Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1 Pharmacodynamic properties
Pharmacotherapeutic group: Drugs for obstructive airway diseases, adrenergics in combination with anticholinergics, ATC code: R03AL05


Mechanism of action
Duaklir Genuair contains two bronchodilators: aclidinium is a long-acting muscarinic antagonist (also known as an anticholinergic) and formoterol is a long-acting β2-adrenergic agonist. The combination of these substances with different mechanisms of action results in additive efficacy compared to that achieved with either component alone. As a consequence of the differential density of muscarinic receptors and β2-adrenoceptors in the central and peripheral airways of the lung, muscarinic antagonists should be more effective in relaxing central airways and β2-adrenergic agonists should be more effective in relaxing peripheral airways; relaxation of both central and peripheral airways with combination treatment may contribute to its beneficial effects on lung function. Further information regarding these two substances is provided below.
Aclidinium is a competitive, selective muscarinic receptor antagonist, 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. Aclidinium has also been shown to provide benefits to patients with COPD in terms of symptoms reduction, improvement in disease-specific health status, reduction in exacerbation rates and improvements in exercise tolerance. Since aclidinium bromide is quickly broken down in plasma, the level of systemic anticholinergic undesirable effects is low.
Formoterol is a potent selective β2-adrenoceptor agonist. Bronchodilation is induced by causing direct relaxation of airway smooth muscle as a consequence of the increase in cyclic AMP through activation of adenylate cyclase. In addition to improving pulmonary function, formoterol has been shown to improve symptoms and quality of life in patients with COPD.


Pharmacodynamic effects
Clinical efficacy studies showed that Duaklir Genuair provides clinically meaningful improvements in lung function (as measured by the forced expiratory volume in 1 second [FEV1]) over 12 hours following administration.
Duaklir Genuair demonstrated a rapid onset of action within 5 minutes of the first inhalation relative to placebo (p<0.0001). The onset of action of Duaklir Genuair was comparable to the effect of the fast-acting β2-agonist formoterol 12 micrograms. Maximal bronchodilator effects (peak FEV1) relative to baseline were evident from day one (304 ml) and were maintained over the 6-month treatment period (326 ml).


Cardiac electrophysiology
No clinically relevant effects of Duaklir Genuair on ECG parameters (including QT-interval) compared with aclidinium, formoterol and placebo were seen in Phase III studies of 6 to 12 months duration conducted in approximately 4,000 patients with COPD. No clinically significant effects of Duaklir Genuair on cardiac rhythm were observed on 24-hour Holter monitoring in a subset of 551 patients, of whom 114 received Duaklir Genuair twice daily.


Clinical Efficacy and Safety
The Phase III clinical development programme included approximately 4,000 patients with a clinical diagnosis of COPD and comprised two 6-month randomised, placebo- and active- controlled studies (ACLIFORM-COPD and AUGMENT), a 6-month extension of the AUGMENT study and a further 12-month randomised controlled study. During these studies, patients were permitted to continue their stable treatment with inhaled corticosteroids, low doses of oral corticosteroids, oxygen therapy (if less than 15h/day) or methylxanthines and to use salbutamol as rescue medication.
Efficacy was assessed by measures of lung function, symptomatic outcomes, disease- specific health status, rescue medication use, and exacerbations. In long-term safety studies, Duaklir Genuair was associated with sustained efficacy when administered over a one-year treatment period with no evidence of tachyphylaxis.


Effects on lung function
Duaklir Genuair 340/12 micrograms twice daily consistently provided clinically meaningful improvements in lung function (as assessed by FEV1, forced vital capacity and inspiratory capacity) compared with placebo. In Phase III studies, clinically meaningful bronchodilator effects were seen within 5 minutes of the first dose and were maintained over the dosing interval. There was a sustained effect over time in the six months and one year Phase III studies.
FEV1 at 1 hour post-dose and trough FEV1 (compared to aclidinium 400 micrograms and formoterol 12 micrograms, respectively) were defined as co-primary endpoints in both 6- month pivotal Phase III studies to demonstrate the bronchodilator contributions of formoterol and aclidinium in Duaklir Genuair, respectively.
In study ACLIFORM-COPD, Duaklir Genuair showed improvements in FEV1 at 1 hour post- dose relative to placebo and aclidinium of 299 ml and 125 ml, respectively (both p<0.0001) and improvements in trough FEV1 relative to placebo and formoterol of 143 ml and 85 ml, respectively (both p<0.0001). In study AUGMENT, Duaklir Genuair showed improvements in FEV1 at 1 hour post-dose relative to placebo and aclidinium of 284 ml and 108 ml (both p<0.0001), respectively, and improvements in trough FEV1 relative to placebo and formoterol of 130 ml (p<0.0001) and 45 ml (p=0.01), respectively.


