Biologic Therapies for Severe Asthma and Triple Therapy for COPD: A New Era in Respiratory Medicine

Introduction

Respiratory diseases represent a significant global health burden, with asthma affecting over 300 million people worldwide and chronic obstructive pulmonary disease (COPD) ranking as the third leading cause of death globally. For patients with severe, uncontrolled disease, conventional treatments often prove inadequate, leading to frequent exacerbations, hospitalisations, and a profoundly diminished quality of life.

The past decade has witnessed a paradigm shift in respiratory medicine, driven by two major therapeutic advances: biologic therapies targeting specific inflammatory pathways in severe asthma, and single-inhaler triple therapy (SITT) for COPD. These innovations have transformed outcomes for patients who previously had few effective treatment options.

Hong Kong, with its world-class respiratory medicine centres and specialists trained at leading international institutions, is ideally positioned to offer GCC patients access to these cutting-edge treatments within a Muslim-friendly healthcare environment.

Understanding Severe Asthma: Beyond Conventional Treatment

Approximately 5–10% of asthma patients have severe disease that remains uncontrolled despite high-dose inhaled corticosteroids and long-acting beta-agonists. These patients account for a disproportionate share of asthma-related healthcare costs, hospitalisations, and mortality. Many require frequent courses of oral corticosteroids, which carry significant long-term side effects including osteoporosis, diabetes, adrenal suppression, and immunosuppression.

The recognition that severe asthma is not a single disease but a collection of distinct phenotypes — characterised by different underlying inflammatory mechanisms — has been the key insight driving the development of targeted biologic therapies. The most important distinction is between Type 2 (T2)-high asthma, driven by eosinophilic inflammation and elevated biomarkers such as blood eosinophils and fractional exhaled nitric oxide (FeNO), and T2-low asthma, which remains more challenging to treat.

Biologic Therapies: Precision Medicine for Severe Asthma

Six biologic agents are now approved for severe asthma, each targeting a specific component of the inflammatory cascade:

Dupilumab: Long-Term Evidence

Dupilumab, which blocks both IL-4 and IL-13 signalling through the IL-4 receptor alpha subunit, has emerged as one of the most widely prescribed biologics for severe asthma. A 2025 study published in the Journal of Allergy and Clinical Immunology: Global reported long-term outcomes in 160 patients treated with dupilumab for up to 36 months. The study found that 59% of patients continued therapy beyond three years, with sustained reductions in exacerbation rates and oral corticosteroid use.

Tezepelumab: A Paradigm Shift

Tezepelumab represents a particularly significant advance because it targets thymic stromal lymphopoietin (TSLP), an upstream epithelial cytokine that initiates multiple inflammatory cascades. Unlike other biologics that are effective primarily in T2-high asthma, tezepelumab has demonstrated efficacy across a broader patient population, including those with lower eosinophil counts.

A multinational retrospective cohort study published in the Journal of Allergy and Clinical Immunology: In Practice in 2025 compared real-world outcomes of tezepelumab and dupilumab. The study found that both biologics provided consistent reductions in asthma exacerbations and systemic corticosteroid use over one year, with similar efficacy profiles in clinical practice.

Achieving Clinical Remission

The concept of clinical remission in asthma — defined as the absence of exacerbations, normalisation of lung function, and elimination of oral corticosteroid use — has emerged as a new treatment goal. Recent data from biologic trials suggest that clinical remission is achievable in a significant proportion of patients, fundamentally changing the prognosis of severe asthma from a disease of inevitable decline to one that can be effectively controlled.

COPD: The Triple Therapy Revolution

Chronic obstructive pulmonary disease (COPD) is characterised by persistent airflow limitation and is associated with significant morbidity and mortality. The management of COPD has been transformed by the development of single-inhaler triple therapy (SITT), which combines an inhaled corticosteroid (ICS), a long-acting muscarinic antagonist (LAMA), and a long-acting beta-agonist (LABA) in a single device.

