Medium term treatment of stable stage cystic fibrosis with recombinant human DNase I

Discontinuation versus continuation of hypertonic saline or dornase alfa in modulator treated people with cystic fibrosis (SIMPLIFY): results from two parallel, multicentre, open-label, randomised, controlled, non-inferiority trials

BACKGROUND

Reducing treatment burden is a priority for people with cystic fibrosis, whose health has benefited from using new modulators that substantially increase CFTR protein function. The SIMPLIFY study aimed to assess the effects of discontinuing nebulised hypertonic saline or dornase alfa in individuals using the CFTR modulator elexacaftor plus tezacaftor plus ivacaftor (ETI).

METHODS

The SIMPLIFY study included two parallel, multicentre, open-label, randomised, controlled, non-inferiority trials at 80 participating clinics across the USA in the Cystic Fibrosis Therapeutics Development Network. We included individuals with cystic fibrosis aged 12-17 years with percent predicted FEV1 (ppFEV1) of 70% or more, or those aged 18 years or older with ppFEV1 of 60% or more, if they had been taking ETI and either (or both) mucoactive therapies (≥3% hypertonic saline or dornase alfa) for at least 90 days before screening. Participants on both hypertonic saline and dornase alfa were randomly assigned to one of the two trials, and those on a single therapy were assigned to the applicable trial. All participants were then randomly assigned 1:1 to continue or discontinue therapy for 6 weeks using permuted blocks of varying size, stratified by baseline ppFEV1 (week 0; ≥90% or <90%), single or concurrent use of hypertonic saline and dornase alfa, previous SIMPLIFY study participation (yes or no), and age (≥18 or <18 years). For participants randomly assigned to continue their therapy during a given trial, this therapy was instructed to be taken at least once daily according to each participant's pre-existing, clinically prescribed regimen. Hypertonic saline concentration was required to be at least 3%. The primary objective for each trial was to determine whether discontinuing was non-inferior to continuing, measured by the 6-week change in ppFEV1 in the per-protocol population. We established a non-inferiority margin of -3% for the difference between groups in the 6-week change in ppFEV1. Safety outcomes were analysed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT04378153.

FINDINGS

From Aug 25, 2020, to May 25, 2022, a total of 672 unique participants were screened for eligibility for one or both trials, resulting in 847 total random assignments across both trials with 594 unique participants. 370 participants were randomly assigned in the hypertonic saline trial and 477 in the dornase alfa trial. Participants across both trials had an average ppFEV1 of 96·9%. Discontinuing treatment was non-inferior to continuing treatment with respect to the absolute 6-week change in ppFEV1 in both the hypertonic saline trial (-0·19% [95% CI -0·85 to 0·48] in the discontinuation group [n=133] vs 0·14% [-0·51 to 0·78] in the continuation group [n=140]; between-group difference -0·32% [-1·25 to 0·60]) and dornase alfa trial (0·18% [-0·38 to 0·74] in the discontinuation group [n=199] vs -0·16% [-0·73 to 0·41] in the continuation group [n=193]; between-group difference 0·35% [-0·45 to 1·14]), with consistent results in the intention-to-treat populations. In the hypertonic saline trial, 64 (35%) of 184 in the discontinuation group versus 44 (24%) of 186 participants in the continuation group and, in the dornase alfa trial, 89 (37%) of 240 in the discontinuation group versus 55 (23%) of 237 in the continuation group had at least one adverse event.

INTERPRETATION

In individuals with cystic fibrosis on ETI with relatively well preserved pulmonary function, discontinuing daily hypertonic saline or dornase alfa for 6 weeks did not result in clinically meaningful differences in pulmonary function when compared with continuing treatment.

Treatment of Pulmonary Disease of Cystic Fibrosis: A Comprehensive Review

Cystic fibrosis (CF) is a genetic disease that causes absence or dysfunction of a protein named transmembrane conductance regulatory protein (CFTR) that works as an anion channel. As a result, the secretions of the organs where CFTR is expressed are very viscous, so their functionality is altered. The main cause of morbidity is due to the involvement of the respiratory system as a result of recurrent respiratory infections by different pathogens. In recent decades, survival has been increasing, rising by around age 50. This is due to the monitoring of patients in multidisciplinary units, early diagnosis with neonatal screening, and advances in treatments. In this chapter, we will approach the different therapies used in CF for the treatment of symptoms, obstruction, inflammation, and infection. Moreover, we will discuss specific and personalized treatments to correct the defective gene and repair the altered protein CFTR. The obstacle for personalized CF treatment is to predict the drug response of patients due to genetic complexity and heterogeneity of uncommon mutations.

Dornase alfa for cystic fibrosis

BACKGROUND

Dornase alfa is currently used as a mucolytic to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis. It reduces mucus viscosity in the lungs, promoting improved clearance of secretions. This is an update of a previously published review.

OBJECTIVES

To determine whether the use of dornase alfa in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other medications that improve airway clearance, and to identify any adverse events associated with its use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences. Date of the most recent search of the Group's Cystic Fibrosis Register: 12 October 2020. Clinicaltrials.gov and the International Clinical Trials Registry Platform were also searched to identify unpublished or ongoing trials. Date of most recent search: 08 February 2021.

SELECTION CRITERIA

All randomised and quasi-randomised controlled trials comparing dornase alfa to placebo, standard therapy or other medications that improve airway clearance.

DATA COLLECTION AND ANALYSIS

Authors independently assessed trials against the inclusion criteria; two authors carried out analysis of methodological quality and data extraction. GRADE was used to assess the level of evidence.

