CLINICAL PHARMACOLOGY
Mechanism Of Action
Tiotropium is a long-acting,
antimuscarinic agent, which is often referred to as an anticholinergic. It has
similar affinity to the subtypes of muscarinic receptors, M1 to M5. In the
airways, it exhibits pharmacological effects through inhibition of M3-receptors
at the smooth muscle leading to bronchodilation. The competitive and reversible
nature of antagonism was shown with human and animal origin receptors and
isolated organ preparations. In preclinical in vitro as well as in vivo studies,
prevention of methacholine-induced bronchoconstriction effects was
dose-dependent and lasted longer than 24 hours. The bronchodilation following
inhalation of tiotropium is predominantly a site-specific effect.
Pharmacodynamics
Cardiac Electrophysiology
In a multicenter, randomized,
double-blind trial using tiotropium dry powder for inhalation that enrolled 198
patients with COPD, the number of subjects with changes from baseline-corrected
QT interval of 30 to 60 msec was higher in the SPIRIVA group as compared with
placebo. This difference was apparent using both the Bazett (QTcB) [20 (20%)
patients vs. 12 (12%) patients] and Fredericia (QTcF) [16 (16%) patients vs. 1
(1%) patient] corrections of QT for heart rate. No patients in either group had
either QTcB or QTcF of > 500 msec. Other clinical trials with SPIRIVA did not
detect an effect of the drug on QTc intervals.
The effect of tiotropium dry
powder for inhalation on QT interval was also evaluated in a randomized,
placebo- and positive-controlled crossover study in 53 healthy volunteers.
Subjects received tiotropium inhalation powder 18 mcg, 54 mcg (3 times the
recommended dose), or placebo for 12 days. ECG assessments were performed at
baseline and throughout the dosing interval following the first and last dose
of study medication. Relative to placebo, the maximum mean change from baseline
in study-specific QTc interval was 3.2 msec and 0.8 msec for tiotropium
inhalation powder 18 mcg and 54 mcg, respectively. No subject showed a new
onset of QTc > 500 msec or QTc changes from baseline of ≥ 60 msec.
Pharmacokinetics
Tiotropium is administered as
an inhalation spray. Some of the pharmacokinetic data described below were
obtained with higher doses than recommended for therapy. A dedicated
pharmacokinetic study in patients with COPD evaluating once-daily tiotropium
delivered from the RESPIMAT inhaler (5 mcg) and as inhalation powder (18 mcg)
from the HandiHaler resulted in a similar systemic exposure between the two
products.
Absorption
Following inhalation of the
solution by young healthy volunteers, urinary excretion data suggests that
approximately 33% of the inhaled dose reaches the systemic circulation. Oral
solutions of tiotropium have an absolute bioavailability of 2% to 3%. Food is
not expected to influence the absorption of tiotropium for the same reason.
Following 4-week SPIRIVA RESPIMAT once daily dosing, maximum tiotropium plasma
concentrations were observed 5-7 minutes after inhalation in COPD and asthma
patients.
Distribution
The drug has a plasma protein
binding of 72% and shows a volume of distribution of 32 L/kg after an
intravenous dose to young healthy volunteers. Local concentrations in the lung
are not known, but the mode of administration suggests substantially higher
concentrations in the lung. Studies in rats have shown that tiotropium does not
penetrate the blood-brain barrier.
Elimination
Metabolism
The extent of metabolism is
small. This is evident from a urinary excretion of 74% of unchanged substance
after an intravenous dose to young healthy volunteers. Tiotropium, an ester, is
nonenzymatically cleaved to the alcohol N-methylscopine and dithienylglycolic
acid, neither of which binds to muscarinic receptors.
In vitro experiments with human liver microsomes and human
hepatocytes suggest that a fraction of the administered dose (74% of an
intravenous dose is excreted unchanged in the urine, leaving 25% for
metabolism) is metabolized by cytochrome P450-dependent oxidation and
subsequent glutathione conjugation to a variety of Phase II metabolites. This
enzymatic pathway can be inhibited by CYP450 2D6 and 3A4 inhibitors, such as
quinidine, ketoconazole, and gestodene. Thus, CYP450 2D6 and 3A4 are involved
in the metabolic pathway that is responsible for the elimination of a small
part of the administered dose. In vitro studies using human liver microsomes
showed that tiotropium in supra-therapeutic concentrations does not inhibit
CYP450 1A1, 1A2, 2B6, 2C9, 2C19, 2D6, 2E1, or 3A4.
