Stunning topline results from Merck Winrevair’s Phase 3 ZENITH trial found that the drug significantly reduced morbidity and mortality risks in patients with pulmonary arterial hypertension, paving the way for stronger commercialization and further functional trials.
- PAH is a rare, progressive disease that increases blood pressure in the lungs, forcing the heart to pump harder.
- Approximately 40,000 people in the U.S. are living with PAH, with a five-year mortality rate of 43%.
- Winrevair (sotatercept-csrk) already received FDA approval earlier this year, and the strong results further validate Merck’s $11.5B acquisition of Acceleron.
The ZENITH trial randomized 172 patients to either receive Winrevair and background PAH therapy, or placebo and PAH therapy. All patients had PAH functional class III or IV and were at high risk of mortality.
Winrevair successfully met ZENITH’s composite primary endpoint of improving time to first morbidity or mortality events, including all-cause death, lung transplantation, or PAH-related hospitalization ≥24 hours.
- Adverse events weren’t serious, but headache (24.5% of recipients), nosebleeds (22.1%), and rash (20.2%) were common.
ZENITH’s results were so strong an independent data monitoring committee called for the trial to be stopped early and recommended that all participants should be offered Winrevair through an open-label extension study.
To become America’s go-to PAH treatment, Winrevair will have to compete with two of Johnson & Johnson’s rapidly expanding drugs:
- Uptravi – A prostacyclin receptor agonist.
- Opsumit – An endothelin receptor agonist (generated $2B in 2023 revenue).
Despite this competition, analysts expect Winrevair to generate between $2B and $5B in yearly revenue, thanks in part to its effectiveness and hefty $247k annual price tag.
- About 20% of that will go to Bristol Myers Squibb as royalties since they own Celgene, the co-developer of Winrevair.
Sotatercept might also expand beyond PAH, as Acceleron and Celgene initially investigated the compound as a treatment for disorders like osteoporosis, anemia, and multiple myeloma.
The Takeaway
Although Winevair tackles a rare disease, the impressive results from ZENITH support estimates that the drug could rake in $5B annually, while providing Merck with a strong launching point for treating other diseases with sotatercept-based therapies.
