RIYADH — The Saudi Food and Drug Authority (SFDA) has approved the registration of Winrevair (sotatercept) for the treatment of adult patients with World Health Organization (WHO) Functional Class II to III pulmonary arterial hypertension (PAH). Previously designated as an orphan drug under SFDA's Orphan Drugs Program, Winrevair addresses a critical need for patients with this life-threatening condition. PAH is characterized by the narrowing and thickening of blood vessels in the lungs, leading to symptoms such as shortness of breath, chest pain, and fatigue. Winrevair introduces a novel mechanism of action by inhibiting activin signaling, which plays a role in the thickening of pulmonary arteries. By restoring cellular growth balance, the drug improves blood flow in the lungs, reduces strain on the heart, and enhances oxygen delivery and physical endurance, thereby improving patients' quality of life. The SFDA confirmed that the drug's approval followed a comprehensive evaluation of its efficacy, safety, and quality, meeting all regulatory requirements. Clinical trials demonstrated a statistically significant and clinically meaningful reduction in the risk of disease progression or death in WHO Class II–III patients. The most common side effects reported were headache, nosebleeds, and skin itching, which were generally mild and manageable. The SFDA reiterated its commitment to supporting access to effective treatments, especially in the rare and difficult-to-treat disease space, which often suffers from limited therapeutic options. The authority's Orphan Drugs Program plays a strategic role in advancing pharmaceutical innovation and addressing unmet medical needs. Under the program, orphan drugs are defined as those intended to treat diseases affecting fewer than five individuals per 10,000 people in Saudi Arabia. The program offers benefits to pharmaceutical companies, including pre-submission meetings, priority review, and scientific consultations.