Significant results from a Phase II clinical study for a novel treatment in anti-GBM disease were presented at the 63rd European Renal Association Congress. The study, led by a team from Peking University First Hospital and sponsored by BAO PHARMA-B (02659), evaluated the investigational drug Ricefidase (KJ103).

The findings indicate that combining Ricefidase with standard immunosuppressive therapy enabled the rapid and sustained clearance of anti-GBM antibodies. The data also suggested potential benefits in several key clinical outcomes, offering a new exploratory treatment direction for this life-threatening rare autoimmune disorder.

About the Investigational Product

KJ103 is a first-in-class, low-immunogenic recombinant immunoglobulin G (IgG) degrading enzyme designed to treat various immune-mediated diseases driven by pathogenic IgG antibodies. The product works by specifically cleaving and degrading these pathogenic antibodies in the bloodstream, thereby inhibiting immune response activation. This mechanism offers a targeted and rapid new therapeutic option for antibody-mediated autoimmune diseases.

Clinical Significance of the Disease

Anti-GBM disease is a rare but rapidly progressive autoimmune condition mediated by antibodies (primarily IgG) against the glomerular basement membrane. It can lead to rapidly progressive kidney failure and pulmonary hemorrhage, resulting in low long-term survival rates, severely impacted quality of life, and high mortality. The disease imposes a significant health and economic burden on patients, families, and society. Currently, there is a lack of standardized treatment and no formally approved drug for anti-GBM disease. Existing clinical strategies cannot achieve rapid clearance of anti-GBM antibodies, leading to poor overall prognosis. Most patients eventually progress to end-stage renal disease and fail to obtain clear clinical benefit from current treatments.

Mechanism of the Novel Therapy

Ricefidase is a novel IgG degrading enzyme developed by BAO PHARMA-B through modification of a streptococcal-derived protein. It specifically clears circulating IgG antibodies, thereby rapidly reducing pathogenic antibody levels. Its characteristics include low levels of pre-existing antibodies and the potential to support repeated dosing at short intervals, enabling the design of multiple-dose regimens.

Key Findings from the Phase II Study

The study results showed that multiple doses of Ricefidase, added to standard immunosuppressive therapy, achieved rapid reduction and sustained control of anti-GBM antibodies. An improving trend was observed in key endpoints such as the six-month dialysis-free survival rate. Furthermore, patients who received the three-dose regimen did not require plasma exchange therapy during the study period, suggesting the regimen may reduce dependence on traditional clearance methods. These results provide an important basis for proceeding to a Phase III confirmatory clinical study.

BAO PHARMA-B plans to continue its collaboration with clinical research centers, including Peking University First Hospital, to accelerate the subsequent clinical development of Ricefidase in the field of anti-GBM disease.