Fiztasovimab (NPC-21; EV2038) is a fully human IgG1λ mAb against human cytomegalovirus (hCMV). Fiztasovimab acts neutralizing activity by binding to the antigenic domain 1 of glycoprotein B on hCMV envelope. Fiztasovimab inhibits cell-to-cell transmission of hCMV.
Fiztasovimab is isolated from Epstein-Barr virus-transformed peripheral B cells of a healt donor[1]. Fiztasovimab has a broadly neutralizing activity against 4 laboratory strains (AD169, Towne, Davis, Merlin) and 42 Japanese clinical isolates, which included GCV-resistant isolates[1].Fiztasovimab shows anti-hMCV activities in MRC-5 human embryonic fibroblast cells and human adult retinal pigment epithelial cells with IC50s of 13-105 ng/mL and IC90s of 0.208-1.026 μg/mL[1].Fiztasovimab also inhibits cell-to-cell infection by hCMV isolates in adult retinal pigment epithelial cells with IC90s of 13-19 μg/mL[1].
References:
[1]. Furihata K, et al. Pharmacokinetics, Safety, and Tolerability of NPC-21, an Anti-Cytomegalovirus Monoclonal Antibody, in Healt Japanese and White Adult Men: A Randomized, Placebo-Controlled, First-in-Human Phase 1 Study. Clin Pharmacol Drug Dev. 2022 Jun;11(6):707-716.