Intrapleural immunotherapy with escalating doses of interleukin-2 in metastatic pleural effusions

The authors assessed the tolerance and efficacy of intrapleural interleukin-2 (IL-2) in patients with malignant effusion.

Twenty-three patients had a total of 25 metastatic pleural effusions; the patients were treated with recombinant IL-2 by means of a continuous intrapleural infusion for 5 days. The daily dosage used in this Phase I/II trial initially was 3 x 10(6) IU/m2/day; the dosage was increased with every third patient, culminating in a dosage of 24 x 10(6) IU/m2/day.

One patient who had received the highest dosage died of renal failure on day 8. Ninety-six percent of patients had Grade 2-3 fever, which was easily controlled with paracetamol administration. Two (8%) patients had pleural empyema. All other side effects were mild and resolved spontaneously by the end of treatment. The objective response rate was 21.7%. The five patients who responded to IL-2 therapy were alive 7-24 months after treatment, and the survival rate of the whole group was 59% after 13 months.

A daily dose of 10-24 x 10(6) IU/m2/day of IL-2 administered intrapleurally gave response rates similar to those reported in the literature using the intravenous route, but a much lower morbidity rate was recorded.