A Phase 2/3 interventional study of GNR-055 1.0-2.0-3.0 mg/kg and GNR-055 2.0 mg/kg in Mucopolysaccharidosis Type II and Metabolic Diseases, sponsored by AO GENERIUM. Active, not recruiting at 5 sites in Russia. Open to male participants. Per ClinicalTrials.gov, last updated 2026-09-21.
Sponsored by AO GENERIUM · Phase 2/3, Interventional, and Treatment
This is phase 2/3 study to evaluate the safety, pharmacokinetics, pharmacodynamics, and efficacy of the investigational product GNR-055 in MPS II (Hunter syndrome) patients of different age groups.
GNR-055 is intended for ERT in patient with Mucopolysaccharidosis type II (MPS II), or Hunter syndrome. MPS II is a recessive X-linked inheritance lysosomal storage disease, which is characterized by a deficiency of the lysosomal enzyme iduronate-2-sulfatase (ID2S), caused by a mutation in the ID2S gene. Enzyme deficiency leads to the accumulation of Glycosaminoglycans (GAG) (mainly of heparan and dermatan sulfates) in lysosomes of almost all types of cells of various tissues and organs. The disease is manifested by growth retardation, damage of many organs and systems, severe deformations of bones and joints, gross facial features, pathology of the respiratory and cardiovascular systems, damage to parenchymal organs (hepatosplenomegaly), and hearing impairment. A severe form of the disease occurs with the involvement of the nervous system in the pathological process, including mental retardation, behavior anomalies, and impaired motor function.
GNR-055 is a recombinant modified ID2S capable to penetrate the blood-brain barrier and thus expected to prevent neurodegenerative consequences and the cognitive deficit and to attain a significant improvement in the life quality and expectancy of patients with MPS II.
Study IDB-MPS-II-III is a multicenter, open-label, multi-cohort study to assess safety, PK and PD, and efficacy of GNR-055 in patients of different age groups with MPS II (Hunter syndrome).
Exclusion Criteria:
GNR-055: 1.0-2.0-3.0 mg/kg
Drug: GNR-055 1.0-2.0-3.0 mg/kg
GNR-055 2.0 mg/kg
Drug: GNR-055 2.0 mg/kg
GNR-055 3.0 mg/kg
Drug: GNR-055 3.0 mg/kg
Weekly IV infusion (lyophilized powder) 1.0-2.0-3.0 mg/kg
Also known as: GNR-055
Weekly IV infusion (lyophilized powder) 2.0 mg/kg
Also known as: GNR-055
Weekly IV infusion (lyophilized powder) 3.0 mg/kg
Also known as: GNR-055
Incidence of Adverse events (AEs) and Serious Adverse Events (SAEs)
Safety assessment will be performed based on the subjective complaints, physical examination, assessment of vital signs, laboratory tests, and 12-lead ECG; Incidence of allergic and infusion-related reactions; Incidence of Anti-Drug Antibodies (ADAs) against GNR-055 and their neutralizing activity.
Time frame: Baseline to Week 56
Urine GAG excretion
Changes in levels of urine GAG excretion after multiple-dose administration of GNR-055
Time frame: Baseline to Week 4, 8, 10, 26, and 52
Serum concentration of the GNR-055
Assessment of the serum concentration of GNR-055 and calculation of Cmax, AUC, T1/2, Cl et other parameters after multiple-dose administration
Time frame: Week 52
GAG level in CerebroSpinal Fluid (CSF)
Changes in levels of CSF GAG after multiple-dose administration of GNR-055
Time frame: Baseline to Week 6, 10, 26, and 52
Serum GAG level
Changes in levels of serum GAG after multiple-dose administration of GNR-055
Time frame: Baseline to Week 4, 8, 10, 26, and 52
Large joint range of motion
Changes over time in the large joint range of motion after multiple-dose administration of GNR-055
Time frame: Week 8, 10, 26, and 52
Liver and spleen volumes (MRI)
Changes over time in liver and spleen volume according to ultrasound/MRI after multiple-dose administration of GNR-055
Time frame: Baseline to Week 8, 10, 26, and 52
6-minute walk test
Changes over time in the results of the 6-minute walk test after multiple-dose administration of GNR-055
Time frame: Baseline to Week 8, 10, 26, and 52
Left ventricular mass by EchoCG
Changes over time in the left ventricular mass according to Echocardiography (Echo-CG) after multiple-dose administration of GNR-055
Time frame: Baseline to Week 8, 10, 26, and 52
Lung Forced Vital Capacity (FVC)
Changes over time in FVC according to spirometry after multiple-dose administration of GNR-055
Time frame: Baseline to Week 8, Week 26, and Week 52
Neurocognitive functions assessment
Changes over time in neurocognitive functions after multiple-dose administration of GNR-055
Time frame: Baseline to Week 12, 26, and 52
Brain white/gray matter structures (MRI)
Changes over time in the quantitative MRI brain structure parameters after multiple-dose administration of GNR-055
Time frame: Baseline to Week 26, and 52
Serum neuromarkers
Changes in levels of serum neuromarkers after multiple-dose administration of GNR-055
Time frame: Baseline to Week 24, and 52
CSF neuromarkers
Changes in levels of CSF neuromarkers after multiple-dose administration of GNR-055
Time frame: Baseline to Week 24, and 52
Plan to share: No
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This study is active, not recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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