CLINICAL PHARMACOLOGY
Mechanism Of Action
SYMBICORT
SYMBICORT contains both
budesonide and formoterol; therefore, the mechanisms of action described below
for the individual components apply to SYMBICORT. These drugs represent two
classes of medications (a synthetic corticosteroid and a long-acting selective
beta2-adrenoceptor agonist) that have different effects on clinical,
physiological, and inflammatory indices of COPD and asthma.
Budesonide
Budesonide is an
anti-inflammatory corticosteroid that exhibits potent glucocorticoid activity
and weak mineralocorticoid activity. In standard in vitro and animal models,
budesonide has approximately a 200fold higher affinity for the glucocorticoid
receptor and a 1000-fold higher topical anti-inflammatory potency than cortisol
(rat croton oil ear edema assay). As a measure of systemic activity, budesonide
is 40 times more potent than cortisol when administered subcutaneously and 25
times more potent when administered orally in the rat thymus involution assay.
In glucocorticoid receptor
affinity studies, the 22R form of budesonide was two times as active as the 22S
epimer. In vitro studies indicated that the two forms of budesonide do not
interconvert.
Inflammation is an important component in the
pathogenesis of COPD and asthma. Corticosteroids have a wide range of
inhibitory activities against multiple cell types (e.g., mast cells,
eosinophils, neutrophils, macrophages, and lymphocytes) and mediators (e.g.,
histamine, eicosanoids, leukotrienes, and cytokines) involved in allergic and
non–allergic-mediated inflammation. These anti-inflammatory actions of
corticosteroids may contribute to their efficacy in COPD and asthma.
Studies in asthmatic patients have shown a favorable
ratio between topical anti-inflammatory activity and systemic corticosteroid
effects over a wide range of doses of budesonide. This is explained by a
combination of a relatively high local anti-inflammatory effect, extensive
first pass hepatic degradation of orally absorbed drug (85%-95%), and the low
potency of formed metabolites.
Formoterol
Formoterol fumarate is a long-acting selective beta2-adrenergic
agonist (beta2-agonist) with a rapid onset of action. Inhaled formoterol
fumarate acts locally in the lung as a bronchodilator. In vitro studies have
shown that formoterol has more than 200-fold greater agonist activity at beta2-receptors
than at beta1receptors. The in vitro binding selectivity to beta2-over beta1-adrenoceptors
is higher for formoterol than for albuterol (5 times), whereas salmeterol has a
higher (3 times) beta2-selectivity ratio than formoterol.
Although beta2-receptors are the predominant adrenergic
receptors in bronchial smooth muscle and beta1receptors are the predominant
receptors in the heart, there are also beta2-receptors in the human heart
comprising 10% to 50% of the total beta-adrenergic receptors. The precise
function of these receptors has not been established, but they raise the possibility
that even highly selective beta2-agonists may have cardiac effects.
The pharmacologic effects of beta2-adrenoceptor agonist
drugs, including formoterol, 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 formoterol is an inhibitor of
the release of mast cell mediators, such as histamine and leukotrienes, from
the human lung. Formoterol also inhibits histamine-induced plasma albumin
extravasation in anesthetized guinea pigs and inhibits allergen-induced
eosinophil influx in dogs with airway hyper-responsiveness. The relevance of
these in vitro and animal findings to humans is unknown.
Pharmacodynamics
Asthma
Cardiovascular Effects
In a single-dose cross-over study involving 201 patients
with persistent asthma, single-dose treatments of 4.5, 9, and 18 mcg of
formoterol in combination with 320 mcg of budesonide delivered via SYMBICORT
were compared to budesonide 320 mcg alone. Dose-ordered improvements in FEV1 were
demonstrated when compared with budesonide. ECGs and blood samples for glucose
and potassium were obtained post-dose. For SYMBICORT, small mean increases in
serum glucose and decreases in serum potassium (+0.44 mmol/L and -0.18 mmol/L
at the highest dose, respectively) were observed with increasing doses of
formoterol, compared to budesonide. In ECGs, SYMBICORT produced small
dose-related mean increases in heart rate (approximately 3 bpm at the highest
dose), and QTc intervals (3-6 msec) compared to budesonide alone. No subject
had a QT or QTc value ≥500 msec.
In the United States, five 12-week, active-and
placebo-controlled studies and one 6-month active-controlled study evaluated
2976 patients aged 6 years and older with asthma. Systemic pharmacodynamic
effects of formoterol (heart/pulse rate, blood pressure, QTc interval,
potassium, and glucose) were similar in patients treated with SYMBICORT,
compared with patients treated with formoterol dry inhalation powder 4.5 mcg, 2
inhalations twice daily. No patient had a QT or QTc value ≥500 msec
during treatment.
In three placebo-controlled studies in adolescents and
adults with asthma, aged 12 years and older, a total of 1232 patients (553
patients in the SYMBICORT group) had evaluable continuous 24-hour
electrocardiographic monitoring. Overall, there were no important differences
in the occurrence of ventricular or supraventricular ectopy and no evidence of
increased risk for clinically significant dysrhythmia in the SYMBICORT group
compared to placebo.
HPA-Axis Effects
Overall, no clinically important effects on HPA-axis, as
measured by 24-hour urinary cortisol, were observed for SYMBICORT treated adult
or adolescent patients at doses up to 640/18 mcg/day compared to budesonide.
Chronic Obstructive Pulmonary Disease
Cardiovascular Effects
In two COPD lung function studies, 6 months and 12 months
in duration including 3668 COPD patients, no clinically important differences
were seen in pulse rate, blood pressure, potassium, and glucose between
SYMBICORT, the individual components of SYMBICORT, and placebo [see Clinical
Studies].
ECGs recorded at multiple clinic visits on treatment in
both studies showed no clinically important differences for heart rate, PR
interval, QRS duration, heart rate, signs of cardiac ischemia or arrhythmias
between SYMBICORT 160/4.5 the monoproducts and placebo, all administered as 2
inhalations twice daily. Based on ECGs, 6 patients treated with SYMBICORT
160/4.5, 6 patients treated with formoterol 4.5 mcg, and 6 patients in the
placebo group experienced atrial fibrillation or flutter that was not present
at baseline. There were no cases of nonsustained ventricular tachycardia in the
SYMBICORT 160/4.5, formoterol 4.5 mcg, or placebo groups.