MAIN RESULTS

The searches identified 74 trials, of which 19 (2565 participants) met our inclusion criteria. 15 trials compared dornase alfa to placebo or no dornase alfa (2447 participants); two compared daily dornase to hypertonic saline (32 participants); one compared daily dornase alfa to hypertonic saline and alternate day dornase alfa (48 participants); one compared dornase alfa to mannitol and the combination of both drugs (38 participants). Trial duration varied from six days to three years. Dornase alfa compared to placebo or no treatment Dornase alfa probably improved forced expiratory volume at one second (FEV₁) at one month (four trials, 248 participants), three months (one trial, 320 participants; moderate-quality evidence), six months (one trial, 647 participants; high-quality evidence) and two years (one trial, 410 participants). Limited low-quality evidence showed treatment may make little or no difference  in quality of life. Dornase alfa probably reduced the number of pulmonary exacerbations in trials of up to two years (moderate-quality evidence). One trial that examined the cost of care, including the cost of dornase alfa, found that the cost savings from dornase alfa offset 18% to 38% of the medication costs. Dornase alfa: daily versus alternate day One cross-over trial (43 children) found little or no difference between treatment regimens for lung function, quality of life or pulmonary exacerbations (low-quality evidence). Dornase alfa compared to other medications that improve airway clearance Results for these comparisons were mixed. One trial (43 children) showed dornase alfa may lead to a greater improvement in FEV₁ compared to hypertonic saline (low-quality evidence), and one trial (23 participants) reported little or no differences in lung function between dornase alfa and mannitol or dornase alfa and dornase alfa plus mannitol (low-quality evidence). One trial (23 participants) found dornase alfa may improve quality of life compared to dornase alfa plus mannitol (low-quality evidence); other comparisons found little or no difference in this outcome (low-quality evidence). No trials in any comparison reported any difference between groups in the number of pulmonary exacerbations (low-quality evidence). When all comparisons are assessed, dornase alfa did not cause significantly more adverse effects than other treatments, except voice alteration and rash.

AUTHORS' CONCLUSIONS

There is evidence to show that, compared with placebo, therapy with dornase alfa may improve lung function in people with cystic fibrosis in trials lasting from one month to two years. There was a decrease in pulmonary exacerbations in trials of six months or longer, probably due to treatment. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials. There is not enough evidence to firmly conclude if dornase alfa is superior to other hyperosmolar agents in improving lung function.

Timing of dornase alfa inhalation for cystic fibrosis

BACKGROUND

Inhalation of the enzyme dornase alfa reduces sputum viscosity and improves clinical outcomes of people with cystic fibrosis. This is an update of a previously published Cochrane Review.

OBJECTIVES

To determine whether the timing of dornase alfa inhalation (in relation to airway clearance techniques or morning versus evening inhalation) has an impact on objective and subjective measures of clinical efficacy in people with cystic fibrosis.

SEARCH METHODS

Relevant randomised and quasi-randomised controlled trials were identified from the Cochrane Cystic Fibrosis Trials Register, the Physiotherapy Evidence Database (PEDro), clinical trial registries and international cystic fibrosis conference proceedings. Date of the most recent search: 12 October 2020.

SELECTION CRITERIA

Any trial of dornase alfa in people with cystic fibrosis where timing of inhalation was the randomised element in the trial with either: inhalation before compared to after airway clearance techniques; or morning compared to evening inhalation.  DATA COLLECTION AND ANALYSIS: Both authors independently selected trials, assessed risk of bias and extracted data with disagreements resolved by discussion. Relevant data were extracted and, where possible, meta-analysed. We assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified 115 trial reports representing 55 trials, of which five trials (providing data on 122 participants) met our inclusion criteria. All five trials used a cross-over design. Intervention periods ranged from two to eight weeks. Four trials (98 participants) compared dornase alfa inhalation before versus after airway clearance techniques. Inhalation after instead of before airway clearance did not significantly change forced expiratory volume at one second (very-low quality evidence). Similarly, forced vital capacity (low-quality evidence) and quality of life (very-low quality evidence) were not significantly affected; forced expiratory flow at 25% was significantly worse with dornase alfa inhalation after airway clearance, mean difference -0.17 litres (95% confidence interval -0.28 to -0.05), based on the pooled data from two small trials in children (7 to 19 years) with well-preserved lung function. All other secondary outcomes were statistically non-significant. In one trial (25 participants), morning versus evening inhalation had no impact on lung function or symptoms (low-quality evidence).

AUTHORS' CONCLUSIONS

The current evidence derived from a small number of participants does not indicate that inhalation of dornase alfa after airway clearance techniques is more or less effective than the traditional recommendation to inhale nebulised dornase alfa 30 minutes prior to airway clearance techniques, for most outcomes. For children with well-preserved lung function, inhalation before airway clearance may be more beneficial for small airway function than inhalation after. However, this result relied on a measure with high variability and trials with variable follow-up. In the absence of strong evidence to indicate that one timing regimen is better than another, the timing of dornase alfa inhalation can be largely based on pragmatic reasons or individual preference with respect to the time of airway clearance and time of day. Further research is warranted.

Timing of dornase alfa inhalation for cystic fibrosis

BACKGROUND

Inhalation of the enzyme dornase alfa reduces sputum viscosity and improves clinical outcomes of people with cystic fibrosis. This is an update of a previously published Cochrane Review.

OBJECTIVES

To determine whether the timing of dornase alfa inhalation (in relation to airway clearance techniques or morning versus evening inhalation) has an impact on objective and subjective measures of clinical efficacy in people with cystic fibrosis.

SEARCH METHODS

Relevant randomised and quasi-randomised controlled trials were identified from the Cochrane Cystic Fibrosis Trials Register, Physiotherapy Evidence Database (PEDro), clinical trial registries and international cystic fibrosis conference proceedings.Date of the most recent search: 06 June 2018.

SELECTION CRITERIA

Any trial of dornase alfa in people with cystic fibrosis where timing of inhalation was the randomised element in the trial with either: inhalation before compared to after airway clearance techniques; or morning compared to evening inhalation.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed risk of bias and extracted data with disagreements resolved by discussion. Relevant data were extracted and, where possible, meta-analysed.

MAIN RESULTS

We identified 115 trial reports representing 55 trials, of which five trials (providing data on 122 participants) met our inclusion criteria. All five trials used a cross-over design. Intervention periods ranged from two to eight weeks. Four trials (98 participants) compared dornase alfa inhalation before versus after airway clearance techniques. Inhalation after instead of before airway clearance did not significantly change forced expiratory volume at one second (very-low quality evidence). Similarly, forced vital capacity (low-quality evidence) and quality of life (very-low quality evidence) were not significantly affected; forced expiratory flow at 25% was significantly worse with dornase alfa inhalation after airway clearance, mean difference -0.17 litres (95% confidence interval -0.28 to -0.05), based on the pooled data from two small trials in children (7 to 19 years) with well-preserved lung function. All other secondary outcomes were statistically non-significant.In one trial (25 participants), morning versus evening inhalation had no impact on lung function or symptoms (low-quality evidence).

