AstraZeneca’s Breztri Achieves Primary Endpoints in KALOS and LOGOS Phase III Trials, Marking a Significant Advance in the Treatment of Uncontrolled Asthma
AstraZeneca announced encouraging high-level results from its pivotal Phase III KALOS and LOGOS clinical trials evaluating Breztri Aerosphere (budesonide/glycopyrronium/formoterol fumarate; BGF) in patients with inadequately controlled asthma. The studies confirmed that Breztri met all of its primary endpoints, showing statistically significant and clinically meaningful improvements in lung function compared with standard dual inhaled corticosteroid/long-acting beta2-agonist (ICS/LABA) therapies. These findings signal a major advancement in asthma treatment, potentially expanding the role of Breztri beyond its currently approved use in chronic obstructive pulmonary disease (COPD).
Breztri, a fixed-dose, triple-combination inhaled therapy consisting of an inhaled corticosteroid (ICS: budesonide), a long-acting muscarinic antagonist (LAMA: glycopyrronium), and a long-acting beta2-agonist (LABA: formoterol fumarate), was previously approved for the treatment of COPD in over 80 countries, including major markets such as the United States, European Union, Japan, and China. The results from the KALOS and LOGOS trials now underscore the potential for this therapeutic regimen to become a new standard of care for asthma patients who remain symptomatic despite existing dual maintenance therapy.
KALOS and LOGOS: Trial Overview
Both KALOS and LOGOS were replicate, randomized, double-blind, parallel-group Phase III clinical trials designed to rigorously assess the efficacy and safety of Breztri compared with conventional ICS/LABA therapies in adults and adolescents with uncontrolled asthma. These studies enrolled a diverse population of patients whose asthma symptoms persisted despite standard maintenance therapy. Importantly, the trial designs allowed for a direct comparison between Breztri and the current therapeutic norm, thereby demonstrating the incremental benefit of adding a LAMA (glycopyrronium) to the conventional ICS/LABA backbone.
The studies evaluated key lung function outcomes, including changes in forced expiratory volume in one second (FEV₁), which is a central metric for determining the severity and control of asthma. According to AstraZeneca’s announcement, Breztri delivered significant improvements across these parameters, surpassing the improvements seen in the dual-therapy control arms. These findings not only met the primary endpoints but also align with growing evidence supporting the use of triple therapy in patients with uncontrolled respiratory disease.
A Global Respiratory Health Challenge
Asthma is one of the most prevalent chronic diseases worldwide, affecting an estimated 262 million people, according to data from the World Health Organization (WHO). It is characterized by chronic inflammation of the airways, bronchoconstriction, and variable airflow obstruction. Common symptoms include shortness of breath, wheezing, chest tightness, and persistent coughing. Although many patients can achieve good control with existing treatments, a significant proportion—nearly 50%—remain symptomatic and inadequately controlled despite dual maintenance therapies, such as ICS/LABA combinations. This suboptimal control can result in frequent exacerbations, hospitalizations, and reduced quality of life.
For these patients, novel therapeutic approaches that target multiple mechanisms of the disease in a single inhaler offer a promising path forward. Breztri’s triple-combination formula addresses inflammation, bronchoconstriction, and airway smooth muscle relaxation through its three complementary components, potentially offering a more robust and sustained control of asthma symptoms.
Expert Perspectives on the Trial Results
Leading investigators involved in the trials expressed optimism about the implications of the data. Professor Alberto Papi, Chair of Respiratory Medicine at the University of Ferrara and Director of the Respiratory Unit at S. Anna University Hospital in Italy, served as one of the primary investigators for the KALOS and LOGOS trials. In response to the positive findings, Professor Papi stated:
“Despite advancements in asthma treatments, millions of patients remain uncontrolled, which can cause frequent breathlessness, coughing and wheezing, significantly impacting their ability to perform daily activities. The results from the KALOS and LOGOS trials are exciting and demonstrate the potential of budesonide/glycopyrronium/formoterol to evolve the standard of care to more effectively treat asthma in a single inhaled triple therapy for patients who remain uncontrolled with dual maintenance therapy.”
This sentiment was echoed by Sharon Barr, Executive Vice President of BioPharmaceuticals R&D at AstraZeneca. Commenting on the broader significance of the data, Barr noted:
“We are excited by the positive results from the KALOS and LOGOS trials, which demonstrate that Breztri could help improve the lives of the millions of patients living with asthma. These asthma data build on the well-established profile of Breztri in COPD, and we look forward to sharing with regulatory authorities to bring this important medicine to a wider group of patients.”
Safety Profile and Tolerability
An important aspect of Breztri’s profile is its safety and tolerability. AstraZeneca confirmed that no new safety signals emerged during the KALOS and LOGOS studies. This reinforces the overall benefit-risk balance of the therapy and strengthens the case for regulatory submission in the asthma indication. The absence of new adverse events is particularly notable given that Breztri is already approved in COPD and has an established safety record in that population.
As with all respiratory medicines, ongoing post-marketing surveillance and real-world evidence will be essential in fully characterizing long-term safety, especially as the patient population expands beyond COPD to include younger and potentially more diverse asthma populations.
Regulatory Pathway and Next Steps
Following these high-level results, AstraZeneca plans to share the full clinical data with global regulatory authorities. The company also intends to present the findings at an upcoming medical congress, where additional secondary endpoints and subgroup analyses are expected to be disclosed. These presentations will provide greater insight into how Breztri performs across different asthma phenotypes, age groups, and levels of disease severity.
If approved, Breztri would become one of the few fixed-dose triple-combination inhalers available for asthma, potentially reshaping treatment algorithms and guideline recommendations for patients not adequately managed by current therapies. Regulatory filings in key markets, including the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA), are anticipated later this year.
Breztri’s Position in AstraZeneca’s Respiratory Portfolio
The success of Breztri in asthma further cements AstraZeneca’s leadership in respiratory medicine. The company has long invested in the development of inhaled therapies, biologics, and precision medicine approaches for both asthma and COPD. Breztri’s established track record in COPD, combined with these new findings in asthma, positions it as a cornerstone therapy for obstructive lung diseases across the severity spectrum.
Beyond Breztri, AstraZeneca is also advancing a range of biologics—including Tezspire (tezepelumab), which was approved for severe asthma and targets thymic stromal lymphopoietin (TSLP)—as well as digital inhaler technologies aimed at enhancing adherence and optimizing inhaler technique.
The positive outcomes from the Phase III KALOS and LOGOS trials mark a critical step forward for patients with uncontrolled asthma and support the growing body of evidence favoring triple-combination therapy in respiratory care. Breztri Aerosphere’s ability to significantly improve lung function over standard ICS/LABA treatment holds promise for millions of patients globally who struggle to control their asthma symptoms. With regulatory submissions on the horizon, Breztri is poised to become an essential tool in the asthma treatment arsenal, offering new hope for improved disease control and quality of life.
