One of the first multicenter trials of a biologic agent to treat asthma in the emergency department is expected to launch in North America this year. As designed, the Tezepelumab in the Treatment of Emergency Room Asthma in Adults (TERAA) trial will randomize 100 adults with asthma exacerbations to tezepelumab or placebo at two centers in Alberta, Canada.

“Currently, all of the biologics for asthma are approved as maintenance [therapies] only,” said Diego J. Maselli, MD, FCCP, Professor and Chief of Pulmonary Diseases and Critical Care at the University of Texas Health, San Antonio. “Trends started changing in the past two years as clinicians have gotten more comfortable with the use of biologics in different settings.”

Dr. Maselli, who is also a Section Editor for the CHEST Physician publication, noted that scattered case reports have suggested clinical benefit from inpatient use of biologics in patients who were hospitalized with asthma and were not responding to systemic corticosteroids. There were also reports of biologics used successfully in the emergency department setting.

TERAA follows positive findings with benralizumab vs prednisolone or benralizumab plus prednisolone combination treatment in the single-center Acute exacerbations treated with BenRAlizumab (ABRA) trial in COPD and asthma reported in late 2024. Used in the emergency department, benralizumab showed a 74% reduction in treatment failures and better treatment outcomes compared with standard-of-care prednisolone.

“Clinicians started thinking that maybe we shouldn’t wait too long for biologics,” Dr. Maselli said. “Maybe we shouldn’t wait until patients are off prednisolone to try biologics. ABRA showed that benralizumab was safe to use in the acute setting and outcomes are potentially better than oral corticosteroids. It’s a change in the treatment paradigm we have for asthma exacerbations.”

Evidence to date suggests that biologics may be more effective than high-dose steroids in treating asthma exacerbations and reducing the risk of future exacerbations, he added.

Using biologics in the acute care setting also has the potential to spare patients the documented adverse effects of high-dose steroids and to initiate these therapies more quickly.

TERAA will randomize patients with a clinician-diagnosed history of asthma and a history of moderate to severe exacerbations. Enrollment will be offered to adults presenting in the emergency department with asthma exacerbations with at least a three-month prescription history for a high-dose inhaled corticosteroid plus a reliever such as a long-acting β₂ agonist, long-acting muscarinic antagonist, or leukotriene receptor antagonist.

The primary outcome will be the number and proportion of patients returning to the emergency department for an asthma exacerbation within 90 days.

The key secondary outcome is the proportion of patients returning to the emergency department for an asthma exacerbation at 180 days following a 90-day, open-label tezepelumab extension. Other secondary outcomes include changes in asthma control questionnaire responses and changes in the levels of thymic stromal lymphopoietin, IL-25, and IL-33, as well as safety and tolerability.

Primary results could be available in late 2025, with complete results expected in late 2026.

“This is an exciting trial to watch because we will be getting more evidence on the potential use of biologics for asthma in the acute care setting,” Dr. Maselli said. “We are definitely looking forward to the results.”