CLINICAL PHARMACOLOGY
Mechanism Of Action
WIXELA™ INHUB™
Wixela™ Inhub™ contains both fluticasone propionate and
salmeterol. The mechanisms of action described below for the individual
components apply to Wixela™ Inhub™. These drugs represent 2 different classes
of medications (a synthetic corticosteroid and a LABA) that have different
effects on clinical, physiologic, and inflammatory indices.
Fluticasone Propionate
Fluticasone propionate is a synthetic trifluorinated
corticosteroid with anti-inflammatory activity. Fluticasone propionate has been
shown in vitro to exhibit a binding affinity for the human glucocorticoid receptor
that is 18 times that of dexamethasone, almost twice that of beclomethasone-17-
monopropionate (BMP), the active metabolite of beclomethasone dipropionate, and
over 3 times that of budesonide. Data from the McKenzie vasoconstrictor assay
in man are consistent with these results. The clinical significance of these
findings is unknown.
Inflammation is an important component in the
pathogenesis of asthma. Corticosteroids have been shown to have a wide range of
actions on multiple cell types (e.g., mast cells, eosinophils, neutrophils, macrophages,
lymphocytes) and mediators (e.g., histamine, eicosanoids, leukotrienes,
cytokines) involved in inflammation. These anti-inflammatory actions of
corticosteroids contribute to their efficacy in asthma.
Inflammation is also a component in the pathogenesis of
COPD. In contrast to asthma, however, the predominant inflammatory cells in
COPD include neutrophils, CD8+ T-lymphocytes, and macrophages. The effects of
corticosteroids in the treatment of COPD are not well defined and ICS and
fluticasone propionate when used apart from Wixela™ Inhub™ are not indicated
for the treatment of COPD.
Salmeterol Xinafoate
Salmeterol is a selective LABA. In vitro studies show
salmeterol to be at least 50 times more selective for beta2-adrenoceptors than
albuterol. Although beta2-adrenoceptors are the predominant adrenergic receptors
in bronchial smooth muscle and beta2-adrenoceptors are the predominant
receptors in the heart, there are also beta2-adrenoceptors in the human heart
comprising 10% to 50% of the total beta-adrenoceptors. The precise function of
these receptors has not been established, but their presence raises the
possibility that even selective beta2-agonists may have cardiac effects.
The pharmacologic effects of beta2-adrenoceptor agonist
drugs, including salmeterol, are at least in part attributable to stimulation
of intracellular adenyl cyclase, the enzyme that catalyzes the conversion of
adenosine triphosphate (ATP) to cyclic-3',5'-adenosine
monophosphate (cyclic AMP). Increased cyclic AMP levels cause relaxation of
bronchial smooth muscle and inhibition of release of mediators of immediate
hypersensitivity from cells, especially from mast cells.
In vitro tests show that salmeterol is a potent and
long-lasting inhibitor of the release of mast cell mediators, such as
histamine, leukotrienes, and prostaglandin D , from human lung. Salmeterol
inhibits histamine-induced plasma protein extravasation and inhibits
platelet-activating factor-induced eosinophil accumulation in the lungs of
guinea pigs when administered by the inhaled route. In humans, single doses of
salmeterol administered via inhalation aerosol attenuate allergen-induced
bronchial hyperresponsiveness.
Pharmacodynamics
Fluticasone Propionate And Salmeterol Inhalation Powder
Healthy Subjects
Cardiovascular Effects
Since systemic pharmacodynamic effects of salmeterol are
not normally seen at the therapeutic dose, higher doses were used to produce
measurable effects. Four (4) trials were conducted with healthy adult subjects:
(1) a single-dose crossover trial using 2 inhalations of fluticasone propionate
and salmeterol inhalation powder 500 mcg/50 mcg, fluticasone propionate
inhalation powder 500 mcg and salmeterol inhalation powder 50 mcg given
concurrently, or fluticasone propionate inhalation powder 500 mcg given alone,
(2) a cumulative dose trial using 50 to 400 mcg of salmeterol inhalation powder
given alone or as fluticasone propionate and salmeterol inhalation powder 500
mcg/50 mcg, (3) a repeat-dose trial for 11 days using 2 inhalations twice daily
of fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg,
fluticasone propionate inhalation powder 250 mcg, or salmeterol inhalation
powder 50 mcg, and (4) a single-dose trial using 5 inhalations of fluticasone
propionate and salmeterol inhalation powder 100 mcg/50 mcg, fluticasone
propionate inhalation powder 100 mcg alone, or placebo. In these trials no
significant differences were observed in the pharmacodynamic effects of
salmeterol (pulse rate, blood pressure, QTc interval, potassium, and glucose)
whether the salmeterol was given as fluticasone propionate and salmeterol
inhalation powder, concurrently with fluticasone propionate from separate
inhalers, or as salmeterol alone. The systemic pharmacodynamic effects of
salmeterol were not altered by the presence of fluticasone propionate in
fluticasone propionate and salmeterol inhalation powder. The potential effect
of salmeterol on the effects of fluticasone propionate on the HPA axis was also
evaluated in these trials.
Hypothalamic-Pituitary-Adrenal Axis Effects
No significant differences across treatments were
observed in 24-hour urinary cortisol excretion and, where measured, 24-hour
plasma cortisol AUC. The systemic pharmacodynamic effects of fluticasone propionate
were not altered by the presence of salmeterol in fluticasone propionate and
salmeterol inhalation powder in healthy subjects.
Subjects With Asthma: Adult and Adolescent Subjects
Cardiovascular Effects
In clinical trials with fluticasone propionate and
salmeterol inhalation powder in adult and adolescent subjects aged 12 years and
older with asthma, no significant differences were observed in the systemic pharmacodynamic
effects of salmeterol (pulse rate, blood pressure, QTc interval, potassium, and
glucose) whether the salmeterol was given alone or as fluticasone propionate
and salmeterol inhalation powder. In 72 adult and adolescent subjects with
asthma given either fluticasone propionate and salmeterol inhalation powder 100
mcg/50 mcg or fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg, continuous 24-hour electrocardiographic monitoring was performed after the
first dose and after 12 weeks of therapy, and no clinically significant
dysrhythmias were noted.
Hypothalamic-Pituitary-Adrenal Axis Effects
In a 28-week trial in adult and adolescent subjects with
asthma, fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg
twice daily was compared with the concurrent use of salmeterol inhalation
powder 50 mcg plus fluticasone propionate inhalation powder 500 mcg from separate
inhalers or fluticasone propionate inhalation powder 500 mcg alone. No
significant differences across treatments were observed in serum cortisol AUC
after 12 weeks of dosing or in 24-hour urinary cortisol excretion after 12 and
28 weeks.
In a 12-week trial in adult and adolescent subjects with
asthma, fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg
twice daily was compared with fluticasone propionate inhalation powder 250 mcg
alone, salmeterol inhalation powder 50 mcg alone, and placebo. For most
subjects, the ability to increase cortisol production in response to stress, as
assessed by 30-minute cosyntropin stimulation, remained intact with fluticasone
propionate and salmeterol inhalation powder. One subject (3%) who received fluticasone
propionate and salmeterol inhalation powder 250 mcg/50 mcg had an abnormal
response (peak serum cortisol less than 18 mcg/dL) after dosing, compared with
2 subjects (6%) who received placebo, 2 subjects (6%) who received fluticasone
propionate 250 mcg, and no subjects who received salmeterol.