In the 12-month study, 520 patients had evaluable
continuous 24-hour ECG (Holter) monitoring prior to the first dose and after
approximately 1 and 4 months on treatment. No clinically important differences
in ventricular or supraventricular arrhythmias, ventricular or supraventricular
ectopic beats, or heart rate were observed among the groups treated with
SYMBICORT 160/4.5, formoterol or placebo taken as 2 inhalations twice daily. Based
on ECG (Holter) monitoring, one patient on SYMBICORT 160/4.5, no patients on
formoterol 4.5 mcg, and three patients in the placebo group experienced atrial
fibrillation or flutter that was not present at baseline.
HPA-axis Effects
Twenty-four hour urinary cortisol measurements were
collected in a pooled subset (n=616) of patients from two COPD lung function
studies. The data indicated approximately 30% lower mean 24-hour urinary free
cortisol values following chronic administration (> 6 months) of SYMBICORT
relative to placebo. SYMBICORT appeared to exhibit comparable cortisol
suppression to budesonide 160 mcg alone or coadministration of budesonide 160
mcg and formoterol 4.5 mcg. For patients treated with SYMBICORT or placebo for
up to 12 months, the percentage of patients who shifted from normal to low for
this measure were generally comparable.
Other Budesonide Products
To confirm that systemic absorption is not a significant
factor in the clinical efficacy of inhaled budesonide, a clinical study in
patients with asthma was performed comparing 400 mcg budesonide administered
via a pressurized metered dose inhaler with a tube spacer to 1400 mcg of oral
budesonide and placebo. The study demonstrated the efficacy of inhaled budesonide
but not orally ingested budesonide, despite comparable systemic levels. Thus,
the therapeutic effect of conventional doses of orally inhaled budesonide are
largely explained by its direct action on the respiratory tract.
Inhaled budesonide has been shown to decrease airway
reactivity to various challenge models, including histamine, methacholine,
sodium metabisulfite, and adenosine monophosphate in patients with
hyperreactive airways. The clinical relevance of these models is not certain.
Pretreatment with inhaled budesonide, 1600 mcg daily (800
mcg twice daily) for 2 weeks reduced the acute (early-phase reaction) and
delayed (late-phase reaction) decrease in FEV1 following inhaled allergen
challenge.
The systemic effects of inhaled corticosteroids are
related to the systemic exposure to such drugs. Pharmacokinetic studies have
demonstrated that in both adults and children with asthma the systemic exposure
to budesonide is lower with SYMBICORT compared with inhaled budesonide
administered at the same delivered dose via a dry powder inhaler [see CLINICAL
PHARMACOLOGY]. Therefore, the systemic effects (HPA-axis and growth) of
budesonide delivered from SYMBICORT would be expected to be no greater than
what is reported for inhaled budesonide when administered at comparable doses
via the dry powder inhaler [see Use In Specific Populations].
HPA-Axis Effects
The effects of inhaled budesonide administered via a dry
powder inhaler on the HPA-axis were studied in 905 adults and 404 pediatric
patients with asthma. For most patients, the ability to increase cortisol
production in response to stress, as assessed by cosyntropin (ACTH) stimulation
test, remained intact with budesonide treatment at recommended doses. For adult
patients treated with 100, 200, 400, or 800 mcg twice daily for 12 weeks, 4%,
2%, 6%, and 13%, respectively, had an abnormal stimulated cortisol response
(peak cortisol <14.5 mcg/dL assessed by liquid chromatography following
short-cosyntropin test) as compared to 8% of patients treated with placebo.
Similar results were obtained in pediatric patients. In another study in
adults, doses of 400, 800, and 1600 mcg of inhaled budesonide twice daily for 6
weeks were examined; 1600 mcg twice daily (twice the maximum recommended dose)
resulted in a 27% reduction in stimulated cortisol (6-hour ACTH infusion) while
10-mg prednisone resulted in a 35% reduction. In this study, no patient on
budesonide at doses of 400 and 800 mcg twice daily met the criterion for an
abnormal stimulated-cortisol response (peak cortisol <14.5 mcg/dL assessed
by liquid chromatography) following ACTH infusion. An open-label, long-term
follow-up of 1133 patients for up to 52 weeks confirmed the minimal effect on
the HPA-axis (both basal-and stimulated-plasma cortisol) of budesonide when
administered at recommended doses. In patients who had previously been
oral-steroid-dependent, use of budesonide in recommended doses was associated
with higher stimulated-cortisol response compared to baseline following 1 year
of therapy.
Other Formoterol Products
While the pharmacodynamic effect is via stimulation of
beta-adrenergic receptors, excessive activation of these receptors commonly
leads to skeletal muscle tremor and cramps, insomnia, tachycardia, decreases in
plasma potassium, and increases in plasma glucose. Inhaled formoterol, like
other beta2-adrenergic agonist drugs, can produce dose-related cardiovascular
effects and effects on blood glucose and/or serum potassium [see WARNINGS
AND PRECAUTIONS]. For SYMBICORT, these effects are detailed in the Clinical
Pharmacology, Pharmacodynamics, SYMBICORT (12.2) section.
Use of LABA drugs can result in tolerance to
bronchoprotective and bronchodilatory effects.
Rebound bronchial hyperresponsiveness after cessation of
chronic long-acting beta-agonist therapy has not been observed.
Pharmacokinetics
SYMBICORT
Absorption
Budesonide
Healthy Subjects
Orally inhaled budesonide is rapidly absorbed in the
lungs and peak concentration is typically reached within 20 minutes. After oral
administration of budesonide peak plasma concentration was achieved in about 1
to 2 hours and the absolute systemic availability was 6%-13% due to extensive
first pass metabolism. In contrast, most of the budesonide delivered to the
lungs was systemically absorbed. In healthy subjects, 34% of the metered dose
was deposited in the lung (as assessed by plasma concentration method and using
a budesonide-containing dry powder inhaler) with an absolute systemic
availability of 39% of the metered dose.
Following administration of SYMBICORT 160/4.5, two or
four inhalations twice daily for 5 days in healthy subjects, plasma
concentration of budesonide generally increased in proportion to dose. The
accumulation index for the group that received 2 inhalations twice daily was
1.32 for budesonide.
