Extended phase I study of human beta-interferon in human cancer.

Ten patients with advanced cancer were treated with weekly intravenous escalating doses of human beta-interferon (HuIFN beta) 4 days each week. The starting dose of HuIFN beta was 3.0 X 10(6) units/m2 and the dose was doubled each week until dose-limiting toxicity was observed. Subjective toxicity included mild fevers and chills, malaise and flu-like symptoms. The lowest dose which caused suppression of the platelet and/or white cell count was 64 X 10(6) units daily, and the maximum dose given was 320 X 10(6) units daily. Both subjective and objective toxicity were not dose-related, easily managed and reversible. Serum interferon levels and the duration of measurable interferon activity on natural killer cells was in general dose-dependent. Two patients had an objective partial response, and two others showed stable disease while receiving HuIFN beta.