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BRONCHIAL THERMOPLASTY
CLINICAL and PROCEDURE SUMMARY REFERENCE
CLINICAL SUMMARY
FDA indication:
The Alair® Bronchial Thermoplasty System is indicated for the treatment of severe persistent
asthma in patients 18 years and older whose asthma is not well controlled with inhaled
corticosteroids and long-acting beta agonists.
Bronchial thermoplasty is not intended to be performed on asthma patients with a known
sensitivity to lidocaine, atropine, or benzodiazepines, those with a pacemaker, implanted
cardioverter defibrillator, or other implanted electronic devices, or those who have previously
been treated with the Alair System.
Procedure Description:
Bronchial thermoplasty is delivered through the working channel of a standard flexible
bronchoscope and involves the controlled application of radiofrequency energy to target
airways. Thermal energy delivered in this manner has been demonstrated to reduce the amount
of airway smooth muscle (ASM) in the airway. Although inflammation of the airways is a
hallmark of asthma, it is contraction of the ASM that is the main cause of airway constriction that
leads to difficulty breathing during asthma attacks. Bronchial thermoplasty reduces ASM in
those bronchial segments where 80% of the total airway resistance occurs. The majority of
patients with asthma can control their symptoms with drugs and stimulus avoidance. However, a
small percentage – estimated 5-10% – of patients with asthma have severe disease that does
not respond sufficiently to asthma medications, including a combination of inhaled
corticosteroids, long-acting beta2-agonists, and sometimes oral corticosteroids. These patients
experience poor quality of life and account for a substantial portion of the overall economic
burden of asthma given frequent physician office visits, emergency room encounters,
hospitalizations, and lost time from work.
Clinical Efficacy:
Bronchial thermoplasty has been studied in five clinical studies, three of which were randomized
controlled clinical trials and the results for which have been published in peer-reviewed journals.
The pre-clinical work in canines confirmed the persistent reduction in ASM out to 3 years; the
three randomized controlled trials each demonstrated improvements in various aspects of
asthma control as follows:
The Asthma Intervention Research 2 (AIR2) Trial, published in the American Journal of
Respiratory and Critical Care Medicine, January 2010, studied patients on high doses of ICS
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BRONCHIAL THERMOPLASTY
CLINICAL and PROCEDURE SUMMARY REFERENCE
and LABA and determined, compared to sham bronchoscopy, bronchial thermoplasty resulted
in improved Asthma Quality of Life and the following clinically meaningful benefits out to one
year following treatment:
• 32% reduction in severe exacerbations requiring systemic steroids
• 84% reduction in emergency department visits for respiratory symptoms
• 66% reduction in days lost from work, school or other daily activities due to asthma
symptoms
• 36% reduction in proportion of patients reporting asthma (multiple symptoms) adverse
events
Long-Term Persistence of Effect (5 years)
The benefits of bronchial thermoplasty have been shown to persist out to at least 5 years
following the procedure. The significant reduction (compared to the Sham group) in percent of
subjects with severe exacerbations that were seen in the first year after bronchial thermoplasty
were also maintained over the second, third, fourth, and fifth years of follow-up.
Over the 5 years of follow-up, the AIR2 extension study has demonstrated:
• Maintained reduction in proportion of subjects having severe exacerbations (Years 15 post BT are consistent with each other);
• Maintained reduction in the rates of severe exacerbations;
• Maintained reduction in proportions subjects having emergency room visits for
respiratory symptoms;
• Maintained reduction in the rates of emergency room visits for respiratory symptoms;
The results of the Asthma Intervention Research (AIR) Trial were published in the New England
Journal of Medicine in March 2007 and demonstrated that compared to a control group
receiving standard-of-care medications, there was a:
• 50% decrease in asthma exacerbations;
• 2.6 fold increase in days with no asthma symptoms;
• 45% reduction in rescue medication use;
• Statistically significant improvement in asthma control and Asthma Quality of Life, as
measured respectively by the validated ACQ and AQLQ scores.
The Research in Severe Asthma (RISA) Trial was a smaller study, also published in the
American Journal of Respiratory and Critical Care Medicine, in December 2007, and studied the
safety of bronchial thermoplasty in symptomatic, severe, refractory asthma patients and the
ability to reduce oral steroid use in these patients. More bronchial thermoplasty treated patients
were able to completely wean off of these medications compared to controls.
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BRONCHIAL THERMOPLASTY
CLINICAL and PROCEDURE SUMMARY REFERENCE
Clinical Safety:
The most common side effect found in these studies of bronchial thermoplasty was an expected
transient increase in the frequency and worsening of respiratory-related symptoms, including
asthma (multiple symptoms), respiratory tract infections, wheezing, dyspnea, and chest pain.
