CLINICAL PHARMACOLOGY
Mechanism Of Action
STIOLTO RESPIMAT
STIOLTO RESPIMAT contains both tiotropium and olodaterol.
The properties described below for the individual components apply to STIOLTO
RESPIMAT. These drugs represent 2 different classes of medication (an
anticholinergic and a beta-agonist) that have different effects on clinical and
physiological indices.
Tiotropium
Tiotropium is a long-acting, muscarinic antagonist 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.
Olodaterol
Olodaterol is a long-acting beta2-adrenergic agonist
(LABA). The compound exerts its pharmacological effects by binding and
activation of beta2-adrenoceptors after topical administration by inhalation.
Activation of these receptors in the airways results in a stimulation of
intracellular adenyl cyclase, an enzyme that mediates the synthesis of
cyclic-3’, 5’ adenosine monophosphate (cAMP). Elevated levels of cAMP induce
bronchodilation by relaxation of airway smooth muscle cells. In vitro studies
have shown that olodaterol has 241-fold greater agonist activity at
beta2-adrenoceptors compared to beta1-adrenoceptors and 2299-fold greater
agonist activity compared to beta3-adrenoceptors. The clinical significance of
these findings is unknown.
Beta-adrenoceptors are divided into three subtypes:
beta1-adrenoceptors predominantly expressed on cardiac muscle, beta2-adrenoceptors
predominantly expressed on airway smooth muscle, and beta3-adrenoceptors
predominantly expressed on adipose tissue. Beta2-agonists cause
bronchodilation. Although the beta2-adrenoceptor is the predominant adrenergic
receptor in the airway smooth muscle, it is also present on the surface of a
variety of other cells, including lung epithelial and endothelial cells and in
the heart. The precise function of beta2-receptors in the heart is not known,
but their presence raises the possibility that even highly selective
beta2-agonists may have cardiac effects.
Pharmacodynamics
Cardiac Electrophysiology
STIOLTO RESPIMAT
In two 52-week randomized, double-blind trials using
STIOLTO RESPIMAT that enrolled 5162 patients with COPD, ECG assessments were performed
post-dose on days 1, 85, 169, and 365. In a pooled analysis the number of
subjects with changes from baseline-corrected QT interval of >30 msec using
both the Bazett (QTcB) and Fredericia (QTcF), corrections of QT for heart rate
were not different for the STIOLTO RESPIMAT group compared to olodaterol 5 mcg
and tiotropium 5 mcg across the assessments conducted.
Tiotropium
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.
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 30–60
msec was higher in the tiotropium 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 tiotropium did not detect
an effect of the drug on QTc intervals.
Olodaterol
The effect of olodaterol on the QT/QTc interval of the
ECG was investigated in 24 healthy male and female volunteers in a
double-blind, randomized, placebo- and active (moxifloxacin)- controlled study
at single doses of 10, 20, 30, and 50 mcg. Dose-dependent QtcI (individual
subject corrected QT interval) prolongation was observed. The maximum mean
(one-sided 95% upper confidence bound) difference in QTcI from placebo after
baseline correction was 2.5 (5.6) ms, 6.1 (9.2) ms, 7.5 (10.7) ms, and 8.5
(11.6) ms following doses of 10, 20, 30, and 50 mcg, respectively.
The effect of 5 mcg and 10 mcg olodaterol on heart rate and
rhythm was assessed using continuous 24-hour ECG recording (Holter monitoring)
in a subset of 772 patients in the 48-week, placebo-controlled phase 3 trials.
There were no dose- or time-related trends or patterns observed for the
magnitudes of mean changes in heart rate or premature beats. Shifts from
baseline to the end of treatment in premature beats did not indicate meaningful
differences between olodaterol 5 mcg, 10 mcg, and placebo.
Pharmacokinetics
STIOLTO RESPIMAT
When STIOLTO RESPIMAT was administered by the inhalation
route, the pharmacokinetic parameters for tiotropium and for olodaterol were
similar to those observed when each active substance was administered
separately.
