Single-Inhaler Triple Therapy and Biologics Reshape COPD Treatment, Review Finds

Chronic obstructive pulmonary disease, or COPD, affects an estimated 300 million people worldwide and remains one of the leading causes of illness and death. A new narrative review published in Frontiers in Pharmacology brings together randomized trial data and real-world evidence to argue that the disease is entering a distinctly personalized era, in which a single inhaler combining three drugs and, for the first time, targeted biologic medicines are reshaping how patients are escalated after exacerbations. The review, written by an international team of pulmonologists and researchers, emphasizes that a substantial gap still separates guideline recommendations from what actually happens in clinics, particularly in the vulnerable weeks following a severe flare-up.

The first pillar of this transformation is single-inhaler triple therapy, known as SITT. The approach combines an inhaled corticosteroid, a long-acting beta2-agonist and a long-acting muscarinic antagonist in one device. Large phase 3 trials such as IMPACT and ETHOS established that fixed triple combinations reduce moderate-to-severe exacerbations compared with dual inhaled regimens, with additional benefits on lung function and health status, although reported mortality signals require cautious interpretation because of trial duration and the possible influence of prior corticosteroid use or withdrawal. Within triple therapy, the single-inhaler format is now generally preferred over multiple-inhaler regimens because merging the drugs into one device can improve adherence, persistence and inhalation technique while promoting synergy between molecules.

Real-world data reinforce that preference. In the SKOPOS-MAZI study, a large propensity-matched cohort comparing budesonide/glycopyrronium/formoterol Aerosphere with multiple-inhaler triple therapy in nearly 19,000 patients, the single-inhaler regimen was associated with an 18 percent lower risk of all-cause mortality, a 12 percent lower risk of severe cardiopulmonary events, and better treatment persistence, including a 37 percent higher persistence, a 32 percent lower exacerbation risk and a 33 percent lower mortality risk reported in a separate 12-month comparative study. The review’s authors are careful to note that no head-to-head randomized trial has compared the two strategies, so these observational findings demand cautious causal interpretation.

Consistent signals come from other settings. The Spanish ORESTES study followed 718 patients with advanced disease burden, including a high proportion with comorbidities and significant breathlessness, and found that after starting budesonide/glycopyrronium/formoterol, moderate and severe exacerbation rates fell by 20.8 percent and 23.1 percent respectively, while hospitalizations declined by 24.7 percent, with 89.3 percent of patients completing 12 months of treatment. A large retrospective analysis of United States Medicare claims, comparing the fluticasone furoate/umeclidinium/vilanterol formulation with budesonide/glycopyrronium/formoterol in patients stepping up from dual bronchodilator therapy, found an 18 percent lower annualized rate of moderate-to-severe exacerbations and 18 percent lower 12-month mortality with the former. The authors flag such head-to-head claims-based comparisons as hypothesis-generating, given residual confounding, but they raise the possibility that formulation differences may matter clinically.

Timing emerges as a critical and frequently overlooked variable. The MITOS EROS + CP studies showed that prompt initiation of budesonide/glycopyrronium/formoterol after an exacerbation was associated with a 26 percent lower annualized exacerbation rate compared with delayed initiation, and 31 percent lower compared with very delayed initiation. Yet Italian administrative data from the ReS database documented a mean delay of 31 to 42 days before triple therapy was started after a severe exacerbation, with only 23 percent of patients beginning single-inhaler triple therapy within 12 months of hospital discharge. The same database recorded a 12-month all-cause mortality of 25.6 percent after severe exacerbation, with 53 percent of deaths occurring within the first 30 days, underscoring the hospitalization event as a sentinel moment that demands immediate therapeutic optimization.

Functional evidence adds further depth. A systematic review and meta-analysis of seven real-world studies of the extrafine beclometasone dipropionate/formoterol/glycopyrronium formulation, covering 5,952 patients, reported pooled reductions of roughly 6 points in CAT symptom scores, exceeding the minimal clinically important difference of 2 points, alongside FEV1 improvements above 100 mL. A European pooled analysis of six prospective studies confirmed exacerbation-free rates of 91.1 percent, 83.9 percent and 64.3 percent at three, six and 12 months. The extrafine particle size allows drug deposition in the peripheral small airways, an early and sustained site of pathology in COPD, and may partly explain the observed gains. A Japanese observational study further suggested that formulation choice could be refined by individual functional profiles, with fluticasone furoate/umeclidinium/vilanterol appearing more effective in severely symptomatic patients with greater hyperinflation, and budesonide/glycopyrronium/formoterol in mildly symptomatic patients with better-preserved inspiratory capacity.

