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Potentiators (specific therapies for class III and IV mutations) for cystic fibrosis

Overview of attention for article published in Cochrane database of systematic reviews, January 2019
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  • Above-average Attention Score compared to outputs of the same age (60th percentile)

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6 tweeters

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Title
Potentiators (specific therapies for class III and IV mutations) for cystic fibrosis
Published in
Cochrane database of systematic reviews, January 2019
DOI 10.1002/14651858.cd009841.pub3
Pubmed ID
Authors

Mica Skilton, Ashma Krishan, Sanjay Patel, Ian P Sinha, Kevin W Southern

Abstract

Cystic fibrosis (CF) is the commonest inherited life-shortening illness in white populations, caused by a mutation in the gene that codes for the cystic fibrosis transmembrane regulator protein (CFTR), which functions as a salt transporter. This mutation mainly affects the airways where excess salt absorption dehydrates the airway lining leading to impaired mucociliary clearance. Consequently, thick, sticky mucus accumulates making the airway prone to chronic infection and progressive inflammation; respiratory failure often ensues. Other complications include malnutrition, diabetes and subfertility.Increased understanding of the condition has allowed pharmaceutical companies to design mutation-specific therapies targeting the underlying molecular defect. CFTR potentiators target mutation classes III and IV and aim to normalise airway surface liquid and mucociliary clearance, which in turn impacts on the chronic infection and inflammation. This is an update of a previously published review. To evaluate the effects of CFTR potentiators on clinically important outcomes in children and adults with CF. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles, reviews and online clinical trial registries. Last search: 21 November 2018. Randomised controlled trials (RCTs) of parallel design comparing CFTR potentiators to placebo in people with CF. A separate review examines trials combining CFTR potentiators with other mutation-specific therapies. The authors independently extracted data, assessed the risk of bias in included trials and used GRADE to assess evidence quality. Trial authors were contacted for additional data. We included five RCTs (447 participants with different mutations) lasting from 28 days to 48 weeks, all assessing the CFTR potentiator ivacaftor. The quality of the evidence was moderate to low, mainly due to risk of bias (incomplete outcome data and selective reporting) and imprecision of results, particularly where few individuals experienced adverse events. Trial design was generally well-documented. All trials were industry-sponsored and supported by other non-pharmaceutical funding bodies.F508del (class II) (140 participants)One 16-week trial reported no deaths, or changes in quality of life (QoL) or lung function (either relative or absolute change in forced expiratory volume in one second (FEV1) (moderate-quality evidence). Pulmonary exacerbations and cough were the most reported adverse events in ivacaftor and placebo groups, but there was no difference between groups (low-quality evidence); there was also no difference between groups in participants interrupting or discontinuing treatment (low-quality evidence). Number of days until the first exacerbation was not reported, but there was no difference between groups in how many participants developed pulmonary exacerbations. There was also no difference in weight. Sweat chloride concentration decreased, mean difference (MD) -2.90 mmol/L (95% confidence interval (CI) -5.60 to -0.20).G551D (class III) (238 participants)The 28-day phase 2 trial (19 participants) and two 48-week phase 3 trials (adult trial (167 adults), paediatric trial (52 children)) reported no deaths. QoL scores (respiratory domain) were higher with ivacaftor in the adult trial at 24 weeks, MD 8.10 (95% CI 4.77 to 11.43) and 48 weeks, MD 8.60 (95% CI 5.27 to 11.93 (moderate-quality evidence). The adult trial reported a higher relative change in FEV1 with ivacaftor at 24 weeks, MD 16.90% (95% CI 13.60 to 20.20) and 48 weeks, MD 16.80% (95% CI 13.50 to 20.10); the paediatric trial reported this at 24 weeks, MD 17.4% (P < 0.0001)) (moderate-quality evidence). These trials demonstrated absolute improvements in FEV1 (% predicted) at 24 weeks, MD 10.80% (95% CI 8.91 to 12.69) and 48 weeks, MD 10.44% (95% CI 8.56 to 12.32). The phase 3 trials reported increased cough, odds ratio (OR) 0.57 (95% CI 0.33 to 1.00) and episodes of decreased pulmonary function, OR 0.29 (95% CI 0.10 to 0.82) in the placebo group; ivacaftor led to increased dizziness in adults, OR 10.55 (95% CI 1.32 to 84.47). There was no difference between groups in participants interrupting or discontinuing treatment (low-quality evidence). Fewer participants taking ivacaftor developed serious pulmonary exacerbations; adults taking ivacaftor developed fewer exacerbations (serious or not), OR 0.54 (95% CI 0.29 to 1.01). A higher proportion of participants were exacerbation-free at 24 weeks with ivacaftor (moderate-quality evidence). Ivacaftor led to a greater absolute change from baseline in FEV1 (% predicted) at 24 weeks, MD 10.80% (95% CI 8.91 to 12.69) and 48 weeks, MD 10.44% (95% CI 8.56 to 12.32); weight also increased at 24 weeks, MD 2.37 kg (95% CI 1.68 to 3.06) and 48 weeks, MD 2.75 kg (95% CI 1.74 to 3.75). Sweat chloride concentration decreased at 24 weeks, MD -48.98 mmol/L (95% CI -52.07 to -45.89) and 48 weeks, MD -49.03 mmol/L (95% CI -52.11 to -45.94).R117H (class IV) (69 participants)One 24-week trial reported no deaths. QoL scores (respiratory domain) were higher with ivacaftor at 24 weeks, MD 8.40 (95% CI 2.17 to 14.63), but no relative changes in lung function were reported (moderate-quality evidence). Pulmonary exacerbations and cough were the most reported adverse events in both groups, but there was no difference between groups; there was no difference between groups in participants interrupting or discontinuing treatment (low-quality evidence). Number of days until the first exacerbation was not reported, but there was no difference between groups in how many participants developed pulmonary exacerbations. No changes in absolute change in FEV1 or weight were reported. Sweat chloride concentration decreased, MD -24.00 mmol/L (CI 95% -24.69 to -23.31). There is no evidence supporting the use of ivacaftor in people with the F508del mutation. Both G551D phase 3 trials demonstrated a clinically relevant impact of ivacaftor on outcomes at 24 and 48 weeks in adults and children (over six years of age) with CF. The R117H trial demonstrated an improvement in the respiratory QoL score, but no improvement in respiratory function.As new mutation-specific therapies emerge, it is important that trials examine outcomes relevant to people with CF and their families and that adverse events are reported robustly and consistently. Post-market surveillance is essential and ongoing health economic evaluations are required.