Asthma Patients
In a single-dose study, higher than recommended doses of
SYMBICORT (12 inhalations of SYMBICORT 160/4.5) were administered to patients
with moderate asthma. Peak budesonide plasma concentration of 4.5 nmol/L
occurred at 20 minutes following dosing. This study demonstrated that the total
systemic exposure to budesonide from SYMBICORT was approximately 30% lower than
from inhaled budesonide via a dry powder inhaler (DPI) at the same delivered
dose. Following administration of SYMBICORT, the half-life of the budesonide
component was 4.7 hours.
In a repeat dose study, the highest recommended dose of
SYMBICORT (160/4.5, two inhalations twice daily) was administered to patients
with moderate asthma and healthy subjects for 1 week. Peak budesonide plasma
concentration of 1.2 nmol/L occurred at 21 minutes in asthma patients. Peak
budesonide plasma concentration was 27% lower in asthma patients compared to that
in healthy subjects. However, the total systemic exposure of budesonide was
comparable to that in asthma patients.
Peak steady-state plasma concentrations of budesonide
administered by DPI in adults with asthma averaged 0.6 and 1.6 nmol/L at doses
of 180 mcg and 360 mcg twice daily, respectively. In asthmatic patients,
budesonide showed a linear increase in AUC and Cmax with increasing dose after
both single and repeated dosing of inhaled budesonide.
COPD Patients
In a single-dose study, 12 inhalations of SYMBICORT
80/4.5 (total dose 960/54 mcg) were administered to patients with COPD. Mean
budesonide peak plasma concentration of 3.3 nmol/L occurred at 30 minutes
following dosing. Budesonide systemic exposure was comparable between SYMBICORT
pMDI and coadministration of budesonide via a metered-dose inhaler and
formoterol via a dry powder inhaler (budesonide 960 mcg and formoterol 54 mcg).
In the same study, an open-label group of moderate asthma patients also
received the same higher dose of SYMBICORT. For budesonide, COPD patients
exhibited 12% greater AUC and 10% lower Cmax compared to asthma patients.
In the 6-month pivotal lung function clinical study,
steady-state pharmacokinetic data of budesonide was obtained in a subset of
COPD patients with treatment arms of SYMBICORT pMDI 160/4.5, SYMBICORT pMDI
80/4.5, budesonide 160 mcg, budesonide 160 mcg and formoterol 4.5 mcg given
together, all administered as 2 inhalations twice daily. Budesonide systemic
exposure (AUC and Cmax) increased proportionally with doses from 80 mcg to 160
mcg and was generally similar between the 3 treatment groups receiving the same
dose of budesonide (SYMBICORT pMDI 160/4.5, budesonide 160 mcg, budesonide 160
mcg and formoterol 4.5 mcg administered together).
Formoterol
Inhaled formoterol is rapidly absorbed; peak plasma
concentrations are typically reached at the first plasma sampling time, within
5-10 minutes after dosing. As with many drug products for oral inhalation, it
is likely that the majority of the inhaled formoterol delivered is swallowed
and then absorbed from the gastrointestinal tract.
Healthy Subjects
Following administration of SYMBICORT (160/4.5, two or
four inhalations twice daily) for 5 days in healthy subjects, plasma concentration
of formoterol generally increased in proportion to dose. The accumulation index
for the group that received 2 inhalations twice daily was 1.77 for formoterol.
Asthma Patients
In a single-dose study, higher than recommended doses of
SYMBICORT (12 inhalations of SYMBICORT 160/4.5) were administered to patients
with moderate asthma. Peak plasma concentration for formoterol of 136 pmol
occurred at 10 minutes following dosing. Approximately 8% of the delivered dose
of formoterol was recovered in the urine as unchanged drug.
In a repeat dose study, the highest recommended dose of
SYMBICORT (160/4.5, two inhalations twice daily) was administered to patients
with moderate asthma and healthy subjects for 1 week. Peak formoterol plasma
concentration of 28 pmol/L occurred at 10 minutes in asthma patients. Peak
formoterol plasma concentration was about 42% lower in asthma patients compared
to that in healthy subjects. However, the total systemic exposure of formoterol
was comparable to that in asthma patients.
COPD Patients
Following single-dose administration of 12 inhalations of
SYMBICORT 80/4.5, mean peak formoterol plasma concentration of 167 pmol/L was
rapidly achieved at 15 minutes after dosing. Formoterol exposure was slightly
greater (~16-18%) from SYMBICORT pMDI compared to coadministration of
budesonide via a metered-dose inhaler and formoterol via a dry powder inhaler
(total dose of budesonide 960 mcg and formoterol 54 mcg). In the same study, an
open label group of moderate asthma patients received the same dose of
SYMBICORT. COPD patients exhibited 12-15% greater AUC and Cmax for formoterol
compared to asthma patients.
In the 6-month pivotal lung function clinical study,
steady-state pharmacokinetic data of formoterol was obtained in a subset of COPD
patients with treatment arms of SYMBICORT pMDI 160/4.5, SYMBICORT pMDI 80/4.5,
formoterol 4.5 mcg, budesonide 160 mcg and formoterol 4.5 mcg given together,
all administered as 2 inhalations twice daily. The systemic exposure of
formoterol as evidenced by AUC, was about 30% and 16% higher from SYMBICORT
pMDI compared to formoterol alone treatment arm and coadministration of
individual components of budesonide and formoterol treatment arm, respectively.
Distribution
Budesonide
The volume of distribution of budesonide was
approximately 3 L/kg. It was 85%-90% bound to plasma proteins. Protein binding
was constant over the concentration range (1-100 nmol/L) achieved with, and
exceeding, recommended inhaled doses. Budesonide showed little or no binding to
corticosteroid binding globulin. Budesonide rapidly equilibrated with red blood
cells in a concentration independent manner with a blood plasma ratio of about
0.8.
Formoterol
Over the concentration range of 10-500 nmol/L, plasma
protein binding for the RR and SS enantiomers of formoterol was 46% and 58%,
respectively. The concentrations of formoterol used to assess the plasma
protein binding were higher than those achieved in plasma following inhalation
of a single 54 mcg dose.
Metabolism
Budesonide
In vitro studies with human liver homogenates have shown
that budesonide was rapidly and extensively metabolized. Two major metabolites
formed via cytochrome P450 (CYP) isoenzyme 3A4 (CYP3A4) catalyzed
biotransformation have been isolated and identified as
16α-hydroxyprednisolone and 6Ã-hydroxybudesonide. The corticosteroid
activity of each of these two metabolites was less than 1% of that of the
parent compound. No qualitative differences between the in vitro and in vivo metabolic
patterns were detected. Negligible metabolic inactivation was observed in human
lung and serum preparations.
