Pharmacotherapeutic group: Other drugs for obstructive airway diseases, inhalants, anticholinergics
ATC code: R03B B04
Mechanism of action
Tiotropium bromide is a long-acting, specific antagonist at muscarinic receptors. It has similar affinity to the subtypes, M1 to M5. In the airways, tiotropium bromide competitively and reversibly binds to the M3 receptors in the bronchial smooth musculature, antagonising the cholinergic (bronchoconstrictive) effects of acetylcholine, resulting in bronchial smooth muscle relaxation. The effect was dose dependent and lasted longer than 24h. As an N-quaternary anticholinergic, tiotropium bromide is topically (broncho-) selective when administered by inhalation, demonstrating an acceptable therapeutic range before systemic anticholinergic effects may occur.
Pharmacodynamic effects
The dissociation of tiotropium from especially M3-receptors is very slow, exhibiting a significantly longer dissociation half-life than ipratropium. Dissociation from M2-receptors is faster than from M3, which in functional in vitro studies, elicited (kinetically controlled) receptor subtype selectivity of M3 over M2. The high potency, very slow receptor dissociation and topical inhaled selectivity found its clinical correlate in significant and long-acting bronchodilation in patients with COPD and asthma.
Clinical efficacy and safety in COPD
The clinical Phase III development programme included two 1-year, two 12-weeks and two 4-weeks randomised, double-blind studies in 2901 COPD patients (1038 receiving the 5 µg tiotropium dose). The 1-year programme consisted of two placebo-controlled trials. The two 12-week trials were both active (ipratropium) - and placebo-controlled. All six studies included lung function measurements. In addition, the two 1-year studies included health outcome measures of dyspnoea, health-related quality of life and effect on exacerbations.
Placebo-controlled studies
Lung function
Tiotropium inhalation solution, administered once daily, provided significant improvement in lung function (forced expiratory volume in one second and forced vital capacity) within 30 minutes following the first dose, compared to placebo (FEV1 mean improvement at 30 minutes: 0.113 litres; 95% confidence interval (CI): 0.102 to 0.125 litres, p< 0.0001). Improvement of lung function was maintained for 24 hours at steady state compared to placebo (FEV1 mean improvement: 0.122 litres; 95% CI: 0.106 to 0.138 litres, p< 0.0001).
Pharmacodynamic steady state was reached within one week.
Spiriva Respimat significantly improved morning and evening PEFR (peak expiratory flow rate) as measured by patient's daily recordings compared to placebo (PEFR mean improvement: mean improvement in the morning 22 L/min; 95% CI: 18 to 55 L/min, p< 0.0001; evening 26 L/min; 95% CI: 23 to 30 L/min, p<0.0001). The use of Spiriva Respimat resulted in a reduction of rescue bronchodilator use compared to placebo (mean reduction in rescue use 0.66 occasions per day, 95% CI: 0.51 to 0.81 occasions per day, p<0.0001).
The bronchodilator effects of Spiriva Respimat were maintained throughout the 1-year period of administration with no evidence of tolerance.
Dyspnoea, Health-related Quality of Life, COPD Exacerbations in long term 1 year studies
Dyspnoea
Spiriva Respimat significantly improved dyspnoea (as evaluated using the Transition Dyspnoea Index) compared to placebo (mean improvement 1.05 units; 95% CI: 0.73 to 1.38 units, p<0.0001). An improvement was maintained throughout the treatment period.
Health-related Quality of Life
The improvement in mean total score of patient's evaluation of their Quality of Life (as measured using the St. George's Respiratory Questionnaire) between Spiriva Respimat versus placebo at the end of the two 1-year studies was 3.5 units (95% CI: 2.1 to 4.9, p<0.0001). A 4-unit decrease is considered clinically relevant.
COPD Exacerbations
In three one-year, randomised, double-blind, placebo-controlled clinical trials Spiriva Respimat treatment resulted in a significantly reduced risk of a COPD exacerbation in comparison to placebo. Exacerbations of COPD were defined as “a complex of at least two respiratory events/symptoms with a duration of three days or more requiring a change in treatment (prescription of antibiotics and/or systemic corticosteroids and/or a significant change of the prescribed respiratory medication)”. Spiriva Respimat treatment resulted in a reduced risk of a hospitalisation due to a COPD exacerbation (significant in the appropriately powered large exacerbation trial).
