Purification and antibody-free ex-vivo expansion of peripheral blood-derived autologous natural killer cells: A Malaysian case series on patient safety and tolerability.

Natural killer cells are the most researched and employed cells for immunotherapy, which have expanded from autologous immune-enhanced therapies to genetically enhanced cell therapies such as chimeric antigen receptors natural killer cells. The present clinical case study aims to analyze and evaluate the safety and tolerability of ex-vivo expanded autologous natural killer cells via an in-house developed culture protocol. The novel, cultivation protocol enables high-yield and pure natural killer cell batches free of antibody usage, prior natural killer cell purification, or any magnetic-bead labeling, resulting in a fully human compatible cell expansion process. In this report, a total of nine patients were clinically infused with the in-house cultured natural killer cells and were monitored pre- and postinfusion for haematological parameters, liver function profile, hypersensitivity, inflammatory markers as well as pretumor markers to assess for the possibilities of natural killer cell-induced or any dose-dependent toxic/adverse reactions. The outcomes indicate that the patient infused with natural killer cells demonstrates good level of clinical safety with no signs of hepatotoxicity, hypersensitivity, inflammation, or any flares of preliminary tumor markers. The study provides supportive evidence of the clinical tolerance of autologous-derived natural killer cells cultured via the in-house protocol on patients in Malaysia and establishes a baseline for future clinical studies with a wider range of patients.