Formoterol
The primary metabolism of formoterol is by direct
glucuronidation and by O-demethylation followed by conjugation to inactive
metabolites. Secondary metabolic pathways include deformylation and sulfate
conjugation. CYP2D6 and CYP2C have been identified as being primarily responsible
for Odemethylation.
Elimination
Budesonide
Budesonide was excreted in urine and feces in the form of
metabolites. Approximately 60% of an intravenous radiolabeled dose was
recovered in the urine.
No unchanged budesonide was detected in the urine. The
22R form of budesonide was preferentially cleared by the liver with systemic
clearance of 1.4 L/min vs. 1.0 L/min for the 22S form. The terminal half-life,
2 to 3 hours, was the same for both epimers and was independent of dose.
Formoterol
The excretion of formoterol was studied in four healthy
subjects following simultaneous administration of radiolabeled formoterol via
the oral and IV routes. In that study, 62% of the radiolabeled formoterol was
excreted in the urine while 24% was eliminated in the feces.
Special Populations
Geriatric
The pharmacokinetics of SYMBICORT in geriatric patients
have not been specifically studied.
Pediatric
Plasma concentrations of budesonide were measured
following administration of four inhalations of SYMBICORT 160/4.5 in a
single-dose study in pediatric patients with asthma, 6 to less than 12 years of
age. Peak budesonide concentrations of 1.4 nmol/L occurred at 20 minutes
post-dose. This study also demonstrated that the total systemic exposure to
budesonide from SYMBICORT was approximately 30% lower than from inhaled
budesonide via a dry powder inhaler that was also evaluated at the same
delivered dose. The dose-normalized Cmax and AUC0-inf of budesonide following
single dose inhalation in children 6 to less than 12 years of age were
numerically lower than that observed in adults.
Following 2 inhalations of SYMBICORT 160/4.5 twice daily
treatment, formoterol Cmax and AUC0-6 at steady state in children 6 to less
than 12 years of age were comparable to that observed in adults.
Gender/Race
Specific studies to examine the effects of gender and
race on the pharmacokinetics of SYMBICORT have not been conducted. Population
PK analysis of the SYMBICORT data indicates that gender does not affect the
pharmacokinetics of budesonide and formoterol. No conclusions can be drawn on
the effect of race due to the low number of non-Caucasians evaluated for PK.
Nursing Mothers
The disposition of budesonide when delivered by
inhalation from a dry powder inhaler at doses of 200 or 400 mcg twice daily for
at least 3 months was studied in eight lactating women with asthma from 1 to 6
months postpartum. Systemic exposure to budesonide in these women appears to be
comparable to that in non-lactating women with asthma from other studies.
Breast milk obtained over eight hours post-dose revealed that the maximum
concentration of budesonide for the 400 and 800 mcg total daily doses was 0.39
and 0.78 nmol/L, respectively, and occurred within 45 minutes after dosing. The
estimated oral daily dose of budesonide from breast milk to the infant is
approximately 0.007 and 0.014 mcg/kg/day for the two dose regimens used in this
study, which represents approximately 0.3% to 1% of the dose inhaled by the
mother. Budesonide levels in plasma samples obtained from five infants at about
90 minutes after breastfeeding (and about 140 minutes after drug administration
to the mother) were below quantifiable levels (<0.02 nmol/L in four infants
and <0.04 nmol/L in one infant) [see Use In Specific Populations].
Renal Or Hepatic Insufficiency
There are no data regarding the specific use of SYMBICORT
in patients with hepatic or renal impairment. Reduced liver function may affect
the elimination of corticosteroids. Budesonide pharmacokinetics was affected by
compromised liver function as evidenced by a doubled systemic availability
after oral ingestion. The intravenous budesonide pharmacokinetics was, however,
similar in cirrhotic patients and in healthy subjects. Specific data with
formoterol is not available, but because formoterol is primarily eliminated via
hepatic metabolism, an increased exposure can be expected in patients with
severe liver impairment.
Drug-Drug Interactions
A single-dose crossover study was conducted to compare
the pharmacokinetics of eight inhalations of the following: budesonide,
formoterol, and budesonide plus formoterol administered concurrently. The
results of the study indicated that there was no evidence of a pharmacokinetic
interaction between the two components of SYMBICORT.
Inhibitors Of Cytochrome P450 Enzymes
Ketoconazole
Ketoconazole, a strong inhibitor of cytochrome P450 (CYP)
isoenzyme 3A4 (CYP3A4), the main metabolic enzyme for corticosteroids,
increased plasma levels of orally ingested budesonide.
Cimetidine
At recommended doses, cimetidine, a non-specific
inhibitor of CYP enzymes, had a slight but clinically insignificant effect on
the pharmacokinetics of oral budesonide.
Specific drug-drug interaction studies with formoterol
have not been performed.
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 significance of
these findings is unknown.
Clinical Studies
Asthma
Patients With Asthma 12 Years Of Age And Older
In two clinical studies comparing SYMBICORT with the
individual components, improvements in most efficacy end points were greater
with SYMBICORT than with the use of either budesonide or formoterol alone. In
addition, one clinical study showed similar results between SYMBICORT and the
concurrent use of budesonide and formoterol at corresponding doses from
separate inhalers.
The safety and efficacy of SYMBICORT were demonstrated in
two randomized, double-blind, placebo-controlled US clinical studies involving
1076 patients 12 years of age and older. Fixed SYMBICORT dosages of 160/9 mcg,
and 320/9 mcg twice daily (each dose administered as 2 inhalations of the
80/4.5 and 160/4.5 mcg strengths, respectively) were compared with the
monocomponents (budesonide and formoterol) and placebo to provide information
about appropriate dosing to cover a range of asthma severity.
Study 1: Clinical Study With SYMBICORT 160/4.5
This 12-week study evaluated 596 patients 12 years of age
and older by comparing SYMBICORT 160/4.5, the free combination of budesonide
160 mcg plus formoterol 4.5 mcg in separate inhalers, budesonide 160 mcg,
formoterol 4.5 mcg, and placebo; each administered as 2 inhalations twice
daily. The study included a 2-week run-in period with budesonide 80 mcg, 2
inhalations twice daily. Most patients had moderate to severe asthma and were
using moderate to high doses of inhaled corticosteroids prior to study entry.
