Alebund Pharmaceuticals (Jiangsu) Limited ("Alebund" or the "Company"; HKEX: 09637), a renal-focused biopharmaceutical company, announced that it has recently received clearance from the U.S. Food and Drug Administration (FDA) of its Investigational New Drug (IND) application for AP308, a first-in-class engineered recombinant IgA protease. The Company plans to initiate the clinical trial in the near term.

The IND clearance marks the transition of the first-in-class new drug from preclinical research into clinical development.

AP308

AP308 is a first-in-class engineered recombinant IgA protease aiming for the functional cure of IgAN. The drug is developed based on an IgA protease derived from Thomasclavelia ramosa, a human commensal bacterium, and can cleave IgA1, galactose-deficient IgA1 (Gd-IgA1), polymeric IgA and IgA immune complexes, and directly clears IgA immune complexes and complement C3 already deposited in the glomeruli; in preclinical studies, it acted within minutes without affecting other immunoglobulins such as IgG and IgM.^[1]

In January 2022, Alebund worked together with Peking University First Hospital ("PUFH") on developing IgA proteases into potential IgAN treatment and entered into a license agreement with PUFH. The Company has since developed and nominated AP308 as a drug candidate using its proprietary Long-Acting Protease Engineering Platform. The platform displays excellent stability and developability, extends circulating half-life, reduces renal clearance, and lowers immunogenicity while preserving the protease's potent cleavage activity against IgA1, thereby enabling long-acting, low-frequency dosing. The Company holds the global rights to develop, manufacture, and commercialize AP308.

IgA Nephropathy and Unmet Medical Need

IgAN is the most common primary glomerulonephritis worldwide. It is characterized by the deposition of IgA-containing immune complexes in the glomeruli, which leads to inflammation and progressive kidney damage with a poor long-term prognosis. Long-term cohort studies in China and the United Kingdom show that, under current treatment strategies, median kidney survival is approximately 11 to 12 years and most patients progress to end-stage renal disease within 10 to 15 years of diagnosis, with approximately 60% of patients in the Chinese cohort reaching end-stage renal disease within 15 years.^[2][3] According to China Insights Consultancy, there were approximately 9.5 million IgAN patients globally in 2025, including approximately 5.1 million in China, more than half of the global total and the largest IgAN patient population in the world.^[4] While existing and emerging therapies mainly target IgA production or downstream inflammation, strategies to directly clear IgA immune complexes already deposited in the kidney remain to be further explored.^[1] By directly cleaving and clearing pathogenic IgA and IgA immune complexes already deposited in the glomeruli, AP308 has the potential to address this unmet medical need.

Preclinical Data

In a humanized mouse model of IgAN, once-weekly subcutaneous dosing of AP308 over an eight-week treatment period reduced circulating human IgA and IgA immune complexes by approximately 80% relative to controls; at the end of treatment, histological examination confirmed that glomerular IgA deposits were almost completely cleared, proteinuria decreased significantly, and kidney pathology improved markedly, while repeated dosing produced no signals of liver or kidney toxicity and no significant increase in anti-drug antibody titers. In a separate paired pre- and post-treatment design, a single dose completely cleared pre-existing chronic glomerular IgA and complement C3 deposits within seven days. These preclinical results were published in May 2026 in Kidney International, the official journal of the International Society of Nephrology.^[1]