A phase I study of recombinant interleukin 2 in melanoma patients. Toxicity and clinical effects

Toxicity and clinical effects of a new brand of recombinant interleukin 2 (rIL2, BioleukinTM, Biogen, Geneva) were evaluated by a phase I study in 12 patients with stage III melanoma. Escalating doses from 100 micrograms/m2 to 800 micrograms/m2 were administered thrice a day with bolus injections given via a peripheral venous catheter for up to a maximum of 7 days. All patients showed malaise, fever and chills and mild gastrointestinal side effects. A modest electrolyte imbalance (hypocalcemia and hypokalemia) was detected in all 12 patients. Renal toxicity as judged by serum creatinine was not observed, and hepatic toxicity was moderate with the possible exception of one patient who had an unclear previous history of liver dysfunction. Mild, transient leukopenia was found in several patients, whereas thrombocytopenia developed in 4 patients; no anemia was observed. Cutaneous rash was seen in half of the patients treated. Fluid retention was minimal, with a weight gain associated to treatment that never exceeded 10% of pretreatment body weight. Electrocardiographic alterations developed in 2 patients in the form of ventricular and supraventricular extrasystoles. In 2 patients given the highest dose of rIL2, a significant reduction in transfer lung factor for carbon monoxide was seen, indicating alterations in pulmonary functions. Other dose-related toxicities were thrombocytopenia and malaise. All side effects disappeared 2-3 days after the end of rIL2 administration. No major responses were seen in association with the 4-8 days of treatment given in this study.