Randomization was stratified by previous inhaled corticosteroid treatment
(71.6% on moderate-and 28.4% on high-dose inhaled corticosteroid). Mean percent
predicted FEV1 at baseline was 68.1% and was similar across treatment groups.
The co-primary efficacy end points were 12-hour-average post-dose FEV1 at week
2, and pre-dose FEV1 averaged over the course of the study. The study also
required that patients who satisfied a predefined asthma-worsening criterion be
withdrawn. The predefined asthma-worsening criteria were a clinically important
decrease in FEV1 or PEF, increase in rescue albuterol use, nighttime awakening
due to asthma, emergency intervention or hospitalization due to asthma, or
requirement for asthma medication not allowed by the protocol. For the
criterion of nighttime awakening due to asthma, patients were allowed to remain
in the study at the discretion of the investigator if none of the other
asthma-worsening criteria were met. The percentage of patients withdrawing due
to or meeting predefined criteria for worsening asthma is shown in Table 4.
Table 4 : The number and percentage of patients
withdrawing due to or meeting predefined criteria for worsening asthma (Study
1)
|
SYMBICORT 160/4.5
n = 124 |
Budesonide 160 mcg plus Formoterol 4.5 mcg
n = 115 |
Budesonide 160 mcg
n = 109 |
Formoterol 4.5 mcg
n = 123 |
Placebo
n = 125 |
Patients withdrawn due to predefined asthma event1 |
13 (10.5) |
13 (11.3) |
22 (20.2) |
44 (35.8) |
62 (49.6) |
Patients with a predefined asthma event1,2 |
37 (29.8) |
24 (20.9) |
48 (44.0) |
68 (55.3) |
84 (67.2) |
Decrease in FEV1 |
4 (3.2) |
8 (7.0) |
7 (6.4) |
15 (12.2) |
14 (11.2) |
Rescue medication use |
2 (1.6) |
0 |
3 (2.8) |
3 (2.4) |
7 (5.6) |
Decrease in AM PEF |
2 (1.6) |
5 (4.3) |
5 (4.6) |
17 (13.8) |
15 (12.0) |
Nighttime awakenings3 |
24 (19.4) |
11 (9.6) |
29 (26.6) |
32 (26.0) |
49 (39.2) |
Clinical exacerbation |
7 (5.6) |
6 (5.2) |
5 (4.6) |
17 (13.8) |
16 (12.8) |
1These criteria were assessed on a daily basis
irrespective of the timing of the clinic visit, with the exception of FEV1,
which was assessed at each clinic visit.
2Individual criteria are shown for patients meeting any predefined
asthma event, regardless of withdrawal status.
3For the criterion of nighttime awakening due to asthma, patients
were allowed to remain in the study at the discretion of the investigator if
none of the other criteria were met. |
Mean percent change from baseline in FEV1 measured
immediately prior to dosing (pre-dose) over 12 weeks is displayed in Figure 1.
Because this study used predefined withdrawal criteria for worsening asthma,
which caused a differential withdrawal rate in the treatment groups, pre-dose
FEV1 results at the last available study visit (end of treatment, EOT) are also
provided. Patients receiving SYMBICORT 160/4.5 had significantly greater mean
improvements from baseline in pre-dose FEV1 at the end of treatment (0.19 L,
9.4%), compared with budesonide 160 mcg (0.10 L, 4.9%), formoterol 4.5 mcg
(-0.12 L, -4.8%), and placebo (-0.17 L, -6.9%).
Figure 1 : Mean Percent Change From Baseline in
Pre-dose FEV1 Over 12 Weeks (Study 1)
The effect of SYMBICORT 160/4.5
two inhalations twice daily on selected secondary efficacy variables, including
morning and evening PEF, albuterol rescue use, and asthma symptoms over 24
hours on a 0-3 scale is shown in Table 5.
Table 5 : Mean values for
selected secondary efficacy variables (Study 1)
Efficacy Variable |
SYMBICORT 160/4.5
(n1=124) |
Budesonide 160 mcg plus Formoterol 4.5 mcg
(n1=115) |
Budesonide 160 mcg
(n1=109) |
Formoterol 4.5 mcg
(n1=123) |
Placebo
(n1=125) |
AM PEF (L/min) Baseline |
341 |
338 |
342 |
339 |
355 |
Change from Baseline |
35 |
28 |
9 |
-9 |
-18 |
PM PEF (L/min) Baseline |
351 |
348 |
357 |
354 |
369 |
Change from Baseline |
34 |
26 |
7 |
-7 |
-18 |
Albuterol rescue use Baseline |
2.1 |
2.3 |
2.7 |
.5 |
2.4 |
Change from Baseline |
-1.0 |
-1.5 |
-0.8 |
-0.3 |
0.8 |
Average symptom score/day (0-3 scale) Baseline |
0.99 |
1.03 |
1.04 |
1.04 |
1.08 |
Change from Baseline |
-0.28 |
-0.32 |
-0.14 |
-0.05 |
0.10 |
1 Number of patients (n)
varies slightly due to the number of patients for whom data were available for
each variable. Results shown are based on last available data for each
variable. |
The subjective impact of asthma
on patients' health-related quality of life was evaluated through the use of
the standardized Asthma Quality of Life Questionnaire (AQLQ(S)) (based on a
7-point scale where 1 = maximum impairment and 7 = no impairment). Patients
receiving SYMBICORT 160/4.5 had clinically meaningful improvement in overall
asthma-specific quality of life, as defined by a mean difference between
treatment groups of >0.5 points in change from baseline in overall AQLQ
score (difference in AQLQ score of 0.70 [95% CI 0.47, 0.93], compared to
placebo).
Study 2: Clinical Study With SYMBICORT
80/4.5
This 12-week study was similar
in design to Study 1, and included 480 patients 12 years of age and older. This
study compared SYMBICORT 80/4.5, budesonide 80 mcg, formoterol 4.5 mcg, and
placebo; each administered as 2 inhalations twice daily. The study included a
2-week placebo run-in period. Most patients had mild to moderate asthma and
were using low to moderate doses of inhaled corticosteroids prior to study entry.
Mean percent predicted FEV1 at baseline was 71.3% and was similar across
treatment groups. Efficacy variables and end points were identical to those in
Study 1.
The percentage of patients
withdrawing due to or meeting predefined criteria for worsening asthma is shown
in Table 6. The method of assessment and criteria used were identical to that
in Study 1.