AUTHORS' CONCLUSIONS

The current evidence derived from a small number of participants does not indicate that inhalation of dornase alfa after airway clearance techniques is more or less effective than the traditional recommendation to inhale nebulised dornase alfa 30 minutes prior to airway clearance techniques, for most outcomes. For children with well-preserved lung function, inhalation before airway clearance may be more beneficial for small airway function than inhalation after. However, this result relied on a measure with high variability and trials with variable follow-up. In the absence of strong evidence to indicate that one timing regimen is better than another, the timing of dornase alfa inhalation can be largely based on pragmatic reasons or individual preference with respect to the time of airway clearance and time of day. Further research is warranted.

Dornase alfa for cystic fibrosis

BACKGROUND

Dornase alfa is currently used as a mucolytic to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis. It reduces mucus viscosity in the lungs, promoting improved clearance of secretions. This is an update of a previously published review.

OBJECTIVES

To determine whether the use of dornase alfa in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other medications that improve airway clearance, and to identify any adverse events associated with its use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences. Date of the most recent search of the Group's Cystic Fibrosis Register: 23 April 2018.Clinicaltrials.gov and the International Clinical Trials Registry Platform were also searched to identify unpublished or ongoing trials. Date of most recent search: 07 June 2018.

SELECTION CRITERIA

All randomised and quasi-randomised controlled trials comparing dornase alfa to placebo, standard therapy or other medications that improve airway clearance.

DATA COLLECTION AND ANALYSIS

Authors independently assessed trials against the inclusion criteria; two authors carried out analysis of methodological quality and data extraction. GRADE was used to assess the level of evidence.

MAIN RESULTS

The searches identified 69 trials, of which 19 (2565 participants) met our inclusion criteria. Fifteen trials compared dornase alfa to placebo or no dornase alfa (2447 participants); two compared daily dornase to hypertonic saline (32 participants); one compared daily dornase alfa to hypertonic saline and alternate day dornase alfa (48 participants); one compared dornase alfa to mannitol and the combination of both drugs (38 participants). Trial duration varied from six days to three years.Dornase alfa compared to placebo or no treatmentDornase alfa improved forced expiratory volume at one second at one month (four trials, 248 participants), three months (one trial, 320 participants; moderate-quality evidence), six months (one trial, 647 participants; high-quality evidence) and two years (one trial, 410 participants). Limited low-quality evidence showed no difference between groups for changes in quality of life. There was a decrease in pulmonary exacerbations with dornase alfa in trials of up to two years (moderate-quality evidence). One trial that examined the cost of care, including the cost of dornase alfa, found that the cost savings from dornase alfa offset 18% to 38% of the medication costs.Dornase alfa: daily versus alternate dayOne cross-over trial (43 children) found no differences between treatment regimens for lung function, quality of life or pulmonary exacerbations (low-quality evidence).Dornase alfa compared to other medications that improve airway clearanceResults for these comparisons were mixed. One trial (43 children) showed a greater improvement in forced expiratory volume at one second for dornase alfa compared to hypertonic saline (low-quality evidence), and one trial (23 participants) reported no difference in lung function between dornase alfa and mannitol or dornase alfa and dornase alfa plus mannitol (low-quality evidence). One trial (23 participants) found a difference in quality of life favouring dornase alfa when compared to dornase alfa plus mannitol (low-quality evidence); other comparisons found no difference in this outcome (low-quality evidence). No trials in any comparison reported any difference between groups in the number of pulmonary exacerbations (low-quality evidence).When all comparisons are assessed, dornase alfa did not cause significantly more adverse effects than other treatments, except voice alteration and rash.

AUTHORS' CONCLUSIONS

There is evidence to show that, compared with placebo, therapy with dornase alfa improves lung function in people with cystic fibrosis in trials lasting from one month to two years. There was a decrease in pulmonary exacerbations in trials of six months or longer. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials. There is not enough evidence to firmly conclude if dornase alfa is superior to other hyperosmolar agents in improving lung function.

Timing of dornase alfa inhalation for cystic fibrosis

BACKGROUND

Inhalation of the enzyme dornase alfa reduces sputum viscosity and improves clinical outcomes of people with cystic fibrosis. This is an update of a previously published Cochrane review.

OBJECTIVES

To determine the effect of timing of dornase alfa inhalation on measures of clinical efficacy in people with cystic fibrosis (in relation to airway clearance techniques or time of day).

SEARCH METHODS

Relevant randomised and quasi-randomised controlled trials were identified from the Cochrane Cystic Fibrosis Trials Register, Physiotherapy Evidence Database (PEDro), and international cystic fibrosis conference proceedings.Date of the most recent search: 25 April 2016.

SELECTION CRITERIA

Any trial of dornase alfa in people with cystic fibrosis where timing of inhalation was the randomised element in the study with either: inhalation before compared to after airway clearance techniques; or morning compared to evening inhalation.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed risk of bias and extracted data with disagreements resolved by discussion. Relevant data were extracted and, where possible, meta-analysed.

MAIN RESULTS

We identified 115 trial reports representing 55 studies, of which five studies (providing data on 122 participants) met our inclusion criteria. All five studies used a cross-over design. Intervention periods ranged from two to eight weeks. Four trials compared dornase alfa inhalation before versus after airway clearance techniques. Inhalation after instead of before airway clearance did not significantly change forced expiratory volume at one second. Similarly, forced vital capacity and quality of life were not significantly affected; forced expiratory flow at 25% was significantly worse with dornase alfa inhalation after airway clearance, mean difference -0.17 litres (95% confidence interval -0.28 to -0.05), based on the pooled data from two small studies in children (seven to 19 years) with well-preserved lung function. All other secondary outcomes were statistically non-significant.In one trial, morning versus evening inhalation had no impact on lung function or symptoms.

AUTHORS' CONCLUSIONS

The current evidence derived from a small number of participants does not indicate that inhalation of dornase alfa after airway clearance techniques is more or less effective than the traditional recommendation to inhale nebulised dornase alfa 30 minutes prior to airway clearance techniques, for most outcomes. For children with well-preserved lung function, inhalation before airway clearance may be more beneficial for small airway function than inhalation after. However, this result relied on a measure with high variability and studies with variable follow up. In the absence of strong evidence to indicate that one timing regimen is better than another, the timing of dornase alpha inhalation can be largely based on pragmatic reasons or individual preference with respect to the time of airway clearance and time of day. Further research is warranted.

