Shanghai, China, September 8, 2026
Alebund Pharmaceuticals has announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for AP308, a first-in-class engineered recombinant IgA protease being developed for IgA nephropathy (IgAN). The regulatory milestone allows Alebund to transition AP308 from preclinical research into clinical development, with the company planning to initiate a clinical trial in the near term. AP308 is designed to directly target pathogenic IgA1 and IgA immune complexes, including deposits already present in the kidney, representing a potentially differentiated therapeutic strategy for a chronic kidney disease with substantial unmet medical need.
AP308 Advances Into Clinical Development
AP308 is an engineered recombinant IgA protease developed from an IgA protease derived from Thomasclavelia ramosa, a human commensal bacterium. According to Alebund, the investigational therapy can cleave several forms of IgA, including IgA1, galactose-deficient IgA1 (Gd-IgA1), polymeric IgA and IgA immune complexes. The company is developing the molecule with the goal of directly clearing pathogenic immune complexes and complement C3 deposited in the glomeruli. The candidate was developed through a collaboration between Alebund and Peking University First Hospital, which began in January 2022 under a license agreement focused on developing IgA proteases as potential treatments for IgAN. Alebund subsequently nominated AP308 as a drug candidate using its proprietary Long-Acting Protease Engineering Platform. The platform is intended to improve stability and developability, extend circulating half-life, reduce renal clearance and lower immunogenicity while maintaining protease activity against IgA1. The FDA IND clearance is an important development milestone because it permits the company to begin evaluating AP308 in human clinical studies. However, the therapy remains investigational, and its safety, tolerability and therapeutic effectiveness in patients have not yet been established.
Preclinical Data Show IgA Deposit Clearance
The rationale for AP308 is based on its ability to target disease-associated IgA directly. IgA nephropathy is characterized by the deposition of IgA-containing immune complexes in the glomeruli, which can trigger inflammation and progressive kidney damage. Current and emerging treatments largely focus on reducing IgA production, modulating immune responses or controlling downstream inflammation, while directly eliminating established renal IgA deposits represents a different therapeutic approach. In a humanized mouse model of IgAN, weekly subcutaneous administration of AP308 for eight weeks reduced circulating human IgA and IgA immune complexes by approximately 80% compared with controls. Histological evaluation at the end of treatment showed that glomerular IgA deposits were almost completely cleared, while proteinuria decreased and kidney pathology improved. Repeated dosing did not produce signals of liver or kidney toxicity or a significant increase in anti-drug antibody titers in the reported model. In another preclinical experiment, a single AP308 dose completely cleared pre-existing chronic glomerular IgA and complement C3 deposits within seven days. These findings were published in Kidney International in May 2026 and provide the preclinical basis for advancing the candidate into clinical testing.
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Novel Approach Targets IgA Nephropathy Pathology
IgAN is the most common primary glomerulonephritis worldwide and can progress to significant kidney dysfunction and end-stage renal disease. Alebund cites long-term cohort data indicating median kidney survival of approximately 11 to 12 years under current treatment strategies, highlighting the need for therapies capable of modifying the underlying disease process. AP308’s development strategy is therefore centered on directly addressing pathogenic IgA and immune-complex deposits rather than solely controlling downstream consequences. The company aims to use its engineered protease technology to provide long-acting, potentially low-frequency dosing while preserving targeted IgA-cleaving activity. With FDA IND clearance now achieved, the next stage will be clinical evaluation of AP308 in patients with IgA nephropathy. The forthcoming clinical program will be important for determining whether the promising preclinical reductions in IgA and renal deposits translate into meaningful improvements in proteinuria, kidney function and disease progression. If successful, AP308 could establish a differentiated therapeutic approach for IgAN and further expand Alebund’s renal-focused drug development pipeline.
Source: Alebund Pharmaceuticals press release