In a repeat-dose, 3-way crossover trial, 1 inhalation
twice daily of fluticasone propionate and salmeterol inhalation powder 100
mcg/50 mcg, FLOVENT® DISKUS® 100 mcg (fluticasone propionate inhalation powder
100 mcg), or placebo was administered to 20 adult and adolescent subjects with
asthma. After 28 days of treatment, geometric mean serum cortisol AUC over 12
hours showed no significant difference between fluticasone propionate and
salmeterol inhalation powder and FLOVENT DISKUS or between either active
treatment and placebo.
Pediatric Subjects
Hypothalamic-Pituitary-Adrenal Axis Effects
In a 12-week trial in subjects with asthma aged 4 to 11
years who were receiving ICS at trial entry, fluticasone propionate and
salmeterol inhalation powder 100 mcg/50 mcg twice daily was compared with
fluticasone propionate inhalation powder 100 mcg administered twice daily via a
dry powder inhaler. The values for 24-hour urinary cortisol excretion at trial
entry and after 12 weeks of treatment were similar within each treatment group.
After 12 weeks, 24-hour urinary cortisol excretion was also similar between the
2 groups.
Subjects With Chronic Obstructive Pulmonary Disease
Cardiovascular Effects
In clinical trials with fluticasone propionate and
salmeterol inhalation powder in subjects with COPD, no significant differences
were seen in pulse rate, blood pressure, potassium, and glucose between fluticasone
propionate and salmeterol inhalation powder, the individual components of
fluticasone propionate and salmeterol inhalation powder, and placebo. In a
trial of fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg, 8 subjects (2 [1.1%] in the group given fluticasone propionate and
salmeterol inhalation powder 250 mcg/50 mcg, 1 [0.5%] in the fluticasone
propionate 250 mcg group, 3 [1.7%] in the salmeterol group, and 2 [1.1%] in the
placebo group) had QTc intervals >470 msec at least 1 time during the
treatment period. Five (5) of these 8 subjects had a prolonged QTc interval at
baseline.
In a 24-week trial, 130 subjects with COPD received
continuous 24-hour electrocardiographic monitoring prior to the first dose and
after 4 weeks of twice-daily treatment with either fluticasone propionate and
salmeterol inhalation powder 500 mcg/50 mcg, fluticasone propionate inhalation
powder 500 mcg, salmeterol inhalation powder 50 mcg, or placebo. No significant
differences in ventricular or supraventricular arrhythmias and heart rate were
observed among the groups treated with fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg, the individual components, or placebo. One
(1) subject in the fluticasone propionate group experienced atrial
flutter/atrial fibrillation, and 1 subject in the group given fluticasone propionate
and salmeterol inhalation powder 500 mcg/50 mcg experienced heart block. There
were 3 cases of nonsustained ventricular tachycardia (1 each in the placebo,
salmeterol, and fluticasone propionate 500 mcg treatment groups).
In 24-week clinical trials in subjects with COPD, the
incidence of clinically significant ECG abnormalities (myocardial ischemia,
ventricular hypertrophy, clinically significant conduction abnormalities,
clinically significant arrhythmias) was lower for subjects who received salmeterol
(1%, 9 of 688 subjects who received either salmeterol 50 mcg or fluticasone
propionate and salmeterol inhalation powder) compared with placebo (3%, 10 of
370 subjects).
No significant differences with salmeterol 50 mcg alone
or in combination with fluticasone propionate as fluticasone propionate and
salmeterol inhalation powder 500 mcg/50 mcg were observed on pulse rate and
systolic and diastolic blood pressure in a subset of subjects with COPD who
underwent 12- hour serial vital sign measurements after the first dose (n =
183) and after 12 weeks of therapy (n = 149). Median changes from baseline in
pulse rate and systolic and diastolic blood pressure were similar to those seen
with placebo.
Hypothalamic-Pituitary-Adrenal Axis Effects
Short-cosyntropin stimulation testing was performed both
at Day 1 and Endpoint in 101 subjects with COPD receiving twice-daily
fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg, fluticasone
propionate inhalation powder 250 mcg, salmeterol inhalation powder 50 mcg, or
placebo. For most subjects, the ability to increase cortisol production in
response to stress, as assessed by short cosyntropin stimulation, remained
intact with fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg. One (1) subject (3%) who received fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg had an abnormal stimulated cortisol response
(peak cortisol < 14.5 mcg/dL assessed by high-performance liquid
chromatography) after dosing, compared with 2 subjects (9%) who received
fluticasone propionate 250 mcg, 2 subjects (7%) who received salmeterol 50 mcg,
and 1 subject (4%) who received placebo following 24 weeks of treatment or
early discontinuation from trial.
After 36 weeks of dosing, serum cortisol concentrations
in a subset of subjects with COPD (n = 83) were 22% lower in subjects receiving
fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg and 21%
lower in subjects receiving fluticasone propionate 500 mcg than in subjects receiving
placebo.
Other Fluticasone Propionate Products
Subjects With Asthma
Hypothalamic-Pituitary-Adrenal Axis Effects
In clinical trials with fluticasone propionate inhalation
powder using dosages up to and including 250 mcg twice daily, occasional
abnormal short cosyntropin tests (peak serum cortisol < 18 mcg/dL assessed
by radioimmunoassay) were noted both in subjects receiving fluticasone
propionate and in subjects receiving placebo. The incidence of abnormal tests
at 500 mcg twice daily was greater than placebo. In a 2-year trial carried out
with a dry powder inhaler in 64 subjects with mild, persistent asthma (mean FEV1
 91% of predicted) randomized to fluticasone propionate 500 mcg twice daily or placebo,
no subject receiving fluticasone propionate had an abnormal response to 6-hour
cosyntropin infusion (peak serum cortisol < 18 mcg/dL). With a peak cortisol
threshold of < 35 mcg/dL, 1 subject receiving fluticasone propionate (4%)
had an abnormal response at 1 year; repeat testing at 18 months and 2 years was
normal. Another subject receiving fluticasone propionate (5%) had an abnormal response
at 2 years. No subject on placebo had an abnormal response at 1 or 2 years.
Subjects With Chronic Obstructive Pulmonary Disease
Hypothalamic-Pituitary-Adrenal Axis Effects
After 4 weeks of dosing, the steady-state fluticasone
propionate pharmacokinetics and serum cortisol levels were described in a
subset of subjects with COPD (n = 86) randomized to twice-daily fluticasone propionate
inhalation powder via a dry powder inhaler 500 mcg, fluticasone propionate
inhalation powder 250 mcg, or placebo. Serial serum cortisol concentrations
were measured across a 12-hour dosing interval. Serum cortisol concentrations
following 250 mcg and 500 mcg twice-daily dosing were 10% and 21% lower than
placebo, respectively, indicating a dose-dependent increase in systemic exposure
to fluticasone propionate.