Dornase alfa for cystic fibrosis

BACKGROUND

Dornase alfa is currently used as a mucolytic to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis. It reduces mucus viscosity in the lungs, promoting improved clearance of secretions. This is an update of a previously published review.

OBJECTIVES

To determine whether the use of dornase alfa in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other medications that improve airway clearance, and to identify any adverse events associated with its use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences. Date of the most recent search of the Group's Cystic Fibrosis Register: 30 November 2015.Clinicaltrials.gov was also searched to identify unpublished or ongoing trials. Date of most recent search: 28 November 2015.

SELECTION CRITERIA

All randomised and quasi-randomised controlled trials comparing dornase alfa to placebo, standard therapy or other medications that improve airway clearance.

DATA COLLECTION AND ANALYSIS

Authors independently assessed trials against the inclusion criteria; two authors carried out analysis of methodological quality and data extraction.

MAIN RESULTS

The searches identified 54 trials, of which 19 (including a total of 2565 participants) met our inclusion criteria. Three additional papers examined the healthcare cost from one of the clinical trials. Fifteen trials compared dornase alfa to placebo or no dornase alfa treatment (2447 participants); two compared daily dornase to hypertonic saline (32 participants); one compared daily dornase alfa with hypertonic saline and alternate day dornase alfa (48 participants); one compared dornase alfa to mannitol and the combination of both drugs (38 participants). Trial duration varied from six days to three years.Compared to placebo, forced expiratory volume at one second improved in the intervention groups, with significant differences at one, three, six months and two years. There was also a significant improvement in lung clearance index at one month. There was a decrease in pulmonary exacerbations compared to placebo in trials of longer duration. The quality of the evidence from placebo-controlled trials was moderate to high for outcomes of lung function and pulmonary exacerbations. Limited, low quality evidence was available for changes in quality of life from baseline. One trial that examined the cost of care, including the cost of dornase alfa, found that the cost savings from dornase alfa offset 18% to 38% of the medication costs.The results for trials comparing dornase alfa to other medications that improve airway clearance (hypertonic saline or mannitol) were mixed, with one trial showing a greater improvement in forced expiratory volume at one second for dornase alfa compared to hypertonic saline, and three trials finding no difference between medications. In the only trial to assess the combination of dornase alfa with another medication compared to dornase alone, there was no benefit seen with the combination of dornase alfa and mannitol. Evidence of dornase alfa compared to other medications was limited and the open-label design of the trials may have induced bias, therefore the quality of the evidence was judged to be low.Dornase alfa did not cause significantly more adverse effects, except voice alteration and rash.

AUTHORS' CONCLUSIONS

There is evidence to show that, compared with placebo, therapy with dornase alfa improves lung function in people with cystic fibrosis in trials lasting one month to two years. There was a decrease in pulmonary exacerbations in trials of six months or longer. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials. There is not enough evidence to firmly conclude if dornase alfa is superior to hyperosmolar agents in improving lung function.

Timing of dornase alfa inhalation for cystic fibrosis

BACKGROUND

Inhalation of the enzyme dornase alfa reduces sputum viscosity and improves clinical outcomes of people with cystic fibrosis.

OBJECTIVES

To determine the effect of timing of dornase alfa inhalation on measures of clinical efficacy in people with cystic fibrosis (in relation to airway clearance techniques or time of day).

SEARCH METHODS

Relevant randomised and quasi-randomised controlled trials were identified from the Cochrane Cystic Fibrosis Trials Register, Physiotherapy Evidence Database (PEDro), and international CF conference proceedings.Date of the most recent search: 22 February 2013.

SELECTION CRITERIA

Any trial of dornase alfa in people with cystic fibrosis where timing of inhalation was the randomised element in the study with either: inhalation before compared to after airway clearance techniques; or morning compared to evening inhalation.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed risk of bias and extracted data with disagreements resolved by discussion. Relevant data were extracted and, where possible, meta-analysed.

MAIN RESULTS

We identified 99 trial reports representing 48 studies, of which five studies (providing data on 122 participants) met our inclusion criteria. All five studies used a cross-over design. Intervention periods ranged from two to eight weeks. Four trials compared dornase alfa inhalation before versus after airway clearance techniques. Inhalation after instead of before airway clearance did not significantly change FEV1. Similarly, FVC and quality of life were not significantly affected; FEF25 was significantly worse with dornase alfa inhalation after airway clearance, MD -0.17 litres (95% CI -0.28 to -0.05), based on the pooled data from two small studies in children (7 to 19 years) with well-preserved lung function. All other secondary outcomes were statistically non-significant.In one trial, morning versus evening inhalation had no impact on lung function or symptoms.

AUTHORS' CONCLUSIONS

The current evidence derived from a small number of participants does not indicate that inhalation of dornase alfa after airway clearance techniques is more or less effective than the traditional recommendation to inhale nebulised dornase alfa 30 minutes prior to airway clearance techniques, for most outcomes. For children with well-preserved lung function, inhalation before airway clearance may be more beneficial for small airway function than inhalation after. However, this result relied on a measure with high variability and studies with variable follow up. In the absence of strong evidence to indicate that one timing regimen is better than another, the timing of dornase alpha inhalation can be largely based on pragmatic reasons or individual preference with respect to the time of airway clearance and time of day. Further research is warranted.

Timing of dornase alfa inhalation for cystic fibrosis

BACKGROUND

Inhalation of the enzyme dornase alfa reduces sputum viscosity and improves clinical outcomes of people with cystic fibrosis.

OBJECTIVES

To determine the effect of timing of dornase alfa inhalation on measures of clinical efficacy in people with cystic fibrosis (in relation to airway clearance techniques or time of day).

SEARCH STRATEGY

Relevant randomised and quasi-randomised controlled trials were identified from the Cochrane Cystic Fibrosis Trials Register, Physiotherapy Evidence Database (PEDro), and international CF conference proceedings.Search date: 6 October 2010.

SELECTION CRITERIA

Any trial of dornase alfa in people with cystic fibrosis where timing of inhalation was the randomised element in the study with either: inhalation before compared to after airway clearance techniques; or morning compared to evening inhalation.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed risk of bias and extracted data with disagreements resolved by discussion. Relevant data were extracted and, where possible, meta-analysed.