Excretion
The terminal half-life of
tiotropium in COPD and asthma patients following once daily inhalation is 25
and 44 hours, respectively. Total clearance was 880 mL/min after an intravenous
dose in young healthy volunteers. Intravenously administered tiotropium bromide
is mainly excreted unchanged in urine (74%). Following 21-day once daily
inhalation of 5 mcg of the solution by patients with COPD, 24-hour urinary
excretion is 18.6% (0.93 mcg) of the dose. The renal clearance of tiotropium
exceeds the creatinine clearance, indicating secretion into the urine. In
comparison, 12.8% (0.32 mcg) of the dose was excreted unchanged in the urine
over 24 hours at steady state after inhalation of 2.5 mcg in patients with
asthma. After chronic once-daily inhalation by COPD and asthma patients,
pharmacokinetic steady-state was reached by day 7 with no accumulation
thereafter.
Specific Populations
Geriatric Patients
As expected for all predominantly renally excreted drugs,
advancing age was associated with a decrease of tiotropium renal clearance (347
mL/min in COPD patients < 65 years to 275 mL/min in COPD patients ≥ 65
years). This did not result in a corresponding increase in AUC0-6,ss and Cmax,ss
values following inhalation of the solution. Exposure to tiotropium was not
found to differ with age in patients with asthma.
Pediatric Patients
The peak and total exposure to tiotropium was not found
to differ between pediatric patients (aged 6 to 17 years) and adults with
asthma.
Renal Impairment
Following 4-week SPIRIVA RESPIMAT 5 mcg once daily dosing
in patients with COPD, mild renal impairment (creatinine clearance 60 - < 90
mL/min) resulted in 23% higher AUC0-6,ss and 17% higher Cmax,ss values;
moderate renal impairment (creatinine clearance 30 - < 60 mL/min) resulted in
57% higher AUC0-6,ss and 31% higher Cmax,ss values compared to COPD patients
with normal renal function (creatinine clearance > 90 mL/min). The influence
of mild or moderate renal impairment on the systemic exposure to SPIRIVA
RESPIMAT 2.5 mcg in patients with asthma was similar to what has been described
for COPD above. There lacks sufficient data of tiotropium exposure in patients
with severe renal impairment (creatinine clearance < 30 mL/min) following
inhalation of SPIRIVA RESPIMAT. However AUC0-4 and Cmax were 94% and 52%
higher, respectively, in patients with severe renal impairment following
intravenous infusion of tiotropium bromide.
Hepatic Impairment
The effects of hepatic impairment on the pharmacokinetics
of tiotropium were not studied.
Drug Interactions
An interaction study with tiotropium (14.4 mcg
intravenous infusion over 15 minutes) and cimetidine 400 mg three times daily
or ranitidine 300 mg once-daily was conducted. Concomitant administration of
cimetidine with tiotropium resulted in a 20% increase in the AUC0-4h, a 28%
decrease in the renal clearance of tiotropium and no significant change in the
Cmax and amount excreted in urine over 96 hours. Co-administration of
tiotropium with ranitidine did not affect the pharmacokinetics of tiotropium.
Common concomitant medications (LABA, ICS) used by
patients with COPD were not found to alter the exposure to tiotropium.
Similarly, common concomitant medications (LABA, ICS+LABA combinations, oral
corticosteroids and leukotriene modifiers) used by patients with asthma were
not found to alter the exposure to tiotropium.
Clinical Studies
Chronic Obstructive Pulmonary Disease
The efficacy of SPIRIVA RESPIMAT compared to placebo was
evaluated in 6 clinical trials: one dose-ranging trial and 5 confirmatory
trials (Trials 1-5). In addition, SPIRIVA RESPIMAT was compared to SPIRIVA
HandiHaler in a long-term active-controlled trial in COPD (Trial 6).
Dose-Ranging Trial
Dose selection for the Phase III clinical program was
supported by a 3-week randomized, double-blind, placebo and active-controlled,
parallel group trial in 202 COPD patients. A total of five doses of tiotropium
RESPIMAT (1.25 to 20 mcg) were evaluated compared to placebo. Results
demonstrated numerical improvements in FEV1 at all doses compared to placebo.
