How Should Biologic Therapy Apply in Pediatric Asthma?

Children with asthma should undergo more stringent evaluation to determine the most appropriate and effective therapies, according to a paper published in the special asthma issue of the Journal of Clinical Medicine.

The review, from a pediatric respiratory specialist at the Imperial College & Royal Brompton Harefield NHS Foundation Trust in London, examined the current literature in order to provide an update on the approach to pediatric asthma when a prescription biologic, such as omalizumab or mepolizumab, are being considered. Given the expense, it is important to highlight the differences between the adult and pediatric data that currently exists, wrote Andrew Bush, MD, adding that it is “dangerous” to extrapolate adult data to apply to children.

Most children with severe therapy resistant asthma (STRA) may not actually have STRA, he said. If a child does not respond to a low-dose inhaled corticosteroid (ICS), health care providers should ask why—it is possible that the asthma diagnosis is incorrect; that there is nonadherence to therapy; that the medication is being used incorrectly.

New concepts of severe asthma would also help, as asthma is an umbrella term that should be discarded, Bush wrote. These sometimes-arbitrary guidelines dictate prescribed levels of medication, which isn’t necessarily effective. Half of asthma deaths were in those who would not have been classified has having severe asthma, he wrote, noting a UK National Review of Asthma Deaths. Instead, those deaths were related to environmental and social factors, not difficult airway pathology.

When a child is referred with respiratory symptoms, the first step should be is a detailed history and examination to rule out other diagnoses such as vascular ring or bronchiectasis. If asthma is confirmed, then a multi-disciplinary assessment should be made to place the child in a more specific category: asthma plus comorbidities; "difficult" asthma, which he described as asthma that could be controlled if the basics were achieved, such as adhereing to ICS or removing environmental triggrs; or STRA. Then, an adequate treatment can be decided.

"We now conclude that refractory difficult asthma due to poor adherence is not a contraindication to the use of biologicals," he wrote.

Bush also discussed the merits of omalizumab and mepolizumab, 2 biologics currently approved for children. Asthma attacks and admissions to hospitals decrease with the use of omalizumab, he noted. He also said that the recommendation that mepolizumab be used as an add-on therapy for patients with severe, uncontrolled asthma was based on “moderate quality of evidence.”

He also cautioned against using adult data and applying it to pediatric populations with asthma, and urged more clinical trials in children. He also urged that

catchall terms like “asthma” should be abandoned in favor of labeling endotypes in a practical and specific way.

“If the basics are got right, and low-dose ICS are used regularly and correctly, then most asthma becomes a disease that is eminently treatable,” he said.

Reference

Bush A. Which child with asthma is a candidate for biological therapies? J. Clin. Med. 2020. 9(4);1237; doi:10.3390/jcm9041237.