This study is a single center, single arm, open-labeled phase 2 clinical study. The aim of
this study is to investigate the efficacy and safety of allogeneic natural killer cell
(MG4101). After lymphodepletion with fludarabine and cyclophosphamide, the patient will
receive MG4101. Each cycle consists of 28 days, and a total of 2 cycles of MG4101 will be
administered with IL-2 to activate the study drug. The efficacy of MG4101 will be evaluated
after 8 weeks from the first day of treatment. We will evaluate the safety of the drug
measuring the vital sign, laboratory tests, and adverse events.