BRINSUPRI: Insmed's Landmark Drug Redefining Non-Cystic Fibrosis Bronchiectasis Treatment

For decades, non-cystic fibrosis bronchiectasis (NCFB) patients had no dedicated, FDA-approved therapy — relying instead on antibiotics, airway clearance techniques, and supportive care to manage a chronic and often debilitating condition. That changed with the arrival of brinsupri (brensocatib), Insmed's first-in-class oral therapy that has become the first and only approved treatment specifically indicated for NCFB. Its approval marks a watershed moment for the respiratory drug landscape and the estimated 390,000 Americans living with the disease.

A Historic Regulatory Milestone

The brinsupri fda approval represents a first on two fronts: it is the first approved therapy for NCFB and the first approved dipeptidyl peptidase 1 (DPP1) inhibitor in any therapeutic category. Supported by data from the landmark Phase III ASPEN trial and the Phase II WILLOW study — both published in the New England Journal of Medicine — the regulatory clearance was grounded in compelling clinical evidence. In the ASPEN trial, patients treated with BRINSUPRI 10 mg and 25 mg doses saw annual exacerbation rates reduced by 21.1% and 19.4%, respectively, versus placebo. The 25 mg dose also produced a statistically significant reduction in lung function decline at 52 weeks.

What Kind of Drug Is BRINSUPRI?

As a brinsupri drug, brensocatib belongs to the DPP1 inhibitor class — an entirely new category of respiratory medicine. It is an oral, once-daily small molecule that works upstream in the neutrophil activation cascade to reduce harmful airway inflammation. The drug is approved for adults and adolescents aged 12 and older, giving it a broad eligible population across the spectrum of NCFB severity.

Insmed has also been exploring expanded brinsupri market beyond NCFB. Chronic rhinosinusitis without nasal polyps (CRSsNP) and hidradenitis suppurativa are both in mid-stage clinical development, indicating that the platform potential of this molecule extends well beyond the lungs. Regulatory submissions to the EMA and MHRA are underway, with European launches anticipated in 2026.

How Does BRINSUPRI Work?

The brinsupri mechanism of action centers on the inhibition of DPP1, also known as cathepsin C — a lysosomal enzyme responsible for activating serine proteases in neutrophils during their maturation in the bone marrow. In NCFB, these overactivated neutrophil proteases drive destructive airway inflammation and the cycle of infection, mucus accumulation, and tissue damage. By blocking DPP1, brinsupril (brensocatib) reduces the release of neutrophil elastase and related enzymes, thereby interrupting the inflammatory cascade at its source rather than merely treating symptoms downstream.

Addressing a Chronic Respiratory Burden

As a brinsupri chronic lung disease treatment, the drug addresses a condition that imposes a significant and persistent burden on patients. NCFB is characterized by permanently dilated airways prone to recurrent infections and exacerbations — each episode worsening lung architecture and quality of life. The US diagnosed population is projected to grow from 390,000 in 2024 to over 470,000 by 2034, underscoring the scale of clinical need. The NCFB market itself, valued at USD 1.5 billion in 2024, is projected to exceed USD 5 billion by 2034, driven largely by mechanism-based therapies like BRINSUPRI replacing non-specific management approaches.

Pricing, Access, and Commercial Strategy

The brinsupri price has been set at approximately USD 88,000 per year before rebates and discounts — in line with other specialty respiratory therapies for chronic conditions. Insmed is commercializing the drug independently through a specialty pharmacy network, having raised around USD 750 million prior to launch to fund pre-commercial and commercial activities. Following FDA approval, Insmed's stock surged approximately 15%, including a single-day gain of 8% on the approval date. DelveInsight analysts estimate peak sales could approach USD 3 billion across the seven major markets by 2034.

Clinical Effectiveness and the Emerging Competitive Landscape

Data on brinsupri ncfbe treatment effectiveness extends beyond exacerbation reduction. Both ASPEN doses significantly delayed time to first exacerbation and increased the proportion of patients who remained exacerbation-free throughout the study period. Safety findings from both ASPEN and WILLOW showed a manageable profile, with the most common adverse events including upper respiratory tract infections, headache, rash, dry skin, and hypertension. Periodontal adverse events were observed at higher rates in WILLOW, a finding that warrants monitoring during long-term use.

Competition is beginning to emerge within the DPP1 inhibitor class. Boehringer Ingelheim's verducatib (BI 1291583) is being evaluated in the Phase III AIRTIVITY trial for NCFB patients regardless of underlying aetiology, with primary endpoints focused on annualized exacerbation rates at 76 weeks. Additional pipeline candidates from Fosun Pharma/Expedition Therapeutics, Haisco/Chiesi, and Melodia/Alivexis are also advancing. Complementary approaches targeting bacterial pathogens (CMS I-neb, Zambon) and mucosal biology (ARINA-1, Renovion) round out a pipeline that is rapidly transforming a historically stagnant therapeutic area.

Conclusion

BRINSUPRI's arrival is more than a single drug approval — it signals the maturation of a field that has long lacked targeted, approved options. With a differentiated mechanism, strong Phase III data, an expanding indication pipeline, and a first-mover position in a multi-billion-dollar market, BRINSUPRI stands to redefine the standard of care for NCFB patients globally. As global regulatory submissions progress and clinical use grows, the real-world impact of this first-in-class therapy will become increasingly clear — and for the hundreds of thousands of patients who have waited years for an approved option, that moment has finally arrived.