Long-term follow-up out to 5 years has been completed in 4 studies: the Feasibility Study, the
AIR Extension Study, the RISA Extension Study, and the AIR2 Extension Study. Data from each
of these studies have shown no safety signal of concern. The safety profile for the BT treated
patients has demonstrated consistency over time based on the percent of subjects reporting
respiratory adverse events, the number of respiratory adverse events per subject, and the
number of hospitalizations and emergency room visits due to respiratory symptoms per subject.
Over the 5 years of follow-up in the Feasibility Study, AIR Extension, RISA Extension, and AIR2
Extension studies there has been an absence of any late clinical complications (specifically
respiratory events) and a stable adverse event profile has been established based on ER visits
and hospitalizations for respiratory symptoms, and maintenance of stable lung function (FEV1).
An assessment of HRCT scans in the Feasibility study (annually out to 5 years) and the AIR2
Extension Study (Years 1, 3 and 5 after BT) showed no structural changes that were of clinical
significance, again demonstrating the long-term safety7 of BT.
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BRONCHIAL THERMOPLASTY
CLINICAL and PROCEDURE SUMMARY REFERENCE
References:
1. Wechsler ME, et al., Bronchial Thermoplasty: Long-Term Safety and Effectiveness in
Patients with Severe Persistent Asthma. J Allergy Clin Immunol. 2013 Dec;132(6):12951302.e3. doi: 10.1016/j.jaci.2013.08.009. Epub 2013 Aug 30.
http://www.jacionline.org/article/S0091-6749(13)01268-2/fulltext
2. Pavord ID, et al; Safety of Bronchial Thermoplasty in Patients with Severe Refractory
Asthma. Ann Allergy Asthma Immunol. 2013 Nov;111(5):402-7. doi:
10.1016/j.anai.2013.05.002. Epub 2013 Jun 13. http://digitalreprints.elsevier.com/t/66735
3. Thomson N, et al. Long-term (5 year) safety of bronchial thermoplasty: Asthma Intervention
Research (AIR) Trial. BMC Pulmonary Medicine 2011, 11:8.
www.biomedcentral.com/content/pdf/1471-2466-11-8.pdf
4.
Castro M, et al. Persistence of Effectiveness of Bronchial Thermoplasty in Patients with
Severe Asthma. Annals of Allergy, Asthma & Immunology, 2011 Jul;107(1):65-70.
http://www.cenveomobile.com/issue/35148
5. Castro M, et al. Effectiveness and Safety of Bronchial Thermoplasty in the Treatment of
Severe Asthma: A Multicenter, Randomized, Double-Blind, Sham-Controlled Clinical Trial.
American Journal of Respiratory & Critical Care Medicine 2010;181: 116-124.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3269231/pdf/AJRCCM1812116.pdf
6. Cox G, et al. Asthma Control During the Year After Bronchial Thermoplasty. New England
Journal of Medicine 2007; 356: 1327-37.
http://www.nejm.org/doi/pdf/10.1056/NEJMoa064707
7. Mayse ML, et al. Clinical pearls for bronchial thermoplasty. Journal of Bronchology 2007; 14:
115–123. http://eorder.sheridan.com/3_0/display/index.php?flashprint=635
8. Pavord I, et al. Safety and Efficacy of Bronchial Thermoplasty in Symptomatic Severe
Asthma. American Journal of Respiratory & Critical Care Medicine 2007; 176: 1185-1191.
http://www.atsjournals.org/doi/pdf/10.1164/rccm.200704-571OC
9.
Wilson SR, Cox G, Miller JD, and Lam S. Global assessment after bronchial thermoplasty:
the patient’s perspective. Journal of Outcomes Research 2007; 10: 37-46.
10. Cox G, et.al. Bronchial thermoplasty for asthma. American Journal of Respiratory & Critical
Care Medicine. 2006;173(9):965-969.
http://www.atsjournals.org/doi/pdf/10.1164/rccm.200507-1162OC
11. Danek, CJ, et al. Reduction in airway hyperresponsiveness to methacholine by the
application of RF energy in dogs. Journal of Applied Physiology 2004; 97: 1946-1953.
http://jap.physiology.org/content/97/5/1946.full.pdf+html
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BRONCHIAL THERMOPLASTY
CLINICAL and PROCEDURE SUMMARY REFERENCE
GENERAL PROCEDURE DESCRIPTION:
During bronchial thermoplasty, the physician introduces a standard flexible bronchoscope through a
patient’s nose or mouth, and into airways of the lung. The small diameter catheter is delivered into
the airways through the working channel of the bronchoscope, and the tip of the catheter is
expanded to contact the walls of targeted airways. The four arms of the expanded catheter array
come in contact with and fit snugly against the airway wall. The expanded array then delivers
controlled thermal energy for a maximum of 10 seconds to heat the airway smooth muscle. A
contiguous series of thermal energy applications are needed to treat along the length of the larger
conducting airways that are accessible with a bronchoscope. Once the treatment session is
completed, the device and the bronchoscope are removed. The treatment is performed in 3
separate procedures covering different regions of the lung, each scheduled about three weeks
apart. The right lower lobe is treated during the first bronchoscopy, the left lower lobe is treated
during the second bronchoscopy, and both the right and left upper lobes are treated during the third
bronchoscopy (as described below).