The second pillar is the arrival of biologic therapy. An estimated 20 to 40 percent of COPD patients show signs of eosinophilic type 2 inflammation, and blood eosinophil count, despite caveats such as intra-patient variability and a 300 cells per microliter threshold that sits within the upper normal range, remains the best available biomarker for predicting corticosteroid responsiveness and biologic benefit. Dupilumab, a fully human monoclonal antibody blocking the shared interleukin-4 receptor alpha subunit and thereby inhibiting IL-4 and IL-13 signaling, became the first biologic approved for COPD after the phase 3 BOREAS and NOTUS trials demonstrated 30 percent and 34 percent reductions in moderate or severe exacerbations respectively, in patients with blood eosinophils of at least 300 cells per microliter and chronic bronchitis who continued to exacerbate despite triple therapy. A prespecified analysis suggested that patients with fractional exhaled nitric oxide of 20 ppb or above achieved even greater reductions, of 36 percent and 52 percent, pointing to FeNO as a possible additional selection biomarker.

Mepolizumab, an anti-IL-5 antibody, has now provided parallel evidence through the phase 3 MATINEE trial. In 804 patients with no asthma history, blood eosinophils of at least 300 cells per microliter and persistent exacerbations on background triple therapy, mepolizumab 100 mg subcutaneously every four weeks reduced the annualized rate of moderate or severe exacerbations by 21 percent compared with placebo, and delayed the median time to first exacerbation by 98 days, from 321 to 419 days. Follow-up extended to 104 weeks, a first for a COPD biologic trial, and the safety profile was comparable to placebo. Notably, patient-reported quality-of-life measures did not reach statistical significance, indicating that the principal benefit of mepolizumab in COPD is exacerbation prevention rather than symptom relief. Earlier anti-IL-5 efforts had been mixed, with the negative GALATHEA, TERRANOVA and RESOLUTE trials of benralizumab indicating that eosinophil depletion through IL-5 receptor alpha blockade has not translated into a confirmed maintenance strategy.

Real-world dupilumab experience, though limited, is informative. A prospective cohort of 23 patients treated off-label after the BOREAS publication reported a 55 percent reduction in total exacerbation rates, and deliberately included patients who would have been excluded from randomized trials, among them seven older than 80 years, four with FEV1 below 30 percent predicted and seven dependent on oxygen. Compassionate-use series of 13 and 12 patients have described rapid improvements in symptoms, lung function and mucus-related outcomes. The review stresses that these small, uncontrolled studies are complementary rather than confirmatory, and that prospective registries are needed to define effectiveness, safety and response criteria. Beyond the type 2 pathway, tozorakimab, an antibody that inhibits both the reduced and oxidized forms of the epithelial alarmin IL-33, may broaden targeted treatment to patients without an eosinophilic signature; the phase 2a FRONTIER-4 study missed its primary endpoint but showed promising signals in a prespecified subgroup, and positive high-level phase 3 results have been announced for the OBERON, TITANIA and MIRANDA trials, though full peer-reviewed data are not yet available.

The review frames all of this within a treatable-traits framework, in which exacerbation risk, eosinophilic inflammation, hyperinflation, chronic bronchitis, comorbidities, adherence and inhaler technique are assessed individually and in combination. Modelling projections cited by the authors estimate that raising single-inhaler triple therapy adoption in Italy to 45 percent over ten years could prevent roughly 40,000 deaths and save more than 646 million euros in hospitalization costs, figures the authors present explicitly as model-based rather than demonstrated effects. The authors also acknowledge their review’s limitations, including the absence of a pre-specified selection protocol and reliance on heterogeneous observational sources in which publication bias cannot be excluded. Their overall message, however, is pragmatic: single-inhaler triple therapy is the preferred inhaled strategy for patients who need corticosteroid-containing triple therapy and should be started promptly after exacerbations, while biologics now offer a targeted add-on for the eosinophilic minority whose exacerbations persist despite optimized inhaled treatment.

Subject of Research: Real-world evidence on single-inhaler triple therapy and the emergence of biologic therapy in COPD

Article Title: COPD: real-world evidence on single-inhaler triple therapy and the emergence of biologic therapy

Article References: Da Re, B., Reccardini, N., Monteleone, G., Capparelli, E., Hughes, M., Bandini, G., Wang, Y., Confalonieri, P., Salton, F., Confalonieri, M., Semenzato, U., & Ruaro, B. (2026). COPD: real-world evidence on single-inhaler triple therapy and the emergence of biologic therapy. Frontiers in Pharmacology, 17, Article 1983112. https://doi.org/10.3389/fphar.2026.1983112

Image Credits: AI Generated

DOI: 10.3389/fphar.2026.1983112

Keywords: COPD, single-inhaler triple therapy, dupilumab, mepolizumab, tozorakimab, real-world evidence, eosinophils, biologic therapy, exacerbations, treatable traits, inhaled corticosteroids, GOLD guidelines