Safety and efficacy of autogeneic NKT cells infusion in advanced melanoma patients: a Phase I clinical trial

Abstract Background: Many melanoma patients benefited from immunotherapy, and cellular immunotherapy has been considered as a form of immunotherapy which is non-interaction with prior chemotherapy or radiation. Nature killer T cells (NKT cells) are a unique population of lymphocytes with potential anti-tumor function which display characteristics of T cell and nature killer cells,This was a prospective, open-label and dose-escalation phase I study designed to evaluate the safety of NKT cells which were purified and expanded in vitro from patients. Methods: Patients were enrolled in three dose-escalation groups of infusion of NKT cells using a traditional 3+3 design. Patients conformed unresectable metastatic melanoma of stage III or IV failed in prior standard therapy were eligible. Each treatment cycle contained two infusions every 28 days. Results: A total of 23 patients were recruited in this trial from October 2015 to June 2019. Almost all the patients were at stage IV. Most of them progressed after immunotherapy consisted of ipilimumab. No serious treatment-related adverse event occurred and the maximum tolerated dose was not reached. All the adverse events were grade 1 and grade 2. Up to 19 April 2021, three patients achieved partial response, five patients exhibited stable disease and 13 patients experienced progressed disease after treatment. The objective response rate was 14.3% and disease control rate was 38.1%, respectively. Conclusions: Infusion of NKT cells was well tolerated and showed moderate antitumor activities in advanced melanoma patients. ClinicalTrials.gov Identifier: NCT02619058. A Clinical Trial of Adoptive Transfer With Autologous NKT Cells in Metastatic Melanoma Patients