Effectiveness of very low doses of immunotherapy in advanced renal cell cancer.

Twenty-one nephrectomized patients with metastatic renal cell cancer were treated with recombinant interleukin 2 (rlL-2) and interferon alpha (rIFN alpha). rIL-2 was administered s.c. at a dose of 1 x 10(6) IU m(-2) every 12 h on days 1 and 2, followed by 0.5 x 10(6) IU twice daily on days 3-5; rIFN alpha-2 was given i.m. as 1.8 x 10(6) IU m(-2) on days 3 and 5 of each week for 4 consecutive weeks. The cycle was regularly repeated at 4-month intervals and continued ad libitum in patients showing some response and in patients with progressing disease. Of 20 patients evaluable for treatment response, one (5%) had a complete response and three (15%) showed partial response. Three patients (15%) achieved stable disease and 13 (65%) were evaluated as having progressive disease. The estimated actuarial 44-month survival rate was 44%. Toxicity was limited to WHO grades 1 and 2 only.