Tiotropium
Tiotropium is administered as an inhalation spray. Some
of the pharmacokinetic data described below were obtained with higher doses
than recommended for therapy.
Olodaterol
Olodaterol showed linear pharmacokinetics. On repeated
once-daily inhalation, steady-state of olodaterol plasma concentrations was
achieved after 8 days, and the extent of exposure was increased up to 1.8-fold
as compared to a single dose.
Absorption
Tiotropium
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. Maximum tiotropium plasma
concentrations were observed 5 to 7 minutes after inhalation.
Olodaterol
Olodaterol reaches maximum plasma concentrations
generally within 10 to 20 minutes following drug inhalation. In healthy
volunteers the absolute bioavailability of olodaterol following inhalation was
estimated to be approximately 30%, whereas the absolute bioavailability was
below 1% when given as an oral solution. Thus, the systemic availability of
olodaterol after inhalation is mainly determined by lung absorption, while any
swallowed portion of the dose only negligibly contributes to systemic exposure.
Distribution
Tiotropium
The drug has a plasma protein binding of 72% and shows a
volume of distribution of 32 L/kg. 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.
Olodaterol
Olodaterol exhibits multi-compartmental disposition
kinetics after inhalation as well as after intravenous administration. The
volume of distribution is high (1110 L), suggesting extensive distribution into
tissue. In vitro binding of [14C] olodaterol to human plasma proteins is
independent of concentration and is approximately 60%.
Elimination
Metabolism
Tiotropium
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, both not binding 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 2 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.
Olodaterol
Olodaterol is substantially metabolized by direct
glucuronidation and by O-demethylation at the methoxy moiety followed by
conjugation. Of the six metabolites identified, only the unconjugated
demethylation product binds to beta2-receptors. This metabolite, however, is
not detectable in plasma after chronic inhalation of the recommended
therapeutic dose.
Cytochrome P450 isozymes CYP2C9 and CYP2C8, with
negligible contribution of CYP3A4, are involved in the O-demethylation of
olodaterol, while uridine diphosphate glycosyl transferase isoforms UGT2B7,
UGT1A1, 1A7, and 1A9 were shown to be involved in the formation of olodaterol
glucuronides.
Excretion
Tiotropium
The terminal half-life of tiotropium in COPD patients
following once daily inhalation of 5 mcg tiotropium was approximately 25 hours.
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%). After inhalation of the solution by patients with
COPD, urinary excretion is 18.6% (0.932 mcg) of the dose, the remainder being
mainly non-absorbed drug in the gut that is eliminated via the feces. The renal
clearance of tiotropium exceeds the creatinine clearance, indicating secretion
into the urine. After chronic once-daily inhalation by COPD patients,
pharmacokinetic steady state was reached by day 7 with no accumulation
thereafter.
Olodaterol
Total clearance of olodaterol in healthy volunteers is
872 mL/min, and renal clearance is 173 mL/min. The terminal half-life following
intravenous administration is 22 hours. The terminal half-life following
inhalation in contrast is about 45 hours, indicating that the latter is
determined by absorption rather than by elimination processes. However, the
effective half-life at daily dose of 5 mcg calculated from Cmax from COPD
patients is 7.5 hours.
Following intravenous administration of [14C]-labeled
olodaterol, 38% of the radioactive dose was recovered in the urine and 53% was
recovered in feces. The amount of unchanged olodaterol recovered in the urine
after intravenous administration was 19%. Following oral administration, only
9% of olodaterol and/or its metabolites was recovered in urine, while the major
portion was recovered in feces (84%). More than 90% of the dose was excreted
within 6 and 5 days following intravenous and oral administration,
respectively. Following inhalation, excretion of unchanged olodaterol in urine
within the dosing interval in healthy volunteers at steady state accounted for
5% to 7% of the dose.
Drug Interactions
STIOLTO RESPIMAT
Pharmacokinetic drug interaction studies with STIOLTO
RESPIMAT have not been performed; however, such studies have been conducted with
individual components tiotropium and olodaterol.
When tiotropium and olodaterol were administered in
combination by the inhaled route, the pharmacokinetic parameters for each
component were similar to those observed when each active substance was administered
separately.