Twitter Demographics

The data shown below were collected from the profiles of 6 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 130 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
United Kingdom 2 2%
Unknown 128 98%

Demographic breakdown

Readers by professional status Count As %
Student > Bachelor 25 19%
Student > Master 24 18%
Student > Ph. D. Student 20 15%
Unspecified 15 12%
Researcher 12 9%
Other 34 26%
Readers by discipline Count As %
Medicine and Dentistry 48 37%
Psychology 18 14%
Unspecified 17 13%
Agricultural and Biological Sciences 13 10%
Nursing and Health Professions 9 7%
Other 25 19%

Attention Score in Context

This research output has an Altmetric Attention Score of 4. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 21 January 2019.
All research outputs
#3,706,493
of 12,830,933 outputs
Outputs from Cochrane database of systematic reviews
#6,831
of 10,434 outputs
Outputs of similar age
#117,654
of 304,386 outputs
Outputs of similar age from Cochrane database of systematic reviews
#31
of 34 outputs
Altmetric has tracked 12,830,933 research outputs across all sources so far. This one has received more attention than most of these and is in the 70th percentile.
So far Altmetric has tracked 10,434 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 20.3. This one is in the 34th percentile – i.e., 34% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 304,386 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 60% of its contemporaries.
We're also able to compare this research output to 34 others from the same source and published within six weeks on either side of this one. This one is in the 8th percentile – i.e., 8% of its contemporaries scored the same or lower than it.