Phenotypic spectrum and treatment outcomes in Russian gaucher disease patients: Real-world experience with biosimilar imiglucerase

Abstract Background Gaucher disease (GD), the most prevalent lysosomal storage disorder, manifests with cytopenia, organomegaly, and skeletal complications. This study characterizes the Russian GD cohort and evaluates outcomes under national therapy protocols, including predominant use of biosimilar imiglucerase. Materials and methods Data were extracted from the Russian GD Registry (single-center, observational study). All enrolled patients (n=383, >18 years, diagnosis confirmed by glucocerebrosidase assay and genetic testing) were followed prospectively with 12-month assessments (2014–2024; 1,590 visits). Electronic case report forms captured demographics, clinical/laboratory parameters, and therapy details. Data cutoff: December 1, 2024. Results Cohort: 383 patients (M:43%, F:57%), median age 42 years (range: 18–93). Splenectomy rate: 35% (median age at procedure: 12.5 years). Presenting hematologic manifestations: anemia 65%, thrombocytopenia 74% (100% in non-splenectomized), leukopenia 43%. Skeletal morbidity: osteonecrosis (femoral diaphyses) occurred in 72% splenectomized vs. 59% non-splenectomized patients (p=0.128); avascular necrosis affected 41% vs. 10% (p<0.001). Therapy: 321 patients received pathogenetic treatment:enzyme replacement therapy (ERT): 92% (imiglucerase-biosimilar [Russia]: 69%, velaglucerase: 30%, taliglucerase: 1%)substrate reduction therapy (eliglustat): 8% Outcomes: after 7 years of ERT, anemia persisted in 6% and severe thrombocytopenia (platelets <60 × 10³/µL) in 4.5%. Maintenance ERT (15–20 U/kg monthly) was administered to 137 patients (46%) achieving therapeutic goals. Conclusion The Russian GD cohort demonstrates significant splenectomy-associated skeletal morbidity. National access programs enable high treatment coverage (84%), with the remaining 16% having mild type 1 GD not meeting current criteria for initiation of therapy. Biosimilar imiglucerase constitutes 69% of ERT use. Maintenance dosing in nearly half of treated patients underscores its role in sustainable disease control. Real-world outcomes confirm efficacy of this approach, with >93% achieving hematologic stability on long-term therapy.