Alpha-interferon treatment of cutaneous T cell lymphoma and chronic lymphocytic leukemia

The interferons represent an important first member of a family of biological response modifiers used in treating human malignancies. Activities associated with the interferons include inhibition of viral replication, influence on cellular protein production, direct antiproliferative effects, and a variety of modulatory effects on the immune response. These regulatory functions of interferon underlie the interest in its use as an anticancer agent. alpha-interferon is the most extensively studied interferon species. While antitumor activity has been seen both in vivo and in vitro in some solid malignancies, the most impressive responses have occurred in the hematologic malignancies. For patients with cutaneous T cell lymphoma (CTCL) (mycosis fungoides and the Sezary syndrome), a response rate of 45%, with 10% complete responses, was seen in patients treated with recombinant alpha-interferon at the National Cancer Institute (NCI). Interferon appears to be one of the most effective single agents for cutaneous T cell lymphoma. Current trials include further phase II trials to determine whether lower doses of alpha-interferon will be as effective as the high doses used in the previously reported studies. Additional trials include phase III trials where interferons are included in combination with chemotherapy agents, as well as using interferon in the adjuvant setting. Results for patients with chronic lymphocytic leukemia (CLL) were not as encouraging. A response rate of 15% was reported for crude and recombinant alpha-interferon in studies outside the NCI, and in our trial, only two of 18 patients (11%) had brief partial responses to recombinant alpha-interferon.