Symptom relief and disease-specific health status benefits
Breathlessness and other symptomatic outcomes:
Duaklir Genuair provided a clinically meaningful improvement in breathlessness (assessed by the Transition Dyspnoea Index [TDI]) with an improvement in the TDI focal score at 6 months compared to placebo of 1.29 units in study ACLIFORM-COPD (p<0.0001) and 1.44 units in study AUGMENT (p<0.0001). The percentages of patients with clinically meaningful improvements in TDI focal score (defined as an increase of at least 1 unit) were higher with Duaklir Genuair than with placebo in ACLIFORM-COPD (64.8% compared to 45.5%; p<0.001) and AUGMENT (58.1% compared to 36.6%; p<0.0001).
The pooled analysis of these two studies showed Duaklir Genuair to be associated with statistically significantly greater improvements in TDI focal score compared to aclidinium (0.4 units, p=0.016) or formoterol (0.5 units, p=0.009). In addition, a higher percentage of patients receiving Duaklir Genuair responded with a clinically meaningful improvement in TDI focal score compared to either aclidinium or formoterol (61.9% compared to 55.7% and 57.0%, respectively; p=0.056 and p=0.100, respectively).
Duaklir Genuair improved daily symptoms of COPD such as 'breathlessness', 'chest symptoms', 'cough and sputum' (assessed by E-RS total score) as well as overall night-time symptoms, overall early morning symptoms and symptoms limiting early morning activities compared to placebo, aclidinium and formoterol but the improvements were not always statistically significant. Aclidinium/formoterol did not statistically significantly reduce the average number of night-time awakenings due to COPD compared with placebo or formoterol.
Health-related quality of life:
Duaklir Genuair provided a clinically meaningful improvement in disease-specific health status (as assessed by the St. George's Respiratory Questionnaire [SGRQ]) in study AUGMENT, with an improvement in the SGRQ total score compared to placebo of -4.35 units (p<0.0001). The percentage of patients in AUGMENT who achieved a clinically meaningful improvement from baseline in SGRQ total score (defined as a decrease of at least 4 units) was higher with Duaklir Genuair than with placebo (58.2% compared to 38.7%, respectively; p<0.001). In study ACLIFORM-COPD, only a small decrease in SGRQ total score compared to placebo was observed due to an unexpectedly large placebo response (p=0.598) and the percentages of patients who achieved clinically meaningful improvements from baseline were 55.3% with Duaklir Genuair and 53.2% with placebo (p=0.669).
In the pooled analysis of these two studies, Duaklir Genuair showed greater improvements in SGRQ total score compared to formoterol (-1.7 units; p=0.018) or aclidinium (-0.79 units, p=0.273). In addition, a higher percentage of patients receiving Duaklir Genuair responded with a clinically meaningful improvement in SGRQ total score compared to aclidinium and formoterol (56.6% compared to 53.9% and 52.2%, respectively; p=0.603 and p=0.270, respectively).
COPD exacerbation reductions
Pooled efficacy analysis of the two 6-month Phase III studies demonstrated a statistically significant reduction of 29% in the rate of moderate or severe exacerbations (requiring treatment with antibiotics or corticosteroids or resulting in hospitalisations) with Duaklir Genuair compared to placebo (rates per patient per year: 0.29 vs. 0.42, respectively; p=0.036).
In addition, Duaklir Genuair statistically significantly delayed the time to first moderate or severe exacerbation compared to placebo (hazard ratio=0.70; p=0.027).


Use of rescue medication
Duaklir Genuair reduced the use of rescue medication over 6 months compared to placebo (by 0.9 puffs per day [p<0.0001]), aclidinium (by 0.4 puffs/day [p<0.001]) and formoterol (by 0.2 puffs/day [p=0.062]).


Lung volumes, exercise endurance and physical activity
The effect of Duaklir Genuair on lung volumes, exercise endurance and physical activity was investigated in an 8-week parallel, randomised, placebo-controlled clinical study in COPD patients with hyperinflation (functional residual capacity [FRC] >120%).


After 4 weeks of treatment Duaklir Genuair implied improvement versus placebo in change from baseline in morning pre-dose (trough) FRC, the primary endpoint, but the difference was not statistically significant (-0.125 L; 95% CI=(-0.259, 0.010); p=0.069*).


Duaklir Genuair showed improvements compared to placebo in lung volumes at 2-3h post dose
(FRC=-0.366 L [95% CI=-0.515, -0.216; p<0.0001]; residual volume [RV]=-0.465 L [95% CI=-0.648, -0.281; p<0.0001] and inspiratory capacity [IC]= 0.293 L [95% CI=0.208, 0.378; p<0.0001]).


Duaklir Genuair also showed improvements in exercise endurance time compared to placebo after 8 weeks of treatment (55 seconds [95% CI=5.6, 104.8; p=0.0292]; baseline value: 456 seconds).


After 4 weeks of treatment, Duaklir Genuair improved the number of steps per day compared to placebo (731 steps/day; 95% CI=279, 1181; p=0.0016) and reduced the percentage of inactive patients (<6000 steps per day) [40.8% compared to 54.5%; p<0.0001]. Improvements in the PROactive total score were observed in patients treated with Duaklir Genuair compared with placebo (p=0.0002).
A behavioural intervention program was added to both treatment groups for an additional 4 weeks. The number of steps/day in the Duaklir Genuair treatment group was maintained resulting in a treatment effect compared to placebo of 510 steps/day (p=0.1588) and a reduction versus placebo in the percentage of inactive patients (<6000 steps per day) (41.5% compared to 50.4%; p=0.1134).


