Efficacy and safety of the long-acting muscarinic antagonist GSK233705 delivered once daily in patients with COPD

Introduction: GSK233705 is a recently developed inhaled anticholinergic being investigated for the potential treatment of chronic obstructive pulmonary disease (COPD). Objectives: This dose‐ranging, parallel‐group, double‐blind study compared the bronchodilator efficacy, safety and pharmacokinetics of GSK233705 with placebo in patients with moderate‐to‐severe COPD. Methods: Patients were randomised to receive 12.5 µg, 25 µg, 50 µg, 100 µg or 200 µg of GSK233705 or placebo once daily for 28 days. The primary endpoint was change from baseline in trough forced expiratory volume in 1 s (FEV₁) on day 29. Results: The intent‐to‐treat population consisted of 576 patients (mean predicted FEV₁ 51%; mean age 62 years). Treatment with GSK233705 produced statistically significant improvements in pulmonary function compared with placebo. Only the 200 µg dose exceeded the predefined target threshold of 130‐mL difference compared with placebo for the primary endpoint of change from baseline in trough FEV₁ on day 29. No clear pattern of dose response was observed for the other doses. Serial FEV₁ (0–24 h) showed a peak effect around 2 h postdose and tended to decline to clinically insignificant levels compared with placebo at 23 and 24 h. Each dose of GSK233705 was well tolerated. The incidence of adverse events was low and similar across all treatment groups. There were no clinically significant effects on laboratory parameters, vital signs or electrocardiograms. Conclusion: All doses of GSK233705 demonstrated bronchodilatory activity and were well tolerated. Although the onset of bronchodilation was rapid, it was not sustained over 24 h making it unsuitable for once‐daily dosing. Please cite this paper as: Bateman E, Feldman G, Kilbride S, Brooks J, Mehta R, Harris S, Maden C and Crater G. Efficacy and safety of the long‐acting muscarinic antagonist GSK233705 delivered once daily in patients with COPD. Clin Respir J 2012; DOI:10.1111/j.1752‐699X.2011.00278.x.     

Cardiovascular Safety of QVA149, a Combination of Indacaterol and NVA237, in COPD Patients

ABSTRACT

This study assessed the cardiovascular safety of QVA149, an inhaled, once daily, bronchodilator combination containing two 24-hour bronchodilators, the long-acting β₂-agonist indacaterol and the long-acting muscarinic antagonist glycopyrronium (NVA237). In this randomised, double-blind, placebo-controlled, parallel-group study, 257 patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) were randomised to receive QVA149 (indacaterol/NVA237) 600/100 μg, 300/100 μg or 150/100 μg, indacaterol 300 μg or placebo, once daily for 14 days. The primary endpoint was change from baseline in 24-h mean heart rate versus placebo on Day 14. 255 patients were included in the safety analysis (mean age 63.8 years, 76.5% male, post-bronchodilator forced expiratory volume in one second [FEV₁] 53.2% predicted, FEV₁/FVC [forced vital capacity] 50.0%, mean 24-h heart rate 79.6 bpm). There were no clinically significant differences in the 24-h mean heart rate on Day 14 between the three doses of QVA149 and placebo or indacaterol. The confidence intervals of these treatment differences (contrasts) were within the pre-specified equivalence limit (-5 to 5 bpm). No clinically relevant differences in QTc interval (Fridericia's) were observed between groups on Days 1, 7 and 14. Once-daily QVA149 was well tolerated in COPD patients with a cardiovascular safety profile and overall adverse event rates similar to placebo.     

Safety and tolerability of NVA237, a once-daily long-acting muscarinic antagonist,in COPD patients

