedule given for 12 weeks followed by a dose escalation to 100 X 10(6) U/m2. Three partial responses were observed in the first 13 patients on this trial treatment. Other studies examining lower dose interferon compared to the 50 X 10(6) U/m2 are in progress. This study establishes interferon alfa-2a as a treatment of choice for patients with advanced cutaneous T-cell lymphomas refractory to chemotherapy and other standard therapies. Trials combining interferon with other standard treatments and the use of interferon in earlier stages of disease are needed.