Clinical pharmacokinetics of AZD3199, an inhaled ultra-long-acting ß2-adrenoreceptor agonist (uLABA).

OBJECTIVE: The clinical pharmacokinetics of AZD3199, an ultra-long-acting ß2-agonist, were investigated in healthy volunteers and patients with asthma or chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Five studies are presented: one single ascending dose study in healthy Caucasian males; two multiple ascending dose studies in healthy males, one in Caucasians and one in Japanese; a Phase IIA asthma study; and a Phase IIB COPD study. Subjects received AZD3199 via a Spira nebulizer (Turbuhaler; equivalent delivered doses 5-3200 µg) or Turbuhaler (single delivered doses of 120-1920 µg or repeated delivered once-daily doses 240-1,680 µg). AZD3199 pharmacokinetics were assessed using total plasma concentration and urinary excretion, and tolerability using adverse events, clinical laboratory tests, and physical examinations. RESULTS: AZD3199 appeared rapidly in the systemic circulation following single and multiple dosing in healthy volunteers and patients (maximum plasma concentration within 30 minutes), with dose-proportional time-independent pharmacokinetics. Plasma exposure to unmetabolized drug was similar in healthy volunteers and patients with asthma, but relatively lower in patients with COPD. Estimated terminal half-life was up to 142 hours in healthy Caucasian males. AZD3199 was well tolerated and showed no or at most mild systemic effects. CONCLUSION: AZD3199 plasma exposure in healthy volunteers and patients suggested linear pharmacokinetics and a long half-life. Systemic availability was similar in healthy subjects and patients with asthma, but was lower in patients with COPD. These clinical trials suggest that AZD3199 is well-tolerated in healthy male volunteers and patients, with no safety concerns identified to preclude further evaluation.

Comparison of the bronchodilator and systemic effects of AZD3199, an inhaled ultra-long-acting ß2-adrenoceptor agonist, with formoterol in patients with asthma.

OBJECTIVES: Pharmacologically mediated bronchodilation is important in the management of asthma, and is primarily achieved with ß2-agonists. Novel compounds should preferably have a longer duration of action and a better systemic side effect profile than established alternatives at comparable peak bronchodilation. This single-dose crossover study was conducted to investigate and compare with formoterol the bronchodilatory and systemic effects, tolerability and safety of AZD3199, a novel ultra-long-acting ß2-agonist (uLABA). METHODS: Patients with asthma (n = 37) were randomized to receive AZD3199 (120, 480, 1920 µg), formoterol (9, 36 µg) or placebo inhaled via a Turbuhaler™. Bronchodilation was evaluated by maximum (E(max)) and average 22-26 h (E22₋26) forced expiratory volume in 1 second (FEV1). Serum potassium was evaluated by minimum (E(min)) and 0-4 h average (E(av)) determined from serial measurements. AZD3199 and formoterol were compared on the basis of relative dose potency. Adverse events, clinical laboratory tests and physical examinations were markers for safety and tolerability, with plasma AZD3199 as the indicator of drug exposure. RESULTS: All active treatments dose-dependently increased E(max) and AZD3199 (480 and 1920 µg) and formoterol (36 µg) significantly increased E(22₋26) versus placebo. Relative dose potency between AZD3199 and formoterol was 50-fold on the microgram scale with respect to E max and 11-fold with respect to E(22₋26). Small, dose-dependent effects on potassium, heart rate and QTc were seen after administration of AZD3199 compared with placebo. These well-known dose-related class effects of ß2-agonists were mild. Notably, serum potassium suppression was less pronounced after AZD3199 compared with formoterol at similar bronchodilation. Overall, AZD3199 was well tolerated. CONCLUSIONS: AZD3199 480 µg and 1920 µg produced 24-hour bronchodilation. At comparable peak bronchodilator effect, AZD3199 was associated with a lower level of systemic side effects than formoterol. AZD3199 was well tolerated, with no safety concerns identified to preclude further investigation. ClinicalTrials.gov study identifier: NCT00736489.

Formoterol used as needed in patients with intermittent or mild persistent asthma.

OBJECTIVE: To study the effectiveness and safety of as-needed treatment of formoterol compared with the short-acting alternative terbutaline. METHODS: Two double-blind, 12-month, parallel-group, non-inferiority trials comparing as-needed use of formoterol (Oxis) 4.5 microg and terbutaline (Bricanyl) 0.5 mg via dry-powder inhaler (Turbuhaler), one in 675 patients with intermittent and one in 455 patients with mild persistent asthma, overall 6-87 years of age. Peak expiratory flow (PEF), symptoms, rescue medication use, exacerbations, airway responsiveness (metacholine challenge; subgroup of 127 patients), systemic effects (high single-dose test; subgroup of 87 patients), and safety (adverse events) were assessed. RESULTS: Formoterol 4.5 microg was as effective as terbutaline 0.5 mg with regard to morning PEF (non-inferiority; lower 95% confidence interval limit above -10 L/min). Metacholine sensitivity, exacerbation rates or use of rescue medication did not differ between treatments. Formoterol 54 microg was shown to give less systemic effects than terbutaline 6 mg. Both treatments were safe and well tolerated. CONCLUSIONS: Formoterol 4.5 microg used as needed was at least as effective and safe as terbutaline 0.5 mg used as needed in intermittent and mild persistent asthma, and was associated with less systemic effects when administered as high single doses.