MAIN RESULTS

We identified 92 trial reports representing 47 studies, of which five studies (providing data on 122 participants) met our inclusion criteria. All five studies used a cross-over design. Intervention periods ranged from two to eight weeks. Four trials compared dornase alfa inhalation before versus after airway clearance techniques. Inhalation after instead of before airway clearance did not significantly change FEV(1). Similarly, FVC and quality of life were not significantly affected; FEF(25) was significantly worse with dornase alfa inhalation after airway clearance, MD -0.17 litres (95% CI -0.28 to -0.05), based on the pooled data from two small studies in children (7 to 19 years) with well-preserved lung function. All other secondary outcomes were statistically non-significant.In one trial, morning versus evening inhalation had no impact on lung function or symptoms.

AUTHORS' CONCLUSIONS

The current evidence derived from a small number of participants does not indicate that inhalation of dornase alfa after airway clearance techniques is more or less effective than the traditional recommendation to inhale nebulised dornase alfa 30 minutes prior to airway clearance techniques, for most outcomes. For children with well-preserved lung function, inhalation before airway clearance may be more beneficial for small airway function than inhalation after. However, this result relied on a measure with high variability and studies with variable follow-up. Apart from this, the timing of dornase alfa inhalation can be largely based on pragmatic reasons or individual preference with respect to the time of airway clearance and time of day. Further research is warranted.

Pseudomonas aeruginosa biofilms in cystic fibrosis

The persistence of chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing) strains. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. In CF lungs, the polysaccharide alginate is the major part of the P. aeruginosa biofilm matrix. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and resist phagocytosis, as well as other components of the innate and the adaptive immune system. As a consequence, a pronounced antibody response develops, leading to immune complex-mediated chronic inflammation, dominated by polymorphonuclear leukocytes. The chronic inflammation is the major cause of the lung tissue damage in CF. Biofilm growth in CF lungs is associated with an increased frequency of mutations, slow growth and adaptation of the bacteria to the conditions in the lungs, and to antibiotic therapy. Low bacterial metabolic activity and increase of doubling times of the bacterial cells in CF lungs are responsible for some of the tolerance to antibiotics. Conventional resistance mechanisms, such as chromosomal β-lactamase, upregulated efflux pumps, and mutations of antibiotic target molecules in the bacteria, also contribute to the survival of P. aeruginosa biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy, and they can be treated by chronic suppressive therapy.

Improved survival at low lung function in cystic fibrosis: cohort study from 1990 to 2007

OBJECTIVES

To evaluate the survival of patients with cystic fibrosis whose lung function has deteriorated to a forced expiratory volume in one second (FEV(1)) below 30% predicted in the recent treatment era and to explore factors associated with any change in survival. Design Cohort study.

SETTING

Adult cystic fibrosis unit in London.

PARTICIPANTS

276 patients (147 (53%) male) whose FEV(1) was first observed to be less than 30% predicted between 1 January 1990 and 31 December 2003.

MAIN OUTCOME MEASURE

Survival during follow-up to 31 December 2007 in two year sub-cohorts.

RESULTS

Median survival improved from 1.2 years in the 1990-1 group to 5.3 years in the 2002-3 group, with a marked improvement in survival from 1994. The use of nebulised recombinant human DNase was significantly associated with a reduced risk of death (hazard ratio 0.59, 95% confidence interval 0.44 to 0.79). Significantly increased risks were associated with a body mass index under 19 (hazard ratio 1.52, 1.10 to 2.10), long term oxygen therapy (3.52, 2.49 to 4.99), and nebulised antibiotics (1.84, 1.05 to 3.22).

CONCLUSION

A marked improvement has occurred in the survival of patients with cystic fibrosis with an FEV(1) less than 30% predicted. Secondary analyses suggest that some of this improvement may be due to use of recombinant human DNase.

Pharmacology, clinical efficacy and safety of recombinant human DNase in cystic fibrosis

Recombinant human DNase (rhDNase) is a mucolytic agent that is primarily used to improve mucociliary clearance in cystic fibrosis (CF). rhDNase is a recombinant human enzyme that is synthesized in a Chinese hamster ovary cell line. rhDNase enzymatically cleaves extracellular DNA into molecules of shorter length. CF sputum shows high concentrations of DNA released by disintegrating inflammatory cells. Free DNA contributes to the abnormally high viscosity of CF sputum and therefore forms an important target in the treatment of CF lung disease. Clinical studies have shown that daily nebulization of rhDNase is associated with an increase in lung function and a decrease in the frequency of exacerbations in patients with CF.

Dornase alfa for cystic fibrosis

BACKGROUND

Dornase alfa is currently used to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis.

OBJECTIVES

To determine whether the use of dornase alfa in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other mucolytics and to identify any adverse events associated with its use.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences.Date of the most recent search of the Group's Cystic Fibrosis Register: 17 July 2009.

SELECTION CRITERIA

All randomised and quasi-randomised controlled trials where dornase alfa was compared to placebo, standard therapy or another mucolytic.

DATA COLLECTION AND ANALYSIS

Authors independently assessed trials for inclusion criteria; the lead author and a colleague carried out analysis of methodological quality and data extraction.

MAIN RESULTS

The searches identified 43 trials, of which 15 met our inclusion criteria, including a total of 2469 participants. Three additional studies examined the healthcare cost from one of the clinical trials. Twelve studies compared dornase alfa to placebo or no dornase alfa treatment; one compared daily dornase alfa with hypertonic saline and alternate day dornase alfa; and two compared daily dornase alfa to hypertonic saline. Study duration varied from six days to two years. The number of deaths was not significant between treatment groups. Spirometric lung function improved in the treated groups, with significant differences at one month, three months, six months and two years, there was a non-significant difference at three years. There was no excess of adverse effects except voice alteration and rash, which were reported more frequently in one trial in the treated groups. Insufficient data were available to analyse differences in antibiotic treatment, inpatient stay and quality of life.

AUTHORS' CONCLUSIONS

There is evidence to show that therapy with dornase alfa over a one-month period is associated with an improvement in lung function in CF; results from a trial lasting six months also showed the same effect. Therapy over a two-year period (based on one trial) significantly improved FEV(1) in children and there was a non-significant reduction in the risk of infective exacerbations. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials.