Table 6 : The number and
percentage of patients withdrawing due to or meetingpredefined criteria for
worsening asthma (Study 2)
|
SYMBICORT 80/4.5
(n=123) |
Budesonide 80 mcg
(n=121) |
Formoterol 4.5 mcg
(n=114) |
Placebo
(n=122) |
Patients withdrawn due to predefined asthma event1 |
9 (7.3) |
8 (6.6) |
21 (18.4) |
40 (32.8) |
Patients with a predefined asthma event1,2 |
23 (18.7) |
26 (21.5) |
48 (42.1) |
69 (56.6) |
Decrease in FEV1 |
3 (2.4) |
3 (2.5) |
11 (9.6) |
9 (7.4) |
Rescue medication use |
1 (0.8) |
3 (2.5) |
1 (0.9) |
3 (2.5) |
Decrease in AM |
3 (2.4) |
1 (0.8) |
8 (7.0) |
14 (11.5) |
PEF Nighttime awakening3 |
17 (13.8) |
20 (16.5) |
31 (27.2) |
52 (42.6) |
Clinical exacerbation |
1 (0.8) |
3 (2.5) |
5 (4.4) |
20 (16.4) |
1 These criteria were assessed on a daily
basis irrespective of the timing of the clinic visit, with the exception of FEV1,
which was assessed at each clinic visit.
2 Individual criteria are shown for patients meeting any predefined
asthma event, regardless of withdrawal status.
3 For the criterion of nighttime awakening due to asthma, patients
were allowed to remain in the study at the discretion of the investigator if
none of the other criteria were met. |
Mean percent change from baseline in pre-dose FEV1 over 12 weeks is displayed in Figure 2.
Figure 2 : Mean Percent Change From Baseline in Pre-dose FEV1 Over 12 Weeks (Study 2)
Efficacy results for other secondary end points,
including quality of life, were similar to those observed in Study 1.
Onset And Duration Of Action And Progression Of Improvement
In Asthma Control
The onset of action and progression of improvement in
asthma control were evaluated in the two pivotal clinical studies. The median
time to onset of clinically significant bronchodilation (>15% improvement in
FEV1) was seen within 15 minutes. Maximum improvement in FEV1 occurred within 3
hours, and clinically significant improvement was maintained over 12 hours.
Figures 3 and 4 show the percent change from baseline in post-dose FEV1 over 12
hours on the day of randomization and on the last day of treatment for Study 1.
Reduction in asthma symptoms and in albuterol rescue use,
as well as improvement in morning and evening PEF, occurred within 1 day of the
first dose of SYMBICORT; improvement in these variables was maintained over the
12 weeks of therapy.
Following the initial dose of SYMBICORT, FEV1 improved
markedly during the first 2 weeks of treatment, continued to show improvement
at the Week 6 assessment, and was maintained through Week 12 for both studies.
No diminution in the 12-hour bronchodilator effect was
observed with either SYMBICORT 80/4.5 or SYMBICORT 160/4.5, as assessed by FEV1,
following 12 weeks of therapy or at the last available visit.
FEV1 data from Study 1 evaluating SYMBICORT 160/4.5 is displayed
in Figures 3 and 4.
Figure 3 : Mean Percent Change From Baseline in FEV1 on
Day of Randomization (Study 1)
Figure 4 : Mean Percent
Change From Baseline in FEV1 at End of Treatment (Study 1)
Patients With Asthma 6 To Less
Than 12 Years Of Age
The clinical program to support
the efficacy of SYMBICORT 80/4.5 in children 6 to less than 12 years of age
included the following: 1) a budesonide dose confirmatory study, 2) a
formoterol dose finding study, and 3) an efficacy and safety study of the
SYMBICORT combination product.
The selection of budesonide 80
mcg is supported by a 6-week, randomized, double-blind, placebo-controlled
study in 304 pediatric patients (152 budesonide, 152 placebo) 6 to less than 12
years of age with asthma. Results showed that budesonide 80 mcg (2 inhalations
twice daily) provided statistically significantly greater improvement compared
to placebo for the primary endpoint of change from baseline to the treatment
period average in pre-dose morning PEF and the key secondary endpoint of change
in pre-dose morning FEV1. The selection of the formoterol dose is supported by
a randomized, single dose, placebo-controlled, active-controlled (Foradil
Aerolizer 12 mcg), 5-way cross-over study in which doses of 2.25, 4.5 and 9 mcg
formoterol were administered in combination with budesonide in 54 pediatric
patients 6 to less than 12 years of age with asthma. Results showed a dose
response of formoterol compared to placebo for the primary endpoint of FEV1 averaged
over 12 hours post-dose and the 9 mcg group showed numerically similar results
compared to the active control.
The confirmatory efficacy study
was a 12-week, randomized, double-blind, multicenter study in which SYMBICORT
80/4.5 was compared with budesonide pMDI 80 mcg, each administered as 2
inhalations twice daily, in 184 pediatric patients 6 to less than 12 years of
age with a documented clinical diagnosis of asthma. At trial entry, the
children had a requirement for daily medium-dose range inhaled corticosteroid
therapy or fixed combination of inhaled corticosteroid and LABA therapy, and
exhibited symptoms despite treatment with a low-dose inhaled corticosteroid
during a 2 to 4 week run-in period. The primary efficacy variable was change
from baseline to Week 12 in clinic-measured 1-hour post-dose FEV1. In patients
receiving SYMBICORT 80/4.5, there was a statistically significant change
compared to budesonide in 1-hour post-dose FEV1 which improved by 0.28 L from
baseline to Week 12, as compared with 0.17 L for those receiving budesonide 80
mcg (mean difference 0.12 L; 95% CI: 0.03, 0.20) (see Figure 5).
Figure 5 : Change From Baseline in Clinic-Measured
1-hour Post-dose FEV1 over 12 Weeks (Efficacy and Safety Study in Patients 6 to
less than 12 years of age).
Similarly, improvement was
noted in change from baseline to Week 12 for 1-hour post-dose clinic PEF (mean
difference 25.5 L/min; 95% CI: 10.9, 40.0). Bronchodilatory effects were
evident from the first assessment at 15 minutes on day 1 and were maintained at
Week 12. The estimated mean difference between SYMBICORT 80/4.5 and budesonide
with respect to change from baseline to Week 12 in 15 minutes post-dose clinic
FEV1 was 0.10 L (95% CI: 0.02, 0.18). No differences between SYMBICORT and
budesonide were noted in nighttime awakenings, rescue albuterol use, or
Pediatric Asthma Quality of Life Questionnaire (PAQLQ) scores. The proportion
of patients with at least 0.5 points improvement from baseline to Week 12 in
PAQLQ was 42% on SYMBICORT 80/4.5 and 46% on budesonide 80 mcg.
