Usage of long-acting muscarinic antagonists and biologics as add-on therapy for patients in the United States with moderate-to-severe asthma.

: Many asthma patients remain uncontrolled on inhaled corticosteroids (ICS) and long-acting beta agonists (LABAs), but guidance for selecting add-on therapies, including long-acting muscarinic antagonists (LAMAs) or biologics, is limited. We describe how prescribing practices for add-on LAMA and biologic therapy have changed with increased treatment options and revised treatment guidelines. We further identify differences in treatment initiation and discontinuation rates by patient characteristics, including concomitant COPD. : This retrospective cohort study analyzed insurance claims in the IBM Marketscan database for adult US asthma patients treated with medium- or high-dose ICS/LABA between 2012 and 2019 (n = 277,373). We used negative binomial regression models to evaluate LAMA and biologic initiation rates and their association with patient characteristics, and survival analysis methods for assessing discontinuation rates. : Between 2012 and 2019, LAMA and biologic uptake increased approximately 5-fold and 20-fold, respectively. LAMA initiation was significantly higher among patients with concomitant COPD, a group typically unstudied in clinical trials, versus those with asthma only (rate ratio of 5.90, 95% CI: 5.76-6.04). High-dose ICS/LABA treatment and the need for oral corticosteroid (OCS) bursts had stronger associations with biologic initiation. Probability of discontinuation (i.e. non-persistence) in the first year was 40.5% and 22.7% for those initiating LAMAs and biologics, respectively, with higher LAMA discontinuation rates among patients with asthma only versus those with concomitant COPD. : Our results provide insights into how clinicians apply treatment guidelines for initiating add-on LAMA and biologic therapies in moderate-to-severe asthma patients and highlight patients who have an unmet treatment need after discontinuation.