Tiotropium
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 (long-acting
beta2-adrenergic agonists (LABA), inhaled corticosterioids (ICS)) used by
patients with COPD were not found to alter Athe exposure to tiotropium.
Olodaterol
Drug-drug interaction studies were carried out using
fluconazole as a model inhibitor of CYP 2C9 and ketoconazole as a potent P-gp
(and CYP3A4, 2C8, 2C9) inhibitor.
Fluconazole: Co-administration of 400 mg fluconazole once
a day for 14 days had no relevant effect on systemic exposure to olodaterol.
Ketoconazole: Co-administration of 400 mg ketoconazole
once a day for 14 days increased olodaterol Cmax by 66% and AUC0-1 by 68%.
Tiotropium: Co-administration of tiotropium bromide,
delivered as a fixed-dose combination with olodaterol, for 21 days had no
relevant effect on systemic exposure to olodaterol, and vice versa.
Specific Populations
Olodaterol
A pharmacokinetic meta-analysis showed that no dose
adjustment is necessary based on the effect of age, gender, and weight on
systemic exposure in COPD patients after inhalation of olodaterol.
Geriatric Patients
Tiotropium
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.
Renal Impairment
Tiotropium
Following inhaled administration of therapeutic doses of
tiotropium to steady-state to 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). In COPD patients with severe renal impairment (CLCR <30
mL/min), a single intravenous administration of tiotropium bromide resulted in
94% higher AUC0-4 and 52% higher Cmax compared to COPD patients with normal
renal function.
Olodaterol
Olodaterol levels were increased by approximately 40% in
subjects with severe renal impairment. A study in subjects with mild and
moderate renal impairment was not performed.
Hepatic Impairment
Tiotropium
The effects of hepatic impairment on the pharmacokinetics
of tiotropium were not studied.
Olodaterol
Subjects with mild and moderate hepatic impairment showed
no changes in Cmax or AUC, nor did protein binding differ between mild and
moderate hepatically impaired subjects and their healthy controls. A study in
subjects with severe hepatic impairment was not performed.
Olodaterol did not impair male or female fertility in rats
at inhalation doses up to 3068 mcg/kg/day (approximately 2322 times the RHDID
on an AUC basis).
Clinical Studies
The safety and efficacy of STIOLTO RESPIMAT were
evaluated in a clinical development program that included three dose ranging
trials, two active-controlled trials, three active- and placebo-controlled
trials, and one placebo-controlled trial. The efficacy of STIOLTO RESPIMAT is
based primarily on two 4-week dose-ranging trials in 592 COPD patients and two
confirmatory active-controlled 52-week trials (Trials 1 and 2) in 5162 COPD
patients.
Dose-Ranging Trials
Dose selection for STIOLTO RESPIMAT was primarily based
on trials for the individual components, tiotropium bromide and olodaterol.
Dose selection was also supported by two randomized, double-blind,
active-controlled, 4-week trials. In one trial in 232 patients with COPD, three
tiotropium doses (1.25, 2.5, and 5 mcg) were given in combination with
olodaterol 5 or 10 mcg and were evaluated compared to olodaterol monotherapy.
Results demonstrated improvement in trough FEV1 for the combination when
compared to olodaterol alone. The difference in trough FEV1 for the tiotropium
bromide/olodaterol doses of 1.25/5, 2.5/5, and 5/5 mcg once daily from
olodaterol 5 mcg were 0.054 L (95% CI 0.016, 0.092), 0.065 L (0.027, 0.103),
and 0.084 L (0.046, 0.122), respectively. In the second trial in 360 patients
with COPD, three olodaterol doses (2, 5, and 10 mcg) were given in combination
with tiotropium 5 mcg and were evaluated compared to tiotropium monotherapy.
The difference in trough FEV1 for the tiotropium/olodaterol doses of 5/2, 5/5,
and 5/10 mcg once daily from tiotropium 5 mcg were 0.024 L (95% CI -0.029,
0.076), 0.033 L (-0.019, 0.085), and 0.057 L (0.004, 0.110), respectively.
