Development, physico-chemical characterization, and in vivo stability of a novel aglycosylated monoclonal antibody targeting FAM19A5

Abstract Introducing aglycosylation into therapeutic monoclonal antibodies (mAbs) can prevent side effects associated with fragment crystallizable (Fc)-mediated effector functions. This modification induces structural changes in the heavy chain constant domain 2-constant domain 3 within Fc regions, which decreases antibody stability at acidic pH and high temperature. In this study, NS101, a novel aglycosylated mAb targeting family with sequence similarity 19, A5 (FAM19A5) for neurological diseases was evaluated with respect to its developability and in vivo stability as therapeutics. When recombinant CHO cells producing NS101 were cultivated using a fed-batch mode in a 500 L bioreactor, cell growth and mAb production profiles were consistent across three consecutive runs. NS101, thus produced, features an additional intra-disulfide bond in the heavy chain complementarity-determining region 3, contributing strong and sophisticated binding to the cryptic epitope. The melting temperature (T m ) of NS101 was lower than that of commercial glycosylated therapeutic mAbs, but NS101 showed better stability at 4 °C for 36 months. The binding affinity of NS101 to FAM19A5 and neonatal Fc receptor were comparable to those of glycosylated NS101. In addition, in three human cohort groups receiving 6, 12, and 24 mg/kg of NS101, the mean half-life was 22 days, and NS101 exhibited in vivo stability, considering that the half-lives of commercialized therapeutic mAbs and endogenous IgGs are 2–4 weeks and 21 days, respectively. Taken together, the results obtained here demonstrate that NS101, a novel aglycosylated mAb, has potential as a therapeutic agent for neurological diseases.