Patients with pulmonary arterial hypertension (PAH) suddenly have a new and potentially powerful treatment option available to them, following the FDA approval of Merck’s sotatercept-csrk, which will be marketed as Winrevair in the US.
- PAH is a rare (40k patients in the US) and usually fatal disease caused by the overproduction of activin proteins.
- Although evolving treatments have helped improve PAH symptoms, available medications haven’t made much of an impact on mortality rates.
Sotatercept emerges as the first activin signaling inhibitor PAH treatment, directly targeting and trapping the proteins that are overproduced in PAH patients, and potentially reversing the blood vessel narrowing and right ventricle damage that it’s known to create.
- Sotatercept is an add-on to standard-of-care PAH therapies, available in 45 mg and 60 mg injections that are administered every 3 weeks.
The approval relied on sotatercept’s STELLAR trial, which found that patients taking sotatercept had far greater improvements to 6-minute walk distances over 24 weeks (+41 vs. +1 meters) compared to patients taking standard therapies and a placebo, with lower rates of all-cause death or nonfatal clinical PAH worsening (5% vs. 26%).
- Sotatercept was also well tolerated, although it still does increase hemoglobin and can carry bleeding risks.
Sotatercept is widely viewed as a strategic win for Merck, which acquired Acceleron for rights to sotatercept for $11.5B in 2021, hoping to bulk up its portfolio before its blockbuster cancer drug Keytruda goes off patent in 2028.
- Some analysts are forecasting that sotatercept will generate $2B to $5B annually by 2030, with 20% of sotatercept revenue going in royalties to Bristol Myers Squibb.
If you’re wondering how a drug with 40k potential patients can bring in $5B, Merck plans to charge a wholesale price of $14k per vial of sotatercept, which will add up to around $243k per patient annually.
- That’s way more than what some would view as fair, noting that the Institute for Clinical and Economic Review estimated sotatercept’s clinical value at roughly $35k per year.
- However, Merck appears well set up to execute its Winrevair strategy, noting that it has marketed its existing PAH drug Adempas for over a decade.
The Takeaway
PAH diagnoses have long been viewed as fatal, and although sotatercept still has lots to prove, it appears that this new drug is on a path to becoming a key part of a redefined PAH standard-of-care, while giving these patients better and potentially longer lives.