NVA237 is a novel once-daily inhaled long-acting muscarinic antagonist administered via a dry powder inhaler. This randomized, double-blind, placebo-controlled study evaluated the safety, tolerability and bronchodilator efficacy of two doses of NVA237 (100 and 200 μg), versus placebo, in patients with moderate-to-severe COPD (forced expiratory volume in 1 s [FEV₁] ≥ 30% and <80% predicted and FEV₁/forced vital capacity [FVC] < 0.7, 30 min after inhalation of 80 μg ipratropium bromide). After appropriate washout periods, patients were randomized to treatment with NVA237 100 μg (n = 92), NVA237 200 μg (n = 98) or placebo (n = 91) for 28 days. The primary objective was evaluation of safety, with efficacy measures included as secondary objectives. NVA237 was generally well tolerated and associated with a frequency and distribution of adverse events similar to placebo. Serious adverse events were uncommon and there was no evidence of adverse cardiovascular effects or unexpected events. Trough FEV₁ was significantly higher in those receiving NVA237 compared with placebo. For NVA237 100 μg the differences were 131 and 161 mL on Days 1 and 28, respectively (p < 0.05), and for NVA237 200 μg the differences were 146 and 151 mL on Days 1 and 28, respectively (p < 0.05). Peak FEV₁, FEV₁ at all timepoints up to 24 h after dosing, and FEV₁ area under the curve during 5 min–5 h post-dosing were also significantly higher in both NVA237 groups, compared with placebo. Patients receiving NVA237 required fewer daily puffs of rescue medication and had a higher percentage of days on which rescue medication was not required. Overall, the present study provides further evidence of the safety, tolerability and bronchodilator efficacy of once-daily treatment with NVA237 100 and 200 μg in patients with moderate-to-severe COPD.     

稳定期慢性阻塞性肺疾病患者夜间睡眠特点及长效抗胆碱能药物治疗的影响

目的:研究稳定期慢性阻塞性肺疾病(COPD)患者夜间睡眠的特点以及噻托溴铵粉吸入剂治疗对COPD患者肺功能及夜间睡眠的影响。方法:入选2010年9月至2011年8月18例中到重度肺功能受损的COPD患者,基线肺功能检查第1秒用力呼气容积(FEV1)在预计值参考范围的30%~80%,且支气管舒张实验阴性。其中男17例,女1例,年龄54~78(65.7±6.6)岁,平均体质量指数(BMI)为24.1±2.5(19.6~27.3)。入组后予以患者吸入皮质激素(ICS)单药洗脱2周后,予正规的ICS+长效抗胆碱支气管扩张剂(LAMA)治疗3个月。在基线期和3个月后分别进行肺功能及全夜多导睡眠图(PSG)检测。结果:稳定期无需氧疗的中重度肺功能损害COPD患者夜间低氧并不显著[呼吸紊乱指数(RDI)7.1±7.5,最低指脉搏氧饱和度(SpO2)83.9%±8.4%、SpO2低于90%的时间(7.4±12.2)min、平均SpO294.2%±2.4%],且与基础肺功能相关性不大,RDI主要仍与患者BMI相关(r=0.3,P=0.02),但睡眠期存在明显的微觉醒时间(平均微觉醒指数27.1±16.0)。经短期治疗前后肺功能[FEV1、用力肺活量(FVC)、残气量/肺总量比(RV/TLC)]及夜间睡眠低氧状况(夜间睡眠期RDI、最低SpO2、SpO2低于90%的时间、平均SpO2)变化不明显。但其中患者治疗后微觉醒指数明显下降(27.1±16.0比17.1±13.4,P=0.01)。结论:中重度肺功能损害的稳定期COPD患者夜间存在以微觉醒增多为特征的睡眠紊乱,LAMA治疗能提高COPD患者夜间睡眠质量;短期治疗对肺功能影响不大。     

NVA237, a long-acting muscarinic antagonist, as an emerging therapy for chronic obstructive pulmonary disease

Bronchodilation with a long-acting muscarinic antagonist (LAMA) or long-acting β(2)-agonist is central to the management of chronic obstructive pulmonary disease (COPD). Tiotropium, the first LAMA available for use in COPD, has been shown to be an effective bronchodilator and is generally safe and well tolerated. However, tiotropium has limitations that include a high incidence of dry mouth, slow onset of action and, in some studies, a part of the patient population did not achieve clinically significant bronchodilation. It also remains unclear whether tiotropium reduces progressive deterioration of lung function in patients with COPD. An ideal LAMA would provide clinically meaningful bronchodilation, deliver symptom relief, prevent disease progression, improve exercise tolerance and health status, prevent and treat complications and exacerbations and reduce mortality risk. A 24-h duration of action, rapid onset of action and a good safety and tolerability profile are also desirable. The once-daily LAMA, NVA237 (glycopyrronium bromide), may meet some of these characteristics. NVA237 has high selectivity for the muscarinic type-3 (M(3)) receptor which might potentially result in a higher therapeutic index than tiotropium, which is less selective for M(3). Phase II studies showed that NVA237 once daily provides clinically significant 24-h bronchodilation with a rapid onset of action and a favourable safety and tolerability profile. Phase III studies are ongoing that will assess the long-term safety and efficacy of NVA237.     