The difference in trough FEV1 from placebo for the 1.25, 2.5, 5, 10 and 20 mcg
once daily doses were 0.08 L (95% CI -0.03, 0.20), 0.03 L (-0.08, 0.15), 0.13 L
(0.02, 0.25), 0.11 L (-0.004, 0.224), and 0.13 L (0.01, 0.24), respectively.
Based on these results, the 5 and 10 mcg doses were further evaluated in the
confirmatory COPD trials.
Confirmatory Trials
A total of 6614 COPD patients (2801 receiving SPIRIVA
RESPIMAT 5 mcg and 2798 receiving placebo) were studied in the five
confirmatory trials of SPIRIVA RESPIMAT. Trials 1 and 2 were 12-week,
randomized, double-blind, placebo- and active-(ipratropium) controlled trials
that evaluated bronchodilation. Trials 3-5 were 48-week, randomized,
double-blind, placebo-controlled, trials that evaluated bronchodilation and
effects on COPD exacerbations. Trials 1-4 included both the tiotropium RESPIMAT
5 mcg and 10 mcg doses, whereas Trial 5 included only the 5 mcg dose. These
trials enrolled patients who had a clinical diagnosis of COPD, were 40 years of
age or older, had a history of smoking greater than 10 pack-years, had an FEV1 less
than or equal to 60% of predicted and a ratio of FEV1/FVC of less than or equal
to 0.7. All treatments were administered once-daily in the morning. Change from
baseline in trough FEV1 was a primary endpoint in all trials. Trials 3-5
included COPD exacerbations as primary endpoints.
Baseline patient characteristics were similar across the
five individual confirmatory trials, except for race in Trial 5 in which there
were more Asian patients (30%) compared to other trials ( < 1%). The mean age
ranged from 62 to 66 years. Most patients were male (64-78%), ex-smokers
(57-65%) and Caucasian (69-99%). Mean pre-bronchodilator FEV1 was between 1.03
and 1.26 L with a mean FEV1/FVC ratio of 42-50%. Except for LABAs and other
inhaled anticholinergic agents, other pulmonary medications were allowed as
concomitant therapy in Trials 1-4. LABA use was permitted in Trial 5.
Effect on Lung Function
SPIRIVA RESPIMAT 5 mcg demonstrated significant
improvement in trough FEV1 compared to placebo in all 5 confirmatory trials (Table
4). The change from baseline in trough FEV1 over time from Trial 4 is depicted
in Figure 1 and is representative of the other two 48-week trials. In Trials 3
and 4 patients treated with SPIRIVA RESPIMAT 5 mcg also used less rescue
medication compared to patients on placebo.
Table 4 : Mean Change from Baseline in Trough FEV1 (L)
at End of Treatment
Trial |
SPIRIVA RESPIMAT 5 mcg
N |
Placebo
N |
Trough FEV1 (L) at End of Treatment Difference from placebo (95% CI) |
Trial 1† |
85 |
87 |
0.11 (0.04, 0.18) |
Trial 2† |
90 |
84 |
0.13 (0.07, 0.18) |
Trial 3‡ |
326 |
296 |
0.14 (0.10, 0.18) |
Trial 4‡ |
324 |
307 |
0.11 (0.08, 0.15) |
Trial 5‡ |
1889 |
1870 |
0.10 (0.09, 0.12) |
† at week 12
‡ at week 48 |
Figure 1 : Trough FEV1 Change
from Baseline over 48 weeks (Trial 4), SPIRIVA RESPIMAT 5 mcg
Exacerbations
Trials 3, 4, and 5 also
evaluated the effect of SPIRIVA RESPIMAT 5 mcg on COPD exacerbations. For
Trials 3 and 4, a pooled analysis of exacerbation rate per patient year was
pre-specified as a primary endpoint, while the primary endpoint for Trial 5 was
time to first exacerbation. Trial 5 also included exacerbation rate per patient
year as a secondary endpoint. Exacerbations were defined as a complex of
respiratory events/symptoms with a duration of ≥ 3 days with ≥ 2 of
the following (increase of symptoms or new onset): shortness of
breath/dyspnea/shallow, rapid breathing; sputum production (volume); occurrence
of purulent sputum; cough; wheezing; chest tightness.
