Extrafine triple therapy and asthma exacerbation seasonality: TRIMARAN and TRIGGER post hoc analyses

Previous studies have shown seasonal variation in asthma exacerbations, peaking over the winter months. A single-inhaler triple therapy containing extrafine formulations of the inhaled corticosteroid (ICS) beclomethasone dipropionate (BDP), long-acting β₂-agonist formoterol fumarate (FF), and long-acting muscarinic antagonist glycopyrronium (G) is in development for asthma.

We sought to evaluate whether calendar season impacted the relative effect of BDP/FF/G versus BDP/FF on moderate and severe asthma exacerbations.

TRIMARAN and TRIGGER were double-blind 52-week studies comparing BDP/FF/G with BDP/FF (TRIMARAN medium-dose ICS; TRIGGER high-dose) in adults with uncontrolled asthma (Asthma Control Questionnaire-7 score ≥1.5), prebronchodilator FEV₁ less than 80% predicted, history of 1 or more asthma exacerbation, who had been receiving ICS/long-acting β₂-agonist for at least 4 weeks before entry. Moderate and severe asthma exacerbations were captured throughout each study. In these post hoc analyses, the annual moderate and severe exacerbation rate was calculated for each month, with rate ratios determined from events grouped by season.

In patients who received BDP/FF alone, there was a marked seasonal effect on the occurrence of asthma exacerbations, with the rate highest in the winter months. However, the addition of the long-acting muscarinic antagonist component to BDP/FF reduced this seasonal variation, especially during the winter, such that the relative effect of BDP/FF/G versus BDP/FF was greatest in the winter (significant 20.3% reduction [P = .0008]). Reductions in the other seasons ranged between 8.6% and 12.0%.

These post hoc analyses indicate that inhaled triple therapy with extrafine BDP/FF/G reduces seasonal peaks in moderate and severe exacerbations, and confirm the overall utility of adding long-acting muscarinic antagonist to ICS/long-acting β₂-agonist in the management of asthma.