[Phase I trial of a recombinant human interleukin 2. Results in patients with disseminated solid tumors]

A phase I trial of Roussel-Uclaf recombinant human interleukin 2 (IL 2) was performed on 31 cancer bearing patients of the Institut Gustave-Roussy, Villejuif, and the Institut Curie, Paris. This study allowed to define a schedule for administration of IL 2 in continuous infusion over 5 day cycles. This schedule is manageable in patients without major visceral failure. It is reproducibly feasible in conventional medical oncology units, without specialized intensive care facilities. Toxicities, although numerous, are acceptable for IL 2 doses below 24,000,000 IU/m2/day. There is a close relationship between secondary effect severity and IL 2 doses received. Main toxicities were: fever with chills, fatigue and general discomfort in 23 patients, nauseas and vomiting in 12, diarrhea in 10 and cutaneous rashes with erythema and dermal vascularitis in 13. One peculiar feature of this study was the minimal occurrence of manifestation related to leaky capillary syndrome prominant in other studies. Oliguria, functional renal failure and edema were observed in only 4 patients with functionally unique kidney. Five patients had severe anemia, 2 grade III thrombocytopenia, 1 grade IV hepatic cytolysis, 4 severe confusion episodes and 2 hypothyroidism with anti-thyroid microsome auto-antibodies. All these toxicities were reversible after withdrawal of IL 2 treatment. During this phase I trial, 3 therapeutic objective responses were observed, all 3 occurring in patients with metastatic melanoma treated with IL 2 doses equal to, or above 16,000,00 IU/m2/d. Recombinant IL 2 Roussel-Uclaf thus can be administered through a simple, manageable and efficient regimen.