Other Salmeterol Xinafoate Products
Subjects With Asthma
Cardiovascular Effects
Inhaled salmeterol, like other beta-adrenergic agonist
drugs, can produce dose-related cardiovascular effects and effects on blood
glucose and/or serum potassium [see WARNINGS AND PRECAUTIONS]. The
cardiovascular effects (heart rate, blood pressure) associated with salmeterol
inhalation aerosol occur with similar frequency, and are of similar type and
severity, as those noted following albuterol administration.
The effects of rising inhaled doses of salmeterol and
standard inhaled doses of albuterol were studied in volunteers and in subjects with
asthma. Salmeterol doses up to 84 mcg administered as inhalation aerosol
resulted in heart rate increases of 3 to 16 beats/min, about the same as
albuterol dosed at 180 mcg by inhalation aerosol (4 to 10 beats/min). Adult and
adolescent subjects receiving 50 mcg doses of salmeterol inhalation powder (N =
60) underwent continuous electrocardiographic monitoring during two 12-hour
periods after the first dose and after 1 month of therapy, and no clinically
significant dysrhythmias were noted.
Concomitant Use Of Wixela™ Inhub™ With Other Respiratory
Medicines
Short-acting Beta2-agonists
In clinical trials in subjects with asthma, the mean
daily need for albuterol by 166 adult and adolescent subjects aged 12 years and
older using fluticasone propionate and salmeterol inhalation powder was approximately
1.3 inhalations/day and ranged from 0 to 9 inhalations/day. Five percent (5%)
of subjects using fluticasone propionate and salmeterol inhalation powder in
these trials averaged 6 or more inhalations per day over the course of the
12-week trials. No increase in frequency of cardiovascular adverse events was
observed among subjects who averaged 6 or more inhalations per day.
In a clinical trial in subjects with COPD, the mean daily
need for albuterol for subjects using fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg was 4.1 inhalations/day. Twenty-six percent
(26%) of subjects using fluticasone propionate and salmeterol inhalation powder
250 mcg/50 mcg averaged 6 or more inhalations of albuterol per day over the
course of the 24-week trial. No increase in frequency of cardiovascular adverse
reactions was observed among subjects who averaged 6 or more inhalations per
day.
Methylxanthines
The concurrent use of intravenously or orally
administered methylxanthines (e.g., aminophylline, theophylline) by adult and
adolescent subjects aged 12 years and older receiving fluticasone propionate and
salmeterol inhalation powder has not been completely evaluated. In clinical
trials in subjects with asthma, 39 subjects receiving fluticasone propionate
and salmeterol inhalation powder 100 mcg/50 mcg, fluticasone propionate and
salmeterol inhalation powder 250 mcg/50 mcg, or fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg twice daily concurrently with a theophylline
product had adverse event rates similar to those in 304 subjects receiving
fluticasone propionate and salmeterol inhalation powder without theophylline.
Similar results were observed in subjects receiving salmeterol 50 mcg plus
fluticasone propionate 500 mcg twice daily concurrently with a theophylline
product (n = 39) or without theophylline (n = 132).
In a clinical trial in subjects with COPD, 17 subjects
receiving fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg twice daily concurrently with a theophylline product had adverse event
rates similar to those in 161 subjects receiving fluticasone propionate and
salmeterol inhalation powder without theophylline. Based on the available data,
the concomitant administration of methylxanthines with fluticasone propionate
and salmeterol inhalation powder did not alter the observed adverse event
profile.
Fluticasone Propionate Nasal Spray
In adult and adolescent subjects aged 12 years and older
receiving fluticasone propionate and salmeterol inhalation powder in clinical
trials, no difference in the profile of adverse events or HPA axis effects was
noted between subjects who were receiving FLONASE® (fluticasone propionate)
Nasal Spray, 50 mcg concurrently (n = 46) and those who were not (n = 130).
Pharmacokinetics
Absorption
Fluticasone Propionate
Healthy Subjects
Fluticasone propionate acts locally in the lung;
therefore, plasma levels do not predict therapeutic effect. Trials using oral
dosing of labeled and unlabeled drug have demonstrated that the oral systemic bioavailability
of fluticasone propionate is negligible (<1%), primarily due to incomplete
absorption and presystemic metabolism in the gut and liver. In contrast, the
majority of the fluticasone propionate delivered to the lung is systemically
absorbed.
Following administration of fluticasone propionate and
salmeterol inhalation powder to healthy adult subjects, peak plasma
concentrations of fluticasone propionate were achieved in 1 to 2 hours. In a single-dose
crossover trial, a higher-than-recommended dose of fluticasone propionate and
salmeterol inhalation powder was administered to 14 healthy adult subjects. Two
(2) inhalations of the following treatments were administered: fluticasone
propionate and salmeterol inhalation powder 500 mcg/50 mcg, fluticasone
propionate inhalation powder 500 mcg and salmeterol inhalation powder 50 mcg
given concurrently, and fluticasone propionate inhalation powder 500 mcg alone.
Mean peak plasma concentrations of fluticasone propionate averaged 107, 94, and
120 pg/mL, respectively, indicating no significant changes in systemic
exposures of fluticasone propionate.
In 15 healthy subjects, systemic exposure to fluticasone
propionate from 4 inhalations of ADVAIR® HFA 230/21 (fluticasone propionate 230
mcg and salmeterol 21 mcg) Inhalation Aerosol (920/84 mcg) and 2 inhalations of
fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg (1,000 mcg/100
mcg) was similar between the 2 inhalers (i.e., 799 versus 832 pg•h/mL,
respectively), but approximately half the systemic exposure from 4 inhalations
of fluticasone propionate CFC inhalation aerosol 220 mcg (880 mcg, AUC = 1,543
pg•h/mL). Similar results were observed for peak fluticasone propionate plasma
concentrations (186 and 182 pg/mL from ADVAIR HFA and fluticasone propionate and
salmeterol inhalation powder, respectively, and 307 pg/mL from the fluticasone
propionate CFC inhalation aerosol). Absolute bioavailability of fluticasone
propionate was 5.3% and 5.5% following administration of ADVAIR HFA and
fluticasone propionate and salmeterol inhalation powder, respectively.
Subjects With Asthma and COPD
Peak steady-state fluticasone propionate plasma
concentrations in adult subjects with asthma (N = 11) ranged from undetectable
to 266 pg/mL after a 500 mcg twice-daily dose of fluticasone propionate inhalation
powder using a dry powder inhaler. The mean fluticasone propionate plasma
concentration was 110 pg/mL.
Full pharmacokinetic profiles were obtained from 9 female
and 16 male subjects with asthma given fluticasone propionate inhalation powder
500 mcg twice daily using a dry powder inhaler and from 14 female and 43 male
subjects with COPD given 250 or 500 mcg twice daily. No overall differences in fluticasone
propionate pharmacokinetics were observed.
