What's Happening?
Palleon Pharmaceuticals, a clinical-stage biotechnology company, announced early proof-of-concept data for its sialidase-Fc fusion protein HLX79/E-602 (efgitasialase alfa) in treating primary membranous nephropathy (pMN). The results were presented at the
American College of Rheumatology (ACR) Convergence 2026. The randomized Phase 2 trial, conducted by Palleon’s partner Shanghai Henlius Biotech in China, involved 26 pMN patients. The study compared rituximab biosimilar alone against rituximab combined with HLX79/E-602 at various doses. Patients receiving 30 mg/kg of HLX79/E-602 with rituximab achieved complete or partial remission in a median of 3 weeks, significantly faster than the 11 weeks for rituximab alone. By week 36, all 7 patients (100%) in this cohort achieved remission, including 3 complete remissions, compared to 50% of patients on rituximab monotherapy. The combination treatment was found to be safe across all doses, with no severe adverse events attributed to HLX79/E-602.
Why It's Important?
These Phase 2 results are important because they demonstrate a potentially faster and more effective treatment option for primary membranous nephropathy, a serious autoimmune kidney disease. Current standard treatments like rituximab can take months to show clinical responses and are effective in only about half of patients. The ability of HLX79/E-602 to accelerate remission and increase the rate of complete or partial remission could significantly improve patient outcomes, reducing the duration of disease activity and potentially preventing long-term kidney damage. Furthermore, the novel mechanism of action of HLX79/E-602, which reduces pro-fibrotic macrophages without compromising beneficial macrophage functions, suggests its potential applicability across a broader range of rheumatologic autoimmune diseases driven by macrophage-mediated organ damage, such as lupus nephritis and systemic sclerosis. This could open new therapeutic avenues for conditions with significant unmet medical needs.
What's Next?
Following these positive Phase 2 results, Palleon Pharmaceuticals will likely advance HLX79/E-602 into further clinical development, potentially larger Phase 3 trials, to confirm its efficacy and safety in a broader patient population and support regulatory submissions. The company will also likely explore the drug's potential in other autoimmune conditions where macrophage-driven organ damage is a key pathological feature. Continued research will focus on understanding the full scope of HLX79/E-602's mechanism of action and its long-term benefits. The collaboration with Shanghai Henlius Biotech may continue to play a role in the drug's development and potential commercialization, particularly in Asian markets. The successful progression of this drug could offer a new class of glycan editing therapeutics for autoimmune diseases.
Beyond the Headlines
The development of HLX79/E-602 represents a significant advancement in the field of glycobiology and its application to medicine. Glycan editing, a novel approach to immune modulation, targets specific sugar structures on cell surfaces to influence immune responses. This precision medicine approach could lead to more targeted therapies with fewer side effects compared to broader immunosuppressants. The success of HLX79/E-602 in pMN highlights the potential of modulating macrophage function as a therapeutic strategy for autoimmune diseases, moving beyond traditional B-cell or T-cell targeting. This could usher in a new era of treatments that specifically address the inflammatory and fibrotic processes driven by macrophages, offering hope for patients with complex autoimmune conditions that currently have limited effective therapies. The underlying scientific principles could also inspire further research into glycan-based therapies for other diseases, including cancer.
