Purpose: Adoptive cell therapy (ACT) with autologous tumor-infiltrating lymphocytes (TILs) and high-dose interleukin-2 (IL-2) administered to lymphodepleted patients with melanoma can cause durable tumor regressions. The optimal TIL product for ACT is unknown. Patients and Methods: Patients with metastatic melanoma were prospectively assigned to receive unselected young TILs versus CD8+-enriched TILs. All patients received lymphodepleting chemotherapy and high-dose IL-2 therapy and were assessed for response, toxicity, survival, and immunologic end points. Results: Thirty-four patients received unselected young TILs with a median of 8.0% CD4+ lymphocytes, and 35 patients received CD8+-enriched TILs with a median of 0.3% CD4+ lymphocytes. One month after TIL infusion, patients who received CD8+-enriched TILs had significantly fewer CD4+ peripheral blood lymphocytes (P = .01). Twelve patients responded to therapy with unselected young TILs (according to Response Evaluation Criteria in Solid Tumors [RECIST]), and seven patients responded to CD8+-enriched TILs (35% v 20%; not significant). Retrospective studies showed a significant association between response to treatment and interferon gamma secretion by the infused TILs in response to autologous tumor (P = .04), and in the subgroup of patients who received TILs from subcutaneous tumors, eight of 15 patients receiving unselected young TILs responded but none of eight patients receiving CD8+-enriched TILs responded. Conclusion: A randomized selection design trial was feasible for improving individualized TIL therapy. Since the evidence indicates that CD8+-enriched TILs are not more potent therapeutically and they are more laborious to prepare, future studies should focus on unselected young TILs.
ASJC Scopus subject areas
- Cancer Research