Why is brensocatib attracting so much attention?

Brensocatib represents a new treatment approach for non-cystic fibrosis bronchiectasis. Instead of primarily treating infection or helping clear mucus, it targets a biological pathway involved in damaging neutrophilic inflammation.

Brensocatib has generated considerable interest in respiratory medicine following publication of the Phase 3 ASPEN trial in 2025 and subsequent regulatory approvals.

On 12 August 2025, the United States Food and Drug Administration approved brensocatib, marketed as Brinsupri, for adults and adolescents aged 12 years and over with non-cystic fibrosis bronchiectasis.

The Medicines and Healthcare products Regulatory Agency then granted UK marketing authorisation on 20 February 2026. This made brensocatib the first medicine licensed in the UK specifically for non-cystic fibrosis bronchiectasis.

Why this is different

Brensocatib is not an antibiotic, mucus-thinning treatment or inhaler. It is a once-daily oral medicine that targets an inflammatory pathway associated with bronchiectasis exacerbations and airway damage.

What is brensocatib?

Brensocatib is a first-in-class oral medicine developed by Insmed. Its brand name is Brinsupri.

It is designed for people with non-cystic fibrosis bronchiectasis, a chronic lung condition in which permanent airway widening and damage make mucus more difficult to clear.

Retained mucus can trap bacteria, contributing to recurrent chest infections, persistent inflammation and further airway damage.

Traditional treatment has focused on airway clearance, antibiotics, exercise, vaccination and management of underlying causes. These remain important. Brensocatib introduces a new option by targeting part of the inflammatory process itself.

Who is included in the UK licence?

The UK marketing authorisation covers patients aged 12 years and over with non-cystic fibrosis bronchiectasis who have experienced two or more exacerbations, or episodes of worsening symptoms, during the previous 12 months.

How does brensocatib work?

Bronchiectasis is often associated with excessive neutrophilic inflammation. Neutrophils are white blood cells that help defend the body against infection.

When neutrophils become overactive, they can release large amounts of enzymes called neutrophil serine proteases. These enzymes can damage airway tissue, increase mucus production and perpetuate inflammation.

Neutrophils produce inflammatory enzymes Neutrophil serine proteases are produced inside developing neutrophils before the cells enter the circulation.
DPP1 activates those enzymes Dipeptidyl peptidase 1, abbreviated to DPP1, is required to activate several neutrophil serine proteases.
Brensocatib inhibits DPP1 By blocking DPP1, brensocatib reduces activation of the inflammatory enzymes within newly formed neutrophils.
Airway enzyme activity is reduced As treated neutrophils reach the lungs, less active protease is available to contribute to airway inflammation and tissue damage.

Does brensocatib suppress the whole immune system?

Brensocatib targets a specific enzyme pathway involved in neutrophil protease activation. It is not generally described as a broad immunosuppressive medicine.

Nevertheless, its benefits and potential risks must still be considered carefully for each patient, particularly as wider real-world experience develops.

Understanding the treatment gap in bronchiectasis

Non-cystic fibrosis bronchiectasis is characterised by permanently damaged airways, impaired mucus clearance and recurrent respiratory infections.

Common symptoms include:

Persistent or recurrent cough
Daily sputum or phlegm production
Repeated chest infections
Breathlessness
Fatigue
Reduced exercise tolerance
Coughing up blood
Slow recovery after exacerbations

Antibiotics can treat bacterial exacerbations and may reduce infection frequency when used long term in selected patients. Airway-clearance physiotherapy helps remove mucus, while inhaled and nebulised treatments may improve symptoms.

Until brensocatib, however, there was no medicine licensed specifically for bronchiectasis that directly targeted the neutrophilic inflammatory pathway.

Clinical trials of brensocatib

Brensocatib was evaluated in two major randomised, placebo-controlled clinical trials: WILLOW and ASPEN.

Phase 2

The WILLOW trial

WILLOW included 256 adults with non-cystic fibrosis bronchiectasis and a history of at least two exacerbations during the previous year.

Participants received brensocatib 10 mg, brensocatib 25 mg or placebo once daily for 24 weeks.

The study found evidence of a longer time to first exacerbation and reduced neutrophil serine protease activity.

Phase 3

The ASPEN trial

ASPEN included 1,680 adults and 41 adolescents with non-cystic fibrosis bronchiectasis.

