SPD8 is GlycoNex's denosumab biosimilar candidate, co-developed with Mitsubishi Gas Chemical (MGC) of Japan since 2018. Denosumab, originally marketed by Amgen as Prolia (osteoporosis) and Xgeva (cancer-related skeletal events), is a fully human IgG2 monoclonal antibody targeting RANKL. SPD8's Phase 3 trial in Japan completed enrollment in October 2025; the trial measured percent change in bone mineral density as the primary endpoint. Topline data are expected in the second quarter of 2026, followed by BLA submission to Japan's PMDA in Q3 2026, with anticipated approvals in Japan (Q3 2027) and Taiwan (Q4 2027). In December 2024, GlycoNex out-licensed Japan commercialization rights for SPD8 to an undisclosed Japanese pharmaceutical partner, structured around upfront and milestone payments. GlycoNex retains all ex-Japan commercialization rights.
SPD8
Denosumab Biosimilar Candidate
GlycoNex's denosumab biosimilar candidate, co-developed with Mitsubishi Gas Chemical since 2018. Phase 3 trial in Japan complete; topline data expected Q2 2026, with BLA filing planned for Q3 2026. Japan commercialization rights have been out-licensed; ex-Japan rights remain available for partnership.
About SPD8
Targeting the RANKL pathway
Denosumab and its biosimilars work by binding to RANKL (Receptor Activator of Nuclear Factor κB Ligand), a key signaling protein that activates osteoclasts — the cells responsible for bone resorption. By neutralizing RANKL, denosumab inhibits osteoclast formation, function, and survival, thereby reducing bone resorption and increasing bone mineral density in osteoporosis. In oncology contexts, the same mechanism prevents the bone destruction caused by tumor cells, reducing skeletal-related events in patients with bone metastases. SPD8 is engineered to deliver this same mechanism with biosimilar levels of analytical, nonclinical, and clinical equivalence to denosumab.
Demonstrating biosimilarity to denosumab
Biosimilar development requires demonstrating equivalence to the reference product across three distinct comparability layers. GlycoNex's approach leverages its proprietary integrated glycan analytical platform — particularly important for denosumab, where glycan composition is a critical quality attribute — alongside conventional structural, functional, and clinical characterization. SPD8's development program is designed around full alignment with ICH Q6B principles and the regulatory expectations of Japan's PMDA, U.S. FDA, and Taiwan's TFDA.
Comparability
Structural and physicochemical characterization including primary sequence, post-translational modifications, N-glycan profile, and higher-order structure.
Key platforms: LC-MS, ion chromatography, capillary electrophoresis, and intact mass spectrometry — covering the critical quality attributes regulators expect for an IgG2 with complex glycosylation.
Comparability
In vitro functional assays, receptor binding, signaling pathway inhibition, and osteoclast function assays in cell-based systems.
Validated against reference denosumab in head-to-head studies, demonstrating equivalent potency, binding kinetics, and downstream biological response across the relevant assay panel.
Comparability
Pharmacokinetic equivalence, pharmacodynamic equivalence, and clinical efficacy and safety trial in patients — Phase 3 trial in Japan completed October 2025.
Primary endpoint: percent change in bone mineral density at the lumbar spine, the standard regulatory measure for postmenopausal osteoporosis biosimilarity readouts.
Supported by GlycoNex's GMP manufacturing facility (50L + 200L scales) and an external advisory team with deep expertise in PMDA and FDA CMC regulatory pathways.
Phase 3 Trial
SPD8's pivotal Phase 3 trial was conducted in Japan to evaluate clinical equivalence with reference denosumab in patients with osteoporosis. Enrollment completed on October 29, 2025. Topline data, including the primary endpoint analysis, are expected in the second quarter of 2026.
Development & regulatory pathway
Topline data readout in Q2 2026 represents the key value-creation milestone for SPD8. All subsequent regulatory and commercial milestones are conditional on positive readout.
Bone health: a sustained therapeutic need
Osteoporosis remains a major global health burden, with fracture-related morbidity and mortality particularly elevated in older populations.
Cancer-related skeletal events also affect a substantial patient population with metastatic bone disease.
Amgen's 2025 denosumab sales reflect emerging biosimilar competition, down from prior-year levels.
Two paths for collaboration
SPD8's development has been validated by a Japan commercialization agreement signed in December 2024. Two distinct partnership opportunities remain — and we welcome inquiries on both.
Proven biosimilar execution
GlycoNex has demonstrated full biosimilar development capability through SPD8, from analytical characterization through Phase 3 clinical trial completion.
- MGC co-development since 2018
- Phase 3 enrollment completed October 2025
- Japan commercialization rights out-licensed December 2024
- BLA filing planned Q3 2026
Companies seeking a development partner with proven end-to-end biosimilar capability — particularly for complex monoclonal antibodies where glycan analytical capability matters.
ex-Japan rights available
GlycoNex retains all ex-Japan commercialization rights for SPD8. With Phase 3 complete and a clear regulatory path, the asset is positioned for partnership discussions with global or regional commercialization partners outside Japan.
- Phase 3 trial complete (October 2025)
- Topline data expected Q2 2026
- Regulatory dossier mature for Japan filing (Q3 2026); ex-Japan filing strategy adaptable to partner preferences
- Manufacturing supported by GlycoNex GMP facility
Pharmaceutical and biopharmaceutical companies seeking commercial-stage biosimilar assets in markets outside Japan, including Asia-Pacific, Europe, North America, and emerging markets.
A clinical-stage biosimilar, validated by Japan licensing
SPD8's Q2 2026 topline data readout will mark a key value-creation milestone.