*As the primary endpoint did not achieve statistical significance, all p-values for secondary endpoints are tested at a nominal significance level of 0.05, and no formal statistical inference can be drawn.

Pharmacokinetic Properties

5.2 Pharmacokinetic properties
When aclidinium and formoterol were administered in combination by the inhaled route, the pharmacokinetics of each component showed no relevant differences from those observed when the medicinal products were administered separately.


Absorption
Following inhalation of a single dose of Duaklir Genuair 340/12 micrograms, aclidinium and formoterol were rapidly absorbed into plasma, reaching peak plasma concentrations within 5 minutes of inhalation in healthy subjects and within 24 minutes of inhalation in patients with COPD. The peak plasma concentrations at steady state of aclidinium and formoterol observed in patients with COPD treated with Duaklir Genuair twice daily for 5 days were reached within 5 minutes post-inhalation and were 128 pg/ml and 17 pg/ml, respectively.


Distribution
Whole lung deposition of inhaled aclidinium via Genuair averaged approximately 30% of the metered dose. The plasma protein binding of aclidinium determined in vitro most likely corresponded to the protein binding of the metabolites due to the rapid hydrolysis of aclidinium in plasma; plasma protein binding was 87% for the carboxylic acid metabolite and 15% for the alcohol metabolite. The main plasma protein that binds aclidinium is albumin.
The plasma protein binding of formoterol is 61% to 64% (34% primarily to albumin). There is no saturation of binding sites in the concentration range reached with therapeutic doses.


Biotransformation
Aclidinium is rapidly and extensively hydrolysed to its pharmacologically inactive alcohol- and carboxylic acid-derivatives. Plasma levels of the acid metabolite are approximately 100-fold greater than those of the alcohol metabolite and the unchanged active substance following inhalation. The hydrolysis occurs both chemically (non-enzymatically) and enzymatically by esterases, butyrylcholinesterase being the main human esterase involved in the hydrolysis.
The low absolute bioavailability of inhaled aclidinium (<5%) is because aclidinium undergoes extensive systemic and pre-systemic hydrolysis whether deposited in the lung or swallowed.
Biotransformation via CYP450 enzymes plays a minor role in the total metabolic clearance of aclidinium. In vitro studies have shown that aclidinium at the therapeutic dose or its metabolites do not inhibit or induce any of the cytochrome P450 (CYP450) enzymes and do not inhibit esterases (carboxylesterase, acetylcholinesterase and butyrylcholinesterase). In vitro studies have shown that aclidinium or its metabolites are not substrates or inhibitors of P-glycoprotein.
Formoterol is eliminated primarily by metabolism. The prominent pathway involves direct glucuronidation, with O-demethylation followed by glucuronide conjugation being a further metabolic pathway. Cytochrome P450 isoenzymes CYP2D6, CYP2C19, CYP2C9 and CYP2A6 are involved in the O-demethylation of formoterol. Formoterol does not inhibit CYP450 enzymes at therapeutically relevant concentrations.


Elimination
Following inhalation of Duaklir Genuair 340/12 micrograms, with plasma sampling up to 24 hours post-dose, the terminal elimination half-life observed for aclidinium bromide ranged from 11-33 hours and for formoterol from 12-18 hours


Mean effective half-lives* observed for both aclidinium and formoterol (based on the accumulation ratio) are approximately 10 hours.
*Half-life consistent with product accumulation based on a known dose regimen.


Following intravenous administration of radiolabelled aclidinium 400 micrograms to healthy subjects, approximately 1% of the dose was excreted as unchanged aclidinium bromide in the urine. Up to 65% of the dose was eliminated as metabolites in the urine and up to 33% as metabolites in the faeces. Following inhalation of aclidinium 200 micrograms and 400 micrograms by healthy subjects or patients with COPD, the urinary excretion of unchanged aclidinium was very low at about 0.1% of the administered dose, indicating that renal clearance plays a minor role in the total aclidinium clearance from plasma.
The major part of a dose of formoterol is transformed by liver metabolism followed by renal elimination. After inhalation, 6% to 9% of the delivered dose of formoterol is excreted in the urine unchanged or as direct conjugates of formoterol.


Special populations

Elderly patients
No pharmacokinetics studies have been performed with aclidinium/formoterol in elderly subjects. Since no dosage adjustments are needed for either aclidinium or formoterol medicinal products in elderly patients, no dosage adjustment is warranted for aclidinium/formoterol in geriatric patients.


Renally and hepatically impaired patients
There are no data regarding the specific use of aclidinium/formoterol in patients with renal or hepatic impairment. Since no dosage adjustments are needed for either aclidinium or formoterol medicinal products in patients with renal or hepatic impairment, no dosage adjustment is warranted for aclidinium/formoterol.
Race
Following repeated inhalations of Duaklir Genuair 340/12 micrograms, the systemic exposure of aclidinium and formoterol, as measured by AUC, is similar in Japanese and Caucasian patients