Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Immunogenicity Profiles of a Single-Dose JYB1904 in Healthy Chinese Participants: A Phase Ia, Randomized, Double-Blind, Placebo-Controlled Study.

Allergic asthma, characterized by airborne allergen sensitivity and Th2 immune responses, is a common and increasing global health concern. Omalizumab, while effective, has limitations such as weight- and IgE-dependent dosing regimens. JYB1904, a recombinant anti-IgE humanized monoclonal antibody (IgG1 subtype), showed superior preclinical properties. We performed a single-center, randomized, double-blind, placebo-controlled, single ascending-dose phase Ia trial to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of JYB1904 in healthy adult participants across five dose levels (range: 75-600 mg; subcutaneously). JYB1904 was well tolerated, with no serious adverse events or safety concerns beyond those observed with omalizumab. Immunogenicity risk was low. PK analysis revealed approximately dose-proportional parameters and an extended half-life (2.5 times that of omalizumab). PD results showed significant free IgE suppression, with JYB1904 demonstrating stronger activity than omalizumab at equivalent doses. JYB1904 offers promising clinical advantages over omalizumab, including extended dosing intervals and enhanced efficacy, warranting further investigation for allergic asthma treatment.