Haploidentical NK Cell Infusion in Malignant Melanoma

Human NK cells recognize and kill transformed cells in a MHC-unrestricted fashion, suggesting the role of cancer immunotherapy. However, autologous NK cells showed the lack of significant clinical effects, because they are inhibited by self MHC class I molecules, based on the missing-self hypothesis. Contrarily, haploidentical NK cells with KIR-ligand incompatibility can mediate graft-versus-leukemia effect and protect patients with acute myelogenous leukemia (AML) from graft-versus-host disease. In addition, adoptive transfer of haploidentical NK cells following high-intensity conditioning induced complete remission (26%) in poor-prognosis AML patients. Thus, this study was designed to investigate the role of adoptive NK cell therapy in patients with refractory or relapsed malignant melanoma using CD3+ depleting CliniMACS® system.