Efficacy and Safety of Aclidinium Bromide Compared with Placebo and Tiotropium in Patients with Moderate-to-Severe Chronic Obstructive Pulmonary Disease: Results from a 6-week,Randomized, Controlled Phase Iiib Study

Abstract

Background: This randomized, double-blind, Phase IIIb study evaluated the 24-hour bronchodilatory efficacy of aclidinium bromide versus placebo and tiotropium in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD). Methods: Patients received aclidinium 400 μg twice daily (morning and evening), tiotropium 18 μg once daily (morning), or placebo for 6 weeks. The primary endpoint was change from baseline in forced expiratory volume in 1 second area under the curve for the 24-hour period post-morning dose (FEV₁ AUC_0–24) at week 6. Secondary and additional endpoints included FEV₁ AUC_12–24, COPD symptoms (EXAcerbations of chronic pulmonary disease Tool-Respiratory Symptoms [E-RS] total score and additional symptoms questionnaire), and safety. Results: Overall, 414 patients were randomized and treated (FEV₁ 1.63 L [55.8% predicted]). Compared with placebo, FEV₁ AUC_0–24 and FEV₁ AUC_12–24 were significantly increased from baseline with aclidinium (? = 150 mL and 160 mL, respectively; p < 0.0001) and tiotropium (? = 140 mL and 123 mL, respectively; p < 0.0001) at week 6. Significant improvements in E-RS total scores over 6 weeks were numerically greater with aclidinium (p < 0.0001) than tiotropium (p < 0.05) versus placebo. Only aclidinium significantly reduced the severity of early-morning cough, wheeze, shortness of breath, and phlegm, and of nighttime symptoms versus placebo (p < 0.05). Adverse-event (AE) incidence (28%) was similar between treatments. Few anticholinergic AEs (<1.5%) or serious AEs (<3%) occurred in any group. Conclusions: Aclidinium provided significant 24-hour bronchodilation versus placebo from day 1 with comparable efficacy to tiotropium after 6 weeks. Improvements in COPD symptoms were consistently numerically greater with aclidinium versus tiotropium. Aclidinium was generally well tolerated.     

Cardiovascular safety of QVA149, a combination of Indacaterol and NVA237, in COPD patients

This study assessed the cardiovascular safety of QVA149, an inhaled, once daily, bronchodilator combination containing two 24-hour bronchodilators, the long-acting β(2)-agonist indacaterol and the long-acting muscarinic antagonist glycopyrronium (NVA237). In this randomised, double-blind, placebo-controlled, parallel-group study, 257 patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) were randomised to receive QVA149 (indacaterol/NVA237) 600/100 microg, 300/100 microg or 150/100 microg, indacaterol 300 μg or placebo, once daily for 14 days. The primary endpoint was change from baseline in 24-h mean heart rate versus placebo on Day 14. 255 patients were included in the safety analysis (mean age 63.8 years, 76.5% male, post-bronchodilator forced expiratory volume in one second [FEV(1)] 53.2% predicted, FEV(1)/FVC [forced vital capacity] 50.0%, mean 24-h heart rate 79.6 bpm). There were no clinically significant differences in the 24-h mean heart rate on Day 14 between the three doses of QVA149 and placebo or indacaterol. The confidence intervals of these treatment differences (contrasts) were within the pre-specified equivalence limit (-5 to 5 bpm). No clinically relevant differences in QTc interval (Fridericia's) were observed between groups on Days 1, 7 and 14. Once-daily QVA149 was well tolerated in COPD patients with a cardiovascular safety profile and overall adverse event rates similar to placebo.     

