Lindsay Shaw

Completed Research Studies


At our center, we participate in different types of research. Therapy related trials involve testing how well a therapy works, or may involve using an existing therapy in a new way. This might include medications, vitamins, physiotherapy techniques etc. Non therapy related studies are often involving basic research (for example on bacteria or antibiotic sensitivity). We also conduct observational trials which would involve surveys and questionnaires.

Our clinic has been involved with many studies over the years. Click below to learn more about each study.

You can refresh your memory about research terminology here before reading on.

Therapy Related Trials

Pilot Study of the in Vivo Efficacy of Tobramycin Inhalation Powder (TIP) in Cystic Fibrosis Patients Infected With Burkholderia Cepacia Complex

Click here for the link to the site for more information about this study. A link to the publication will be posted here when avaialble.

Ivacaftor/Tezacaftor Phase 2 Trial (VX 661-101 Study)

The Vertex 661-101 study was a Phase 2 clinical Trial looking at VX-661(tezacaftor) and VX-770 (ivacaftor) in CF patients. VX-661 is being studied to see if alone or in combination with ivacaftor it can help decrease some of the effects caused by CF. The study was designed to learn more about the safety and efficacy of VX-661 when given alone and in combination with ivacaftor to subjects with CF. It also looked at how VX-661 and ivacaftor may affect the body and how the body breaks down and eliminates the drugs.


Orkambi (lumacaftor/ivacaftor) Phase 3 Trial (VX 809-103 Study) and Open label extension (VX809-105)

The Vertex 809-103 study was a phase 3 clinical trial looking at a new compound developed by Vertex called lumacaftor (VX-809) in combination with Ivacaftor to target the underlying defect that causes CF by modifying protein function and enhancing ion transport. This drug is now approved by Heath Canada for people with two copies of the F508del CF mutation. The phase 3 study results are available on

Click on the following links to read the abstracts:

Efficacy and safety of lumacaftor/ivacaftor combination therapy in patients with cystic fibrosis homozygous for Phe508del CFTR by pulmonary function subgroup: a pooled analysis. 

Lumacaftor-Ivacaftor in Patients with Cystic Fibrosis Homozygous for Phe508del CFTR.


G551D Observational Study in Patients Taking Ivacaftor

Recently, a new drug (ivacaftor – formerly known as VX-770) was developed to treat people with CF that have the G551D mutation. Ivacaftor is designed to help by unlocking the CFTR protein door to improve the flow of salt and fluids in and out of the cells. Although we know that ivacaftor leads to improvement in lung function and nutrition, we do not know how this improvement occurs. Further, we don’t understand why the response to this drug varies among different people. We are doing this research study to test certain clinical and biological parameters before and after people with CF and the G551D mutation start treatment with ivacaftor. If you are started on ivacaftor by your CF doctor, you will also be asked if you would be interested in participating in this study. 

Impact of CFTR Modulation on Intestinal pH, Motility, and Clinical Outcomes in Patients With Cystic Fibrosis and the G551D Mutation

Click here for full abstract


Effect of pulmonary exacerbations on long-term lung function decline in cystic fibrosis

This study is examining pulmonary exacerbations (basically flare-ups of your lung disease) and how this may impact the rate of change in your lung function. The researchers want to see how exacerbations requiring hospitalizations may be affecting the rate at which your lung function declines. They studied over 800 patients and found that just over half of the lung function decline seen in patients could be attributed to their hospitalizations.

Click for full abstract


Cholecalciferol significantly increases 25-hydroxyvitamin D concentration in adults with cystic fibrosis

What does this mean? The purpose of this study was to determine the prevalence (how many people have a certain disease) of patients with cystic fibrosis that are vitamin D deficient (not receiving enough vitamin D). This study measured the levels of vitamin D in 360 patients and determined that 69% were deficient.  The lowest levels of vitamin D were found in patients with lower BMI (body mass index) and lower lung function. After administering cholecalciferol, (vitamin D3, an inactive form of vitamin D), Vitamin D levels increased significantly in 92% of patients.

Click for full abstract

Non Therapy Related Trials


Infection with Burkholderia cepacia in Cystic Fibrosis Outcome Following Lung Transplantation

What does this mean? Patients who chronically grow Burkholderia cepacia complex in their sputum samples were studied to determine their outcome after lung transplantation. The article discusses outcome and implications for future treatment for these patients.

Click for full abstract

Exacerbation frequency and clinical outcomes in adult patients with cystic fibrosis

What does this mean? This study is also examining how pulmonary exacerbations (flare-ups of your lung disease) affects the rate of decline in lung function as well as the time to various clinical outcomes including lung transplant. Researchers examined 446 adult cystic fibrosis patients from Ontario to determine results. It was found that having more than 2 exacerbations per year put one at increased risk of a 5% decline in lung function (FEV1)

Click for full abstract

Randomized controlled trial of biofilm antimicrobial susceptibility testing in cystic fibrosis patients.