Peak steady-state fluticasone propionate plasma
concentrations in subjects with COPD averaged 53 pg/mL (range: 19.3 to 159.3
pg/mL) after treatment with 250 mcg twice daily (n = 30) and 84 pg/Ml (range:
24.3 to 197.1 pg/mL) after treatment with 500 mcg twice daily (n = 27) via a
fluticasone propionate dry powder inhaler. In another trial in subjects with
COPD, peak steady-state fluticasone propionate plasma concentrations averaged
115 pg/mL (range: 52.6 to 366.0 pg/mL) after treatment with 500 mcg twice daily
via a fluticasone propionate dry powder inhaler (n = 15) and 105 pg/mL (range: 22.5
to 299.0 pg/mL) via fluticasone propionate and salmeterol inhalation powder (n
= 24).
Salmeterol Xinafoate
Healthy Subjects
Salmeterol xinafoate, an ionic salt, dissociates in
solution so that the salmeterol and 1-hydroxy-2- naphthoic acid (xinafoate)
moieties are absorbed, distributed, metabolized, and eliminated independently. Salmeterol
acts locally in the lung; therefore, plasma levels do not predict therapeutic
effect.
Following administration of fluticasone propionate and
salmeterol inhalation powder to healthy adult subjects, peak plasma
concentrations of salmeterol were achieved in about 5 minutes.
In 15 healthy subjects receiving ADVAIR HFA 230/21
Inhalation Aerosol (920/84 mcg) and fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg (1,000 mcg/100 mcg), systemic exposure to
salmeterol was higher (317 versus 169 pg•h/mL) and peak salmeterol
concentrations were lower (196 versus 223 pg/mL) following ADVAIR HFA compared
with fluticasone propionate and salmeterol inhalation powder, although
pharmacodynamic results were comparable.
Subjects With Asthma
Because of the small therapeutic dose, systemic levels of
salmeterol are low or undetectable after inhalation of recommended dosages (50
mcg of salmeterol inhalation powder twice daily). Following chronic
administration of an inhaled dose of 50 mcg of salmeterol inhalation powder
twice daily, salmeterol was detected in plasma within 5 to 45 minutes in 7
subjects with asthma; plasma concentrations were very low, with mean peak
concentrations of 167 pg/mL at 20 minutes and no accumulation with repeated
doses.
Distribution
Fluticasone Propionate
Following intravenous administration, the initial
disposition phase for fluticasone propionate was rapid and consistent with its
high lipid solubility and tissue binding. The volume of distribution averaged
4.2 L/kg.
The percentage of fluticasone propionate bound to human
plasma proteins averages 99%. Fluticasone propionate is weakly and reversibly
bound to erythrocytes and is not significantly bound to human transcortin.
Salmeterol
The percentage of salmeterol bound to human plasma
proteins averages 96% in vitro over the concentration range of 8 to 7,722 ng of
salmeterol base per milliliter, much higher concentrations than those achieved
following therapeutic doses of salmeterol.
Metabolism
Fluticasone Propionate
The total clearance of fluticasone propionate is high
(average, 1,093 mL/min), with renal clearance accounting for <0.02% of the
total. The only circulating metabolite detected in man is the 17β- carboxylic
acid derivative of fluticasone propionate, which is formed through the CYP3A4
pathway. This metabolite had less affinity (approximately 1/2,000) than the
parent drug for the glucocorticoid receptor of human lung cytosol in vitro and
negligible pharmacological activity in animal studies. Other metabolites
detected in vitro using cultured human hepatoma cells have not been detected in
man.
Salmeterol
Salmeterol base is extensively metabolized by
hydroxylation, with subsequent elimination predominantly in the feces. No
significant amount of unchanged salmeterol base was detected in either urine or
feces.
An in vitro study using human liver microsomes showed
that salmeterol is extensively metabolized to α- hydroxysalmeterol
(aliphatic oxidation) by CYP3A4. Ketoconazole, a strong inhibitor of CYP3A4, essentially
completely inhibited the formation of α-hydroxysalmeterol in vitro.
Elimination
Fluticasone Propionate
Following intravenous dosing, fluticasone propionate
showed polyexponential kinetics and had a terminal elimination half-life of
approximately 7.8 hours. Less than 5% of a radiolabeled oral dose was excreted
in the urine as metabolites, with the remainder excreted in the feces as parent
drug and metabolites. Terminal half-life estimates of fluticasone propionate
for ADVAIR HFA, fluticasone propionate and salmeterol inhalation powder, and
fluticasone propionate CFC inhalation aerosol were similar and averaged 5.6
hours.
Salmeterol
In 2 healthy adult subjects who received 1 mg of
radiolabeled salmeterol (as salmeterol xinafoate) orally, approximately 25% and
60% of the radiolabeled salmeterol was eliminated in urine and feces, respectively,
over a period of 7 days. The terminal elimination half-life was about 5.5 hours
(1 volunteer only).
The xinafoate moiety has no apparent pharmacologic
activity. The xinafoate moiety is highly protein bound (> 99%) and has a
long elimination half-life of 11 days. No terminal half-life estimates were calculated
for salmeterol following administration of fluticasone propionate and
salmeterol inhalation powder.
Specific Populations
A population pharmacokinetic analysis was performed for
fluticasone propionate and salmeterol utilizing data from 9 controlled clinical
trials that included 350 subjects with asthma aged 4 to 77 years who received
treatment with fluticasone propionate and salmeterol inhalation powder, the
combination of HFA-propelled fluticasone propionate and salmeterol inhalation
aerosol (ADVAIR HFA), fluticasone propionate inhalation powder (FLOVENT
DISKUS), HFA-propelled fluticasone propionate inhalation aerosol (FLOVENT®
HFA), or CFC-propelled fluticasone propionate inhalation aerosol. The
population pharmacokinetic analyses for fluticasone propionate and salmeterol
showed no clinically relevant effects of age, gender, race, body weight, body
mass index, or percent of predicted FEV1 Â on apparent clearance and apparent
volume of distribution.
Age
When the population pharmacokinetic analysis for
fluticasone propionate was divided into subgroups based on fluticasone
propionate strength, formulation, and age (adolescents/adults and children),
there were some differences in fluticasone propionate exposure. Higher
fluticasone propionate exposure from fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg compared with FLOVENT DISKUS 100 mcg was
observed in adolescents and adults (ratio 1.52 [90% CI: 1.08, 2.13]). However,
in clinical trials of up to 12 weeks' duration comparing fluticasone propionate
and salmeterol inhalation powder 100 mcg/50 mcg and FLOVENT DISKUS 100 mcg in
adolescents and adults, no differences in systemic effects of corticosteroid
treatment (e.g., HPA axis effects) were observed. Similar fluticasone
propionate exposure was observed from fluticasone propionate and salmeterol inhalation
powder 500 mcg/50 mcg and FLOVENT DISKUS 500 mcg (ratio 0.83 [90% CI: 0.65,
1.07]) in adolescents and adults.
Steady-state systemic exposure to salmeterol when
delivered as fluticasone propionate and salmeterol inhalation powder 100 mcg/50
mcg, fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg, or
ADVAIR HFA 115/21 (fluticasone propionate 115 mcg and salmeterol 21 mcg) Inhalation
Aerosol was evaluated in 127 subjects aged 4 to 57 years. The geometric mean
AUC was 325 pg•h/mL (90% CI: 309, 341) in adolescents and adults.