The role of long-acting muscarinic antagonist/long-acting β agonist fixed-dose combination treatment for chronic obstructive pulmonary disease in China: a narrative review

ObjectiveTo provide an overview of the existing international and Chinese evidence regarding dual bronchodilator inhalation therapy and to make recommendations for the further improvement of chronic obstructive pulmonary disease (COPD) management in clinical practice in China.BackgroundCOPD is a progressive lung disease that is characterized by persistent airflow limitation and is a major contributor to the disease burden in China. Symptoms in Chinese patients are relatively more severe. Currently, many Chinese COPD patients are undertreated. Dual bronchodilator therapy consisting of a long-acting muscarinic antagonist (LAMA) and a long-acting β agonist (LABA) is considered a good choice for COPD patients due to the increased bronchodilation without an increase in adverse events; these combinations can fill in the gap in currently available COPD treatments and provide new pharmacotherapy options for Chinese patients. LAMA/LABA fixed-dose combinations (FDCs) have become more important in clinical practice and guidelines in China regarding their therapeutic effects and safety.MethodsClinical trials on LAMA/LABA in COPD were retrieved in ClinicalTrials.gov, while important COPD guidelines published in English or Chinese were found in PubMed and Wanfang Database.ConclusionsWe recommend the adoption of a clinical pathway in China that includes an assessment and management algorithm that considers the clinical characteristics in China and classifies the phenotypic characteristics of COPD according to a suitable system. Based on the current information, we can conclude that LAMA/LABA FDCs are a suitable and economically viable choice to reduce symptoms and improve the quality of life (QoL) of patients.     

Comparison of tiotropium once daily, formoterol twice daily and both combined once daily in patients with COPD.

This study compared the bronchodilator effects of tiotropium, formoterol and both combined in chronic obstructive pulmonary disease (COPD). A total of 71 COPD patients (mean forced expiratory volume in one second (FEV1) 37% predicted) participated in a randomised, double-blind, three-way, crossover study and received tiotropium 18 microg q.d., formoterol 12 microg b.i.d. or both combined q.d. for three 6-week periods. The end-points were 24-h spirometry (FEV1, forced vital capacity (FVC)) at the end of each treatment, rescue salbutamol and safety. Compared with baseline (FEV1 prior to the first dose in the first period), tiotropium produced a significantly greater improvement in average daytime FEV1 (0-12 h) than formoterol (127 versus 86 mL), while average night-time FEV1 (12-24 h) was not different (tiotropium 43 mL, formoterol 38 mL). The most pronounced effects were provided by combination therapy (daytime 234 mL, night-time 86 mL); both differed significantly from single-agent therapies. Changes in FVC mirrored the FEV1 results. Compared with both single agents, daytime salbutamol use was significantly lower during combination therapy (tiotropium plus formoterol 1.81 puffs.day(-1), tiotropium 2.41 puffs x day(-1), formoterol 2.37 puffs x day(-1)). All treatments were well tolerated. In conclusion, in chronic obstructive pulmonary disease patients, tiotropium q.d. achieved a greater improvement in daytime and comparable improvement in night-time lung function compared with formoterol b.i.d. A combination of both drugs q.d. was most effective and provided an additive effect throughout the 24-h dosing interval.     

Effects of H2-receptor antagonist and selective muscarinic receptor antagonist on early gastric stagnation after pylorus-preserving pancreaticoduodenectomy: Results of a randomized controlled study

The suppressive effects of an H₂-receptor antagonist, ranitidine, and a selective muscarinic receptor antagonist, pirenzepine, in improving gastric stasis during the early postoperative period after pylorus-preserving pancreaticoduodenectomy (PPPD) were assessed. Thirty-two PPPD patients were divided into four groups of 8 patients each. Group 1 served as controls and were given no medication. Group 2 received i.v. ranitidine alone, group 3 received i.v. pirenzepine alone, and group 4 received i.v. ranitidine and pirenzepine combined. The daily volume and the total acidity of the gastric juice, aspirated via a nasogastric tube, were measured on post-PPPD days 1–13. One patient in group 1 was withdrawn from this study due to severe gastric bleeding. The mean daily aspirated volume of gastric juice in group 1 (n=7) was 1043±362 ml on the 3rd postoperative day, and it gradually fell after the 5th postoperative day, but still exceeded 500 ml on day 13. In group 2 (n=8), the mean maximum volume, 614±251ml, was reached on the 4th postoperative day, and in group 3 (n=8), the mean maximum volume, 680 + 391 ml, was reached on the 3rd postoperative day. In contrast, in group 4 (n=8), the gastric juice output appeared to be suppressed and the mean maximum volume was 380±218 ml, this being reached on the 6th postoperative day. Gastric juice secretion was significantly higher in group 1 than in the other three groups (P<0.01). The total acidity was significantly lower in groups 3 and 4 than in group 1 (P<0.01). These results indicate that the postoperative administration of the combination of ranitidine and pirenzepine suppresses the volume and acidity of the gastric juice after a PPPD.     

