The interferons.

In the 10 years since the interferons (IFN) entered large-scale clinical trials, much has been learned much about their uses as single agents. alpha-IFN, the most widely studied, has shown antitumor and antiviral efficacy against various tumors and tumor-related viruses; it has been approved by the Food and Drug Administration for the treatment of patients with hairy cell leukemia, acquired immune deficiency syndrome-related Kaposi sarcoma, and condylomata acuminata. Although IFN are effective as single agents in certain clinical situations, increasing experience with these cytokines suggests that their greatest therapeutic potential may be in combination with other biologic response-modifying, cytotoxic, or antiviral drugs. Trials combining alpha-IFN with 5-fluorouracil to treat colorectal carcinoma or with zidovudine to treat acquired immune deficiency syndrome have shown the significant impact that IFN administered in conjunction with other carefully selected agents can have. To design the most effective combination regimens, better preclinical models that clarify the mechanisms of action of IFN and define their biochemical interactions with other agents are needed.