Resumen

The Purpose of this study is to characterize the single and multiple-dose pharmacokinetic (PK) and pharmacokinetic/pharmacodynamic (PK/ PD) profiles after oral rivaroxaban therapy administered to pediatric participants 2 to 8 years of age with single ventricle physiology who have completed the Fontan procedure within 4 months prior to enrollment (Part A) and to evaluate the safety and efficacy of rivaroxaban, administered twice daily (exposure matched to rivaroxaban 10 milligram \[mg\] once daily in adults) compared to acetylsalicylic acid (ASA), given once daily (approximately 5 milligram per kilogram \[mg/kg\]) for thromboprophylaxis in pediatric participants 2 to 8 years of age with single ventricle physiology who have completed the Fontan procedure within 4 months prior to enrollment.

Descripción detallada

Part A: This part includes a 12-day Initial PK, PD, and Safety Assessment Period. Participants in Part A will not participate in Part B. Randomization in Part B of this study will begin once the cumulative data from the Initial PK, PD, and Safety Assessment Period in Part A are deemed acceptable by the Independent Data Monitoring Committee. Part A of the study will consist of an up to 21-day Screening Period, a 12-day Initial PK, PD, and Safety Assessment Period, a 12-month Open-Label Treatment Period, and a 30-day Follow-Up phone contact. Part B: Participants will be randomly assigned to two treatment groups and randomization ratio will be 2:1 for rivaroxaban and ASA. ASA will be used as control. There will be an up to a 21-day Screening Period, a 12 month Open-Label Treatment Period and a 30-day Follow-Up phone contact.

Elegibilidad

Edad mínima: 2 YearsEdad máxima: 8 YearsSexo: ALL

Criterios de inclusión

Participant must be considered to be clinically stable by the investigator and able to tolerate oral or enteral administration of a suspension formulation and oral/enteral feedings
Satisfactory initial post-Fontan transthoracic echocardiographic Screening as defined in the Post-Fontan Echocardiographic Examination Research Protocol
Parent/legally acceptable representative must sign an informed consent form (ICF) and child assent will also be provided, if applicable, according to local requirements

Criterios de exclusión

Evidence of thrombosis, including those that are asymptomatic confirmed by post-Fontan procedure transthoracic echocardiogram, or other imaging techniques, during the Screening period of the study
History of gastrointestinal disease or surgery associated with clinically relevant impaired absorption
History of or signs/symptoms suggestive of protein-losing enteropathy
Active bleeding or high risk for bleeding contraindicating antiplatelet or anticoagulant therapy, including a history of intracranial bleeding
Platelet count less than (\<)50\*10\^9/Liters (L) at Screening
Estimated glomerular filtration rate (eGFR) \<30 milliliters per minute per 1.73 meter square (mL/min/1.73m\^2)
Known clinically significant liver disease

Intervenciones

drug

Rivaroxaban

Participants will receive oral suspension containing rivaroxaban 1 milligram per milliliter (mg/ml) twice daily in Part A and Part B. Following total daily doses of Rivaroxaban will be administered based on the weight of the participants: 7 to \<8 kilogram (kg) will receive 2.2 milligram (mg); 8 to \<10 kg will receive 3.2 mg; 10 to\<12 kg will receive 3.4 mg; 12 to \<20 will receive 4.0 mg and 20 to \<30 will receive 5.0 mg.

drug

Acetylsalicylic Acid

Participants will receive 5 milligram per kilogram (mg/kg) of acetylsalicylic acid once daily up to 12 months in Part B.

A Prospective, Open-Label, Active-Controlled Study to Evaluate the Pharmacokinetics, Pharmacodynamics, Safety, and Efficacy of Rivaroxaban for Thromboprophylaxis in Pediatric Subjects 2 to 8 Years of Age After the Fontan Procedure