In the pooled analysis of
Trials 3 and 4, SPIRIVA RESPIMAT 5 mcg significantly reduced the number of COPD
exacerbations compared to placebo with 0.78 exacerbations/patient year versus
1.0 exacerbations/patient year, respectively, with a rate ratio of 0.78 (95% CI
0.67, 0.92). Time to first exacerbation was also delayed in SPIRIVA RESPIMAT 5
mcg patients. For Trial 5, in addition to the definition above, an exacerbation
also had to result in a change in or requirement of treatment. In Trial 5,
treatment with SPIRIVA RESPIMAT 5 mcg delayed the time to first COPD
exacerbation compared to treatment with placebo [hazard ratio of 0.69 (95% CI
0.63, 0.77)]. Consistent with the pooled analysis of Trials 3 and 4, for Trial
5, exacerbation rate was also lower in SPIRIVA RESPIMAT 5 mcg compared to
placebo. In Trial 5, SPIRIVA RESPIMAT 5 mcg also reduced the risk of COPD
exacerbation-related hospitalization (HR = 0.73; 95% CI = 0.59, 0.90) compared
to placebo.
Long-term Active-Controlled
Mortality Trial
Survival
In a pooled analysis of SPIRIVA
RESPIMAT placebo-controlled clinical trials with complete vital status
(mortality) follow-up, including the three 48-week trials (Trial 3, 4, and 5)
and one 24-week placebo-controlled trial, 68 deaths (Incidence Rate 2.64 deaths
per 100 patient years) were observed in the SPIRIVA RESPIMAT 5 mcg treatment
group compared to 51 deaths (Incidence Rate 1.98 deaths per 100 patient years)
in those treated with placebo. In a 4-year, randomized, double-blind,
placebo-controlled, multicenter clinical trial of tiotropium bromide inhalation
powder (SPIRIVA HandiHaler) in 5992 COPD patients a similar incidence rate of
death had been observed between SPIRIVA HandiHaler and placebo treated groups.
For clarification of the
observed difference in fatal events, a long-term, randomized, double-blind,
double dummy, active-controlled trial with an observation period up to 3 years
was conducted to evaluate the risk of all-cause mortality associated with the
use of SPIRIVA RESPIMAT compared to SPIRIVA HandiHaler (Trial 6). The objective
of this trial was to rule out a relative excess mortality risk of 25% for
SPIRIVA RESPIMAT versus SPIRIVA HandiHaler. The primary endpoints were
all-cause mortality and time to first COPD exacerbation. Trial 6 also included
a lung function sub-study which measured trough FEV1 measured every 24 weeks
for 120 weeks (461 patients receiving SPIRIVA RESPIMAT 5 mcg, 445 patients
receiving SPIRIVA HandiHaler).
In Trial 6, 5711 patients
received SPIRIVA RESPIMAT 5 mcg and 5694 patients received SPIRIVA HandiHaler.
All patients were followed for vital status (mortality) at the end of the
trial. At baseline, patient characteristics were balanced between the two
treatment arms. The mean age was 65 years and approximately 70% of subjects
were male. Approximately, 82% of patients were Caucasian, 14% were Asian, and
2% were Black. Mean post-bronchodilator FEV1 was 1.34 L with a mean FEV1/FVC
ratio of 50%. The majority of patients were GOLD II or III (48% and 40%,
respectively).
The vital status was confirmed in 99.7% of patients. The
median exposure to treatment was 835 days for both treatment groups. All-cause
mortality was similar between SPIRIVA RESPIMAT 5 mcg and SPIRIVA HandiHaler
with an estimated hazard ratio of 0.96 [(95% CI of (0.84 to 1.09), Table 5].
