Palleon Pharmaceuticals, a clinical-stage biotechnology company developing glycan editing therapeutics for autoimmune disease and cancer, today announced early proof-of-concept data for its first-in-class sialidase-Fc fusion protein HLX79/E-602 (efgitasialase alfa) in primary membranous nephropathy (pMN). The results were presented in an oral session at the American College of Rheumatology (ACR) Convergence 2026 in Orlando.

Palleon’s partner, Shanghai Henlius Biotech (2696.HK), conducted the randomized Phase 2 trial (NCT07038382) in China enrolling 26 patients with pMN. The study compared rituximab biosimilar (Henlius’ HANLIKANG) alone to the same regimen combined with HLX79/E-602 at 10, 20, and 30 mg/kg. Dosing was weekly for four weeks, with re-dosing at six months.

Rituximab, which depletes antibody-producing B cells, is a standard treatment for pMN, but clinical responses can take months, and only about half of patients achieve remission. Patients receiving 30 mg/kg of HLX79/E-602 combined with rituximab achieved complete or partial remission in a median of 3 weeks, compared to 11 weeks for those receiving rituximab alone. By week 36, all 7 treated patients in this cohort (100%) were in complete or partial remission, including 3 complete remissions, whereas only 3 of 6 patients (50%) receiving rituximab monotherapy achieved remission. The combination was safe across all doses, with no severe adverse events attributed to HLX79/E-602.

“Growing evidence suggests that macrophages persist in the kidney after B cells are gone and continue to drive damage. HLX79/E-602 reduces pro-fibrotic macrophages in inflamed tissue without compromising the beneficial functions macrophages perform elsewhere in the body,” said Jim Broderick, M.D., Chief Executive Officer and Founder of Palleon Pharmaceuticals. “As these macrophages are an important driver of progressive organ damage in many autoimmune conditions beyond pMN, including lupus nephritis, systemic sclerosis, and interstitial lung disease, this mechanism offers a potential new path forward for addressing unmet needs in rheumatology.”

HLX79/E-602 is comprised of a sialidase enzyme that removes sialic acid from cell surfaces, reducing pro-fibrotic CD163⁺ macrophage populations in inflamed tissue while preserving healthy macrophage function. This targeted glycan editing approach represents a novel mechanism for modulating the macrophage-driven organ damage that characterizes multiple autoimmune diseases.

About Palleon Pharmaceuticals

Palleon Pharmaceuticals is a clinical-stage biotechnology company developing glycan editing, a new approach to immune modulation in autoimmune disease and cancer. The company was founded on the glycobiology research of Carolyn Bertozzi, 2022 Nobel Laureate in Chemistry. Its pipeline includes E-602/HLX79 (Phase 2, membranous nephropathy) and E-688/HLX316 (Phase 1, advanced solid tumors). www.palleonpharma.com

Media gallery

About The Author
Business Wire