Sunho (China) BioPharmaceutical has registered a Phase Ia first-in-human clinical trial for ISH0613, an internally developed bifunctional bispecific antibody intended for systemic lupus erythematosus (SLE). Sunho has publicly disclosed that ISH0613 is an internally developed bifunctional antibody fusion protein derived from its AIC platform that simultaneously inhibits B cell activation and interferon-α (IFNα) secretion. This dual mechanism positions the asset at the intersection of two validated SLE pathways: autoreactive B cell activity and type I interferon signaling. While B cell-directed therapies such as belimumab have demonstrated clinical benefit, and IFN pathway inhibition has been validated by anifrolumab, neither approach alone fully controls disease in a substantial proportion of patients.
The randomized, double-blind, placebo-controlled single-ascending-dose study will enroll approximately 26 healthy adult volunteers at the Affiliated Drum Tower Hospital of Nanjing University in China. Four intravenous dose levels (80–640 mg) will be evaluated, with primary endpoints focused on safety and tolerability over a 57-day observation period. Secondary endpoints include pharmacokinetics and pharmacodynamic measures such as circulating B cell counts and serum immunoglobulin levels.
The inclusion of B cell and immunoglobulin pharmacodynamic readouts in a healthy-volunteer study is consistent with this mechanism, providing an early signal of target engagement across both arms of the biology. The dual-action design also reflects broader industry interest in engineered biologics capable of modulating multiple immune pathways within a single molecule, rather than relying on combination regimens.
The study is not yet recruiting, with primary and overall completion expected in Q4 2026. The dataset will determine whether ISH0613 demonstrates acceptable safety and measurable pharmacodynamic activity to support progression into SLE patient cohorts.