The use of human deoxyribonuclease (rhDNase) in the management of cystic fibrosis

In patients with cystic fibrosis (CF), the poor clearance of airway secretions promotes recurrent cycles of pulmonary infection and inflammation. In recent years, novel drugs have been developed to alter the properties of the secretions in an attempt to aid chest physiotherapy in improving airway clearance. Once-daily nebulised recombinant human deoxyribonuclease (rhDNase; dornase alfa; Pulmozyme) is the most widely used mucoactive therapy in patients with CF. It has been shown to reduce the viscoelasticity of sputum from patients with CF and enhance the clearance of secretions. Clinical trials have shown rhDNase to be a well tolerated treatment that improves pulmonary function and reduces respiratory exacerbations. However, the response to treatment is heterogeneous and only a proportion of patients with CF actually benefit from the treatment. At present, we are unable to predict which patients will benefit from rhDNase. Many CF centers have developed formal n-of-1 trials of treatment to find out who benefits and to justify prescribing the agent. rhDNase is an expensive therapy and is mainly used in patients over the age of 5 years with moderate to severe lung disease. However, studies have shown that rhDNase may be useful in patients with milder lung disease. Comparisons with another mucoactive drug, hypertonic saline, have shown rhDNase to be more effective. Recently, it has been shown that giving rhDNase on an alternate-day basis, rather than daily, is equally effective, potentially reducing costs and treatment time.

Cystic fibrosis lung disease: genetic influences, microbial interactions, and radiological assessment

Cystic fibrosis (CF) is a multiorgan disease caused by mutation of the CF transmembrane conductance regulator (CFTR) gene. Obstructive lung disease is the predominant cause of morbidity and mortality; thus, most efforts to improve outcomes are directed toward slowing or halting lung-disease progression. Current therapies, such as mucolytics, airway clearance techniques, bronchodilators, and antibiotics, aim to suppress airway inflammation and the processes that stimulate it, namely, retention and infection of mucus plaques at the airway surface. New approaches to therapy that aim to ameliorate specific CFTR mutations or mutational classes by restoring normal expression or function are being investigated. Because of its sensitivity in detecting changes associated with early airway obstruction and regional lung disease, high-resolution CT (HRCT) complements pulmonary function testing in defining disease natural history and measuring response to both conventional and experimental therapies. In this review, perspectives on the genetics and microbiology of CF provide a context for understanding the increasing importance of HRCT and other imaging techniques in assessing CF therapies.

DNase in stable cystic fibrosis infants: a pilot study

OBJECTIVE

To assess the feasibility of measuring short-term effects of inhaled recombinant human deoxyribonuclease (rhDNase, Pulmozyme on lung function, pulse oximetry and symptom scores in infants and toddlers with stable cystic fibrosis.

DESIGN

open-label randomized placebo controlled cross-over pilot study.

PATIENTS AND METHODS

We treated nine CF patients (0.7-1.9 years) with nebulised rhDNase (2.5 mg) and NaCl 0.9% (10 ml) via jet nebulizer cross-over once daily during 2-week treatment blocks. Measurements were performed at baseline and after treatment blocks and consisted of lung function tests (plethysmography and tidal rapid thoraco-abdominal compression technique), overnight pulse oximetry, and daily symptom scores.

RESULTS

DNase treatment and the different assessments were well tolerated by all children and their parents. Lung function showed increased airway patency after treatment with rhDNase (P < 0.001), but not after NaCl 0.9%. Overnight pulse oximetry and daily symptom scores did not change during the study period.

CONCLUSIONS

This pilot study indicates that objective assessment of the effects of rhDNase is feasible in infants with CF who have little or no respiratory symptoms. Our results warrant a larger randomized placebo-controlled trial.

Effect of DNase on exercise capacity in cystic fibrosis

DNase can reduce viscosity and facilitate expectoration of airway secretions in cystic fibrosis (CF) lung disease. We evaluated its effect on exercise performance in relation to resting pulmonary function. Fifteen sputum-producing CF patients (aged 9-28 years; FEV1 22-83% predicted) performed spirometry, body plethysmography, nitrogen washout, and incremental cardiopulmonary exercise testing before and after 8 weeks of first-time treatment with daily inhaled rhDNase. Most subjects reported increased amounts and fluidity of sputum. The effect on objective parameters was heterogeneous, without statistical significance. Groupwise, FEV1 increased by 6% without correlation to baseline values; individual patients gained up to 40%. Indices of hyperinflation and air trapping were slightly raised. Maximal workload and oxygen uptake (V'O2) increased by up to 20% in a number of patients. The treatment effect on V'O2 was neither related to baseline levels of pulmonary function and exercise capacity nor to the change in FEV1. Ventilatory equivalents for oxygen and carbon dioxide during exercise were slightly but insignificantly lower after DNase treatment; minimal O2 saturation was unaffected. We conclude that improvement of exercise performance with DNase is restricted to a subgroup of CF patients and may not be predicted or identified by spirometry and subject report alone.

Dornase alfa in the treatment of cystic fibrosis in Europe: a report from the Epidemiologic Registry of Cystic Fibrosis

Dornase alfa (Pulmozyme) treatment for patients with cystic fibrosis (CF) has been shown to improve pulmonary function and reduce exacerbations of infection in a number of placebo-controlled double-blind studies. Data in the Epidemiologic Registry of Cystic Fibrosis (ERCF) in November 1998 were used to assess the long-term effectiveness in routine clinical practice of dornase alfa in terms of pulmonary function and frequency of acute pulmonary exacerbations in CF. At that time, the ERCF contained data on 13,684 CF patients, with a mean observation period of 2.3 years. To be included in the analysis, patients had to have 2 years of data in the Registry in appropriate detail. Overall, untreated patients showed a decline in forced expiratory volume in 1 sec over a 2-year period of -2.3% predicted, but treated patients were stable, showing a change of 0.3% predicted, i.e., a treatment benefit of 2.5%. Compared to untreated patients, there were 25 fewer exacerbations per 100 treated patients per year. The analysis suggested that younger patients were likely to benefit more from treatment. The findings of randomized clinical trials were supported by the data collected in routine clinical practice.

Traitements inhales bronchodilatateurs et fluidifiants dans la mucoviscidose

Poor clearance of airway secretions contributes to the pulmonary disease in cystic fibrosis (CF). Bronchodilator therapy might benefit in CF, but the efficacy is controversial. Effects of mucolytic agents have not been demonstrated conclusively. Only, efficacy of recombinant human deoxyribonuclease (rhDNase) is established with a rapid onset of benefit.

