A clinically relevant large‐scale biomanufacturing workflow to produce natural killer cells and natural killer cell‐derived extracellular vesicles for cancer immunotherapy

Abstract

Abstract Natural killer cell‐derived extracellular vesicles (NK‐EVs) have shown promising potential as biotherapeutics for cancer due to their unique attributes as cytotoxic nanovesicles against cancer cells and immune‐modulatory activity towards immune cells. However, a biomanufacturing workflow is needed to produce clinical‐grade NK‐EVs for pre‐clinical and clinical applications. This study established a novel biomanufacturing workflow using a closed‐loop hollow‐fibre bioreactor to continuously produce NK‐EVs from the clinically relevant NK92‐MI cell line under serum‐free, Xeno‐free and feeder‐free conditions following GMP‐compliant conditions. The NK92 cells grown in the bioreactor for three continuous production lots resulted in large quantities of both NK cell and NK‐EV biotherapeutics at the end of each production lot (over 109 viable cells and 1013 EVs), while retaining their cytotoxic payload (granzyme B and perforin), pro‐inflammatory cytokine (interferon‐gamma) content and cytotoxicity against the human leukemic cell line K562 with limited off‐target toxicity against healthy human fibroblast cells. This scalable biomanufacturing workflow has the potential to facilitate the clinical translation of adoptive NK cell‐based and NK‐EV‐based immunotherapies for cancer with GMP considerations.

Keywords

• biomanufacturing workflow
• cancer immunotherapy
• clinical‐grade
• extracellular vesicles (EVs)
• natural killer (NK) cells
• scalable production