Immunomodulatory activities of human leukocyte interferon in advanced cancer patients.

Natural killing and antibody-dependent cellular cytotoxicity of peripheral blood lymphocytes from 33 advanced cancer patients were monitored during the course of treatment with human leukocyte interferon in a phase I trial. Ten patients receiving 10 to 60 X 10(6) international units (IU)/m2 in a single injection showed augmentation of cytolytic activity above pretreatment values. The most typical response consisted of a decrease in activity at day 1 followed by a significant increase on day 3 with a return to baseline at day 7. No clearcut minimal immunomodulatory dose was achieved, although four of six patients treated at 60 X 10(6) IU/m6 showed increased activity at day 3. Of these, three subsequently received repeated 60 X 10(6) IU/m2 doses on a weekly basis, and two of these showed repetitive augmentation after 3-4 weeks.