Results of these trials supported the evaluation of once-daily doses of tiotropium
bromide/olodaterol 2.5/5 mcg and 5/5 mcg in the confirmatory trials.
Confirmatory Trials
A total of 5162 COPD patients (1029 receiving STIOLTO
RESPIMAT, 1038 receiving olodaterol 5 mcg, and 1033 receiving tiotropium
bromide 5 mcg) were studied in two confirmatory trials of STIOLTO RESPIMAT.
Trials 1 and 2 were 52-week, replicate, randomized, double-blind, active
controlled, parallel group trials that compared STIOLTO RESPIMAT to tiotropium
5 mcg and olodaterol 5 mcg. In these trials, all products were administered via
the RESPIMAT inhaler.
The trials enrolled patients 40 years of age or older
with a clinical diagnosis of COPD, a smoking history of more than 10
pack-years, and moderate to very severe pulmonary impairment
(post-bronchodilator FEV1 less than 80% predicted normal [GOLD Stage 2-4];
post-bronchodilator FEV1 to FVC ratio of less than 70%). All treatments were
administered once daily in the morning. The primary endpoints were change from
baseline in FEV1 AUC0-3hr and trough FEV1 after 24-weeks of treatment.
The majority of the 5162 patients were male (73%), white
(71%) or Asian (25%), with a mean age of 64.0 years. Mean post-bronchodilator
FEV1 was 1.37 L (GOLD 2 [50%], GOLD 3 [39%], GOLD 4 [11%]). Mean beta2-agonist
responsiveness was 16.6% of baseline (0.171 L). Pulmonary medications allowed
as concomitant therapy included inhaled steroids [47%] and xanthines [10%].
In both Trials 1 and 2, STIOLTO RESPIMAT demonstrated
significant improvements in FEV1 AUC0-3hr and trough FEV1 after 24 weeks
compared to tiotropium 5 mcg and olodaterol 5 mcg (Table 2). The increased
bronchodilator effects of STIOLTO RESPIMAT compared to tiotropium 5 mcg and
olodaterol 5 mcg were maintained throughout the 52-week treatment period.
STIOLTO RESPIMAT displayed a mean increase in FEV1 from baseline of 0.137 L
(range: 0.133-0.140 L) within 5 minutes after the first dose. Patients treated
with STIOLTO RESPIMAT used less rescue medication compared to patients treated with
tiotropium 5 mcg and olodaterol 5 mcg.
Table 2 : FEV1 AUC0-3hr and Trough FEV1 response for
STIOLTO RESPIMAT compared to tiotropium 5 mcg and olodaterol 5 mcg after 24
weeks (primary endpoints; Trials 1 and 2)
|
Trial 1 |
Trial 2 |
n |
Mean (L) |
Difference (L) (95% CI) |
n |
Mean (L) |
Difference (L) (95% CI) |
FEV1 AUC0-3hr response |
STIOLTO RESPIMAT |
522 |
0.256 |
- |
502 |
0.268 |
- |
Tiotropium 5 mcg |
526 |
0.139 |
0.117 (0.094, 0.140) |
500 |
0.165 |
0.103 (0.078, 0.127) |
Olodaterol 5 mcg |
525 |
0.133 |
0.123 (0.100, 0.146) |
507 |
0.136 |
0.132 (0.108, 0.157) |
Trough FEV1 response |
STIOLTO RESPIMAT |
521 |
0.136 |
- |
497 |
0.145 |
- |
Tiotropium 5 mcg |
520 |
0.065 |
0.071 (0.047, 0.094) |
498 |
0.096 |
0.050 (0.024, 0.075) |
Olodaterol 5 mcg |
519 |
0.054 |
0.082 (0.059, 0.106) |
503 |
0.057 |
0.088 (0.063, 0.113) |
Pre-treatment baseline FEV1: Trial 1=1.16 L; Trial 2=1.15
L
p≤0.0001 for all comparisons between STIOLTO RESPIMAT and the
monotherapies. |
For the subset of patients (n=521) who completed extended
lung function measurements up to 12 hours post-dose, STIOLTO RESPIMAT showed a
significantly greater FEV1 response compared to tiotropium 5 mcg and olodaterol
5 mcg over the full 24-hour dosing interval. Results from Trial 2 are shown in
Figure 1.