The population pharmacokinetic analysis included 160
subjects with asthma aged 4 to 11 years who received fluticasone propionate and
salmeterol inhalation powder 100 mcg/50 mcg or FLOVENT DISKUS 100 mcg. Higher
fluticasone propionate exposure (AUC) was observed in children from fluticasone
propionate and salmeterol inhalation powder 100 mcg/50 mcg compared with
FLOVENT DISKUS 100 mcg (ratio 1.20 [90% CI: 1.06, 1.37]). Higher fluticasone
propionate exposure (AUC) from fluticasone propionate and salmeterol inhalation
powder 100 mcg/50 mcg was observed in children compared with adolescents and
adults (ratio 1.63 [90% CI: 1.35, 1.96]). However, in clinical trials of up to
12 weeks' duration comparing fluticasone propionate and salmeterol inhalation
powder 100 mcg/50 mcg and FLOVENT DISKUS 100 mcg in both adolescents and adults
and in children, no differences in systemic effects of corticosteroid treatment
(e.g., HPA axis effects) were observed.
Exposure to salmeterol was higher in children compared
with adolescents and adults who received fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg (ratio 1.23 [90% CI: 1.10, 1.38]). However, in
clinical trials of up to 12 weeks' duration with fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg in both adolescents and adults and in
children, no differences in systemic effects of beta2-agonist treatment (e.g.,
cardiovascular effects, tremor) were observed.
Male And Female Patients
The population pharmacokinetic analysis involved 202
males and 148 females with asthma who received fluticasone propionate alone or
in combination with salmeterol and showed no gender differences for fluticasone
propionate pharmacokinetics.
The population pharmacokinetic analysis involved 76 males
and 51 females with asthma who received salmeterol in combination with
fluticasone propionate and showed no gender differences for salmeterol pharmacokinetics.
Patients With Hepatic And Renal Impairment
Formal pharmacokinetic studies using fluticasone
propionate and salmeterol inhalation powder have not been conducted in patients
with hepatic or renal impairment. However, since both fluticasone propionate and
salmeterol are predominantly cleared by hepatic metabolism, impairment of liver
function may lead to accumulation of fluticasone propionate and salmeterol in
plasma. Therefore, patients with hepatic disease should be closely monitored.
Drug Interaction Studies
In the repeat- and single-dose trials, there was no
evidence of significant drug interaction in systemic exposure between
fluticasone propionate and salmeterol when given alone or in combination via a
dry powder inhaler. The population pharmacokinetic analysis from 9 controlled
clinical trials in 350 subjects with asthma showed no significant effects on
fluticasone propionate or salmeterol pharmacokinetics following
co-administration with beta2-agonists, corticosteroids, antihistamines, or theophyllines.
Inhibitors Of Cytochrome P450 3A4
Ritonavir
Fluticasone Propionate
Fluticasone propionate is a substrate of CYP3A4.
Coadministration of fluticasone propionate and the strong CYP3A4 inhibitor
ritonavir is not recommended based upon a multiple-dose, crossover drug interaction
trial in 18 healthy subjects. Fluticasone propionate aqueous nasal spray (200
mcg once daily) was coadministered for 7 days with ritonavir (100 mg twice
daily). Plasma fluticasone propionate concentrations following fluticasone
propionate aqueous nasal spray alone were undetectable (<10 pg/mL) in most
subjects, and when concentrations were detectable peak levels (Cmax) averaged
11.9 pg/mL (range: 10.8 to 14.1 pg/mL) and AUC(0-τ)
averaged 8.43 pg•h/mL (range: 4.2 to 18.8 pg•h/mL). Fluticasone propionate Cmax
and AUC(0-τ) increased to 318 pg/mL
(range: 110 to 648 pg/mL) and 3,102.6 pg•h/mL (range: 1,207.1 to 5,662.0
pg•h/mL), respectively, after coadministration of ritonavir with fluticasone
propionate aqueous nasal spray. This significant increase in plasma fluticasone
propionate exposure resulted in a significant decrease (86%) in serum cortisol
AUC.
Ketoconazole
Fluticasone Propionate
In a placebo-controlled crossover trial in 8 healthy
adult volunteers, coadministration of a single dose of orally inhaled fluticasone
propionate (1,000 mcg) with multiple doses of ketoconazole (200 mg) to steady
state resulted in increased plasma fluticasone propionate exposure, a reduction
in plasma cortisol AUC, and no effect on urinary excretion of cortisol.
Salmeterol
In a placebo-controlled, crossover drug interaction trial
in 20 healthy male and female subjects, coadministration of salmeterol (50 mcg
twice daily) and the strong CYP3A4 inhibitor ketoconazole (400 mg once daily)
for 7 days resulted in a significant increase in plasma salmeterol exposure as determined
by a 16-fold increase in AUC (ratio with and without ketoconazole 15.76 [90%
CI: 10.66, 23.31]) mainly due to increased bioavailability of the swallowed
portion of the dose. Peak plasma salmeterol concentrations were increased by
1.4-fold (90% CI: 1.23, 1.68). Three (3) out of 20 subjects (15%) were
withdrawn from salmeterol and ketoconazole coadministration due to
beta-agonist–mediated systemic effects (2 with QTc prolongation and 1 with
palpitations and sinus tachycardia). Coadministration of salmeterol and
ketoconazole did not result in a clinically significant effect on mean heart
rate, mean blood potassium, or mean blood glucose. Although there was no
statistical effect on the mean QTc, coadministration of salmeterol and
ketoconazole was associated with more frequent increases in QTc duration
compared with salmeterol and placebo administration.
Erythromycin
Fluticasone Propionate
In a multiple-dose drug interaction trial,
coadministration of orally inhaled fluticasone propionate (500 mcg twice daily)
and erythromycin (333 mg 3 times daily) did not affect fluticasone propionate pharmacokinetics.
Salmeterol
In a repeat-dose trial in 13 healthy subjects,
concomitant administration of erythromycin (a moderate CYP3A4 inhibitor) and
salmeterol inhalation aerosol resulted in a 40% increase in salmeterol Cmax at steady
state (ratio with and without erythromycin 1.4 [90% CI: 0.96, 2.03], P = 0.12),
a 3.6-beat/min increase in heart rate ([95% CI: 0.19, 7.03], P<0.04), a 5.8-msec
increase in QTc interval ([95% CI: - 6.14, 17.77], P = 0.34), and no change in
plasma potassium.
Animal Toxicology And/Or Pharmacology
Preclinical
Studies in laboratory animals (minipigs, rodents, and
dogs) have demonstrated the occurrence of cardiac arrhythmias and sudden death
(with histologic evidence of myocardial necrosis) when beta-agonists and methylxanthines
are administered concurrently. The clinical relevance of these findings is
unknown.
