Real-world use of inhaled corticosteroid/formoterol as needed in adults with mild asthma: the PRIME study

Inhaled corticosteroid/formoterol fumarate (ICS/FF) as needed is recommended by the Global Initiative for Asthma (GINA) as sole therapy in adults with mild asthma, with low-dose maintenance ICS plus short-acting β₂-agonist (SABA) as an alternative. SABA alone is no longer recommended. Given these changes in recommendations, the observational PRIME study aimed to describe real-world treatment patterns in mild asthma in Europe.

Adults with asthma receiving low-dose maintenance ICS, or as needed ICS/FF or SABA were followed for 6 months. Data collected included Asthma Control Test (ACT), Asthma Control Questionnaire 5-item (ACQ-5), forced expiratory volume in 1 s (FEV₁) and asthma exacerbations.

The study was conducted in 883 patients in Germany, Italy, Poland and Spain; 833 (94.3%) completed follow-up. At enrolment, 32.2% received maintenance ICS, 56.3% ICS/FF as needed and 11.6% SABA as needed; 57.4%, 61.2% and 54.9%, respectively, had well-controlled asthma (ACQ-5/ACT definition). After 6 months, changes in mean FEV₁ were small in the maintenance ICS and ICS/FF as needed groups, whereas there was a decline in FEV₁ in the SABA as needed group. ACQ-5 total score improved from baseline in all three groups; 0.4%, 0.4% and 2.0% patients, respectively, had a severe exacerbation during the study.

More patients received ICS/FF as needed than SABA as needed, suggesting that physicians are aware of the latest treatment recommendations. This real-world study provides additional support to the use of ICS/FF as needed as preferred treatment for patients with mild asthma, whereas SABA as needed was associated with a fall in lung function and more severe exacerbations.