Table 5 : All-cause Mortality of SPIRIVA RESPIMAT vs
SPIRIVA HandiHaler (Trial 6)
|
SPIRIVA RESPIMAT 5 mcg
(N = 5711) |
SPIRIVA HandiHaler
(N = 5694) |
Number (%) of Deaths |
423 (7.4) |
439 (7.7) |
Incidence Rate per 100 patient years |
3.22 |
3.36 |
HR (95% CI)a |
0.96 (0.84, 1.09) |
a Hazard ratios were estimated from a Cox
proportional hazard model. |
Cause of death was adjudicated
by a blinded, independent committee. Cardiovascular deaths included cardiac
death, sudden cardiac death, and sudden death; as well as fatal events caused
by a cardiac disorder, vascular disorder, or stroke. There were 113 patients
(2%) treated with SPIRIVA RESPIMAT 5 mcg who had cardiovascular deaths compared
to 101 (2%) patients treated with SPIRIVA HandiHaler. Of the cardiovascular
deaths, 11 (0.2%) and 3 (0.1%) deaths were due to myocardial infarction in
SPIRIVA RESPIMAT 5 mcg patients and SPIRIVA HandiHaler patients, respectively.
For cardiac deaths, sudden cardiac death, and sudden death, there were a total
of 69 (1.2%) and 68 (1.2%) deaths in SPIRIVA RESPIMAT 5 mcg patients and
SPIRIVA HandiHaler patients, respectively.
Effect On Lung Function And Exacerbations
In the lung function sub-study
the effect of SPIRIVA RESPIMAT 5 mcg on trough FEV1 over 120 weeks was similar
to SPIRIVA HandiHaler with a mean difference of -0.010 L (95% CI -0.038 to
0.018 L).
Trial 6 also included time to
first exacerbation as a co-primary endpoint (exacerbations defined as in Trials
3-5). SPIRIVA RESPIMAT 5 mcg failed to demonstrate superiority to SPIRIVA
HandiHaler with a similar time to first COPD exacerbation between treatment
groups [hazard ratio of 0.98 (95% CI 0.93 to 1.03)].
Asthma
The SPIRIVA RESPIMAT clinical
development program included six 4-week to 8-week cross-over design trials and
ten 12-week to 48-week parallel-arm design trials in adult, adolescent (aged 12
to 17 years) and pediatric (aged 1 to 11 years) patients with asthma
symptomatic on at least ICS. In all trials, SPIRIVA RESPIMAT was administered
on a background of ICS therapy.
Dose Selection
Dose selection for the
confirmatory trials was based on three randomized, double-blind,
placebo-controlled, 4-week to 8-week, cross-over trials in 256 adult patients,
105 adolescent (age 12 to 17 years) patients, and 101 pediatric (age 6 to 11
years) patients that assessed doses ranging from 1.25 mcg to 10 mcg once daily.
Results demonstrated numerical improvements in FEV1 at all doses compared to
placebo; however, across the trials, the response was not dose-ordered. For
adult patients, in the 4-week trial the difference in peak FEV1 within 3 h
post-dosing (peak FEV1, 0-3hr) from placebo for the tiotropium RESPIMAT 1.25,
2.5, and 5 mcg doses were 0.138 L (95% CI 0.090, 0.186), 0.128 L (0.080,
0.176), and 0.188 L (0.140, 0.236), respectively. For adolescent patients, the
difference in peak FEV1, 0-3hr from placebo for the tiotropium RESPIMAT 1.25,
2.5, and 5 mcg doses were 0.067 L (95% CI -0.005, 0.138), 0.057 L
(-0.021, 0.135), and 0.113 L (0.036, 0.190), respectively. For pediatric
patients, the difference in peak FEV1, 0-3h from placebo for the tiotropium
RESPIMAT 1.25, 2.5, and 5 mcg doses were 0.075 L (95% CI, 0.030, 0.120), 0.104
L (0.059, 0.149), and 0.087 L (0.042, 0.132), respectively. The 10 mcg dose
offered no substantial benefit over lower doses and resulted in more systemic
anticholinergic side effects (e.g., dry mouth).
The two dose regimen trials in
adults with asthma were randomized, double-blind, 4-week, cross-over trials
comparing tiotropium RESPIMAT 2.5 mcg twice-daily with 5 mcg once-daily.
24-hour FEV1 results demonstrated comparable treatment effects for twice-daily
and once-daily dosing.
