Phase I study comparing continuous infusion of recombinant interleukin-2 by subcutaneous or intravenous...

22 cancer patients entered a randomised phase Ib trial comparing the effects of low-dose recombinant interleukin-2 (300 micrograms/m2, approximately equivalent to 6.4 x 10(6) cetus units or 38 x 10(6) U per day) given continuously by intravenous or subcutaneous infusion. At 48 h after two 5-day courses, median lymphocyte levels (x 10(9)/l) were 6.0 (387% increase) in the subcutaneous arm (n = 9) and 5.9 (369% increase) in the intravenous arm (n = 8). Liver and renal toxicity were similar in the two groups. One minor response lasting 4 months occurred in 12 renal cancer/melanoma patients receiving subcutaneous treatment and one durable complete remission continuing at 30 months and one minor response lasting 10 months occurred in 6 renal cancer/melanoma patients receiving intravenous treatment.