Alebund Pharmaceuticals (HKEX: 09637) received US FDA clearance of its investigational new drug (IND) application for AP308, an engineered recombinant IgA protease being developed for IgA nephropathy (IgAN), clearing the path for a Phase I clinical trial expected to begin in the near term.
AP308 takes a mechanistic approach distinct from current IgAN therapies. Rather than suppressing IgA production or blocking downstream inflammatory pathways, the molecule is designed to directly cleave IgA1, galactose-deficient IgA1, polymeric IgA, and IgA immune complexes, including deposits already present in the glomeruli. The enzyme is derived from an IgA protease isolated from Thomasclavelia ramosa and engineered to extend circulating half-life and reduce immunogenicity while preserving cleavage activity. Alebund said AP308 does not affect other immunoglobulins, including IgG and IgM.
Preclinical data published in May 2026 in Kidney International supported clinical advancement. In a humanized mouse model of IgAN, once-weekly subcutaneous dosing reduced circulating human IgA and IgA immune complexes by approximately 80% and produced near-complete clearance of glomerular IgA deposits, alongside reductions in proteinuria and improved kidney pathology. In a separate single-dose experiment, pre-existing glomerular IgA and complement C3 deposits were reported to be cleared within seven days. The company reported no liver or kidney toxicity signals or significant increase in anti-drug antibody titers with repeat dosing.