The pooled analysis of two Phase III trials and separate analysis of an additional exacerbation trial is displayed in Table 1. All respiratory medications except anticholinergics and long-acting beta-agonists were allowed as concomitant treatment, i.e. rapidly acting beta-agonists, inhaled corticosteroids and xanthines. Long-acting beta-agonists were allowed in addition in the exacerbation trial.
Table 1: Statistical Analysis of Exacerbations of COPD and Hospitalized COPD Exacerbations in Patients with Moderate to Very Severe COPD
| Study (NSpiriva, Nplacebo) | Endpoint | Spiriva Respimat | Placebo | % Risk Reduction (95% CI)a | p-value |
| 1-year Ph III studies, pooled analysisd(670, 653) | Days to first COPD exacerbation | 160a | 86a | 29 (16 to 40)b | <0.0001b |
| Mean exacerbation incidence rate per patient year | 0.78c | 1.00c | 22 (8 to 33)c | 0.002c |
| Time to first hospitalised COPD exacerbation | | | 25 (-16 to 51)b | 0.20b |
| Mean hospitalised exacerbation incidence rate per patient year | 0.09 c | 0.11 c | 20 (-4 to 38) c | 0.096 c |
| 1-year Ph IIIb exacerbation study (1939, 1953) | Days to first COPD exacerbation | 169a | 119a | 31 (23 to 37)b | <0.0001b |
| Mean exacerbation incidence rate per patient year | 0.69c | 0.87c | 21 (13 to 28)c | <0.0001c |
| Time to first hospitalised COPD exacerbation | | | 27 (10 to 41)b | 0.003b |
| Mean hospitalised exacerbation incidence rate per patient year | 0.12c | 0.15c | 19 (7 to 30)c | 0.004c |
a Time to first event: days on treatment by when 25% of patients had at least one exacerbation of COPD / hospitalized COPD exacerbation. In study A 25% of placebo patients had an exacerbation by day 112, whereas for Spiriva Respimat 25% had an exacerbation by day 173 ( p=0.09);in study B 25% of placebo patients had an exacerbation by day 74, whereas for Spiriva Respimat 25% had an exacerbation by day 149 (p<0.0001).
b Hazard ratios were estimated from a Cox proportional hazard model. The percentage risk reduction is 100(1 - hazard ratio).
c Poisson regression. Risk reduction is 100(1 - rate ratio).
d Pooling was specified when the studies were designed. The exacerbation endpoints were significantly improved in individual analyses of the two one year studies.
Long-term tiotropium active- controlled study
A long-term large scale randomised, double-blind, active-controlled study with an observation period up to 3 years has been performed to compare the efficacy and safety of Spiriva Respimat and Spiriva HandiHaler (5,711 patients receiving Spiriva Respimat; 5,694 patients receiving Spiriva HandiHaler). The primary endpoints were time to first COPD exacerbation, time to all-cause mortality and in a sub-study (906 patients) trough FEV1 (pre-dose).
The time to first COPD exacerbation was numerically similar during the study with Spiriva Respimat and Spiriva HandiHaler (hazard ratio (Spiriva Respimat/Spiriva HandiHaler) 0.98 with a 95% CI of 0.93 to 1.03). The median number of days to the first COPD exacerbation was 756 days for Spiriva Respimat and 719 days for Spiriva HandiHaler.
The bronchodilator effect of Spiriva Respimat was sustained over 120 weeks, and was similar to Spiriva HandiHaler. The mean difference in trough FEV1 for Spiriva Respimat versus Spiriva HandiHaler was -0.010 L (95% CI -0.038 to 0.018 L).
In the post-marketing TIOSPIR study comparing Spiriva Respimat and Spiriva HandiHaler, all-cause mortality (including vital status follow up) was similar with hazard ratio (Spiriva Respimat/Spiriva HandiHaler) = 0.96 , 95% CI 0.84 -1.09). Respective treatment exposure was 13,135 and 13,050 patient-years.