Recombinant human deoxyribonuclease for cystic fibrosis

BACKGROUND

Recombinant human deoxyribonuclease (rhDNase) is currently used to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis.

OBJECTIVES

To determine whether the use of rhDNase in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other mucolytics and to identify any adverse events associated with its use.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences. Date of the most recent search of the Group's register: January 2003.

SELECTION CRITERIA

All randomized and quasi-randomized controlled trials where rhDNase was compared to either placebo, standard therapy or another mucolytic.

DATA COLLECTION AND ANALYSIS

Trials were independently assessed for inclusion criteria and the lead reviewer and a colleague carried out analysis of methodological quality and data extraction.

MAIN RESULTS

The searches identified 38 trials, of which 12 trials met our inclusion criteria, including a total of 2294 participants. Three additional studies examined the health care cost from one of the clinical trials. Ten studies compared rhDNase to placebo; one compared daily rhDNase with hypertonic saline and alternate day rhDNase; and one compared daily rhDNase to hypertonic saline. Study duration varied from six days to two years. The number of deaths was not significant between treatment groups. Lung function improved in the treated groups, with significant differences at one month, three months, six months and two years. The mean percentage change in FEV1in the two largest trials were 5.80 (95% CI 3.99 to 7.61) and 3.24 (95% CI 1.03 to 5.45). There was no excess of adverse effects except voice alteration (and rash, which were reported more frequently in one trial in the treated groups. Insufficient data were available to analyse differences in antibiotic treatment, inpatient stay and quality of life.

REVIEWER'S CONCLUSIONS

There is evidence to show that therapy with rhDNase over a one month period is associated with an improvement in lung function in CF, results from a trial lasting six months also showed the same effect. Therapy over a two year period (based on one trial) significantly improved FEV1 in children and there was a non-significant reduction in the risk of infective exacerbations. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials.

[Complementary therapies in cystic fibrosis: evidence of therapeutic benefits and treatment recommendations]

Cystic fibrosis (CF) is an autosomal-recessive disorder that predominantly affects the respiratory system. When this disease was described in 1938 the mortality rate was approximately 70 % in the first year of life. Survival has dramatically increased from a median of approximately 4 years in the 1960s to 19 years in the 1970s and 33 years in 2001 according to figures from the American Cystic Fibrosis Foundation. This impressive increase in the life expectancy of individuals with CF is undoubtedly related to recent advances in the organization of specialized CF units and to the use of new therapies against respiratory involvement.The traditional basis of treatment for CF lung disease includes nutritional support, antibiotic therapy, chest physical therapy and aerobic exercise. Preventive measures such as influenza vaccination and avoidance of tobacco smoke are also useful. Several new approaches such as ion transport therapy, protein therapy and gene therapy are currently being developed. Many studies have provided clear evidence of the therapeutic benefits of antibiotics, respiratory physiotherapy, exercise, and nutrition. In this article we review the scientific evidence on the advantages of the use of several therapeutic interventions against inflammation, increased sputum viscoelasticity and adhesiveness, and bronchial obstruction in CF patients.

Outcomes of intensive care unit care in adults with cystic fibrosis

Cystic fibrosis (CF) causes progressive respiratory failure and death in more than 90% of patients. Mechanical ventilation has been discouraged in CF because of poor outcomes, but improved survival and the availability of lung transplantation have increased the indications for care of CF patients in the intensive care unit (ICU). We studied the outcomes of all CF patients admitted to the University of North Carolina Hospitals Medical ICU from January 1990 through December 1998. Seventy-six patients, ranging in ages from 17 to 45 yr (mean: 27 yr), and of whom 53% were female, had 136 admissions for exacerbations of CF with respiratory failure (RF, n = 65), hemoptysis (n = 33), antibiotic desensitization (n = 30), pneumothorax (n = 3), or other reasons (n = 5). Eighty-six percent of the patients with hemoptysis and all of those with desensitization and pneumothorax were alive 1 yr after ICU discharge. Of the 42 patients with RF, 37 (88%) required assisted ventilation. Twenty-three (55%) of the patients with RF survived to ICU discharge and 19 (45%) died. Seventeen (40%) of the patients with RF received lung transplants and 14 were alive 1 yr later. Without transplantation, three (7%) of the patients with RF were alive and three (7%) were dead 1 yr later. Sex, body mass index, and respiratory bacteria did not correlate with survival. We conclude that ICU care for adults with CF who have reversible complications is appropriate and effective. Ventilatory support is appropriate for some transplant candidates.

rhDNase therapy for the treatment of cystic fibrosis patients with mild to moderate lung disease

OBJECTIVE

To assess the cost-effectiveness of rhDNase (Pulmozyme(R)) for patients with cystic fibrosis (CF) aged 5 years or more, with mild to moderate lung disease. The review addresses four questions: a) does rhDNase therapy work in the short term?, b) does rhDNase therapy work more effectively in certain groups of patients?, c) does rhDNase therapy work in the long term? and d) what is the cost-effectiveness of rhDNase therapy?

METHODS

A structured rapid review with modelling and cost-effectiveness calculations. Electronic searches were carried out to identify randomised controlled trials (RCTs), systematic reviews, epidemiological and economic information. Databases searched included Cochrane Library, Medline, Healthstar, Embase, PreMedline and NHS Economic Evaluation Database (NHS EED). Exclusion criteria were trials of very short duration (14 days or less) and those which looked at CF patients with severe lung disease. Open label extensions providing information on longer term outcomes were included.

RESULTS

Nine published RCTs were identified, although only one met the inclusion criteria. This large RCT was of good methodological quality, and shows that treatment with rhDNase over a 6-month period improves lung function, and decreases the risk of respiratory exacerbations. Expert opinion suggests that there are identifiable subgroups of patients showing improvement, little or no change, and deterioration after treatment with rhDNase. However, the best supporting evidence for this comes from a retrospective case series, showing that response to rhDNase is highly variable, and that early improvement was a good predictive marker for long-term benefit. Evidence for the long-term impact of rhDNase is not yet available from any RCTs. A simplified model was therefore developed to estimate the decline in lung function for patients treated with rhDNase, compared with those who were not treated. From this model it appears that the continued use of rhDNase over the lifetime of a CF patient might extend their life expectancy by 2 years. If treatment is limited to a subgroup of patients with moderate lung disease who respond to treatment, the continued use of rhDNase might extend their life expectancy by 7 years. Using the model, the discounted cost per life year gained for all patients is estimated at approximately pound52 500, with a range of between approximately pound25 000-57 000 from sensitivity analysis. For the subgroup of patients, the discounted cost per life year gained is estimated at approximately pound16 000, with a range of between approximately pound18 000-36 600 from sensitivity analysis.