Participants received brensocatib 10 mg, brensocatib 25 mg or placebo once daily for 52 weeks.

The primary outcome was the annualised rate of pulmonary exacerbations over one year.

Feature	WILLOW	ASPEN
Trial phase	Phase 2	Phase 3
Participants	256 adults	1,680 adults and 41 adolescents
Treatment period	24 weeks	52 weeks
Treatment groups	10 mg, 25 mg or placebo	10 mg, 25 mg or placebo
Core purpose	Explore efficacy, biological effect and safety	Confirm exacerbation reduction and safety in a larger population

What did the ASPEN trial show?

The ASPEN trial found that both once-daily brensocatib doses reduced the annualised rate of pulmonary exacerbations compared with placebo.

The treatment also increased the proportion of patients who remained free from exacerbations during the study period.

52 weeks

Duration of treatment in the pivotal Phase 3 ASPEN trial.

10 mg and 25 mg

Both once-daily doses reduced exacerbation rates compared with placebo.

25 mg

The 25 mg group also showed a smaller decline in FEV1 than the placebo group.

What about quality of life?

Patient-reported outcome measures showed some improvement, but not every quality-of-life comparison reached the prespecified threshold for statistical significance.

This means the evidence for reducing exacerbations is clearer than the evidence for producing a large improvement in daily symptoms for every patient.

Does it prevent disease progression?

The trial provides encouraging information about exacerbation reduction and lung-function decline, particularly with the 25 mg dose.

Longer follow-up and real-world studies are still needed to determine whether treatment consistently changes the long-term course of bronchiectasis or delays structural disease progression.

What are the possible side effects?

Overall adverse-event rates in the major trials were broadly similar between the brensocatib and placebo groups, although some specific effects occurred more frequently with brensocatib.

Nose and throat infections
Diarrhoea
Vomiting or nausea
Headache
Gum or periodontal problems
Skin thickening or hyperkeratosis
Skin rash or dermatitis
Hair loss

Dental and skin monitoring

DPP1 is involved in biological processes outside the lungs. Dental, periodontal and skin effects therefore received particular attention during the clinical-development programme.

Patients prescribed brensocatib should follow the monitoring and safety advice provided by their specialist and report new gum, dental, skin or hair symptoms.

The complete safety profile will become clearer as more patients use the medicine outside clinical trials and longer-term pharmacovigilance data accumulate.

From clinical trial to licensed medicine

2020 WILLOW results published Phase 2 findings supported further investigation of DPP1 inhibition in bronchiectasis.
April 2025 ASPEN results published The Phase 3 study confirmed a reduction in annualised pulmonary exacerbation rates.
12 August 2025 FDA approval Brinsupri became the first FDA-approved treatment specifically for non-cystic fibrosis bronchiectasis.
November 2025 European approval Brinsupri received European authorisation for eligible patients aged 12 years and over.
20 February 2026 UK marketing authorisation The MHRA licensed brensocatib for eligible UK patients aged 12 years and over.

When will brensocatib be available in the UK?

Brensocatib is now licensed in the UK. It can legally be prescribed within the terms of its marketing authorisation once the medicine is commercially supplied and an appropriate prescriber considers it suitable.

Licensing does not automatically create routine NHS access. NICE must assess clinical effectiveness and cost-effectiveness before recommending routine NHS funding in England.

NICE currently lists its appraisal as in development, but the evaluation has been paused at the request of the manufacturer. No final publication date has been announced.

Could private prescribing happen sooner?

Private prescribing may become possible once the licensed medicine is commercially available in the UK and a specialist believes that the patient meets the indication and is clinically suitable.

Availability, cost, monitoring arrangements and local pharmacy supply may influence when private treatment becomes practically accessible.

What about NHS availability?

Routine NHS availability in England is unlikely before a NICE recommendation or another formal commissioning arrangement.

Patients should avoid relying on speculative launch dates. NICE currently gives no confirmed publication date for its appraisal.

Why could brensocatib be a breakthrough?

Fewer exacerbations

The strongest demonstrated benefit is a reduction in the rate of pulmonary exacerbations in patients at increased risk.

A new biological target

Brensocatib targets neutrophilic inflammation rather than primarily targeting bacteria, mucus or airway narrowing.

Once-daily tablet

Oral once-daily dosing may be more convenient than treatments requiring repeated nebulisation or complex equipment.

