Purpose: Previous preclinical and clinical studies have demonstrated that autologous tumor vaccines can induce relatively specific tumor-reactive T cells in draining lymph nodes. The adoptive transfer of these cells can result in tumor regression.
Patients and methods: Patients with stage IV renal cell cancer (RCC) were vaccinated with irradiated autologous tumor cells admixed with Calmette-Guérin bacillus. Approximately 7 days later, vaccine-primed lymph nodes (VPLNs) were harvested and the lymphoid cells secondarily activated with anti-CD3 monoclonal antibody and expanded in interleukin 2 (IL-2). The activated cells were subsequently infused intravenously along with the concomitant administration of bolus IL-2 (360,000 U/kg intravenously x 15 doses).
Results: Thirty-nine patients were entered onto the study, of whom 34 completed an initial course of cell therapy consisting of a mean (SEM) number of 4.3 (2.2) x 10(10) VPLN cells. Among subjects who received cell therapy, there were nine responses (four complete responses [CRs] and five partial responses [PRs]), for an overall response rate of 27%. The durations of the CRs were > 48, 45, > 35, and 12 months, and the durations of the PRs were > 63, 48, 15, 12, and 4 months. Cultured tumor cells were available to assess in vitro cytokine release of VPLN cells in 24 subjects. The median cytokine release ratio of interferon gamma (IFNgamma) to IL-10 for responders and nonresponders was 992 and 5, respectively, which was significantly different (P =.047).
Conclusion: The treatment protocol resulted in durable tumor responses in patients with advanced RCC. The ratio of IFNgamma and IL-10 cytokines released in response to tumor by the VPLN cells was a significant correlate with tumor response.