In the placebo-controlled studies with vital status follow-up to the end of the intended treatment period, Spiriva Respimat showed a numerical increase in all-cause mortality compared to placebo (rate ratio (95% confidence interval) of 1.33 (0.93, 1.92) with treatment exposure to Spiriva Respimat of 2,574 patient years; the excess in mortality was observed in patients with known rhythm disorders. Spiriva HandiHaler showed a 13 % reduction in the risk of death ((hazard ratio including vital status follow-up (tiotropium/placebo) = 0.87; 95% CI, 0.76 to 0.99)). Treatment exposure to Spiriva HandiHaler was 10,927 patient-years. No excess mortality risk was observed in the subgroup of patients with known rhythm disorders in the placebo controlled Spiriva HandiHaler study as well as in the TIOSPIR Spiriva Respimat to HandiHaler comparison.
Clinical efficacy and safety in asthma
The clinical Phase III programme for persistent asthma in adults included two 1-year randomised, double-blind, placebo-controlled studies in a total of 907 asthma patients (453 receiving Spiriva Respimat) on a combination of ICS (≥ 800 µg budesonide/day or equivalent) with a LABA. The studies included lung function measurements and severe exacerbations as primary endpoints.
PrimoTinA-asthma studies
In the two 1-year studies in patients who were symptomatic on maintenance treatment of at least ICS (≥800 µg budesonide/day or equivalent) plus LABA, Spiriva Respimat showed clinically relevant improvements in lung function over placebo when used as add-on to background treatment.
At week 24, mean improvements in peak and trough FEV1 were 0.110 litres (95% CI: 0.063 to 0.158 litres, p<0.0001) and 0.093 litres (95% CI: 0.050 to 0.137 litres, p<0.0001), respectively. The improvement of lung function compared to placebo was maintained for 24 hours.
In the PrimoTinA-asthma studies, treatment of symptomatic patients (N=453) with ICS plus LABA plus tiotropium reduced the risk of severe asthma exacerbations by 21% as compared to treatment of symptomatic patients (N=454) with ICS plus LABA plus placebo. The risk reduction in the mean number of severe asthma exacerbations/patient year was 20%.
This was supported by a reduction of 31% in risk for asthma worsening and 24% risk reduction in the mean number of asthma worsenings/patient year (see Table 2).
Table 2: Exacerbations in Patients Symptomatic on ICS (≥800 µg budesonide/day or equivalent) plus LABA (PrimoTinA-asthma studies)
| Study | Endpoint | Spiriva Respimat, added-on to at least ICSa/LABA (N=453) | Placebo, added-on to at least ICSa/LABA (N=454) | % Risk Reduction (95% CI) | p-value |
| two 1-year Phase III studies, pooled analysis | Days to 1st severe asthma exacerbation | 282c | 226c | 21b (0, 38) | 0.0343 |
| Mean number of severe asthma exacerbations / patient year | 0.530 | 0.663 | 20d (0, 36) | 0.0458 |
| Days to 1st worsening of asthma | 315c | 181c | 31b (18, 42) | <0.0001 |
| Mean number of asthma worsenings / patient year | 2.145 | 2.835 | 24d (9, 37) | 0.0031 |
a ≥800 µg budesonide/day or equivalent
b Hazard ratio, confidence interval and p-value obtained from a Cox proportional hazards model with only treatment as effect. The percentage risk reduction is 100(1 - hazard ratio).
c Time to first event: days on treatment by when 25%/50% of patients had at least one severe asthma exacerbation/worsening of asthma
d The rate ratio was obtained from a Poisson regression with log exposure (in years) as offset. The percentage risk reduction is 100 (1-rate ratio).
Paediatric population
COPD
The European Medicines Agency has waived the obligation to submit the results of studies with Spiriva Respimat in all subsets of the paediatric population in COPD (see section 4.2 for information on paediatric use).
Asthma
All studies in the clinical Phase III program for persistent asthma in paediatric patients (1 - 17 years) were randomised, double-blind and placebo-controlled. All patients were on background treatments that include an ICS.
Severe Asthma
Adolescents (12 - 17 years)
In the 12-week PensieTinA-asthma study a total of 392 patients (130 receiving Spiriva Respimat) who were symptomatic on a high dose of ICS with one controller or a medium dose of ICS with 2 controllers were included.