The term “game-changer” should still be used carefully. Brensocatib does not cure bronchiectasis, reverse established airway damage or remove the need for airway clearance and infection management.

Not every patient will meet the licensed indication, tolerate the medicine or experience the same degree of benefit.

A major advance, not a cure

Brensocatib adds the first licensed anti-inflammatory treatment developed specifically for non-cystic fibrosis bronchiectasis, but it should form part of a complete, individualised bronchiectasis management plan.

What treatment remains important alongside brensocatib?

Brensocatib does not replace the established foundations of bronchiectasis management.

Individualised airway-clearance physiotherapy
Regular physical activity where appropriate
Sputum cultures when symptoms change
Prompt treatment of bacterial exacerbations
Vaccination where eligible
Smoking cessation
Management of asthma or COPD where present
Treatment of reflux or aspiration risk
Investigation of underlying causes
Long-term antibiotic review where indicated

A specialist would need to consider exacerbation history, microbiology, current medicines, comorbidities, dental and skin health, and the balance between expected benefit and potential adverse effects.

Conclusion

Brensocatib is a major milestone in bronchiectasis treatment. It is the first licensed medicine designed specifically to reduce DPP1-mediated neutrophilic inflammation in non-cystic fibrosis bronchiectasis.

The ASPEN trial showed that once-daily brensocatib reduced pulmonary exacerbation rates compared with placebo. The 25 mg dose also produced evidence of a smaller decline in lung function over 52 weeks.

The medicine is now authorised in the United States, European Union and United Kingdom for patients aged 12 years and over within the relevant licensed criteria.

UK marketing authorisation does not yet mean routine NHS access. NICE’s appraisal remains paused, and there is currently no confirmed date for a funding recommendation.

Real-world evidence will be important in determining how much benefit patients experience outside clinical trials, which groups benefit most and whether treatment alters long-term disease progression.

Frequently asked questions

Is brensocatib approved in the UK?

Yes. The MHRA granted UK marketing authorisation in February 2026 for eligible patients aged 12 years and over with non-cystic fibrosis bronchiectasis and at least two exacerbations during the previous 12 months.

Is brensocatib currently available on the NHS?

Routine NHS availability has not yet been recommended. NICE’s appraisal is currently paused at the request of the manufacturer, with no confirmed final publication date.

Is brensocatib an antibiotic?

No. Brensocatib is a DPP1 inhibitor. It targets a pathway involved in activation of inflammatory neutrophil enzymes rather than directly killing bacteria.

Does brensocatib cure bronchiectasis?

No. It does not reverse established airway widening or cure the underlying condition. Its demonstrated benefit is mainly a reduction in pulmonary exacerbations in eligible patients.

Who may be eligible for brensocatib?

Under the UK licence, eligibility includes patients aged 12 years and over with non-cystic fibrosis bronchiectasis who have experienced at least two exacerbations during the preceding 12 months. A specialist must still determine whether treatment is appropriate.

How is brensocatib taken?

Brensocatib is taken as an oral tablet once daily. The prescribed strength and monitoring arrangements depend on the applicable licence and specialist assessment.

What side effects can brensocatib cause?

Reported effects include gastrointestinal symptoms, headache, nose and throat infection, gum or periodontal problems, hyperkeratosis, rash, dermatitis and hair loss. Patients should follow the monitoring advice provided by their prescriber.

Will I still need airway-clearance physiotherapy?

Yes. Brensocatib does not replace airway clearance, sputum-guided infection treatment, exercise, vaccination or management of underlying causes.

References and regulatory sources

Chalmers JD, et al. Phase 3 Trial of the DPP-1 Inhibitor Brensocatib in Bronchiectasis. New England Journal of Medicine. 2025. View publication
U.S. Food and Drug Administration. Drug Trials Snapshot: Brinsupri. View FDA information
Medicines and Healthcare products Regulatory Agency. Brensocatib licensed for non-cystic fibrosis bronchiectasis. Published 23 February 2026. View MHRA announcement
National Institute for Health and Care Excellence. Brensocatib for treating non-cystic fibrosis bronchiectasis in people aged 12 years and over. View NICE appraisal status
European Medicines Agency. Brinsupri European Public Assessment Report. View EMA information

Brensocatib: Is this breakthrough a Game-Changer for Bronchiectasis?

Brensocatib: Is This Breakthrough a Game-Changer for Bronchiectasis?

Now licensed in the UK

NHS access is not yet routine