OpSumit® Approved as New Treatment for Pediatric PAH Patients

Johnson & Johnson's OpSumit® Receives Approval for Pediatric Patients

On October 22, Johnson & Johnson, through its affiliate Janssen Pharma, announced that OpSumit®, an endothelin receptor antagonist (ERA), has been approved in Japan as a treatment option for pediatric patients suffering from pulmonary arterial hypertension (PAH). This approval includes new formulations of 1.0mg and 2.5mg dispersible tablets designed for children, along with an extension of the dosage for patients weighing over 50kg.

The approval is grounded in the results of three key clinical trials: PAH1010, TOMORROW, and the domestic PAH3001 trials, which collectively demonstrate the effectiveness and consistent safety profile of OpSumit®. This new treatment option addresses a significant unmet need in pediatric PAH, a serious condition affecting over 4,900 patients in Japan, classified as a specified intractable disease.

PAH is characterized by narrowing of the small arteries in the lungs, leading to increased blood pressure in the pulmonary arteries as the heart struggles to pump blood to the lungs. Children with PAH often present with multiple comorbidities requiring individualized treatment strategies, including idiopathic diseases, congenital heart conditions, and pulmonary developmental diseases.

Since its initial approval in 2015 for adult PAH treatment, OpSumit® has become the most widely prescribed ERA globally, often recommended as a first-line therapy in guidelines. Although there are existing treatment options for pediatric patients, a gap in effective therapies has persisted. OpSumit® is expected to address this gap, providing not only a new treatment option but contributing to the management of these patients’ challenges as well.

Chris Rieger, President of Johnson & Johnson, stated, “This approval enables new treatment options for pediatric PAH patients in Japan. With access to OpSumit®'s once-daily oral administration in dispersible tablets, we can help alleviate the burden on patients and their families. We look forward to delivering this new treatment option as quickly as possible to pediatric patients in need across the nation.”

Dr. Shinichi Takatsuki, a pediatrician at Toho University Omori Medical Center, expressed optimism regarding the approval, highlighting OpSumit®’s high safety and tolerability. “Currently, it is the most commonly prescribed treatment for adult PAH patients in Europe, where it has already been approved for use in pediatric cases. The potential for OpSumit® to improve treatment strategies for previously poor-prognosis pediatric PAH patients is significant,” he stated.

In Japan, OpSumit® was designated as a “drug for rare diseases” in November 2024 and is expected to receive specific pharmaceutical use designation for pediatric dosing by March 2025.

Janssen Pharma will collaborate with Japan’s Shin Nippon Pharmaceutical Co., Ltd. to provide vital information about OpSumit® to healthcare professionals.

Understanding Pediatric Pulmonary Arterial Hypertension (PAH)

PAH is a specific form of pulmonary hypertension (PH) that leads to thickening and stiffening of the walls of pulmonary arteries, narrowing the spaces through which blood flows and resulting in elevated blood pressure within the lungs. PAH is a severe, progressive disease with a myriad of causes, significantly impacting patients' physical, psychological, and social well-being. Currently, there is no definitive cure for PH, with many cases leading to severe complications or death.

In the past decade, advances in understanding the pathophysiology of PAH have shifted therapeutic focus from merely enhancing exercise tolerance to delaying disease progression.

Overview of Clinical Trials

PAH1010 Trial (NCT05433675): This Phase I study aimed at assessing the bioequivalence of OpSumit® dispersible tablets compared to standard tablets in healthy participants.

TOMORROW Trial (NCT02932410): This Phase III trial evaluated the pharmacokinetics, safety, and efficacy of OpSumit® in pediatric PAH patients aged 1 month to 17 years, providing critical data supporting its approval.

PAH3001 Trial (NCT05167825): Focused on pediatric patients aged 3 months to 15 years in Japan, this multi-center trial assessed OpSumit®'s safety and efficacy, revealing significant improvements in pulmonary vascular resistance.

About Johnson & Johnson

Johnson & Johnson is committed to the belief that health is everything. Their strength in healthcare innovation aims to prevent, treat, and cure complex diseases, crafting solutions tailored to individual patients' needs. With expertise in Innovative Medicine and MedTech, they continue to push healthcare solutions for significant impacts on global health.

For more information about Johnson & Johnson Innovative Medicine in Japan, please visit innovativemedicine.jnj.com/japan/.