The recent approval from the Food and Drug Administration for Merck’s new drug marks a significant breakthrough in treating a severe lung condition, benefitting both the pharmaceutical company and patients grappling with this rare disease.
Referred to as Winrevair, the FDA has given the green light to this therapy for adults afflicted with pulmonary arterial hypertension.
This decision is particularly monumental for the approximately 40,000 individuals in the U.S. afflicted by this ailment, as Winrevair stands out as the first medication to directly address the underlying cause of the condition. Unlike existing treatments that merely alleviate symptoms, Winrevair targets the root issue.
Pulmonary arterial hypertension involves the narrowing of blood vessels in the lungs, leading to elevated blood pressure in the arteries transporting blood from the heart to the lungs.
This condition can severely compromise heart function and limit physical activity, with a distressingly high mortality rate of 43% within five years of diagnosis, according to Merck.
Merck anticipates Winrevair’s availability in specialized pharmacies across the U.S. by the end of April, as outlined in a company statement. Administered via injection every three weeks, the drug will come in single-vial or double-vial kits.
Priced at $14,000 per vial before insurance coverage, Merck acknowledges the financial burden it may pose for patients. However, the company has established a program to assist eligible individuals with out-of-pocket expenses and copayments.
Winrevair is intended to complement existing treatments, aiming to enhance exercise capacity, mitigate the severity of pulmonary arterial hypertension, and lower the risk of disease progression.
This regulatory approval holds considerable importance for Merck, particularly as it seeks to diversify its revenue sources with the impending loss of market exclusivity for its leading cancer immunotherapy, Keytruda, in 2028.
According to a recent analysis by JPMorgan’s Chris Schott, Winrevair is projected to achieve global annual sales of approximately $5 billion by 2030, positioning it as one of Merck’s primary growth catalysts.
Merck’s Chief Medical Officer, Eliav Barr, emphasized the significance of this development, stating that it not only presents a substantial opportunity for the company but, more importantly, offers significant benefits to patients. Barr highlighted Winrevair as a potential “paradigm shift” for individuals coping with pulmonary arterial hypertension (PAH).
Merck secured the rights to Winrevair through its acquisition of Acceleron Pharma for $11.5 billion in 2021, anticipating a PAH market value of roughly $7.5 billion by 2026.
The FDA’s approval was based on data from a late-stage trial involving over 300 patients at a moderate stage of PAH who were already undergoing treatment for the condition with another medication.
The trial revealed that the combination of Winrevair and existing therapy enabled patients to walk approximately 40.8 meters farther in six minutes compared to those receiving a placebo after 24 weeks.
Barr emphasized the significant improvement in patients’ ability to exercise and engage in daily activities, noting the debilitating impact of PAH, which often confines individuals to their homes due to shortness of breath and limited mobility.
Winrevair, alongside an existing medication, also significantly enhanced eight of nine secondary objectives in the study. This includes reducing the risk of death or worsening of the condition by 84% compared to an existing drug alone.
Severe adverse events were less common among the group of patients who took Winrevair compared to those who received a placebo, according to the trial. Side effects that occurred more frequently included nose bleeds, headaches, and rashes, among others.
One notable advantage of Winrevair is that patients or caregivers can inject it under the skin with appropriate training from a healthcare provider. Meanwhile, some existing treatments for PAH must be administered by medical professionals at an infusion center.
“One of the things we heard very loud and very clear, from both patients and physicians, is that they wanted something that you could get at home,” Barr said.
Merck is continuing to study Winrevair in other phase two and phase three trials.
Those trials include late-stage studies on patients with more advanced PAH disease, and those who are within the first year after diagnosis. Merck has said it expects those trials to finish around 2025 and 2026.
