Purpose: Metastatic renal cell carcinoma is a disease with a mean survival of 6 to 10 months. Interleukin-2 (IL-2), the only approved therapy for metastatic renal cell carcinoma, is associated with a 14% response rate and durable remissions in some patients with high performance status. We performed a series of trials of IL-2 plus tumor infiltrating lymphocyte cell therapy and report the clinical results from 62 patients enrolled in these trials.
Materials and methods: Patients were eligible if they had metastatic renal cell carcinoma with the primary tumor in place and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were treated with cytokines before nephrectomy and preparation of cytokine primed tumor infiltrating lymphocytes or CD8(+) tumor infiltrating lymphocytes were isolated for infusion into patients. Of 62 patients enrolled 55 were treated with tumor infiltrating lymphocytes and IL-2, and were evaluable for toxicity, response and survival.
Results: There were no postoperative mortalities. Of the patients 7 (11%) could not undergo systemic therapy. No unexpected IL-2 related toxicities or significant toxicities related to cell infusion were noted. Overall 5 patients (9.1%) achieved a complete response and 14 (25.5%) achieved a partial response. The responses were durable with a median duration of 14 months (range 0.8+ to 64+). The actuarial survival was 65% at 1 year and 43% at 2 years from the time of nephrectomy, with an overall median survival for all patients of 22 months (range 2 to 70+). The median survival for the responding patients has not yet been reached (range 2 to 63+).
Conclusions: These results demonstrate that immunotherapy with radical nephrectomy, tumor infiltrating lymphocytes, and IL-2 provides substantial clinical benefit in the majority of patients. Component cellular therapy with enriched cell fractions allows the administration of a more standardized cell product. The present results with nephrectomy, tumor infiltrating lymphocytes and IL-2 are encouraging, and a randomized clinical trial of nephrectomy, CD8(+) tumor infiltrating lymphocytes, plus IL-2 versus nephrectomy and IL-2 alone is currently in progress.