Clinical Studies
Asthma
Adult And Adolescent Subjects Aged 12 Years And Older
In clinical trials comparing fluticasone propionate and
salmeterol inhalation powder with its individual components, improvements in most
efficacy endpoints were greater with fluticasone propionate and salmeterol
inhalation powder than with the use of either fluticasone propionate or
salmeterol alone. In addition, clinical trials showed similar results between
fluticasone propionate and salmeterol inhalation powder and the concurrent use
of fluticasone propionate plus salmeterol at corresponding doses from separate
inhalers.
Trials Comparing Fluticasone Propionate And Salmeterol
Inhalation Powder With Fluticasone Propionate Alone Or Salmeterol Alone
Three (3) double-blind, parallel-group clinical trials
were conducted with fluticasone propionate and salmeterol inhalation powder in
1,208 adult and adolescent subjects (aged 12 years and older, baseline FEV1 Â 63%
to 72% of predicted normal) with asthma that was not optimally controlled on
their current therapy. All treatments were inhalation powders given as 1
inhalation from a dry powder inhaler twice daily, and other maintenance
therapies were discontinued.
Trial 1: Clinical Trial with Fluticasone Propionate and
Salmeterol Inhalation Powder 10 0 mcg /50 mcg
This placebo-controlled, 12-week, U.S. trial compared
fluticasone propionate and salmeterol inhalation powder 100 mcg/50 mcg with its
individual components, fluticasone propionate 100 mcg and salmeterol 50 mcg.
The trial was stratified according to baseline asthma maintenance therapy;
subjects were using either ICS (n = 250) (daily doses of beclomethasone
dipropionate 252 to 420 mcg; flunisolide 1,000 mcg; fluticasone propionate
inhalation aerosol 176 mcg; or triamcinolone acetonide 600 to 1,000 mcg) or
salmeterol (n = 106). Baseline FEV1 Â measurements were similar across
treatments: fluticasone propionate and salmeterol inhalation powder 100 mcg/50
mcg, 2.17 L; fluticasone propionate 100 mcg, 2.11 L; salmeterol, 2.13 L; and
placebo, 2.15 L.
Predefined withdrawal criteria for lack of efficacy, an
indicator of worsening asthma, were utilized for this placebo-controlled trial.
Worsening asthma was defined as a clinically important decrease in FEV1 Â or
PEF, increase in use of VENTOLIN® (albuterol, USP) Inhalation Aerosol, increase
in night awakenings due to asthma, emergency intervention or hospitalization
due to asthma, or requirement for asthma medication not allowed by the
protocol. As shown in Table 4, statistically significantly fewer subjects
receiving fluticasone propionate and salmeterol inhalation powder 100 mcg/50
mcg were withdrawn due to worsening asthma compared with fluticasone
propionate, salmeterol, and placebo.
Table 4: Percent of Subjects Withdrawn due to
Worsening Asthma in Subjects Previously Treated with Either Inhaled
Corticosteroids or Salmeterol (Trial 1)
Fluticasone Propionate and Salmeterol Inhalation Powder 100 mcg/50 mcg
(n = 87) |
Fluticasone Propionate 100 mcg
(n = 85) |
Salmeterol 50 mcg
(n = 86) |
Placebo
(n = 77) |
3% |
11% |
35% |
49% |
The FEV1 Â results are displayed in Figure 1. Because this
trial used predetermined criteria for worsening asthma, which caused more
subjects in the placebo group to be withdrawn, FEV1 Â results at Endpoint (last
available FEV1 Â result) are also provided. Subjects receiving fluticasone
propionate and salmeterol inhalation powder 100 mcg/50 mcg had significantly
greater improvements in FEV1 (0.51 L, 25%) compared with fluticasone propionate
100 mcg (0.28 L, 15%), salmeterol (0.11 L, 5%), and placebo (0.01 L, 1%). These
improvements in FEV1 with fluticasone propionate and salmeterol inhalation
powder were achieved regardless of baseline asthma maintenance therapy (ICS or salmeterol).
Figure 1: Mean Percent Change from Baseline in FEV1 in
Subjects with Asthma Previously Treated with Either Inhaled Corticosteroids or
Salmeterol (Trial 1)
The effect of fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg on morning and evening PEF endpoints is shown
in Table 5.
Table 5: Peak Expiratory Flow Results for Subjects
with Asthma Previously Treated with Either Inhaled Corticosteroids or
Salmeterol (Trial 1)
Efficacy Variable* |
Fluticasone Propionate and Salmeterol Inhalation Powder 100 mcg/50 meg
(n = 87) |
Fluticasone Propionate 100 meg
(n = 85) |
Salmeterol 50 meg
(n = 86) |
Placebo
(n = 77) |
AM PEF (L/min) |
Baseline |
393 |
374 |
369 |
382 |
Change from baseline |
53 |
17 |
-2 |
-24 |
PM PEF (L/min) |
Baseline |
418 |
390 |
396 |
398 |
Change from baseline |
35 |
18 |
-7 |
-13 |
*Change from baseline = change from baseline at Endpoint
(last available data). |
The subjective impact of asthma on subjects' perception
of health was evaluated through use of an instrument called the Asthma Quality
of Life Questionnaire (AQLQ) (based on a 7 point scale where 1 = maximum
impairment and 7 = none). Subjects receiving fluticasone propionate and
salmeterol inhalation powder 100 mcg/50 mcg had clinically meaningful
improvements in overall asthma-specific quality of life as defined by a
difference between groups of ≥0.5 points in change from baseline AQLQ
scores (difference in AQLQ score of 1.25 compared with placebo).
Trial 2: Clinical Trial With Fluticasone Propionate And Salmeterol
Inhalation Powder 250 mcg /50 mcg
This placebo-controlled, 12-week, U.S. trial compared
fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg with its
individual components, fluticasone propionate 250 mcg and salmeterol 50 mcg, in
349 subjects with asthma using ICS (daily doses of beclomethasone dipropionate
462 to 672 mcg; flunisolide 1,250 to 2,000 mcg; fluticasone propionate
inhalation aerosol 440 mcg; or triamcinolone acetonide 1,100 to 1,600 mcg).
Baseline FEV1 Â measurements were similar across treatments: fluticasone
propionate and salmeterol inhalation powder 250 mcg/50 mcg, 2.23 L; fluticasone
propionate 250 mcg, 2.12 L; salmeterol, 2.20 L; and placebo, 2.19 L.
Efficacy results in this trial were similar to those
observed in Trial 1. Subjects receiving fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg had significantly greater improvements in FEV1
 (0.48 L, 23%) compared with fluticasone propionate 250 mcg (0.25 L, 13%),
salmeterol (0.05 L, 4%), and placebo (decrease of 0.11 L, decrease of 5%).
Statistically significantly fewer subjects receiving fluticasone propionate and
salmeterol inhalation powder 250 mcg/50 mcg were withdrawn from this trial for
worsening asthma (4%) compared with fluticasone propionate (22%), salmeterol (38%),
and placebo (62%). In addition, fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg was superior to fluticasone propionate,
salmeterol, and placebo for improvements in morning and evening PEF. Subjects
receiving fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg also had clinically meaningful improvements in overall asthma-specific
quality of life as described in Trial 1 (difference in AQLQ score of 1.29
compared with placebo).
