The SPIRIVA HANDIHALER (tiotropium bromide inhalation powder) clinical
development program consisted of six Phase 3 studies in 2663 patients
with COPD (1308 receiving SPIRIVA HANDIHALER): two 1-year, placebo-controlled
studies, two 6-month, placebo-controlled studies and two 1-year, ipratropium-controlled
studies. These studies 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 a forced expiratory volume in one second (FEV1) less than or equal to 60% or 65% of predicted, and
a ratio of FEV1/FVC of less than or equal to
0.7.
In these studies, SPIRIVA
HANDIHALER, administered once-daily in the morning, provided improvement
in lung function (FEV1), with peak effect occurring
within 3 hours following the first dose.
Two additional trials evaluated exacerbations: a 6-month,
randomized, double-blind, placebo-controlled, multicenter clinical
trial of 1829 COPD patients in a US Veterans Affairs setting and a
4-year, randomized, double-blind, placebo-controlled, multicenter,
clinical trial of 5992 COPD patients. Long-term effects on lung function
and other outcomes, were also evaluated in the 4-year multicenter
trial.
6-Month
to 1-Year Effects on Lung Function
In
the 1-year, placebo-controlled trials, the mean improvement in FEV1 at 30 minutes was 0.13 liters (13%) with a peak improvement
of 0.24 liters (24%) relative to baseline after the first dose (Day
1). Further improvements in FEV1 and forced
vital capacity (FVC) were observed with pharmacodynamic steady state
reached by Day 8 with once-daily treatment. The mean peak improvement
in FEV1, relative to baseline, was 0.28 to
0.31 liters (28% to 31%), after 1 week (Day 8) of once-daily treatment.
Improvement of lung function was maintained for 24 hours after a single
dose and consistently maintained over the 1-year treatment period
with no evidence of tolerance.
In the two 6-month, placebo-controlled trials, serial spirometric
evaluations were performed throughout daytime hours in Trial A (12
hours) and limited to 3 hours in Trial B. The serial FEV1 values over 12 hours (Trial A) are displayed in Figure
1. These trials further support the improvement in pulmonary function
(FEV1) with SPIRIVA HANDIHALER, which persisted
over the spirometric observational period. Effectiveness was maintained
for 24 hours after administration over the 6-month treatment period.
Figure 1 Mean FEV1 Over Time (prior to and after administration of study
drug) on Days 1 and 169 for Trial A (a Six-Month Placebo-Controlled
Study)*
*Means adjusted for center, treatment, and baseline effect. On Day
169, a total of 183 and 149 patients in the SPIRIVA HANDIHALER and
placebo groups, respectively, completed the trial. The data for the
remaining patients were imputed using the last observation or least
favorable observation carried forward.
Results of each of the 1-year ipratropium-controlled
trials were similar to the results of the 1-year placebo-controlled
trials. The results of one of these trials are shown in Figure 2.
Figure 2 Mean
FEV1 Over Time (0 to 6 hours post-dose) on
Days 1 and 92, Respectively for One of the Two Ipratropium-Controlled
Studies*
*Means adjusted for center, treatment, and baseline effect. On Day
92 (primary endpoint), a total of 151 and 69 patients in the SPIRIVA
HANDIHALER and ipratropium groups, respectively, completed through
3 months of observation. The data for the remaining patients were
imputed using the last observation or least favorable observation
carried forward.
A randomized,
placebo-controlled clinical study in 105 patients with COPD demonstrated
that bronchodilation was maintained throughout the 24-hour dosing
interval in comparison to placebo, regardless of whether SPIRIVA HANDIHALER
was administered in the morning or in the evening.
Throughout each week of the 1-year treatment period
in the two placebo-controlled trials, patients taking SPIRIVA HANDIHALER
had a reduced requirement for the use of rescue short-acting beta2-agonists. Reduction in the use of rescue short-acting
beta2-agonists, as compared to placebo, was
demonstrated in one of the two 6-month studies.
