NCT06978439

Model-informed Dose Optimization for Rivaroxaban in Children With Giant Coronary Artery Aneurysm After Kawasaki Disease

Rivaroxaban in Chinese Children With Giant Coronary Artery Aneurysm After Kawasaki Disease: a Pilot Study

• Status: Recruiting
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 10 (estimated)
• Sponsor: Children's Hospital of Fudan University · Academic / Other
• Sex: All
• Age: 1 Month – 18 Years
• Healthy volunteers: Not accepted

Summary

Based on a population pharmacokinetic model-based dose optimization study, a 15 mg-equivalent, age-, and bodyweight-adjusted dosing regimen for Chinese children with giant coronary artery aneurysms after Kawasaki disease was proposed. This single-center, single-arm, pilot study aims to evaluate the feasibility of the 15 mg-equivalent dosing regimen within a limited sample size. Patients will be followed for more than 6 months. Clinical outcomes, including coronary artery thrombosis, major adverse cardiovascular events, and bleeding events, will be recorded. Rivaroxaban levels will be measured to assess the robustness of the model-informed dose optimization.

Detailed description

Giant coronary artery aneurysm (GCAA) is a rare but severe cardiac complication of Kawasaki disease (KD). Due to the abnormal blood rheology and the hyper-inflammatory response accompanied by thrombocytosis during the acute phase, patients with GCAA are at high risk of coronary artery thrombosis and major adverse cardiovascular events.In such instances, lifelong antiplatelet (aspirin or clopidogrel) and anticoagulant therapy (warfarin or low molecular weight heparin, LMWH) may become necessary. In 2022, two compounds, the direct activated Factor X (FXa) inhibitor rivaroxaban was approved by international regulatory agencies for two specific pediatric indications, supported by pharmacometrics models. For instance, a dosing regimen matching exposures of 20 mg daily in adults (the 20 mg-equivalent dosing regimen) is indicated for children under 18 years with venous thromboembolism (VTE). Secondly, a dosing regimen matching exposures of 10 mg daily in adults (the 10 mg-equivalent dosing regimen) is indicated for post-Fontan patients aged two years or older, as shown in the UNIVERSE study, which compared rivaroxaban to aspirin. However, no trials have yet compared rivaroxaban with warfarin/LMWH in pediatric patients with GCAA after KD. Inter-ethnic population pharmacokinetic (PPK) analyses have suggested that Asian patients may require a lower dosage of rivaroxaban, consistent with the findings from the J-ROCKET trail in Japanese adults. Accordingly, the maximum dosage for Japanese children with VTE (≥ 50 kg) has reduced from 20 mg q24h (every 24 hours) to 15 mg q24h. However, reports on rivaroxaban use in pediatric patients with GCAA after KD, especially in those from Asian countries, remains limited. Its application is more challenging due to (i) increased bleeding risk from concomitant antiplatelet drug use; (ii) the predominance of younger patients (typically \< 3 years) with variability in hepatic and renal function, as well as growth and development.3 Given the low incidence of GCAA, quantitative pharmacometrics is a highly promising approach for precision dosing of rivaroxaban in these patients. Therefore, the investigators retrospectively collected the clinical experience of rivaroxaban off-label use in Chinese pediatric patients with GCAA after KD from 2023.1 to 2023.12. With clinical evidence and model-extrapolation, the investigators conducted a quantitative pharmacometrics model-based dose optimization study and proposed a 15 mg-equivalent dosing regimen for thromboprophylaxis in Chinese children with GCAA after KD, those who require dual antithrombotic therapy. This pilot study aims to assess the potential of rivaroxaban for thromboprophylaxis in pediatric patients with KD after GCAA. Specifically, this study seeks to: (ⅰ) preliminarily evaluate the feasibility, efficacy and safety of the 15 mg-equivalent dosing regimen in target population, (ii) provide pharmacokinetic (PK)/pharmacodynamic (PD) data on rivaroxaban in Chinese children.

Conditions

• Kawasaki Disease
• Pilot Study
• Coronary Artery Aneurysm
• Rivaroxaban

Interventions

Type	Name	Description
DRUG	Rivaroxaban (Xarelto)	Administered in an age- and bodyweight-adjusted, 15 mg-equivalent dose regimen proposed by model-informed dose optimization study

Timeline

• Start date: 2024-01-10
• Primary completion: 2025-12-31
• Completion: 2025-12-31
• First posted: 2025-05-18
• Last updated: 2025-09-08

Locations

1 site across 1 country: China