Bioprocess Development of a Human Monoclonal Antibody against MERS-CoV: Analytical and Preclinical Studies

Middle East Respiratory Syndrome coronavirus (MERS-CoV) is a zoonotic virus first identified in 2012, responsible for severe respiratory illness and a high case fatality rate of approximately 35%. MERS-CoV is primarily transmitted from dromedary camels to humans, but human-to-human transmission, particularly in healthcare settings, has led to outbreaks beyond the Middle East, including a major epidemic in South Korea in 2015. Despite its significant public health threat and potential for future outbreaks, no approved vaccines or therapeutic agents are available for MERS-CoV. To address this urgent need, the Korea National Institute of Health (KNIH) developed therapeutic monoclonal antibodies derived from B cells of convalescent MERS patients. Among these, KNIH-88, a non-receptor-binding domain (non-RBD) S1-specific antibody, was selected for preclinical development. In this study, KNIH-88 was produced with high purity under controlled manufacturing conditions and extensively characterized for structural and physicochemical properties, including molecular weight, charge, hydrophobicity, and high molecular weight (HMW) profile. KNIH-88 demonstrated strong binding affinity to MERS-CoV Spike protein and potent neutralizing activity in vitro. To ensure stability and facilitate rapid deployment in outbreak scenarios, a lyophilized formulation of KNIH-88 was developed, maintaining structural integrity and biological activity under long-term storage. Collectively, these findings support KNIH-88 as a promising therapeutic antibody for MERS-CoV, combining potent antiviral efficacy, structural stability, and a formulation suitable for stockpiling and emergency use in endemic regions.