Addition of Tiotropium to ICS+LABA Decreases Risk of Asthmatic Exacerbation

Bradley Chipps, MD

Adding tiotropium (Spiriva Respimat) to inhaled corticosteroid (ICS) plus long-acting β₂ -agonist (LABA) decreased the risk and rate of asthmatic exacerbation by 35%, compared with step-up ICS plus LABA therapy, according to new findings supported by Boehringer Ingelheim Pharmaceuticals.

Bradley Chipps, MD, and a team of investigators compared the efficacy of the 2 therapies by assessing their impact on health outcomes in a cohort of patients with asthma newly initiated on ICS plus LABA. The addition of tiotropium (1.25 μg [2 puffs once daily]) also reduced healthcare resource utilization (HCRU) compared with increasing the dose of ICS plus LABA.

Chipps, from the Capital Allergy & Respiratory Disease Center, and colleagues included patients >12 years old with asthma who were on ICS plus LABA. The patients were required to have used ICS plus LABA therapy and then were either started on add-on tiotropium or had their therapy increased (inc-ICS plus LABA). Patients involved were required to be enrolled for 6 months before (pre-index period) and >1 month after (follow-up period) the index date.

The primary endpoint was risk of exacerbation—an emergency department visit or hospitalization with primary diagnosis of asthma or asthma exacerbation—after the index date. Additional measures included the rate of exacerbations within 6-12 months after the index date, HCRU, and short-acting β₂ -agonist (SABA) refills within 12 months post-index.

Overall, 7857 patients were included in the study—2619 patients were in the tiotropium group and 5238 were in the inc-ICS group. Follow-up time was shorter for the tiotropium group (9.7 months) than the inc-ICS group (24.1 months).

The risk of exacerbation was 35% lower in the tiotropium group than the inc-ICS group (HR, .65; 95% CI, .43-.99; P <.05). Exacerbation rate was also significantly lower in the tiotropium group than the inc-ICS group at both 6 months (64% lower; P <.0001) and 12 months (73% lower; P <.0001).

All-cause and asthma-related emergency department visits were significantly lower in the tiotropium versus the inc-ICS group (all-cause, 47% lower; P <.0001; asthma-related visits, 74% lower; P <.0001). All-cause and asthma-related hospitalizations were also lower in the tiotropium group (all-cause, 48% lower; P = .004; asthma-related, 76% lower; P = .0003).

There was no significant difference in all-cause or asthma-related outpatient visits between the 2 groups (all-cause difference, 26 visits; P <.349; asthma-related difference, 26 visits; P = .219).

Fewer patients in the tiotropium group had SABA refills (56%; P <.0001) as opposed to the inc-ICS (67%; P <.0001). Of the patients with SABA refills, those in the tiotropium group refilled significantly fewer prescriptions within 12 months post-index (2.95; P = .019) than those in the inc-ICS group (3.61; P = .019).

Study limitations included lack of information about events and rate events not leading to paid claims, actual SABA use, and inhaler technique. Investigators also reported medication adherence and influence of comorbidities on uncontrolled symptoms as possible limitations of the research. What’s more, the study may have included bias due to remnant confounding post-propensity score matching and because of different durations of follow-up between the 2 groups.

The study, “The effectiveness of tiotropium add-on to inhaled corticosteroid (ICS)+long-acting β₂ -agonist (LABA) therapy vs step-up ICS+LABA therapy in a real-world cohort of patients with asthma,” was presented at the Western Society of Allergy, Asthma and Immunology 2020 Annual Scientific Session in Kauai, Hawaii.