Renal cell carcinoma treated with continuous-infusion interleukin-2 with ex vivo-activated killer cells.

High-dose recombinant interleukin-2 (rIL-2) results in tumor responses in patients with metastatic renal cell carcinoma ranging from 9 to 31%. Continuous infusion regimens of rIL-2 may be less toxic and may result in greater in vivo lymphokine-activated killer (LAK) cell production. The current trial used a continuous infusion of rIL-2 with ex vivo LAK cells. These cells were pretreated with phenylalanine methyl ester to remove monocytes to allow cell culture at higher concentrations. Twenty-three patients were entered into the trial. Two patients had complete responses (9%) lasting 15+ and 20+ months. Four patients had partial responses (17%) of 9+, 6+, 3, and 3 months, respectively. One partial responder at 9+ months had only minimal residual retroperitoneal disease that may represent scar tissue. All responders had prior nephrectomies. All but one of the responding patients completed a full cycle of rIL-2 at the highest (starting) dose, 6 x 10(6) U/m2. This rIL-2/LAK regimen appears to be an effective therapy for metastatic renal cell carcinoma.