4-Year Effects on Lung Function
A 4-year, randomized, double-blind, placebo-controlled,
multicenter clinical trial involving 5992 COPD patients was conducted
to evaluate the long-term effects of SPIRIVA HANDIHALER on disease
progression (rate of decline in FEV1). Patients
were permitted to use all respiratory medications (including short-acting
and long-acting beta-agonists, inhaled and systemic steroids, and
theophyllines) other than inhaled anticholinergics. The patients were
40 to 88 years of age, 75% male, and 90% Caucasian with a diagnosis
of COPD and a mean pre-bronchodilator FEV1 of
39% predicted (range = 9% to 76%) at study entry. There was no difference
between the groups in either of the co-primary efficacy endpoints,
yearly rate of decline in pre- and post-bronchodilator FEV1, as demonstrated by similar slopes of FEV1 decline over time (Figure 3).
SPIRIVA HANDIHALER maintained improvements in trough
(pre-dose) FEV1 (adjusted means over time:
87 to 103 mL) throughout the 4 years of the study (Figure 3).
Figure 3 Trough
(pre-dose) FEV1 Mean Values at Each Time Point
Repeated measure ANOVA was used to estimate means. Means are adjusted
for baseline measurements. Baseline trough FEV1 (observed mean) = 1.12. Patients with ≥3 acceptable pulmonary function
tests after Day 30 and non-missing baseline value were included in
the analysis.
Exacerbations
The effect of SPIRIVA
HANDIHALER on COPD exacerbations was evaluated in two clinical trials:
a 4-year clinical trial described above and a 6-month clinical trial
of 1829 COPD patients in a Veterans Affairs setting. In the 6-month
trial, COPD exacerbations were defined as a complex of respiratory
symptoms (increase or new onset) of more than one of the following:
cough, sputum, wheezing, dyspnea, or chest tightness with a duration
of at least 3 days requiring treatment with antibiotics, systemic
steroids, or hospitalization. The population had an age ranging from
40 to 90 years with 99% males, 91% Caucasian, and had COPD with a
mean pre-bronchodilator FEV1 percent predicted
of 36% (range = 8% to 93%). Patients were permitted to use respiratory
medications (including short-acting and long-acting beta-agonists,
inhaled and systemic steroids, and theophyllines) other than inhaled
anticholinergics. In the 6-month trial, the co-primary endpoints were
the proportion of patients with COPD exacerbation and the proportion
of patients with hospitalization due to COPD exacerbation. SPIRIVA
HANDIHALER significantly reduced the proportion of COPD patients who
experienced exacerbations compared to placebo (27.9% vs 32.3%, respectively;
Odds Ratio (OR) (tiotropium/placebo) = 0.81; 95% CI = 0.66, 0.99;
p = 0.037). The proportion of patients with hospitalization due to
COPD exacerbations in patients who used SPIRIVA HANDIHALER compared
to placebo was 7.0% vs 9.5%, respectively; OR = 0.72; 95% CI = 0.51,
1.01; p = 0.056.
Exacerbations
were evaluated as a secondary outcome in the 4-year multicenter trial.
In this trial, COPD exacerbations were defined as an increase or new
onset of more than one of the following respiratory symptoms (cough,
sputum, sputum purulence, wheezing, dyspnea) with a duration of three
or more days requiring treatment with antibiotics and/or systemic
(oral, intramuscular, or intravenous) steroids. SPIRIVA HANDIHALER
significantly reduced the risk of an exacerbation by 14% (Hazard Ratio
(HR) = 0.86; 95% CI = 0.81, 0.91; p<0.001) and reduced the risk
of exacerbation-related hospitalization by 14% (HR = 0.86; 95% CI
= 0.78, 0.95; p<0.002) compared to placebo. The median time to
first exacerbation was delayed from 12.5 months (95% CI = 11.5, 13.8)
in the placebo group to 16.7 months (95% CI = 14.9, 17.9) in the SPIRIVA
HANDIHALER group.
All-Cause Mortality
In the 4-year placebo-controlled
lung-function trial described above, all-cause mortality compared
to placebo was assessed. There were no significant differences in
all-cause mortality rates between SPIRIVA HANDIHALER and placebo.
The all-cause mortality of
SPIRIVA HANDIHALER was also compared to tiotropium inhalation spray
5 mcg (SPIRIVA RESPIMAT 5 mcg) in an additional long-term, randomized,
double-blind, double-dummy active-controlled study with an observation
period up to 3 years. All-cause mortality was similar between SPIRIVA
HANDIHALER and SPIRIVA RESPIMAT.