This study aimed to determine whether antimicrobial susceptibility testing of Pseudomonas aeruginosa grown as a biofilm, rather than planktonically, improves efficacy of antibiotic treatment for pulmonary exacerbations. This was a multicenter randomized, double-blind controlled trial of 14 days of intravenous antibiotic treatment for pulmonary exacerbations chosen based on conventional vs. biofilm antimicrobial susceptibility results in CF patients with chronic P. aeruginosa infection. There were 74 exacerbations in 39 patients. A total of 46% (12/26) exacerbations in the conventional group compared to 40% (19/48) exacerbations in the biofilm group achieved a ≥3 log drop in P. aeruginosa sputum density (difference -0.03, 95% CI -0.5 to 0.4, p=0.9). Lung function improvements were similar in both groups. Biofilm antimicrobial susceptibility testing did not lead to improved microbiological or clinical outcomes compared to conventional methods in the treatment of pulmonary exacerbations in CF patients with chronic P. aeruginosa. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Click for more information


Stenotrophomonas maltophilia and cystic fibrosis - serologic response and effect on lung disease 

Rationale: Stenotrophomonas maltophilia is one of the more common multidrug-resistant organisms isolated from the respiratory tract of patients with cystic fibrosis (CF), but the effect of chronic S. maltophilia infection on CF lung disease is unknown. Objectives: To determine the impact of chronic S. maltophilia infection on lung disease in CF. Methods: We developed a serologic assay specific for S. maltophilia and in a cross-sectional study, measured serum antibodies to S. maltophilia in patients with CF to determine if a definition of chronic S. maltophilia isolation based on culture results corresponded to an immunologic response (serologic study). We then used this validated definition to examine the effect of chronic S. maltophilia on the severity of lung disease in a retrospective cohort study using the Toronto CF Database from 1997–2008 (cohort study). Measurements and Main Results: Serum antibody levels to S. maltophilia were measured in 179 patients with CF. Patients with chronic S. maltophilia had significantly higher mean antibody levels to S. maltophilia flagellin (P , 0.0001) and whole cell (P 5 0.0004) compared with patients with intermittent or no S. maltophilia. The cohort study included 692 patients with an average follow-up of 8.3 years. In an adjusted log linear model, patients with chronic S. maltophilia infection had a significantly increased risk of pulmonary exacerbation requiring hospitalization and antibiotics compared with patients who had never had S. maltophilia (relative risk 5 1.63; P 5 0.0002). Conclusions: Chronic S. maltophilia infection in patients with CF is associated with a specific immune response to this organism and is an independent risk factor for pulmonary exacerbations. Keywords: cystic fibrosis; Stenotrophomonas maltophilia; antibodies; lung function; pulmonary exacerbation 

Click here for the abstract

Click here for the study registration information

Assessing the impact of polymicrobial pulmonary infections in CF and bronchiectasis via metagenomics

The metagenome study has been ongoing since 2010. For this study, patients are asked to provide additional sputum samples at clinic visits so that a research lab can identify genetic variants of bacteria and other microorganisms in CF patients.

Below are the links to the abstracts of related articles:
1. Lung microbiota across age and disease state in cystic fibrosis
2. Phenotypic diversity within a Pseudomonas aeruginosa population infecting an adult with cystic fibrosis
3. Global analysis of the fungal microbiome in cystic fibrosis patients reveals loss of function of the transcriptional repressor Nrg1 as a mechanism of pathogen adaptation
4. Selective sweeps and parallel pathoadaptation drive Pseudomonas aeruginosa evolution in the cystic fibrosis lung

Lung Clearance Index Trial with Sick Kids

As a result of improved clinical care, many patients with Cystic Fibrosis (CF) have normal lung function as measured by standard breathing tests (spirometry). This makes it more difficult to evaluate the effect of a therapy on lung function. The Lung Clearance Index (LCI) has been shown to be better able to detect abnormalities in lung function and it shows changes after treatment for one month. However, it is unclear how useful this technique is in detecting short-term changes following one inhalation. Hypertonic saline (salty sterile water) has been shown to improve mucus clearance, lung function and the LCI in patients with CF. This study will assess whether treatment with hypertonic saline improves ventilation differences within the lungs as measured by the Lung Clearance Index in patients with CF after a single inhalation. The study will include five visits over a period of about 2-3 weeks. The time commitment for two of the visits is six to eight hours each and one to two hours each for the remaining two visits. All of the study visits take place at the Hospital for Sick Children.

Click here for the study results

Healthy Control Database

The Respiratory Division Healthy Controls Database is a list of healthy people with no lung disease who are willing to be contacted for research participation. The database only contains the name, date of birth, gender and contact information as well as comments concerning availability, etc. and will only be used by physicians and research staff in the Respiratory Division. Members of the public, friends and family of patients as well as staff, are welcome to enroll in the database. If you or someone you know would be interested in being a healthy control please contact Katie Griffin at or by phone at 416-864-6060 x 3936.