SPECIFIC PROCEDURE DESCRIPTIONS
Procedure Description - Lower Lobes:
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Patient is prepared for vital sign monitoring and supplemental oxygen provided if warranted.
Patient is administered prophylactic prednisone.
Patient is administered albuterol 30 minutes before the start of the procedure.
A drying agent is administered to prepare the airways for the procedure.
A standard patient return electrode is affixed to the patient to provide a complete circuit for the
ablation procedure.
Sedation is administered.
A standard flexible bronchoscope is inserted through the [mouth/nose] for access to the lung.
A detailed inspection of the targeted lobe of the lung is performed to plan the application of
bronchial thermoplasty and ensure that the entire length of each and every accessible bronchial
tube in the targeted lobe is treated. [For the Left Lower lobe treatment, a detailed inspection of the
previously treated Right Lower lobe is performed to confirm healing.]
A small radiofrequency catheter with an expandable electrode array is advanced through the
accessory channel of a standard bronchoscope and positioned under direct bronchoscopic
visualization into the first treatment area of the targeted lobe(s).
The electrode array is then expanded and held in contact with the bronchial wall for approximately
10 seconds while the radio-frequency controller delivers energy with foot pedal activation to the
location.
The bronchoscope and catheter are repositioned systematically approximately [55] times such that
the electrode array is brought into contact with the entire length of each and every accessible
bronchial tube in the targeted lobe. Mucus-filled airways often necessitate periodic cleaning of the
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BRONCHIAL THERMOPLASTY
CLINICAL and PROCEDURE SUMMARY REFERENCE
catheter with a saline rinse. A consistent and thorough thermal treatment is delivered throughout
the targeted lung region.
 Re-administration of sedation medication is often required to keep the patient comfortable for the
entire procedure (approximately 45 minutes with the bronchoscope in the lung).
 The patient is followed in the recovery room until lung function returns to pre-procedure baseline.
This often takes up to 4 hours.
Procedure Description - Upper Lobes:
 Patient is prepared for vital sign monitoring and supplemental oxygen as is typical for
bronchoscopy.
 Patient is administered prophylactic prednisone.
 Patient is administered albuterol 30 minutes before the start of the procedure.
 A drying agent is administered to prepare the airways for the procedure.
 A standard patient return electrode is affixed to the patient to provide a complete circuit for the
ablation procedure.
 Sedation is administered.
 A standard flexible bronchoscope is inserted through the [mouth/nose] for access to the lung.
 A detailed inspection of the previously treated Right and Left Lower lobes is performed to confirm
sufficient healing.
 A detailed inspection of the targeted lobes of the lung is performed to plan the application of
bronchial thermoplasty and ensure that the entire length of each and every accessible bronchial
tube in the targeted lobes is treated. A small radiofrequency catheter with an expandable electrode
array is advanced through the accessory channel of a standard bronchoscope and positioned under
direct bronchoscopic visualization into the first treatment area of the targeted lobes.
 The electrode array is then expanded and held in contact with the bronchial wall for approximately
10 seconds while the radio-frequency controller delivers energy via foot pedal activation to the
location.
 The bronchoscope and catheter are repositioned systematically approximately [75] times such that
the electrode array is brought into contact with the entire length of each and every accessible
bronchial tube in the targeted lobes. Mucus-filled airways often necessitate periodic cleaning of the
catheter with a saline rinse. A consistent and thorough thermal treatment is delivered throughout
the targeted lung regions.
 Re-administration of sedation medication is often required to keep the patient comfortable for the
entire procedure (approximately 1 hour with the bronchoscope in the lung).
 The patient is followed in the recovery room until lung function returns to pre-procedure baseline.
This often takes up to 4 hours.
Brief Statement of Relevant Indications for Use, Contraindications, Warnings, and Adverse Events: The Alair® Bronchial
Thermoplasty System is indicated for the treatment of severe persistent asthma in patients 18 years and older whose asthma is not well
controlled with inhaled corticosteroids and long acting beta agonists. The Alair® System is not for use in patients with an active
implantable electronic device or known sensitivity to medications used in bronchoscopy. Previously treated airways of the lung should not
be retreated with the Alair® System. Patients should be stable and suitable to undergo bronchoscopy. The most common side effect of
bronchial thermoplasty is an expected transient increase in the frequency and worsening of respiratory-related symptoms.
10-068 Rev D/ MVG17080
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All rights reserved.