Effect of Aclidinium Bromide on Exacerbations in Patients with Moderate-to-Severe COPD: A Pooled Analysis of Five Phase III,Randomized, Placebo-Controlled Studies

We investigated the effect of the long-acting muscarinic antagonist aclidinium bromide on chronic obstructive pulmonary disease (COPD) exacerbations by pooling data from five randomized, placebo-controlled, parallel-group Phase III studies of 3–6 months’ duration. Data were pooled from the aclidinium 400 μg twice-daily (BID) and placebo arms (N = 2,521) and stratified by Global initiative for chronic Obstructive Lung Disease (GOLD) group (A, B, C and D). Results showed that fewer patients experienced ≥1 exacerbation with aclidinium (any severity: 12.5%; moderate to severe: 10.9%) compared with placebo (any severity: 15.7%; moderate to severe: 13.3%) and the odds of experiencing ≥1 exacerbation of any severity were reduced in patients receiving aclidinium (odds ratio = 0.78, p = 0.039). Furthermore, aclidinium reduced the rate of exacerbations compared with placebo (any severity: rate ratio = 0.79, p = 0.026; moderate to severe: 0.80, p = 0.044). The time to first exacerbation of any severity was delayed with aclidinium compared with placebo (hazard ratio = 0.79, p = 0.026) and there was a numerical delay in time to first moderate-to-severe exacerbation. Finally, the effects of aclidinium on exacerbations versus placebo were greater in patients in GOLD Groups B and D; however, it is of note that only 10.7% of patients were classified in Group A or C. In summary, the results indicate that aclidinium 400 μg BID reduces the frequency of COPD exacerbations compared with placebo and that these effects are greater in symptomatic patients.     

Adding a Second Bronchodilator in COPD: A Meta-Analysis on the Risk of Specific Cardiovascular Serious Adverse Events of Tiotropium/Olodaterol Fixed-Dose Combination

Abstract

Dual bronchodilation therapy represents the cornerstone for the treatment of COPD. A large retrospective study reports that adding a second long-acting bronchodilator in patients with COPD significantly increases the risk of heart failure. Nevertheless, retrospective studies are characterized by limitations including misdiagnosis and inaccuracy of recordkeeping. This study aimed to ascertain whether tiotropium/olodaterol (T/O) 5/5?μg fixed-dose combination (FDC) may modulate the risk of main cardiovascular outcomes in COPD patients enrolled in randomized controlled trials (RCTs). A meta-analysis (CRD42017070100) was performed by selecting RCTs reporting raw data from the ClinicalTrials.gov database concerning the impact of T/O 5/5?µg FDC vs. monocomponents on the occurrence of specific cardiovascular serious adverse events: arrhythmia, heart failure, myocardial infarction, and stroke. Data were reported as relative risk and 95% Confidence Interval, and the risk of publication bias assessed via Egger’s test. Eighty six full text articles were identified, and 10 RCTs published in 7 studies between 2015 and 2018 were included into the analysis. Data obtained from 12,690 COPD patients (44.47% T/O FDC, 55.53% monocomponents) were extracted. T/O 5/5?μg FDCs did not significantly modulate (p-value > 0.05) the risk of arrhythmia (1.02, 0.55 - 1.92), heart failure (0.88, 0.41 - 1.92), myocardial infarction (1.15, 0.70 - 1.87), and stroke (0.98, 0.44 - 2.16) vs. monocomponents. No significant publication bias affected the effect estimates of this meta-analysis. The results of this quantitative synthesis indicate that dual bronchodilation with T/O 5/5?μg FDC is characterized by an acceptable cardiovascular safety profile in COPD patients.     

Additive benefits of tiotropium in COPD patients treated with long-acting beta agonists and corticosteroids