Postmarketing Safety And Efficacy Study
A randomized, double-blind, parallel-group, safety study
compared SYMBICORT with budesonide, each administered as 2 inhalations twice
daily over 26 weeks (NCT01444430). The primary safety objective was to evaluate
whether the addition of formoterol to budesonide therapy (SYMBICORT) was
non-inferior to budesonide in terms of the risk of serious asthma-related
events (asthma-related hospitalization, endotracheal intubation, and death).
The study was designed to rule out a pre-defined risk margin of serious
asthma-related events of 2.0. A blinded adjudication committee determined
whether events were asthma-related.
This study enrolled patients who were 12 years of age and
older, had a clinical diagnosis of asthma for at least 1 year, and had at least
1 asthma exacerbation requiring treatment with systemic corticosteroids or an
asthma-related hospitalization in the previous year. Patients were stratified
to one of the two dose levels of SYMBICORT or budesonide based on assessment of
asthma control and ongoing asthma therapy. Patients with a history of
life-threatening asthma were excluded. The study included 11,693 patients [5846
receiving SYMBICORT (80/4.5 or 160/4.5) and 5847 receiving budesonide (80 or
160 mcg)], whose mean age was 44 years, and of whom 66% were female and 69%
were Caucasian.
SYMBICORT was non-inferior to budesonide in terms of time
to first serious asthma-related events based on the pre-specified risk margin,
with an estimated hazard ratio of 1.07 [95% CI: 0.70, 1.65] (Table 7).
Table 7 : Serious Asthma-Related Events (Postmarketing
Safety and Efficacy study)
|
SYMBICORT
(N1 =5846) n2 (%) |
Budesonide
(N1 =5847) n2 (%) |
SYMBICORT vs. Budesonide Hazard ratio (95% CI)3 |
Serious asthma-related event4 |
43 (0.7) |
40 (0.7) |
1.07 (0.70, 1.65) |
Asthma-related death |
2 (<0.1) |
0 |
|
Asthma-related endotracheal intubation |
1 (<0.1) |
0 |
|
Asthma-related hospitalization |
42 (0.7) |
40 (0.7) |
|
1N = total number of patients
2n = number of patients with the event
3The hazard ratio for time to first event was based on a
non-stratified Cox proportional hazard model with covariates of treatment
(SYMBICORT vs. budesonide) and inhaled corticosteroid dose level (160 mcg vs.
80 mcg), as randomized. If the resulting upper 95% CI estimate for the relative
risk was < 2.0, then non-inferiority was concluded.
4Asthma-related hospitalization, endotracheal intubation, or death
that occurred within 6 months after the first use of study drug or 7 days after
the last date of study drug, whichever date was later. Patients can have one or
more events, but only the first event was counted for analysis. A single,
blinded, independent adjudication committee determined whether events were
asthma-related. |
The primary efficacy endpoint
was asthma exacerbations, defined as a deterioration of asthma that led to use
of systemic corticosteroids for at least 3 days, or a hospitalization, or an
emergency room visit that required systemic corticosteroids. The estimated
hazard ratio for time to first asthma exacerbation rate for SYMBICORT relative
to budesonide was 0.84 [95% CI: 0.75, 0.94]. This outcome was primarily driven
by a reduction in systemic corticosteroid use.
Chronic Obstructive Pulmonary Disease
Lung Function
The efficacy of SYMBICORT 80/4.5 and SYMBICORT 160/4.5 in
the maintenance treatment of airflow obstruction in COPD patients was evaluated
in two randomized, double-blind, placebo-controlled multinational studies,
conducted over 6 months (Study 1) and 12 months (Study 2), in a total of 3668
patients (2416 males and 1252 females). The majority of patients (93%) were
Caucasian. All patients were required to be at least 40 years of age, with a
FEV1 of less than or equal to 50% predicted, a clinical diagnosis of COPD with
symptoms for at least 2 years, and a smoking history of at least 10 pack years,
prior to entering the trial. The mean prebronchodilator FEV1 at baseline of the
patients enrolled in the study was 34% predicted. Forty-eight percent of the
patients enrolled were on inhaled corticosteroids and 52.7% of patients were on
short-acting anticholinergic bronchodilators during run-in. On randomization,
inhaled corticosteroids were discontinued, and ipratropium bromide was allowed
at a stable dose for those patients previously treated with short-acting
anticholinergic bronchodilators. The co-primary efficacy variables in both
studies were the change from baseline in average pre-dose and 1-hour post-dose
FEV1 over the treatment period. The results of both studies 1 and 2 are
described below.
Study 1
This was a 6-month, placebo-controlled study of 1704 COPD
patients (mean % predicted FEV1 at baseline ranging from 33.5% -34.7%)
conducted to demonstrate the efficacy and safety of SYMBICORT in the treatment
of airflow obstruction in COPD. The patients were randomized to one of the
following treatment groups: SYMBICORT 160/4.5 (n=277), SYMBICORT 80/4.5
(n=281), budesonide 160 mcg + formoterol 4.5 mcg (n=287), budesonide 160 mcg
(n=275), formoterol 4.5 mcg (n=284), or placebo (n=300). Patients receiving
SYMBICORT 160/4.5, two inhalations twice daily, had significantly greater mean
improvements from baseline in pre-dose FEV1 averaged over the treatment period
[0.08 L, 10.7%] compared with formoterol 4.5 mcg [0.04 L, 6.9%] and placebo
[0.01 L, 2.2%] (see Figure 6). Patients receiving SYMBICORT 80/4.5, two
inhalations twice daily, did not have significantly greater improvement from
baseline in the pre-dose FEV1 averaged over the treatment period compared with
formoterol 4.5 mcg.
Figure 6 : Mean Percent
Change From Baseline in Pre-dose FEV1 over 6 Months (Study 1)
Patients receiving SYMBICORT
160/4.5, two inhalations twice daily, had significantly greater mean
improvements from baseline in 1-hour post-dose FEV1 averaged over the treatment
period [0.20 L, 22.6%], compared with budesonide 160 mcg [0.03 L, 4.9%] and
placebo [0.03 L, 4.1%] (see Figure 7).