The ETHOS and IMPACT Trials

Two landmark randomised controlled trials have established the evidence base for triple therapy in COPD:

The ETHOS Trial (Efficacy and Safety of Triple Therapy in Obstructive Lung Disease), published in the New England Journal of Medicine, enrolled over 8,500 patients with moderate to very severe COPD. The 52-week trial demonstrated that triple therapy with budesonide/glycopyrrolate/formoterol (BGF) significantly reduced the rate of moderate or severe COPD exacerbations compared to dual therapy. Most notably, the higher-dose ICS triple therapy regimen reduced all-cause mortality by 46% compared to LAMA/LABA dual therapy.

The IMPACT Trial (Informing the Pathway of COPD Treatment) enrolled over 10,000 patients and demonstrated similar benefits for fluticasone furoate/umeclidinium/vilanterol triple therapy, with significant reductions in exacerbations and hospitalisations compared to dual therapy.

A 2025 post-hoc analysis of the ETHOS trial, published in the American Journal of Respiratory and Critical Care Medicine, further demonstrated that triple therapy reduced cardiovascular endpoints and severe cardiopulmonary events compared to LAMA/LABA dual therapy — a finding of particular relevance given the high cardiovascular comorbidity burden in COPD patients.

Interventional Pulmonology: Bronchial Thermoplasty and Endobronchial Valves

Beyond pharmacological advances, interventional pulmonology has introduced novel procedures for patients with refractory respiratory disease:

Bronchial Thermoplasty delivers controlled radiofrequency energy to the airway smooth muscle in patients with severe, persistent asthma. By reducing smooth muscle mass, the procedure decreases bronchoconstriction and has been shown to reduce severe exacerbations and emergency department visits for up to five years post-treatment.

Endobronchial Valve Therapy offers a minimally invasive alternative to lung volume reduction surgery for patients with severe emphysema. Small one-way valves are placed bronchoscopically to redirect airflow away from hyperinflated, non-functional lung segments, allowing healthier regions to expand and function more effectively. A 2024 review in Precision Clinical Medicine confirmed the efficacy and safety of this approach.

Why Choose Hong Kong for Respiratory Treatment?

Hong Kong offers several compelling advantages for GCC patients seeking advanced respiratory care:

Comprehensive diagnostic capabilities: Hong Kong's respiratory centres offer complete pulmonary function testing, cardiopulmonary exercise testing, exhaled nitric oxide measurement, and advanced imaging — all essential for accurate phenotyping and treatment selection.

Access to the latest biologics: All six approved biologic therapies for severe asthma are available in Hong Kong, allowing specialists to select the optimal agent based on each patient's biomarker profile and clinical characteristics.

Multidisciplinary approach: Complex respiratory patients benefit from integrated care involving pulmonologists, allergists, immunologists, and thoracic surgeons, ensuring comprehensive management of both airway disease and comorbidities.

Muslim-friendly healthcare: Hong Kong's hospitals provide halal meal options, prayer facilities, and culturally sensitive care to ensure GCC patients feel welcome and comfortable throughout their treatment.

Conclusion

The treatment landscape for severe asthma and COPD has been transformed by biologic therapies and triple inhalation therapy. These advances offer hope to millions of patients worldwide who previously had limited treatment options. Hong Kong's respiratory medicine specialists, including Dr. Wong King Ying — a fellowship-trained respiratory physician with qualifications from the University of Hong Kong and the Royal Colleges of Physicians of Edinburgh and Glasgow — are equipped to deliver these cutting-edge treatments with the highest standards of clinical care.

For GCC patients living with severe respiratory disease, Hong Kong represents an excellent destination for accessing the latest evidence-based treatments in a welcoming, culturally sensitive environment. Early specialist assessment and appropriate biologic or triple therapy initiation can dramatically improve quality of life and reduce the burden of disease.

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This article is authored by Dr. Wong King Ying, MB BS (HK), BSc (Biomedical Sc) (HK), MRCP (UK), FRCP (Edin), FRCP (Glasg), FHKAM (Medicine), FHKCP, Specialist in Respiratory Medicine. The information provided is for educational purposes and should not replace professional medical advice.