OBJECTIVE AND BACKGROUND: The addition of an alternative class of long-acting bronchodilator is recommended for COPD patients who do not respond satisfactorily to monotherapy. The aim of this study was to investigate the additive benefit of tiotropium in severe COPD and to establish whether the improvement in lung function in these patients can be predicted from their acute bronchodilator response to ipratropium or salbutamol. METHODOLOGY: Forty-six patients with severe COPD treated with inhaled long-acting beta(2) agonists and corticosteroids (LABA/CS) were enrolled. Their prebronchodilator FEV(1) was less than 50% of the predicted value. Tiotropium (18 microg, once daily) was added via a dry-powder inhaler device. After a month of treatment, tiotropium was stopped but their previous medication was continued. Patients were reassessed a month later. Acute bronchodilator response to ipratropium and salbutamol was assessed prior to tiotropium treatment. Pulmonary function and health status were evaluated. RESULTS: Adding tiotropium significantly improved FVC, FEV(1) and inspiratory capacity (IC). The increase in FVC was significantly associated with an increase in IC (r = 0.36, P = 0.019) and a decrease in residual volume (r =-0.56, P < 0.001). Total scores of St. George Respiratory Questionnaire scores were significantly improved after adding tiotropium treatment (P < 0.001). After tiotropium withdrawal, FVC, FEV(1) and IC decreased markedly. Bronchodilator response to ipratropium did not predict the tiotropium-mediated improvement in FEV(1) or FVC. CONCLUSIONS: Adding tiotropium to inhaled LABA/CS can yield clinical benefits in lung function and improved quality of life in COPD patients, as both drugs act through separate yet complementary pathways to maintain airway calibre.     

Pharmacodynamics of GSK961081, a bi-functional molecule,in patients with COPD

GSK961081 is an inhaled bi-functional molecule with both muscarinic antagonism and β₂-agonism (MABA) properties.This randomised, double-blind, double-dummy, crossover study evaluated 14 days treatment with the MABA GSK961081 400 μg and 1200 μg once daily and tiotropium 18 μg once daily plus salmeterol 50 μg twice daily (TIO + SAL), versus placebo in 50 patients with moderate COPD. The primary endpoint was forced expiratory volume in 1 s (FEV₁) at 24 h on Days 1 and 14.MABA 400 (n = 29), MABA 1200 (n = 32) and TIO + SAL (n = 41) resulted in significant increases in FEV₁ over 24 h. Mean (95% CI) 24 h trough FEV₁ (L) values relative to placebo (n = 43) were, for Day 1, MABA 400: 0.141 (0.060, 0.222); MABA 1200: 0.184 (0.105, 0.263); TIO + SAL: 0.162 (0.092, 0.231); for Day 14, MABA 400: 0.115 (0.024, 0.205); MABA 1200: 0.168 (0.080, 0.255); TIO + SAL: 0.103 (0.026, 0.180). Onset of bronchodilation was faster for both MABA doses versus TIO + SAL. No clinically relevant systemic pharmacodynamic effects were observed. Adverse events were similar across groups; however tremor (n = 2, MABA 1200), dysgeusia (n = 2, MABA 1200; n = 2, MABA 400) and dry mouth (n = 1, MABA 1200) were reported after GSK961081 only.GSK961081 demonstrated sustained bronchodilation similar to TIO + SAL, but with a more rapid onset, and was well tolerated at the tested doses.     

Association of beta2-adrenoreceptor genotypes with bronchodilatory effect of tiotropium in COPD

Background and objective: Recently, there has been interest in interactions of β₂ adrenergic receptors (β₂‐AR) and muscarinic acetylcholine receptors (mAChR), which share intracellular signal transduction systems. The aim of the present study was to investigate whether bronchodilator response to tiotropium is influenced by β₂‐AR genotype in patients with COPD who show poor responsiveness to inhaled β₂‐agonists. Methods: After a 4‐week run‐in period, patients with COPD were treated with inhaled tiotropium bromide (18 μg once daily) for 8 weeks. Spirometric measurements and reversibility testing with inhaled β₂‐AR agonists were performed and health‐related quality of life was assessed using the St George's respiratory questionnaire (SGRQ) before and after treatment. Genomic DNA was prepared from peripheral blood and individual genotypes at amino acid 16 of the β₂‐AR were examined. Results: Forty‐four patients with COPD completed the study. COPD patients with the Arg/Arg genotype (n = 22) had a significant increase in FEV₁ during treatment compared with those without the Arg/Arg genotype (n = 22) (FEV₁, P = 0.009; FEV₁%, P = 0.006). While all component and total scores on the SGRQ improved significantly in both genetic groups, changes in impact and total scores were significantly greater in patients with Arg/Arg compared with those without (total scores, P = 0.005; impact scores, P < 0.001). Conclusions: These findings indicate that the homozygous Arg/Arg genotype at amino acid 16 of the β₂‐AR could affect bronchodilator response to tiotropium in patients with COPD with significant effects on health‐related quality of life.