A groundbreaking twice-yearly injection that could spare thousands of asthma patients from life-threatening attacks is set to become available in Britain within months, offering new hope to those living with severe, uncontrolled disease.
Clinical trials show the ultra-long-acting drug, depemokimab, reduced hospital admissions by 72 per cent and was associated with minimal side effects. The injectable treatment, known as a biologic, works by using laboratory-engineered antibodies to suppress inflammation in the lungs and is expected to transform the treatment landscape for severe asthma.
The Medicines and Healthcare products Regulatory Agency (MHRA) has granted marketing authorisation for the drug, developed by British pharmaceutical giant GSK. It will be marketed under the brand name Exdensur.
Depemokimab is expected to be available privately in the first half of 2026, while the National Institute for Health and Care Excellence (NICE) considers whether it should be approved for prescription on the NHS. If approved, it would become the first asthma biologic that requires just two injections a year.
Around six million people in England are living with asthma. Of these, an estimated 58,000 adults have severe, uncontrolled disease, a form of asthma that cannot be adequately managed with inhalers alone and often requires repeated courses of steroid tablets.
We spoke to Dr Pujan Patel, consultant in respiratory medicine at the Royal Brompton Hospital and a member of Asthma + Lung UK’s Healthcare Professional Council, about why this new treatment could be so significant.
“Only about five to ten per cent of people with asthma fall into the category of severe asthma,” he explains. “These are patients who need repeated treatment, particularly repeated courses of oral steroid tablets. Needing steroids two or three times within a 12-month period is a lot.”
Biologic treatments for severe asthma have been available for around a decade, but until now they have required injections every two, four or eight weeks. “There are about five or six different biologics currently available,” Dr Patel says. “The real difference with this new drug is the frequency. It’s given once every six months, meaning just two injections a year.”
The injections are administered under the skin, typically in the thigh, abdomen or arm, and can be self-given at home, removing the need for frequent hospital visits or specialist supervision. For patients juggling work, travel or caring responsibilities, this could be life-changing.
The innovation also addresses one of the most damaging aspects of severe asthma treatment: long-term steroid use. While steroids are highly effective at controlling inflammation, repeated use, particularly in tablet form, comes at a cost.
“Asthma is fundamentally an inflammatory condition,” Dr Patel explains. “Steroids are the most potent anti-inflammatory medicines we have. But when inhalers aren’t enough and patients rely on tablets again and again, that’s where serious side effects build up.”
Studies involving tens of thousands of patients have shown that repeated courses of oral steroids significantly increase the risk of heart disease, stroke, diabetes, osteoporosis, weight gain, blood clots, infections, anxiety and depression.
“Ten years ago, clinics were full of patients who were miserable, obese and burdened with steroid-related side effects,” Dr Patel says. “Biologics have been genuinely transformative.”
In contrast, the side-effect profile of asthma biologics, including depemokimab, is comparatively mild. The most commonly reported effects include short-lived headaches, fatigue, mild injection-site soreness and, in some cases, a temporary sore throat. These symptoms typically resolve within 24 to 48 hours.
“Unlike steroid tablets, which suppress inflammation everywhere in the body, biologics target very specific inflammatory pathways in the lungs,” Dr Patel explains. “That precision is why the side effects are far fewer.”
While biologics are expensive, costing the NHS an estimated £10,000 to £15,000 per patient per year, evidence suggests they may reduce overall healthcare spending. A UK cost analysis found that patients with severe asthma account for four times the healthcare costs of those with non-severe disease, largely due to hospital admissions and treatment for steroid-related complications.
“Even though this is a small group of patients, they use a disproportionate amount of healthcare resources,” Dr Patel says. “Keeping them out of hospital and reducing long-term complications ultimately saves money.”
Depemokimab has already completed Phase 3 trials and has been approved by the US Food and Drug Administration, meaning it is expected to be rolled out in the United States this year. In the UK, NICE approval is awaited. A preliminary NICE review is expected in April 2026, with a final decision likely later in the year. If approved, patients could begin receiving the treatment on the NHS before the end of 2026.
“For people with severe asthma, this could be a game-changer,” Dr Patel says. “Two injections a year, fewer side effects, fewer hospital admissions; it represents a major step forward in how we treat this disease.”
