Subcutaneous treatments (sotatercept)

Page last reviewed 22^nd July 2026

Sotatercept was approved for NHS prescription for adults in the UK in the spring of 2026. It is used alongside existing treatments, and it is not suitable for everyone.

Patients must meet specific clinical criteria to be eligible for this drug, which is given as an injection under the skin every three weeks.

Sotatercept (brand name Winrevair) is a totally new type of drug for pulmonary arterial hypertension (PAH). There are already a number of existing drugs that are known as ‘vasodilators’ – which work by opening up some of the arteries that have narrowed or closed down. But these drugs are treating the symptoms of PH, rather than what’s causing the disease.

While these medicines are effective, they do not directly address the underlying changes in the lung blood vessel walls that drive PAH. This is why many patients still experience symptoms or their condition gets worse over time.

How it works

Sotatercept targets a signalling pathway involved in how blood vessels grow and repair themselves. In PAH, this system is out of balance, leading to thickening and narrowing of the lung blood vessels. Sotatercept helps to restore this balance, aiming to treat part of the underlying disease process rather than focusing only on lowering lung blood pressure.

It’s the first time a PAH drug is getting to the root cause of the problem, rather than treating the consequences of it.

Sotatercept isn’t suitable for everyone. It is designed to be taken by some people alongside other medications, via an injection under the skin administered every three weeks. It needs to be stored in the fridge and handled according to specific instructions.

What have the clinical trials shown?

Several clinical trials have studied sotatercept in people with PAH, including patients in the UK:

• In the STELLAR study, people taking sotatercept alongside their usual PAH treatment were able to walk significantly further in six minutes and had a lower risk of their condition worsening.
• The ZENITH study, which focused on people with more advanced PAH, showed a reduction in serious outcomes such as hospitalisation or death.
• In the HYPERION study, sotatercept was started earlier in treatment and improvements were seen in exercise ability and markers of heart strain.

Together, these studies show significant benefits across a range of stages of PAH. Longer-term studies are ongoing to better understand its safety and benefits over time.

Possible side effects

As with any treatment, there are possible side effects. The most commonly reported include:

• Raised blood pressure
• Headaches
• Nosebleeds
• Changes in blood counts

More rarely, some people may experience more serious events such as internal bleeding. Regular monitoring and follow-up appointments are important to ensure medical teams can check that the treatment remains safe and catch any problems early.