The effect of formoterol over 24 h in patients with asthma: the role of enantiomers.

The single-dose effect of formoterol racemate and enantiomers on bronchodilatation up to 24 h was determined. Forty-six reversible asthmatic patients were randomised to this double blind, crossover study. Formoterol was inhaled by nebulizer (HaloLite); 4.5 and 36 microg of the racemate (rac-formoterol), 2.25 and 18 microg of (R;R)-formoterol, 18 mirog of (S;S)-formoterol, or placebo. Airway and systemic effects were assessed by serial measurements of forced expiratory volume during the first second, FEV1 (24 h), and heart rate (4 h). Rac- and (R;R)-formoterol significantly and dose-dependently increased FEV1 with similar mean maximal effect. (S;S)-formoterol was without significant effects on FEV1 and heart rate. (R;R)- and rac-formoterol were still effective 22-24 h after single high doses, but this was associated with some systemic side effect (increased heart rate) initially. Average 22-24 h FEV1 was 8% (rac-formoterol 36 microg) and 11% ((R;R)-formoterol 18 microg) over placebo, respectively. No significant differences in effects were observed between rac- and (R;R)-formoterol. Thus, the single dose bronchodilatating effect of formoterol resides in (R;R)-formoterol. This study does not indicate a clinically important advantage of (R;R)-formoterol as acute bronchodilator compared to the racemate.

Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline.

OBJECTIVES: To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children. METHODS: Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxis) 4.5 microg (F4.5) or terbutaline (Bricanyl) 500 microg (T500) were inhaled cumulatively via a dry powder inhaler (Turbuhaler) over 1 h (three patients) or 2.5 h (17 patients) and compared to a day of no treatment, in a randomised, double-blind (active treatments only), crossover trial. Blood pressure (BP), ECG, plasma potassium, glucose, lactate, and adverse events were monitored up to 10 h to assess tolerability and relative systemic dose potency. RESULTS: Formoterol and terbutaline had significant beta2-adrenergic effects on most outcomes. Apart from the effect on systolic BP, QRS duration and PR interval, the systemic effects were significantly more pronounced with terbutaline than with formoterol. Thus, mean minimum plasma potassium, was suppressed from 3.56 (95% confidence interval, CI: 3.48-3.65) mmol l(-1) on the day of no treatment to 2.98 (CI: 2.90-3.08) after 10 x F4.5 and 2.70 (CI: 2.61-2.78) mmol l(-1) after 10 x T500, and maximum Q-Tc (heart rate corrected Q-T interval [Bazett's formula]) was prolonged from 429 (CI: 422-435) ms on the day of no treatment, to 455 (CI: 448-462) ms after 10 x F4.5 and 470 (CI: 463-476) ms after 10 x T500. Estimates of relative dose potency indicated that F4.5 microg had the same systemic activity as the clinically less effective dose of 250 microg terbutaline. The duration of systemic effects differed marginally between treatments. Spontaneously reported adverse events (most frequently tremor) were fewer with formoterol (78% of the children) than with terbutaline (95%). A serious adverse event occurred after inhalation of 45 microg formoterol over the 1 h dosing time, that prompted the extension of dosing time to 2.5 h. CONCLUSIONS: Multiple inhalations over 2.5 h of formoterol (4.5 microg) via Turbuhaler) are at least as safe as and associated with less systemic effects than multiple inhalations of the clinically equipotent dose of terbutaline (500 microg) in children with asthma.

Assessment of a relative therapeutic index between inhaled formoterol and salbuterol in asthma patients.

OBJECTIVE: To quantify the relation between local and systemic magnitudes of effects of inhaled formoterol and salbutamol. METHODS: Twenty-eight stable asthmatic patients completed this double-blind, randomised crossover study. Pre-drug administration FEV1 (mean 2.08 L) was 49-93% of predicted and reversibility 16-82% after inhalation of salbutanmol. Patients inhaled three single doses of formoterol fumarate dihydrate (Oxis) (delivered doses of 4.5, 18 and 54 microg) via Turbuhaler, two single doses of salbutamol (200 and 1800 microg) via a pressurised metered dose inhaler (pMDI) and placebo at intervals of 48 h or more. Individual maximum FEV1 and minimum S-K+ were calculated. A classic sigmoid model of log-dose response was used to discriminate pharmacologically between formoterol and salbutamol. Relative local (maximum FEV1) and systemic (minimum S-KC) dose potencies, and their ratio, the relative therapeutic index, were estimated using an on-linear mixed effect model. RESULTS: The drug effects were well tolerated and dose dependent The bronchodilating effect was on a part of the dose response curve that could be well approximated by a log-linear function, the serum potassium suppressing effect sometimes was not (the lowest doses differed only marginally from placebo). Thus, a log-linear approximation was used to describe bronchodilation, whereas a sigmoid approximation was more apt to describe the decrease in serum potassium concentration. A bivariate dose-response model based on these principles was fitted simultaneously to all data. The mean relative therapeutic index was estimated to be 2.5 (95%confidence interval: 0.9-6.5). CONCLUSIONS: The mean relative therapeutic index between formoterol (Oxis) 4.5-54 microg given via Turbuhaler and salbutamol 200-1800 microg given via pMDI was estimated to 2.5 in favour of formoterol; this trend was not statistically significant.