Figure 7 : Mean Percent
Change From Baseline in 1-hour Post-dose FEV1 Over 6 months (Study 1)
Study 2
This was a 12-month,
placebo-controlled study of 1964 COPD patients (mean % predicted FEV1 at
baseline ranging from 33.7% -35.5%) conducted to demonstrate the efficacy and
safety of SYMBICORT in the treatment of airflow obstruction in COPD. The
patients were randomized to one of the following treatment groups: SYMBICORT
160/4.5 (n=494), SYMBICORT 80/4.5 (n=494), formoterol 4.5 mcg (n=495), or
placebo (n=481). Patients receiving SYMBICORT 160/4.5, two inhalations twice
daily, had significantly greater improvements from baseline in mean pre-dose
FEV1 averaged over the treatment period [0.10 L, 10.8%] compared with
formoterol 4.5 mcg [0.06 L, 7.2%] and placebo [0.01 L, 2.8%]. Patients
receiving SYMBICORT 80/4.5, two inhalations twice daily, did not have
significantly greater improvements from baseline in the mean pre-dose FEV1 averaged
over the treatment period compared to formoterol. Patients receiving SYMBICORT
160/4.5, two inhalations twice daily, also had significantly greater mean
improvements from baseline in 1-hour post-dose FEV1 averaged over the treatment
period [0.21 L, 24.0%] compared with placebo [0.02 L, 5.2%].
Serial FEV1 measures over 12
hours were obtained in a subset of patients in Study 1 (n=99) and Study 2
(n=121). The median time to onset of bronchodilation, defined as an FEV1 increase
of 15% or greater from baseline, occurred at 5 minutes post-dose. Maximum
improvement (calculated as the average change from baseline at each timepoint)
in FEV1 occurred at approximately 2 hours post-dose.
In both Studies 1 and 2,
improvements in secondary endpoints of morning and evening peak expiratory flow
and reduction in rescue medication use were supportive of the efficacy of
SYMBICORT 160/4.5.
Exacerbations
Studies 3 and 4 were primarily designed to evaluate the
effect of SYMBICORT 160/4.5 on COPD exacerbations.
Study 3
This was a 6-month, active-control study conducted to
evaluate the effect of SYMBICORT 160/4.5 compared to formoterol 4.5 mcg, each
administered as 2 inhalations twice daily, on the rate of moderate and severe
COPD exacerbations. COPD exacerbations were defined as worsening of 2 or more
major symptoms (dyspnea, sputum volume, sputum color/purulence) or worsening of
any 1 major symptom together with at least 1 of the minor symptoms: sore
throat, colds (nasal discharge and/or nasal congestion), fever without other
cause, increased cough or increased wheeze for at least 2 consecutive days.
COPD exacerbations were considered of moderate severity if treatment of
symptoms with systemic corticosteroids (≥3 days) and/or antibiotics were
required, and were considered severe if hospitalization was required. The study
randomized 1219 subjects to SYMBICORT 160/4.5 (606) and formoterol 4.5 mcg
(613) of which 57% were male and 92% were Caucasian. They had a mean age of 64
years and a median smoking history of 39 pack years, with 46% identified as
current smokers. At run-in, the mean post-bronchodilator % predicted normal FEV1
was 48.7% (range: 16.0% to 78.1%), and patients had a history of at least 1
COPD exacerbation in the previous year treated with systemic corticosteroids
and/or hospitalization. All subjects were treated with SYMBICORT 160/4.5, two
inhalations twice daily during a 4-week run-in period prior to being assigned
trial treatment.
Study 4
This was a 12-month, active-control study which included
811 subjects treated with SYMBICORT 160/4.5 or formoterol 4.5 mcg, each
administered as 2 inhalations twice daily. The study was conducted to evaluate
for COPD exacerbation reduction in patients with COPD. COPD exacerbations were
defined as worsening of COPD that required a course of oral steroids for
treatment and/or hospitalization. This study randomized 407 subjects to
SYMBICORT 160/4.5 and 404 to formoterol 4.5 mcg of which 61% were male and 83%
were Caucasian. They had a mean age of 63 years and a median smoking history of
45 pack years, with 36% identified as current smokers. At run-in, the mean
post-bronchodilator % predicted normal FEV1 was 37.8% (range: 11.75% to
76.50%), and a history of at least 1 COPD exacerbation in the previous year
treated with systemic corticosteroids and/or antibiotics.
In Study 3, subjects treated with SYMBICORT 160/4.5, two
inhalations twice daily had a significantly lower annual rate of
moderate/severe COPD exacerbations compared with formoterol 4.5 mcg with a
reduction of 26% (95% CI: 9%, 39%). In Study 4, a significantly lower annual
rate of exacerbations was also observed in subjects treated with SYMBICORT
160/4.5 compared with formoterol 4.5 mcg with a reduction of 35% (95% CI: 20%,
47%) (Table 8).
Table 8 : Chronic Obstructive Pulmonary Disease
Exacerbations
Treatment |
n |
Annual Rate Estimate |
Rate ratio Symbicort 160/4.5 vs. Formoterol 4.5 mcg |
Estimate |
95% CI |
Study 3 |
SYMBICORT 160/4.5 |
606 |
0.94 |
0.74 |
0.61, 0.91 |
Formoterol 4.5 mcg |
613 |
1.27 |
|
|
Study 4 |
SYMBICORT 160/4.5 |
404 |
0.68 |
0.65 |
0.53, 0.80 |
Formoterol 4.5 mcg |
403 |
1.05 |
|
|
n – Number of patients included
in efficacy analysis set. |
Health-related quality of life
was measured using the St. George's Respiratory Questionnaire (SGRQ) in both
COPD exacerbation clinical studies.
In Study 3, the SGRQ responder
rates at 6-months (defined as an improvement in score of 4 or more as a
threshold) were 40% and 33% for SYMBICORT 160/4.5 and formoterol 4.5 mcg,
respectively, with an odds ratio of 1.5 (95% CI: 1.0, 2.0) for SYMBICORT
160/4.5 vs. formoterol 4.5 mcg. In Study 4, the responder rates at 12-months
were 50% and 49% for SYMBICORT 160/4.5 and formoterol 4.5 mcg, respectively,
with an odds ratio of 1.0 (95% CI: 0.8, 1,4) for SYMBICORT 160/4.5 vs.
formoterol 4.5 mcg.