Figure 1 : FEV1 profile for STIOLTO RESPIMAT,
tiotropium 5 mcg and olodaterol 5 mcg over a 24-hour dosing interval after 24
weeks (12 hr PFT subset from Trial 2)
The St. George’s Respiratory Questionnaire (SGRQ) was
assessed in Trials 1 and 2 and in two additional 12-week placebo-controlled
trials (Trials 3 and 4).
In the first 12-week trial, SGRQ responder rates at week
12 (defined as an improvement in score of 4 or more as a threshold) were 53%,
42%, and 31% for STIOLTO RESPIMAT, tiotropium 5 mcg, and placebo, respectively,
with odds ratios of 1.6 (95% CI 1.1, 2.4) and 2.5 (95% CI 1.6, 3.8) for STIOLTO
RESPIMAT vs. tiotropium 5 mcg and STIOLTO RESPIMAT vs. placebo, respectively.
In the second 12-week trial, results were similar with odds ratios of 1.5 (95%
CI 1.0, 2.3) and 2.2 (95% CI 1.5, 3.4) for STIOLTO RESPIMAT vs. tiotropium 5
mcg and STIOLTO RESPIMAT vs. placebo, respectively. For the 52-week trials
similar responder rates were seen. In Trial 1, the odds ratios for STIOLTO vs.
tiotropium 5 mcg and STIOLTO vs. olodaterol 5 mcg at week 24 were 1.6 (95% CI
1.2, 2.0) and 1.9 (95% CI 1.5, 2.4), respectively. The results were similar in
the 52-week Trial 2, with odds ratios for STIOLTO vs. tiotropium 5 mcg and
STIOLTO vs. olodaterol 5 mcg of 1.3 (95% CI 1.0, 1.7) and 1.5 (95% CI 1.1,
1.9), respectively.
Exacerbations
Tiotropium 5 mcg Trials Evaluating Exacerbations
The effect of tiotropium 5 mcg inhalation spray on
exacerbations was evaluated in three 48-week randomized, double-blind,
placebo-controlled clinical trials that included COPD exacerbations as the
primary endpoint. Exacerbations of COPD were defined as a complex of lower respiratory
events/symptoms (increase or new onset) related to the underlying COPD, with
duration of three days or more, requiring a prescription of antibiotics and/or
systemic steroids and/or hospitalization. In a pooled analysis of the first two
trials, tiotropium 5 mcg significantly reduced the number of COPD exacerbations
compared to placebo with a rate ratio of 0.78 (95% CI 0.67, 0.92). In the third
trial, tiotropium 5 mcg delayed the time to first COPD exacerbation compared to
placebo with a hazard ratio of 0.69 (95% CI 0.63, 0.77).
STIOLTO RESPIMAT Trial Evaluating Exacerbations
In a one-year, randomized, double-blind,
active-controlled parallel group clinical trial (Trial 5), the effect of
STIOLTO RESPIMAT on COPD exacerbations was compared with tiotropium 5 mcg
inhalation spray. Exacerbations were defined as above. Enrolled patients (3939
patients receiving STIOLTO RESPIMAT and 3941 patients receiving tiotropium 5
mcg inhalation spray) had a history of COPD exacerbation in the previous 12
months. The primary endpoint was the annualized rate of moderate to severe COPD
exacerbations. The majority of patients were male (71%) and Caucasian (79%).
The mean age was 66 years, and mean post-bronchodilator FEV1 percent predicted
was 45%. STIOLTO RESPIMAT treatment did not demonstrate superiority to
tiotropium 5 mcg inhalation spray for the primary endpoint, the annualized rate
of moderate to severe COPD exacerbations, with a rate ratio of 0.93 (99% CI,
0.85-1.02, p=0.0498). The study did not reach the pre-specified significance
level of 0.01.