Challenges in severe asthma

Challenges in the management of patients with asthma

In the USA, asthma affects approximately 25 million people,³ of whom 5–10% have severe asthma.⁴

Severe asthma is defined by the Global Initiative for Asthma (GINA) as asthma that remains uncontrolled despite adherence to optimized high-dose inhaled corticosteroids (ICS) and long-acting β₂-agonist (LABA) therapy and the treatment of contributory factors, or asthma that worsens when high-dose therapy is decreased.² 

The long-term goals of severe asthma management include achieving good symptom control, reducing the future risk of exacerbations, and minimizing lung function decline and airflow limitation.² In many cases where patients have poor symptom control and/or exacerbations despite medium- or high-dose ICS and LABA therapy, their asthma may appear difficult to treat because of contributory factors, such as incorrect inhaler technique, poor adherence, smoking or comorbidities, or because of incorrect diagnosis.² For these patients, GINA recommends assessment of these contributory factors and consideration of an add-on therapy.² If problems persist, referral to a specialist center for phenotypic assessment and consideration for add-on biologic targeted treatments are recommended.² 

Confirming the diagnosis of asthma, assessing contributory factors, and optimizing treatment strategy are the key steps for consideration in the diagnosis and management of severe asthma.² 

To date, there has been great progress in the diagnosis and management of severe asthma,^5,6 with biologics representing a major advancement in the treatment landscape.⁷ However, many patients with severe asthma are poorly controlled. 

A recent study found that approximately 50% of patients with severe asthma in the USA remained suboptimally controlled despite treatment with standard-of-care medications.⁸ This significant finding was described following a retrospective and prospective analysis of the International Severe Asthma Registry – a data set including 3286 US patients receiving GINA Step 5 treatment or with severe asthma remaining uncontrolled at GINA Step 4 (December 2014 to December 2017). Poorly controlled asthma was defined in this study according to Asthma Control Test (score 5–15) or Asthma Control Questionnaire (score >1.5) categorizations.⁸

What is the impact of poorly controlled severe asthma for patients?

Below is an example of a typical patient with severe asthma. Despite adherence to daily ICS-LABA treatment, he continues to experience symptoms that hinder his daily life and remains susceptible to severe exacerbations. 

Suboptimal asthma control can have a significant impact on patient outcomes:

• Exacerbations potentially leading to hospitalization^8–10
• Increased risk of comorbidities and systemic side effects (eg, pneumonia, osteoporosis, and type 2 diabetes) associated with frequent bursts of oral corticosteroids (OCS)^11,12
• Poor quality of life (eg, activity limitation)¹³
• Increased healthcare costs¹⁴

What challenges are associated with existing treatments for poorly controlled asthma?

OCS are the primary therapy for resolution of acute exacerbations.¹⁵ However, patients with severe asthma are often exposed to multiple courses of OCS,¹⁶ and cumulative and chronic exposure is associated with an increased risk of side effects.^12,17,18 As little as 0.5–1 g (or four lifetime courses) of OCS can cause serious adverse effects, including cataracts, pneumonia, type 2 diabetes, cardiovascular disease, renal impairment, and osteoporosis.¹²

In the USA, real-world evidence studies estimate that 8–30% of patients with severe asthma have received long-term or frequent short-term courses of OCS.^8,19–22 The annualized cost of OCS-related adverse events in patients with severe asthma on low-, medium-, and high-dose OCS is estimated to be $2712, $4724, and $8560, respectively.²³

Major challenges persist owing to lack of access and inadequate response to or ineligibility for currently available treatments.¹ There are several factors restricting accessibility to treatment, including high cost and poor awareness and expertise relating to severe asthma and patient identification. This is particularly relevant to the accessibility of biologic treatments for patients with severe uncontrolled asthma, where specialist knowledge is required to phenotype and identify eligible patients.^1,24

Globally, approximately 75% of patients with poorly controlled severe asthma (GINA Step 4/5) are not receiving biologics.⁸ Improved validation and utilization of patient-reported outcome measures in clinical practice may further aid the diagnosis and management of patients with severe asthma.²⁵ To learn more about patient-reported outcomes in severe asthma, click here.