For patients aged 12 - 17 years, a high dose ICS was defined as a dose of > 800 - 1600 µg budesonide/day or equivalent; a medium dose ICS as 400 - 800 µg budesonide/day or equivalent. In addition, patients aged 12 - 14 years could receive an ICS dose > 400 µg budesonide/day or equivalent and at least one controller or ≥ 200 µg budesonide/day or equivalent and at least two controllers.
In this study, Spiriva Respimat showed improvements in lung function over placebo when used as add-on to background treatment, however, the differences in peak and trough FEV1 were not statistically significant.
• At week 12, mean improvements in peak and trough FEV1 were 0.090 litres (95% CI: -0.019 to 0.198 litres, p=0.1039) and 0.054 litres (95% CI: -0.061 to 0.168 litres, p=0.3605), respectively.
• At week 12, Spiriva Respimat significantly improved morning and evening PEF (morning 17.4 L/min; 95% CI: 5.1 to 29.6 L/min; evening 17.6 L/min; 95% CI: 5.9 to 29.6 L/min).
Children (6 - 11 years)
In the 12-week VivaTinA-asthma study a total 400 patients (130 receiving Spiriva Respimat) who were symptomatic on a high dose ICS with one controller or a medium dose ICS with 2 controllers were included. A high dose ICS was defined by a dose of > 400 µg budesonide/day or equivalent, a medium dose as 200 - 400 µg budesonide/day or equivalent.
In this study, Spiriva Respimat showed significant improvements in lung function over placebo when used as add-on to background treatment.
• At week 12, mean improvements in peak and trough FEV1 were 0.139 litres (95% CI: 0.075 to 0.203 litres, p<0.0001) and 0.087 litres (95% CI: 0.019 to 0.154 litres, p=0.0117), respectively.
Moderate Asthma
Adolescents (12 - 17 years)
In the 1-year RubaTinA-asthma study in a total of 397 patients (134 receiving Spiriva Respimat) who were symptomatic on a medium dose ICS (200 - 800 µg budesonide/day or equivalent for patients aged 12 - 14 years or 400 - 800 µg budesonide/day or equivalent for patients aged 15 - 17 years),
Spiriva Respimat showed significant improvements in lung function over placebo when used as add-on to background treatment.
Children (6 - 11 years)
In the 1-year CanoTinA-asthma study in a total of 401 patients (135 receiving Spiriva Respimat) who were symptomatic on a medium dose ICS (200 - 400 µg budesonide/day or equivalent), Spiriva Respimat showed significant improvements in lung function over placebo when used as add-on to background treatment.
Children (1 - 5 years)
One 12-week randomised, double-blind, placebo-controlled, phase II/III clinical study (NinoTinA-asthma) was conducted in a total of 101 children (31 received Spiriva Respimat) with asthma on background treatments that include an ICS. An Aerochamber Plus Flow-Vu® valved holding chamber with face mask was used to administer trial medication in 98 patients.
The primary objective of the study was safety; efficacy assessments were exploratory.
The number and percentage of patients reporting adverse events (AEs) irrespective of relatedness are shown in Table 3. The number of asthma adverse events was lower for Spiriva Respimat compared to placebo. Exploratory efficacy evaluations did not show differences for Spiriva Respimat from placebo.
Table 3: Frequency of patients with AEs reported for ≥ 5 patients in the NinoTinA-asthma study (children aged 1 to 5 years)
| | Placebo N (%) | Spiriva Respimat N (%) |
| Number of patients | 34 (100.0) | 31 (100.0) |
| Patients with any AE | 25 (73.5) | 18 (58.1) |
| Nasopharyngitis | 5 (14.7) | 2 (6.5) |
| Upper respiratory tract infection | 1 (2.9) | 5 (16.1) |
| Asthma* | 10 (29.4) | 2 (6.5) |
| Pyrexia | 6 (17.6) | 3 (9.7) |
*The MedDRA low level terms under the preferred term "Asthma" were either “Asthma aggravated” or “Exacerbation of asthma”
The European Medicines Agency has waived the obligation to submit the results of studies with Spiriva Respimat in the subset of paediatric patients below 1 year of age (see section 4.2 for information on paediatric use).
