Phase I/II trial of recombinant gamma-interferon in patients with renal cell carcinoma: immunologic and biologic effects

Thirteen patients with metastatic renal cell carcinoma were entered on a Phase I/II trial of recombinant gamma-interferon (gamma-IFN). Patients (3) were entered on escalating dose levels, and each patient was escalated to the next dose until an individual maximum tolerated treatment dose (MTD) was established. Multiple parameters of biologic response were measured. Patients were studied twice baseline and at frequent intervals after the initial treatment and every treatment until the patient's individual MTD was reached. The MTD for most patients was less than 75 X 10(6) U/m2. Small, but statistically significant, enhancement of monocyte antibody-dependent cellular cytotoxicity and mononuclear cell inhibition of MBL-2 growth were noted in vitro at gamma-IFN concentrations greater than 250 U/ml. Clinically obvious biologic effects were observed: fever, chills, hypotension, and malaise. However, laboratory assays of peripheral blood mononuclear cell natural killer cell activity, tumor (MBL-2) growth inhibition, antibody-dependent cellular cytotoxicity, lymphoblastic T-cell subsets, and 2'5'-oligonucleotide synthetase were not altered in vivo.