Immunotherapy of metastatic renal cell carcinoma with polyinosinic-polycytidylic acid.

Polyinosinic-polycytidylic acid, a double-stranded ribonucleic acid that is a potent inducer of interferon production, was used in a stabilized form to treat 11 patients with metastatic renal cell carcinoma. Seven patients completed a full course of 8 infusions at maximum tolerated dosage. All patients experienced transient fever and marked fatigue. Anorexia was mild. Transient leukopenia occurred in 3 patients and reversible elevation in creatinine was observed in 1. All 4 patients with brain metastases became lethargic, and 3 died during or shortly after therapy. Only 2 patients demonstrated measurable total regression of isolated metastases (pleural/pulmonary in 1 and bone in 1) but in both metastases at other sites progressed. No partial regressions were seen. Metastases at all other sites (liver, brain and renal fossa) progressed during therapy. Patients who appeared to respond and who performed best during therapy generally demonstrated a higher performance status initially. Expression of natural cytotoxicity in in vitro testing did not correlate with a demonstrated response to treatment.