12-week To 48-week Parallel-Arm
Design
Trials in Adults The program
for persistent asthma in adult patients included one 12-week (Trial 1), two
replicate 24-week (Trials 2 and 3), and two replicate 48-week (Trials 4 and 5)
randomized, double-blind, placebo-controlled trials in a total of 3476 asthma
patients (673 receiving SPIRIVA RESPIMAT 2.5 mcg once-daily, 1128 receiving
SPIRIVA RESPIMAT 5 mcg once-daily, 541 receiving salmeterol 50 mcg twice daily,
and 1134 receiving placebo) on background treatment of at least ICS. Trial 1
evaluated three treatments: SPIRIVA RESPIMAT 2.5 mcg once-daily, SPIRIVA
RESPIMAT 5 mcg once-daily, and placebo. Trials 2 and 3 evaluated four
treatments: SPIRIVA RESPIMAT 2.5 mcg once-daily, SPIRIVA RESPIMAT 5 mcg
once-daily, salmeterol 50 mcg twice daily, and placebo. Trials 4 and 5
evaluated two treatments: SPIRIVA RESPIMAT 5 mcg once-daily and placebo. All
trials enrolled patients who had a diagnosis of asthma, were 18 to 75 years of
age, and were not current smokers. Patients enrolled in Trials 4 and 5 were
required to have airway obstruction that was not fully reversible
(post-bronchodilator FEV1/FVC, 0.70). The majority of the 3476 patients in the
adult asthma trials were female (60%), Caucasian (61%) or Asian (31%), and had
never smoked (81%) with a mean age of 46 years. The patient characteristics for
the 12 week to 48 week trials in adult patients with asthma are summarized in
Table 6.
Table 6 : Summary of Baseline Patient Characteristics,
Adult Confirmatory Studies
|
Adults, 18 yrs and older |
Trial 1 |
Trial 2 |
Trial 3 |
Trial 4 |
Trial 5 |
Demographics |
Mean age in years (range) |
42.9
(18 - 74) |
43.3
(18 - 75) |
42.9
(18 - 75) |
53.4
(18-75) |
52.5
(19-75) |
Mean duration of asthma (years) |
16.2 |
21.7 |
21.8 |
31.5 |
29.1 |
Smoking status, ex-smoker (%) |
18 |
14 |
19 |
22 |
26 |
Laboratory (median) |
Absolute eosinophils (109/L) |
0.33 |
0.36 |
0.35 |
0.35 |
0.38 |
Total IgE (microgram/L) |
536 |
638 |
641 |
601 |
449 |
Pulmonary function test (mean) |
Pre-bronchodilator FEV1 (L) |
2.30 |
2.18 |
2.21 |
1.55 |
1.59 |
Reversibility (%) |
24.8 |
22.8 |
22.0 |
15.4 |
15.0 |
Absolute reversibility (mL) |
556 |
488 |
477 |
215 |
218 |
Post-bronchodilator FEV1/FVC (%) |
74 |
72 |
72 |
60 |
59 |
The primary efficacy endpoint
in Trial 1 was change from pre-treatment baseline in peak FEV1, 0-3hr at week
12. The co-primary efficacy endpoints in Trials 2 and 3 were change from
pre-treatment baseline in peak FEV1, 0-3hr and change from pre-treatment
baseline in trough FEV1 at week 24. Additional efficacy measures included
asthma exacerbation, Asthma Control Questionnaire (ACQ), and Asthma Quality of
Life Questionnaire (AQLQ).
For Trials 1, 2, and 3, SPIRIVA
RESPIMAT 2.5 mcg showed statistically significant improvements in lung function
over placebo when used in addition to background treatment of ICS (Table 7).
