[A phase I study of recombinant interleukin 2 (S6820)]

Forty patients with refractory malignancies were treated with recombinant human interleukin 2 (IL2) in a cooperative phase I study. IL2 was administered intravenously in six groups of patients at doses of 1 x 10(4), 3.3 - 5 x 10(4), 1 x 10(5), 3.3-5 x 10(5), 1 x 10(6) and 3.3 x 10(6) U/day and subcutaneously in 4 patients at a dose of 1 x 10(6) U/day for 5 days, respectively. Toxicity was dose related and consisted of fever and chills (52.7%), gastrointestinal disturbance (19.4%), rash, arthralgia, eosinophilia and hepatotoxicities. All the patients recovered from these soon after the administration was completed. Hypotension was observed in 3 patients at a dose of 3.3 x 10(6) U/day and in one instance was so severe that withdrawal was necessary. Enhancement in NK and LAK cell activity was noted at doses of 1 x 10(6) U/day or higher. This investigation indicates that the optimal dose is 1 x 10(6) U/day and will aid in the design of a phase 2 study with IL2.