Trial 3: Clinical Trial With Fluticasone Propionate And Salmeterol
Inhalation Powder 50 0 mcg /50 mcg
This 28-week, non-U.S. trial compared fluticasone
propionate and salmeterol inhalation powder 500 mcg/50 mcg with fluticasone
propionate 500 mcg alone and concurrent therapy (salmeterol 50 mcg plus fluticasone
propionate 500 mcg administered from separate inhalers) twice daily in 503
subjects with asthma using ICS (daily doses of beclomethasone dipropionate
1,260 to 1,680 mcg; budesonide 1,500 to 2,000 mcg; flunisolide 1,500 to 2,000
mcg; or fluticasone propionate inhalation aerosol 660 to 880 mcg [750 to 1,000
mcg inhalation powder]). The primary efficacy parameter, morning PEF, was collected
daily for the first 12 weeks of the trial. The primary purpose of weeks 13 to
28 was to collect safety data.
Baseline PEF measurements were similar across treatments:
fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg, 359
L/min; fluticasone propionate 500 mcg, 351 L/min; and concurrent therapy, 345
L/min. Morning PEF improved significantly with fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg compared with fluticasone propionate 500 mcg
over the 12-week treatment period. Improvements in morning PEF observed with
fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg were
similar to improvements observed with concurrent therapy.
Onset Of Action And Progression Of Improvement In Asthma
Control
The onset of action and progression of improvement in
asthma control were evaluated in the 2 placebo-controlled U.S. trials.
Following the first dose, the median time to onset of clinically significant bronchodilatation
(≥15% improvement in FEV1 ) in most subjects was seen within 30 to 60
minutes. Maximum improvement in FEV1 Â generally occurred within 3 hours, and
clinically significant improvement was maintained for 12 hours (Figure 2).
Following the initial dose, predose FEV1 Â relative to Day 1 baseline improved
markedly over the first week of treatment and continued to improve over the 12
weeks of treatment in both trials. No diminution in the 12-hour bronchodilator
effect was observed with either fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg (Figures 2 and 3) or fluticasone propionate
and salmeterol inhalation powder 250 mcg/50 mcg as assessed by FEV1Â following
12 weeks of therapy.
Figure 2: Percent Change in Serial 12-Hour FEV1 Â in
Subjects with Asthma Previously Using Either Inhaled Corticosteroids or
Salmeterol (Trial 1)
Figure 3: Percent Change in Serial 12-Hour FEV1 Â in
Subjects with Asthma Previously Using Either Inhaled Corticosteroids or
Salmeterol (Trial 1)
Reduction in asthma symptoms and use of rescue VENTOLIN
Inhalation Aerosol and improvement in morning and evening PEF also occurred
within the first day of treatment with fluticasone propionate and salmeterol
inhalation powder, and continued to improve over the 12 weeks of therapy in
both trials.
Pediatric Subjects
In a 12-week U.S. trial, fluticasone propionate and
salmeterol inhalation powder 100 mcg/50 mcg twice daily was compared with
fluticasone propionate inhalation powder 100 mcg twice daily in 203 children with
asthma aged 4 to 11 years. At trial entry, the children were symptomatic on low
doses of ICS (beclomethasone dipropionate 252 to 336 mcg/day; budesonide 200 to
400 mcg/day; flunisolide 1,000 mcg/day; triamcinolone acetonide 600 to 1,000
mcg/day; or fluticasone propionate 88 to 250 mcg/day). The primary objective of
this trial was to determine the safety of fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg compared with fluticasone propionate
inhalation powder 100 mcg in this age group; however, the trial also included
secondary efficacy measures of pulmonary function. Morning predose FEV1 Â was
obtained at baseline and Endpoint (last available FEV1Â result) in children aged
6 to 11 years. In subjects receiving fluticasone propionate and salmeterol
inhalation powder 100 mcg/50 mcg, FEV1 Â increased from 1.70 L at baseline (n =
79) to 1.88 L at Endpoint (n = 69) compared with an increase from 1.65 L at
baseline (n = 83) to 1.77 L at Endpoint (n = 75) in subjects receiving fluticasone
propionate 100 mcg.
The findings of this trial, along with extrapolation of
efficacy data from subjects aged 12 years and older, support the overall
conclusion that fluticasone propionate and salmeterol inhalation powder 100 mcg/50
mcg is efficacious in the treatment of asthma in subjects aged 4 to 11 years.
Chronic Obstructive Pulmonary Disease
The efficacy of fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg and fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg in the treatment of subjects with COPD was
evaluated in 6 randomized, double-blind, parallel-group clinical trials in
adult subjects aged 40 years and older. These trials were primarily designed to
evaluate the efficacy of fluticasone propionate and salmeterol inhalation
powder on lung function (3 trials), exacerbations (2 trials), and survival (1
trial).
Lung Function
Two (2) of the 3 clinical trials primarily designed to
evaluate the efficacy of fluticasone propionate and salmeterol inhalation
powder on lung function were conducted in 1,414 subjects with COPD associated with
chronic bronchitis. In these 2 trials, all the subjects had a history of cough
productive of sputum that was not attributable to another disease process on
most days for at least 3 months of the year for at least 2 years. The trials
were randomized, double-blind, parallel-group, 24-week treatment duration. One
(1) trial evaluated the efficacy of fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg compared with its components fluticasone
propionate 250 mcg and salmeterol 50 mcg and with placebo, and the other trial
evaluated the efficacy of fluticasone propionate and salmeterol inhalation
powder 500 mcg/50 mcg compared with its components fluticasone propionate 500
mcg and salmeterol 50 mcg and with placebo. Trial treatments were inhalation
powders given as 1 inhalation from the dry powder inhaler twice daily.
Maintenance COPD therapies were discontinued, with the exception of
theophylline. The subjects had a mean pre-bronchodilator FEV1 of 41% and 20% reversibility
at trial entry. Percent reversibility was calculated as 100 times (FEV1 post-albuterol
minus FEV1Â pre-albuterol)/FEV1 pre-albuterol.
Improvements in lung function (as defined by predose and
postdose FEV1 ) were significantly greater with fluticasone propionate and
salmeterol inhalation powder than with fluticasone propionate, salmeterol, or
placebo. The improvement in lung function with fluticasone propionate and
salmeterol inhalation powder 500 mcg/50 mcg was similar to the improvement seen
with fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg.
Figures 4 and 5 display predose and 2-hour postdose,
respectively, FEV1 results for the trial with fluticasone propionate and
salmeterol inhalation powder 250 mcg/50 mcg. To account for subject withdrawals
during the trial, FEV1 at Endpoint (last evaluable FEV1 ) was evaluated.
Subjects receiving fluticasone propionate and salmeterol inhalation powder 250
mcg/50 mcg had significantly greater improvements in predose FEV1 at Endpoint
(165 mL, 17%) compared with salmeterol 50 mcg (91 mL, 9%) and placebo (1 mL,
1%), demonstrating the contribution of fluticasone propionate to the improvement
in lung function with fluticasone propionate and salmeterol inhalation powder
(Figure 4). Subjects receiving fluticasone propionate and salmeterol inhalation
powder 250 mcg/50 mcg had significantly greater improvements in postdose FEV1 at
Endpoint (281 mL, 27%) compared with fluticasone propionate 250 mcg (147 mL,
14%) and placebo (58 mL, 6%), demonstrating the contribution of salmeterol to
the improvement in lung function with fluticasone propionate and salmeterol
inhalation powder (Figure 5).