Table 7 : Differences from
Placebo in Peak FEV1, 0-3 hr and Trough FEV1, Adult Confirmatory Studies at
Primary Endpoint Time Evaluation
Treatment (Duration) ICS Background Treatmentb,c |
Treatment in mcg/day |
n |
Peak FEV1, 0-3hr, in La |
Trough FEV1 in La |
Δ from baseline |
Difference from placebo |
A from baseline |
Difference from placebo |
Mean |
95% CI |
Mean |
95% CI |
Adult patients, age 18 years and older |
Trial 1 (12 weeks) |
SPIRIVA RESPIMAT 2.5 mcg |
154 |
0.29 |
0.16 |
0.09, 0.23 |
0.13 |
0.11 |
0.04, 0.18 |
Placebo |
155 |
0.13 |
|
|
0.02 |
|
|
Low dose ICS |
Trial 2 (24 weeks) |
SPIRIVA RESPIMAT 2.5 mcg |
259 |
0.29 |
0.24 |
0.18, 0.29 |
0.15 |
0.19 |
0.13, 0.24 |
Salmeterol 100 mcg |
271 |
0.27 |
0.21 |
0.16, 0.27 |
0.09 |
0.12 |
0.06, 0.18 |
Medium dose ICS |
Placebo |
265 |
0.05 |
|
|
-0.03 |
|
|
Trial 3 |
SPIRIVA RESPIMAT 2.5 mcg |
256 |
0.29 |
0.21 |
0.16, 0.26 |
0.16 |
0.18 |
0.12, 0.23 |
(24 weeks) |
Salmeterol 100 mcg |
264 |
0.25 |
0.18 |
0.12, 0.23 |
0.09 |
0.11 |
0.05, 0.16 |
Medium dose ICS |
Placebo |
253 |
0.08 |
|
|
-0.01 |
|
|
a Means adjusted for treatment,
center/country, visit, visit*treatment, baseline, baseline*visit.
b Additional asthma medications allowed in stable doses prior to and
throughout the trials.
c Low dose ICS = 200-400 mcg budesonide-equivalent. Medium dose ICS
= 400-800 mcg budesonide-equivalent. |
Trials 1, 2, and 3 also
included a SPIRIVA RESPIMAT 5 mcg once daily treatment arm. In these asthma
trials, the FEV1 response (change from baseline for tiotropium compared to
placebo) was generally lower for the 5 mcg dose compared to the 2.5 mcg dose.
The peak FEV1 0-3hr response was 16% to 20% lower for the 5 mcg dose compared
to the 2.5 mcg dose in all three trials, and, the trough FEV1 response was 11%
higher for the 5 mcg dose compared to the 2.5 mcg dose for one trial (Trial 1)
and 18% and 24% lower for the 5 mcg dose compared to the 2.5 mcg dose for the
other two trials (Trials 2 and 3).
Improvements in morning and
evening peak expiratory flow (PEF) were consistent with the observed FEV1 treatment
response. Examination of age, gender, smoking history, and serum IgE level
subgroups did not identify differences in response among these subgroups.
The improvement of lung
function compared to placebo was maintained for 24 hours (Figure 2). The
bronchodilator effects of SPIRIVA RESPIMAT 2.5 mcg were apparent after first
dose; however, maximum bronchodilator effect took up to 4 to 8 weeks to be
achieved.
Figure 2 : FEV1 Response over 24-Hours following
24-Weeks of Treatment, Trial 3
Asthma exacerbation was
assessed in Trials 2 and 3 over the 24-week treatment periods. An asthma
exacerbation was defined as an episode of progressive increase in ≥ 1
asthma symptom(s), such as shortness of breath, cough, wheezing, chest
tightness or some combination of these symptoms or a decrease of a patient's
best morning PEF of 30% from a patient's mean morning PEF for ≥ 2
consecutive days that required the initiation or increase in treatment with
systemic steroids for ≥ 3 days. Results of asthma exacerbation are shown
in Table 8.
Table 8 : Exacerbations in
Patients on ICS over 24-Weeks
|
Trial 2 |
Trial 3 |
SPIRIVA RESPIMAT 2.5 mcg
(N=259) |
Placebo
(N=265) |
SPIRIVA RESPIMAT 2.5 mcg
(N=256) |
Placebo
(N=253) |
Number of patients with at least 1 event, n (%) |
9 (3.5) |
24 (9.1) |
13 (5.1) |
19 (7.5) |
Rate of exacerbations per patient year |
Mean rate of events |
0.08 |
0.24 |
0.13 |
0.18 |
Comparison to Placebo, Rate ratio (95% CI) |
0.32 (0.20, 0.51) |
|
0.70 (0.46, 1.08) |
|
Time to first asthma exacerbation |
Comparison to Placebo, Hazard ratio (95% CI) |
0.37 (0.17, 0.80) |
|
0.66 (0.33, 1.34) |
|
Trials 2 and 3 also evaluated
the rate of exacerbations and time to first asthma exacerbation for the SPIRIVA
RESPIMAT 5 mcg dose. The rate of asthma exacerbations compared to placebo for
SPIRIVA RESPIMAT 5 mcg was 0.78 (95% CI 0.55, 1.10) in Trial 2 and 0.76 (0.50,
1.16) in Trial 3. The hazard ratio for time to first asthma exacerbation for
SPIRIVA RESPIMAT 5 mcg compared to placebo was 0.72 (95% CI 0.39, 1.35), in
Trial 2 and 0.72 (0.36, 1.43) in Trial 3.
