The Food and Drug Administration (FDA) has granted approval to Merck’s drug, Winrevair, for the treatment of pulmonary arterial hypertension (PAH), a rare and life-threatening lung condition. This approval is a significant milestone for both the drugmaker and patients suffering from PAH, as Winrevair is the first drug to target the root cause of the condition.
Previously available medicines only helped manage the symptoms of PAH, but Winrevair aims to increase exercise capacity, lessen the severity of the disease, and reduce the risk of it worsening when used alongside existing therapies. The condition occurs when the small blood vessels in the lungs narrow, leading to high blood pressure in the arteries carrying blood from the heart to the lungs. This can result in heart damage and limited physical activity.
According to Merck, the mortality rate of patients diagnosed with PAH is 43% within five years. Therefore, the approval of Winrevair brings hope to the roughly 40,000 people in the U.S. living with this disease.
Merck estimates that Winrevair will be available in select specialty pharmacies in the U.S. by the end of April. The drug is administered through injection every three weeks and is distributed in single-vial or double-vial kits. The cost of Winrevair is set at $14,000 per vial before insurance, but Merck offers a program to help eligible patients with out-of-pocket costs and copays.
The approval of Winrevair is crucial for Merck as it seeks to diversify its revenue stream, especially with its top-selling cancer immunotherapy Keytruda approaching a loss of market exclusivity in 2028. JPMorgan analyst Chris Schott predicts that Winrevair could reach worldwide annual sales of around $5 billion by 2030, making it one of Merck’s “largest growth drivers.”
Merck Chief Medical Officer Eliav Barr has expressed his enthusiasm for the approval, stating that it is not only a great opportunity for the company but also for patients. He believes that Winrevair will be a “paradigm shift” for PAH patients, providing them with significant improvements in their ability to exercise and move around.
The rights to Winrevair were obtained by Merck through its acquisition of Acceleron Pharma in 2021. At the time, Merck estimated that the PAH market would be worth approximately $7.5 billion by 2026.
The FDA’s approval of Winrevair is based on data from a late-stage trial involving over 300 patients with moderate-stage PAH who were already taking another medication for the condition. The study showed that patients treated with Winrevair in combination with an existing therapy were able to walk about 40.8 meters more in six minutes compared to those who received a placebo.
Winrevair also demonstrated significant improvements in eight out of nine secondary goals in the study, including an 84% reduction in the risk of death or worsening of the condition compared to the existing drug alone. The trial also found that severe and serious adverse events were less common in the group of patients who took Winrevair.
Some of the side effects of Winrevair include nose bleeds, headaches, and rashes. However, one notable advantage of the drug is that it can be self-administered by patients or caregivers, as it can be injected under the skin with appropriate training from a healthcare provider. This offers convenience to patients who prefer to receive treatment at home rather than at an infusion center.
Merck is continuing to study Winrevair in other phase two and phase three trials. These trials include late-stage studies on patients with more advanced PAH and those within the first year after diagnosis. Merck expects these trials to be completed around 2025 and 2026.
Overall, the FDA’s approval of Winrevair marks a significant breakthrough in the treatment of PAH. This drug offers hope to patients by targeting the root cause of the condition and providing significant improvements in their ability to exercise and carry out daily activities. With its potential for substantial sales, Winrevair is expected to be a major growth driver for Merck, contributing to the company’s revenue diversification strategy.