Figure 4 : Predose FEV1 : Mean Percent Chang e from
Baseline in Subjects with Chronic Obstructive Pulmonary Disease
Figure 5: Two-Hour Postdose FEV1 : Mean Percent Changes
from Baseline over Time in Subjects with Chronic Obstructive Pulmonary Disease
The third trial was a 1-year trial that evaluated
fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg,
fluticasone propionate 500 mcg, salmeterol 50 mcg, and placebo in 1,465
subjects. The subjects had an established history of COPD and exacerbations, a
pre-bronchodilator FEV1 <70% of predicted at trial entry, and 8.3%
reversibility. The primary endpoint was the comparison of prebronchodilator
FEV1 in the groups receiving fluticasone propionate and salmeterol inhalation
powder 500 mcg/50 mcg or placebo. Subjects treated with fluticasone propionate
and salmeterol inhalation powder 500 mcg/50 mcg had greater improvements in FEV1
(113 mL, 10%) compared with fluticasone propionate 500 mcg (7 mL, 2%),
salmeterol (15 mL, 2%), and placebo (-60 mL, -3%).
Exacerbations
Two (2) trials were primarily designed to evaluate the
effect of fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg on exacerbations. In these 2 trials, exacerbations were defined as worsening
of 2 or more major symptoms (dyspnea, sputum volume, and sputum purulence) or
worsening of any 1 major symptom together with any 1 of the following minor
symptoms: sore throat, colds (nasal discharge and/or nasal congestion), fever
without other cause, and increased cough or wheeze for at least 2 consecutive
days. COPD exacerbations were considered of moderate severity if treatment with
systemic corticosteroids and/or antibiotics was required and were considered
severe if hospitalization was required.
Exacerbations were also evaluated as a secondary outcome
in the 1- and 3-year trials with fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg. There was not a symptomatic definition of
exacerbation in these 2 trials. Exacerbations were defined in terms of severity
requiring treatment with antibiotics and/or systemic corticosteroids (moderately
severe) or requiring hospitalization (severe).
The 2 exacerbation trials with fluticasone propionate and
salmeterol inhalation powder 250 mcg/50 mcg were identical trials designed to
evaluate the effect of fluticasone propionate and salmeterol inhalation powder
250 mcg/50 mcg and salmeterol 50 mcg, each given twice daily, on exacerbations
of COPD over a 12-month period. A total of 1,579 subjects had an established
history of COPD (but no other significant respiratory disorders). Subjects had
a pre-bronchodilator FEV1 of 33% of predicted, a mean reversibility of 23% at
baseline, and a history of ≥ 1 COPD exacerbation in the previous year
that was moderate or severe. All subjects were treated with fluticasone
propionate and salmeterol inhalation powder 250 mcg/50 mcg twice daily during a
4-week run-in period prior to being assigned trial treatment with twice-daily
fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg or salmeterol
50 mcg. In both trials, treatment with fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg resulted in a significantly lower annual rate
of moderate/severe COPD exacerbations compared with salmeterol (30.5% reduction
[95% CI: 17.0, 41.8], P< 0.001) in the first trial and (30.4% reduction [95%
CI: 16.9, 41.7], P< 0.001) in the second trial. Subjects treated with
fluticasone propionate and salmeterol inhalation powder 250 mcg/50 mcg also had
a significantly lower annual rate of exacerbations requiring treatment with
oral corticosteroids compared with subjects treated with salmeterol (39.7%
reduction [95% CI: 22.8, 52.9], P< 0.001) in the first trial and (34.3%
reduction [95% CI: 18.6, 47.0], P< 0.001) in the second trial. Secondary
endpoints including pulmonary function and symptom scores improved more in
subjects treated with fluticasone propionate and salmeterol inhalation powder
250 mcg/50 mcg than with salmeterol 50 mcg in both trials.
Exacerbations were evaluated in the 1- and the 3-year
trials with fluticasone propionate and salmeterol inhalation powder 500 mcg/50
mcg as 1 of the secondary efficacy endpoints. In the 1-year trial, the group
receiving fluticasone propionate and salmeterol inhalation powder 500 mcg/50
mcg had a significantly lower rate of moderate and severe exacerbations
compared with placebo (25.4% reduction compared with placebo [95% CI: 13.5,
35.7]) but not when compared with its components (7.5% reduction compared with
fluticasone propionate [95% CI: -7.3, 20.3] and 7% reduction compared with salmeterol
[95% CI: -8.0, 19.9]). In the 3-year trial, the group receiving fluticasone
propionate and salmeterol inhalation powder 500 mcg/50 mcg had a significantly
lower rate of moderate and severe exacerbations compared with each of the other
treatment groups (25.1% reduction compared with placebo [95% CI: 18.6, 31.1],
9.0% reduction compared with fluticasone propionate [95% CI: 1.2, 16.2], and
12.2% reduction compared with salmeterol [95% CI: 4.6, 19.2]).
There were no trials conducted to directly compare the
efficacy of fluticasone propionate and salmeterol inhalation powder 250 mcg/50
mcg with fluticasone propionate and salmeterol inhalation powder 500 mcg/50 mcg
on exacerbations. Across trials, the reduction in exacerbations seen with fluticasone
propionate and salmeterol inhalation powder 500 mcg/50 mcg was not greater than
the reduction in exacerbations seen with fluticasone propionate and salmeterol
inhalation powder 250 mcg/50 mcg.
Survival
A 3-year multicenter, international trial evaluated the
efficacy of fluticasone propionate and salmeterol inhalation powder 500 mcg/50
mcg compared with fluticasone propionate 500 mcg, salmeterol 50 mcg, and
placebo on survival in 6,112 subjects with COPD. During the trial subjects were
permitted usual COPD therapy with the exception of other ICS and long-acting
bronchodilators. The subjects were aged 40 to 80 years with an established
history of COPD, a pre-bronchodilator FEV1 <60% of predicted at trial entry,
and <10% of predicted reversibility. Each subject who withdrew from
doubleblind treatment for any reason was followed for the full 3-year trial
period to determine survival status. The primary efficacy endpoint was
all-cause mortality. Survival with fluticasone propionate and salmeterol
inhalation powder 500 mcg/50 mcg was not significantly improved compared with
placebo or the individual components (all-cause mortality rate 12.6%
fluticasone propionate and salmeterol inhalation powder versus 15.2% placebo).
The rates for all-cause mortality were 13.5% and 16.0% in the groups treated
with salmeterol 50 mcg and fluticasone propionate 500 mcg, respectively.
Secondary outcomes, including pulmonary function (post-bronchodilator FEV1 ),
improved with fluticasone propionate and salmeterol inhalation powder 500
mcg/50 mcg, salmeterol 50 mcg, and fluticasone propionate 500 mcg compared with
placebo.