Introduction

Asthma poses a substantial burden on mortality and healthcare costs. Uncontrolled asthma negatively affects the work productivity as well as the quality of life of the patient. Inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA) combinations are recommended as maintenance therapy in symptomatic uncontrolled asthma by the Global Initiative for Asthma (GINA) 2024 report. Clinical trials have demonstrated the efficacy of ICS/LABA combinations such as fluticasone propionate/salmeterol (FP/SAL) and budesonide/formoterol (BUD/FOR), in achieving good asthma control, improved adherence to treatment and fewer exacerbations. However, real-world studies comparing the efficacy of both combinations are lacking.

Aim

To compare the real-world efficacy of FP/SAL and BUD/FOR on asthma control, exacerbation rates and treatment adherence.

Patient Profile

• Asthmatic patients aged ≥18 years at GINA treatment steps 3 or 4
• Had ≥1 pharmacy claim for FP/SAL or BUD/FOR (index)
• Patients with medical and pharmacy coverage >12 months before and after the index date
• Having medical claim with an asthma diagnosis at baseline
• Administered either fixed-dose combination of FP/SAL or BUD/FOR, twice daily

Method

Study Design

• Non-interventional, retrospective, US-based cohort study

Treatment

• The data on demographics, clinical characteristics and asthma status of the eligible patients was recorded at baseline
• Inverse probability of treatment weighting was adjusted for confounding variables
• Outcomes were categorized based on the severity of asthma
• Asthma was defined as well-controlled, partially controlled and uncontrolled based on the ACT scores of >20, 16-19 and <16 respectively
• Multivariable analyses were conducted for each outcome

Endpoints

Primary Endpoint

• Asthma control using asthma control test (ACT) and short-acting β-agonist (SABA) dispensing

Secondary Endpoints

• No of SABA canister fills per month
• Treatment adherence using proportion of days covered (PDC)
• Number of severe asthma exacerbations
• Time to first index treatment switch

Results

• The overall cohort comprised of 57,000 patients; of which 28,639 were assigned to FP/SAL and 28,361 received BUD/FOR treatment
• Baseline characteristics of cohort were
  • Females 69.1%
  • Ever smokers: 27.4% vs 32.1% in the FP/SAL and BUD/FOR groups respectively
  • 1-2 comorbidities were prevalent in 82.4%
  • Spirometry data was similar
  • Proportion of patients with asthma treated at GINA step 4 was higher in BUD/FOR cohort; 99.96% vs 83.40%
  • FP/SAL group had less frequent SABA fills, higher proportion of patients with no SABA fills, less frequent asthma exacerbations and lower use of maintenance therapies
• During the 12-month follow-up period, the ACT scores and SABA fills were similar
• Treatment adherence was higher in FP/SAL cohort, especially those with PDC ≥0.8, (5.4 % vs 4.4 %)
• There were no significant differences in time to first exacerbation, exacerbation frequency and hospitalization
• Among patients treated for asthma at GINA step 4, the risk of hospitalization due to asthma exacerbations was higher in the FP/SAL group
• FP/SAL cohort had better treatment persistence as indicated by a longer time to treatment switch
• The outcomes are compared in Table 1.

Table 1. Comparative outcomes

• Index medication was continued for a longer duration in the FP/SAL group; 268.5 vs 255.8 days

Conclusion

• Asthma control was comparable in patients who received fluticasone propionate/salmeterol (FP/SAL) and budesonide/formoterol (BUD/FOR) fixed-dose combinations in real-world settings
• However, higher medication adherence was observed in those receiving FP/SAL

Respir Med. 2025 Aug-Sep: 245:108172. Doi: 10.1016/j.rmed.2025.108172.