Pembrolizumab plus allogeneic NK cells in advanced non-small cell lung cancer patients

BACKGROUND. The anti-programmed cell death 1 (anti-PD-1) antibody pembrolizumab is clinically active against non-small cell lung cancer (NSCLC). In addition to T cells, human natural killer (NK) cells, reported to have the potential to prolong the survival of patients with advanced NSCLC, also express PD-1. This study aimed to investigate the safety and efficacy of pembrolizumab plus allogeneic NK cells in patients with previously treated advanced NSCLC. METHODS. In total, 109 enrolled patients with a programmed death ligand 1 (PD-L1) tumor proportion score (TPS) of 1% or higher were randomly allocated to group A (n = 55 patients given pembrolizumab plus NK cells) or group B (n = 54 patients given pembrolizumab alone). The patients received i.v. pembrolizumab (10 mg/kg) once every 3 weeks and continued treatment until the occurrence of tumor progression or unacceptable toxicity. The patients in group A continuously received 2 cycles of NK cell therapy as 1 course of treatment. RESULTS. In our study, patients in group A had longer survival than did patients in group B (median overall survival [OS]: 15.5 months vs. 13.3 months; median progression-free survival [PFS]: 6.5 months vs. 4.3 months; P < 0.05). In group A patients with a TPS of 50% or higher, the median OS and PFS was significantly longer. Moreover, the patients in group A treated with multiple courses of NK cell infusion had better OS (18.5 months) than did those who received a single course of NK cell infusion (13.5 months). CONCLUSION. Pembrolizumab plus NK cell therapy yielded improved survival benefits in patients with previously treated PD-L1(+) advanced NSCLC.