Pharmacotherapeutic group: Drugs for obstructive airway diseases, anticholinergics; ATC Code: R03BB05.
Mechanism of action
Aclidinium bromide is a competitive, selective muscarinic receptor antagonist (also known as an anticholinergic), with a longer residence time at the M3 receptors than the M2 receptors. M3 receptors mediate contraction of airway smooth muscle. Inhaled aclidinium bromide acts locally in the lungs to antagonise M3 receptors of airway smooth muscle and induce bronchodilation. Nonclinical in vitro and in vivo studies showed rapid, dose-dependent and long-lasting inhibition by aclidinium of acetylcholine-induced bronchoconstriction. Aclidinium bromide is quickly broken down in plasma, the level of systemic anticholinergic side effects is therefore low.
Pharmacodynamic effects
Clinical efficacy studies showed that Eklira Genuair provided clinically meaningful improvements in lung function (as measured by the forced expiratory volume in 1 second [FEV1]) over 12 hours following morning and evening administration, which were evident within 30 minutes of the first dose (increases from baseline of 124-133 mL). Maximal bronchodilation was achieved within 1-3 hours after dosing with mean peak improvements in FEV1 relative to baseline of 227-268 mL at steady-state.
Cardiac electrophysiology
No effects on QT interval (corrected using either the Fridericia or Bazett method or individually-corrected) were observed when aclidinium bromide (200 µg or 800 µg) was administered once daily for 3 days to healthy subjects in a thorough QT study.
In addition, no clinically significant effects of Eklira Genuair on cardiac rhythm were observed on 24‑hour Holter monitoring after 3 months treatment of 336 patients (of whom 164 received Eklira Genuair 322 µg twice daily).
Clinical efficacy and safety
The Eklira Genuair Phase III clinical development programme included 269 patients treated with Eklira Genuair 322 µg twice daily in one 6-month randomised, placebo-controlled study and 190 patients treated with Eklira Genuair 322 µg twice daily in one 3-month randomised, placebo-controlled study. Efficacy was assessed by measures of lung function and symptomatic outcomes such as breathlessness, disease-specific health status, use of rescue medication and occurrence of exacerbations. In the long-term safety studies, Eklira Genuair was associated with bronchodilatory efficacy when administered over a 1-year treatment period.
Bronchodilation
In the 6‑month study, patients receiving Eklira Genuair 322 µg twice daily experienced a clinically meaningful improvement in their lung function (as measured by FEV1). Maximal bronchodilatory effects were evident from day one and were maintained over the 6-month treatment period. After 6 months treatment, the mean improvement in morning pre-dose (trough) FEV1 compared to placebo was 128 mL (95% CI=85‑170; p<0.0001).
Similar observations were made with Eklira Genuair in the 3 month study.
Disease-Specific Health Status and Symptomatic Benefits
Eklira Genuair provided clinically meaningful improvements in breathlessness (assessed using the Transition Dyspnoea Index [TDI]) and disease-specific health status (assessed using the St. George's Respiratory Questionnaire [SGRQ]). The Table below shows symptom relief obtained after 6 months treatment with Eklira Genuair.
| Variable | Treatment | Improvement over placebo | p-value |
| Eklira Genuair | Placebo |
| TDI |
| Percentage of Patients who achieved MCIDa | 56.9 | 45.5 | 1.68-foldc increase in likelihood | 0.004 |
| Mean Change from baseline | 1.9 | 0.9 | 1.0 unit | <0.001 |
| SGRQ |
| Percentage of Patients who achieved MCIDb | 57.3 | 41.0 | 1.87-foldc increase in likelihood | <0.001 |
| Mean Change from baseline | -7.4 | -2.8 | - 4.6 units | <0.0001 |
| a Minimum clinically important difference (MCID) of at least 1 unit change in TDI. b MCID of at least - 4 units change in SGRQ. c Odds ratio, increase in the likelihood of achieving the MCID compared to placebo. |
Patients treated with Eklira Genuair required less rescue medication than patients treated with placebo (a reduction of 0.95 puffs per day at 6 months [p=0.005]). Eklira Genuair also improved daily symptoms of COPD (dyspnoea, cough and sputum production) and night-time and early morning symptoms.