Clinical efficacy and safety in cystic fibrosis (CF):
The clinical development programme in CF included 3 multicentre studies in 959 patients aged 5 months and above. Patients below 5 years used a spacer (AeroChamber Plus®) with face mask and were included for safety assessment only. The two pivotal studies (a dose finding Phase II study and a confirmatory Phase III study) compared lung function effects (percent predicted FEV1 AUC 0-4h and trough FEV1) of Spiriva Respimat (tiotropium 5 µg: 469 patients) versus placebo (315 patients) in 12-weeks randomised, double-blind periods; the Phase III study also included a long term open label extension, up to 12 months. In these studies, all respiratory medications, except anticholinergics, were allowed as concomitant treatment, e.g. long acting beta agonists, mucolytics and antibiotics.
Effects on lung function are displayed in Table 4. No significant improvement in symptoms and health status (exacerbations by Respiratory and Systemic Symptoms Questionnaire and quality of life by Cystic Fibrosis Questionnaire) have been observed.
Table 4: Adjusted mean difference from placebo for absolute changes from baseline after 12 weeks
| | Phase II | Phase III |
| All patients (NSpiriva = 176, Nplacebo = 168) | All patients (NSpiriva = 293, Nplacebo = 147) | ≤11 years | ≥12 years |
| (NSpiriva = 95, Nplacebo = 47) | (NSpiriva = 198, Nplacebo = 100) |
| mean (95% CI) | p-value | mean (95% CI) | p-value | mean (95% CI) | mean (95% CI) |
| FEV1AUC0-4h (% predicted) a absolute changes | 3.39 (1.67, 5.12) | <0.001 | 1.64 (-0.27, 3.55) | 0.092 | -0.63 (-4.58, 3.32) | 2.58 (0.50, 4.65) |
| FEV1AUC0-4h (litres) absolute changes | 0.09 (0.05, 0.14) | <0.001 | 0.07 (0.02, 0.12) | 0.010 | 0.01 (-0.07, 0.08) | 0.10 (0.03, 0.17) |
| Trough FEV1 (% predicted) a absolute changes | 2.22 (0.38, 4.06) | 0.018 | 1.40 -0.50, 3.30 | 0.150 | -1.24 (-5.20, - 2.71) | 2.56 (0.49, 4.62) |
| Trough FEV1 (litres) absolute changes | 0.06 (0.01, 0.11) | 0.028 | 0.07 (0.02, 0.12) | 0.012 | -0.01 (-0.08, 0.06) | 0.10 (0.03, 0.17) |
a Co-primary endpoints
All Adverse Drug Reactions (ADRs) observed in the CF studies are known undesirable effects of tiotropium (see 4.8). The most commonly observed adverse events considered related during the 12 week double blind period were cough (4.1%) and dry mouth (2.8%).
The number and percentage of patients reporting adverse events (AEs) of special interest in cystic fibrosis irrespective of relatedness are shown in Table 5. Signs and symptoms considered to be manifestations of cystic fibrosis increased numerically, although not statistically significantly, with tiotropium, especially in patients ≤11 years old.
Table 5: Percentage of patients with AEs of special interest in cystic fibrosis by age group over 12 weeks of treatment irrespective of relatedness (pooled Phase II and Phase III)
| | ≤11 years | ≥12 years |
| | Nplacebo = 96 | NSpiriva = 158 | Nplacebo = 215 | NSpiriva = 307 |
| Abdominal pain | 7.3 | 7.0 | 5.1 | 6.2 |
| Constipation | 1.0 | 1.9 | 2.3 | 2.6 |
| Distal intestinal obstruction syndrome | 0.0 | 0.0 | 1.4 | 1.3 |
| Respiratory tract infections | 34.4 | 36.7 | 28.4 | 28.3 |
| Sputum increased | 1.0 | 5.1 | 5.6 | 6.2 |
| Exacerbations | 10.4 | 14.6 | 18.6 | 17.9 |
"Distal intestinal obstruction syndrome" and "Sputum increased" are MedDRA preferred terms. "Respiratory tract infections" is the MedDRA higher level group term. "Abdominal pain", "Constipation" and "Exacerbations" are collections of MedDRA preferred terms.
Thirty-four (10.9 %) patients randomised to placebo and 56 (12.0%) patients randomised to Spiriva Respimat experienced a serious adverse event.
The European Medicines Agency has waived the obligation to submit the results of studies with Spiriva Respimat in the subset of paediatric patients below 1 year of age.