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.