Pooled efficacy analysis of the 6-month and 3-month placebo controlled studies demonstrated a statistically significant reduction in the rate of moderate to severe exacerbations (requiring treatment with antibiotics or corticosteroids or resulting in hospitalisations) with aclidinium 322 µg twice daily compared to placebo (rate per patient per year: 0.31 vs 0.44 respectively; p=0.0149).
Long Term Safety and Efficacy Trial up to 3 years
The effect of aclidinium bromide on the occurrence of major adverse cardiovascular events (MACE) was assessed in a randomised, double-blind, placebo-controlled, parallel-group study in 3630 adult patients between 40 and 91 years of age with moderate to very severe COPD, treated for up to 36 months. 58.7% were male and 90.7% were Caucasian, with a mean postbronchodilator FEV1 of 47.9% of predicted value and a mean CAT (COPD Assessment Test) of 20.7. All patients had a history of cardiovascular or cerebrovascular disease and/or significant cardiovascular risk factors. 59.8% of patients had at least one COPD exacerbation within the past 12 months from the screening visit. Approximately 48% of enrolled patients had a prior history of at least 1 documented previous cardiovascular event; cerebrovascular disease (13.1%), coronary artery disease (35.4%), peripheral vascular disease or history of claudication (13.6%).
The study had an event-driven design and was terminated once sufficient MACE events for the primary safety analysis were observed. Patients discontinued treatment if they experienced a MACE event and entered into the post-treatment follow-up period during the study. 70.7% of patients completed the study per investigator assessment. The median time on-treatment in the Eklira Genuair and placebo groups was 1.1 and 1 year, respectively. The median time on-study in the Eklira Genuair and placebo groups was approximately 1.4 and 1.3 years, respectively.
The primary safety endpoint was the time to first occurrence of MACE, defined as any of the following adjudicated events: cardiovascular death, non-fatal myocardial infarction (MI), or non-fatal ischemic stroke. The frequency of patients with at least one MACE was 3.85% vs. 4.23% patients in the aclidinium and placebo groups, respectively. Eklira Genuair did not increase the MACE risk in patients with COPD compared to placebo when added to current background therapy (hazard ratio (HR) 0.89; 95% CI: 0.64, 1.23). The upper bound of the confidence interval excluded a pre-defined risk margin of 1.8.
The rate of moderate or severe COPD exacerbations per patient per year during the first year of treatment was evaluated as the primary efficacy endpoint in the study. Patients treated with Eklira Genuair showed a statistically significant reduction of 22% compared to placebo (rate ratio [RR] 0.78; 95% CI 0.68 to 0.89; p<0.001). In addition, Eklira Genuair showed a statistically significant reduction of 35% in the rate of hospitalisations due to COPD exacerbations while on-treatment during the first year compared with placebo (RR 0.65; 95% CI 0.48 to 0.89; p=0.006).
The Eklira Genuair group showed a statistically significant delay in the time to first moderate or severe exacerbation while on-treatment compared to the placebo group. Patients in the aclidinium bromide group had a 18% relative reduction of the risk of an exacerbation (HR 0.82; 95% CI [0.73, 0.92], p<0.001).
Exercise tolerance
In a 3-week crossover, randomised, placebo-controlled clinical study Eklira Genuair was associated with a statistically significant improvement in exercise endurance time in comparison to placebo of 58 seconds (95% CI=9-108; p=0.021; pre-treatment value: 486 seconds). Eklira Genuair statistically significantly reduced lung hyperinflation at rest (functional residual capacity [FRC]=0.197 L [95% CI=0.321, 0.072; p=0.002]; residual volume [RV]=0.238 L [95% CI=0.396, 0.079; p=0.004]) and also improved trough inspiratory capacity (by 0.078 L; 95% CI=0.01, 0.145; p=0.025) and reduced dyspnoea during exercise (Borg scale) (by 0.63 Borg units; 95% CI=1.11, 0.14; p=0.012).
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with Eklira Genuair in all subsets of the paediatric population in COPD (see section 4.2 for information on paediatric use).