ACQ and AQLQ were assessed in
Trials 2 and 3 at week 24. In Trial 2, the ACQ-7 (7 items) responder rate
(defined as a change in score ≥ 0.5) for the SPIRIVA RESPIMAT 2.5 mcg treatment arm was 63%
compared to 53% for placebo with an odds ratio of 1.47 (95% CI 1.02, 2.11). The
ACQ-5 (derived from ACQ 7 by removing the FEV1 component and rescue
bronchodilator component) results also had a similar trend. In Trial 2, the
AQLQ responder rate (defined as a change in score ≥ 0.5) for the
SPIRIVA RESPIMAT 2.5 mcg treatment arm was 58% compared to 50% for placebo with
an odds ratio of 1.34 (95% CI 0.94, 1.93).
12-week And 48-week
Parallel-Arm Design Trials In Adolescents 12-17 Years Of Age
Efficacy in adolescents was
based on partial extrapolation of efficacy in adults and two randomized,
double-blind, placebo-controlled trials of 12 and 48 weeks duration in a total
of 789 asthma patients 12 to 17 years of age (252 receiving SPIRIVA RESPIMAT
2.5 mcg once-daily, 264 receiving 5 mcg once-daily, and 273 receiving placebo).
The 12-week trial enrolled patients with severe asthma who were on background
treatment of ICS plus one or more controller medications (e.g. LABA). The
48-week trial enrolled patients with moderate asthma on background treatment of
at least ICS. The majority of the patients in the trials were male (63.4%),
Caucasian (93.7%) and had never smoked (99.9%) with a mean age of 14.3 years.
The primary efficacy endpoint
in both trials was change from pre-treatment baseline in peak FEV1, 0-3hr. The
primary endpoint evaluation for FEV1 was defined at week 24 for the 48-week
trial and at end of the treatment period (week 12) for the 12-week trial. Given
the demonstration of efficacy in the adult population, the results of the 2
trials support the efficacy of SPIRIVA RESPIMAT 2.5 mcg once daily in
adolescent patients 12-17 years of age with asthma (mean difference in peak FEV1,
0-3hr from placebo for SPIRIVA RESPIMAT 2.5 mcg were 0.13 L (95% CI 0.03, 0.23)
and 0.11 L (0.002, 0.22) for the 48-week and 12-week trials, respectively).
12-week And 48-week
Parallel-Arm Design Trials In Pediatric Patients 6-11 Years Of Age
Efficacy in pediatric patients
6-11 years of age was based on partial extrapolation of efficacy in adults and
two randomized, double-blind, placebo-controlled trials of 12 and 48 weeks
duration in a total of 801 asthma patients 6 to 11 years of age (271 receiving
SPIRIVA RESPIMAT 2.5 mcg once-daily, 265 receiving 5 mcg once-daily, and 265
receiving placebo). The 12-week trial enrolled patients with severe asthma who
were on background treatment of ICS plus one or more controller medications (e.g.
LABA). The 48-week trial enrolled patients with moderate asthma on background
treatment of at least ICS. The primary efficacy endpoint in both trials was change
from pre-treatment baseline in peak FEV1, 0-3hr with the evaluation defined at
week 24 for the 48-week trial and at end of the treatment period (week 12) for
the 12-week trial. The majority of the patients in the trials were male (67.8%)
and Caucasian (87.0%) with a mean age of 9.0 years.
Compared to placebo, SPIRIVA RESPIMAT 2.5 mcg once daily
had a significant effect on the primary endpoint in the 48 week, but not the 12
week trial, with mean differences in peak FEV1, 0-3hr from placebo of 0.17 L
(95% CI 0.11, 0.23) and 0.04 L (95% CI -0.03, 0.10) for the 48-week and 12-week
trials, respectively. Given the demonstration of efficacy in the adult and
adolescent population, the results support the efficacy of SPIRIVA RESPIMAT 2.5
mcg once daily in pediatric patients 6-11 years of age with asthma..