Phase II trial of interleukin-2 and interferon-alpha in patients with renal cell carcinoma: clinical results and immunologic correlates of response.

A phase II trial was conducted in patients with metastatic renal cell carcinoma, to assess the clinical efficacy and immunoregulatory effects of continuous-infusion recombinant interleukin-2 (rIL-2) (9.0 x 10(6) IU/m2/day on days 1-5, 8-12, 15-19, and 22-26) and subcutaneously administered recombinant human interferon-alpha 2b (rHuIFN alpha 2b) (10.0 x 10(6) U/m2/day TIW). Thirty-six patients with metastatic renal cell carcinoma, performance status of 0-1, and measurable disease who had not received prior rIL-2, rHuIFN alpha 2b, or chemotherapy were treated. Patients with CNS metastases, active infections, history of another malignancy within 3 years, and those requiring corticosteroids were ineligible. Cycles of rIL-2 and rHuIFN alpha 2b were administered in the outpatient department every 6-8 weeks in stable or responding patients until patient tolerance or a complete response were reached. Doses were modified for grade III or IV toxicity. Ancillary studies included three-color immunocytometric analysis of peripheral blood lymphocytes, repetitive tumor biopsies for immunohistologic analysis of infiltrating cells and proliferative responses of tumor infiltrating lymphocytes, and preliminary studies of changes in peripheral blood T-lymphocyte signal transduction molecules [T-cell receptor (TCR)-zeta, p56ick, p59fyn]. Thirty-six eligible patients were treated, with 6 of 36 patients (17%, 95% confidence interval 6-33%) responding (3 complete response, 3 partial response). In two of the partial responders, and in an additional three patients with either minimal tumor regression (one patient) or stable disease (two patients), surgical removal of residual disease was undertaken. The median survival of all patients was 14 months. The toxicity of this regimen was severe, but outpatient administration was possible in most instances. Immunoregulatory effects on T-cell subsets included increases in various CD3+ CD25+/- HLADr+/- subsets unrelated to response. Tumor biopsies before and/or during therapy were obtained in 17 patients, and no consistent alterations in the degree of T-lymphocyte or macrophage infiltrates could be detected. In a subset of patients, tumor infiltrating lymphocyte proliferative responses and levels of peripheral blood T-cell signal transduction molecules (TCR-zeta, p56lck, p59fyn) were investigated. Abnormalities were found in selected patients, which improved during rIL-2/rHuIFN alpha 2b therapy. This cytokine combination produces tumor regression in selected patients with metastatic renal cell carcinoma. Surrogate immunologic markers associated with response were not identified; however, preliminary studies demonstrate investigation of immune defects and their reversal with cytokine therapy is possible.