A real-world, multi-center, prospective, observational study for paroxysmal nocturnal haemoglobinuria (PNH) in China: Baseline characteristics, disease burden and treatment patterns

Background Paroxysmal nocturnal hemoglobinuria (PNH) is a rare life-threatening hematologic disorder with high thromboembolic mortality. In the context of large patient population and limited use of complement inhibitors, the clinical characteristics and disease progression of patients in China have not been well studied. Objectives The China PNH Registry was initiated to advance understanding of the disease by collecting data and describing PNH disease burden, progression, and clinical outcomes with different medical interventions. Design This is a multi-center, prospective observational study in patients with PNH regardless of treatment for PNH. Methods This real-world study enrolled 716 PNH patients irrespective of treatment, collecting baseline demographics, clinical/laboratory data, and treatment patterns (including eculizumab dosing and safety) for descriptive analyses across PNH subtypes. Results 52.0% of the enrolled patients had classic PNH, 47.2% had bone marrow failure (BMF/PNH), and 0.8% had subclinical PNH. Classic PNH patients had a higher proportion of PNH red blood cells (RBCs) (39.0% vs. 18.0%), PNH neutrophils (86.1% vs. 52.4%), and PNH monocytes (90.2% vs. 47.7%) than BMF/PNH patients. 343/496 patients had LDH > 1.5 ULN, with a higher proportion in classic PNH than BMF/PNH (74.7% vs. 63.1%). 582 patients had at least one of the PNH-related symptoms, the most common being fatigue (63.7%), red/dark urine (46.6%). Although eculizumab has become a reimbursable complement inhibitor in China, only 28.5% of the patients received eculizumab treatment during the study period. The other main treatment methods were supportive care (46.6%), corticosteroids (28.1%), and RBC transfusion (7.5%). Conclusion Current data revealed a gap between real-world practice and guideline recommendations, indicating that standard treatment — particularly complement inhibitors — remains underutilized despite being essential for improving long-term patient outcomes. Trial registry name The China Paroxysmal Nocturnal Hemoglobinuria (PNH) Registry. Registration number NCT06154512.