CONCLUSIONS

Although there is short-term evidence that the use of rhDNase improves lung function and decreases the risk of respiratory exacerbations, at present there is no evidence from RCTs to indicate whether this effect is sustained over a longer time period, or whether rhDNase is associated with a reduction in mortality. RCTs to date have been of insufficient duration to answer important questions about long term outcomes, particularly the effects of rhDNase on lung function, respiratory exacerbations and mortality. Further long-term research is needed, with economic analysis to evaluate the long term cost-effectiveness of rhDNase. Research is also needed to identify, in advance, which patients would benefit most from this expensive treatment.

Targeting of dornase alpha therapy in adult cystic fibrosis

Although dornase alpha (recombinant human DNase) can thin the viscid pulmonary secretions of cystic fibrosis (CF), clinical trials in groups of unselected patients have shown only modest average improvements in pulmonary function. The product is very expensive, so in conjunction with purchasers we designed selection criteria and a protocol for a 2-week trial to target CF individuals who might gain most benefit. Treatment was to be continued in those showing > or = 10% improvement in pulmonary function. Those who had a trial of dornase alpha were followed up for 2 years. Of 25 patients who had a 2-week trial of dornase alpha, 17 met the criteria for continuation (average gain in forced expiratory volume 37%). The 11 of these who were still alive at 2 years had a greater initial average FEV1 improvement than those who had died (45% versus 22%), and still had an average improvement of 31% at 2 years. The 8 patients who did not meet the criteria for continuation were older and had required fewer intravenous antibiotic courses. All these were alive at 2 years with unchanged clinical indices. This method of selection for dornase alpha treatment allows targeting to those who gain most benefit without disadvantaging the remaining patients. Furthermore, production of such guidelines in conjunction with purchasers obviates funding difficulties and allows rational prescribing.

RhDNase I aerosol deposition and related factors in cystic fibrosis

To identify factors influencing lung dose of aerosolized recombinant human deoxyribonuclease (rhDNase I), we used gamma camera and filter techniques to measure deposition in 15 clinically stable patients with cystic fibrosis (CF) (five males and 10 females, age 6-31 yr, mean 16.9) who were on chronic daily therapy. Total and regional deposition were correlated with breathing pattern, pulmonary function, demographic factors, and disease severity. In addition, the effects of each patient's measured lung dose on pulmonary function was estimated by stopping the drug and observing changes in spirometry over a 2-wk follow-up period. After discontinuance of the drug, all patients reported worsening of dyspnea and difficulty producing sputum. There was a significant decrease in FEV1 (% predicted, mean +/- SE, 86.9% +/- 5.57 to 77.8% +/- 5.73, p < 0.005), but all patients completed the study. In some patients, as much as 48% of the deposited aerosol was found in the pharynx (range 0.0 to 0.30 mg, mean 0.089 mg +/- 0.029), and pharyngeal deposition correlated negatively with tidal volume (r = -0.696, p < 0.006) and age (r = -0.743, p < 0.005). For the lungs, deposition ranged between 0.16 mg and 0.78 mg of the 2.5 mg nebulizer dose (mean 0.47 +/- 0.04 mg) and correlated negatively with FEV1 (% predicted, r = -0.611, p = 0.0152). However, the spirometric decrements following cessation of therapy did not correlate with the lung dose of the drug. Analysis of regional deposition within the lungs indicated a wide range of distribution between central and peripheral zones. In conclusion, the deposition pattern of rhDNase I aerosols in patients with CF is largely influenced by respiratory physiology, which itself depends upon age and severity of lung disease. As the patients grow there is a decrease in upper airway deposition and more particles are presented to the lungs where those patients with more airways disease have enhanced pulmonary deposition. Upper airway deposition of rhDNase I is significant, especially in younger patients, and may be related to laryngeal side effects.

Retrospective review of the effects of rhDNase in children with cystic fibrosis

Trials of rhDNase in mixed groups of adults and children with cystic fibrosis (CF) have demonstrated improvements in lung function and well-being. This has led to many pediatric CF patients receiving regular rhDNase therapy although their response to treatment may not be the same as that seen in adults. We have retrospectively reviewed the effects of rhDNase during the first year of therapy in 65 children receiving the drug at two tertiary referral centers. Outcome measures included changes in lung function, oxygen saturation, use of intravenous antibiotics, and subjective improvement. Median baseline lung function (% of predicted) was 45% for forced expiratory volume in 1 second (FEV1) and 58% for forced vital capacity (FVC). At 3-4 months following initiation of therapy the group demonstrated median (95% CI) increases of 14.2% (95% CI 7.3; 21.1%) in FEV1 and 7% (0; 14%) in FVC. Within this wide scatter of responses, one-quarter of children deteriorated, but almost 50% showed significant improvements of > 10%. A similar pattern was seen at 9 months, with median increases for the group of 11.1% (0; 18.8%) in FEV1 and 5.6% (0; 17%) in FVC, again with approximately one-third of the group deteriorating and one-half improving significantly. Intravenous antibiotic use decreased significantly. Almost all the children (89%), including those with a fall in lung function, described subjective improvement. There were no predictive markers at baseline of a good response to the drug. However, there was a good correlation between lung function response at 3 months and that at 6, 9, and 12 months. Thus, children respond to rhDNase at least as well as adults, and a therapeutic trial is justified in those over 5 years with significantly impaired lung function. Response is highly variable, making careful individual assessment mandatory. Baseline characteristics are not useful in predicting those children who will respond well to treatment, but long-term response to the drug can be predicted on the basis of spirometric improvement at 3 months. Therefore, this would be a useful time period for a therapeutic trial.

[New prospects in cystic fibrosis treatment]

Only a few years ago, cystic fibrosis (CF) was considered the most frequent genetic disease in childhood, although survival has increased considerably in recent years owing to improved treatment. We discuss treatments that are still relevant as well as others that are under investigation now, aiming for better understanding of the disease and the therapies that have improved quality of life for CF patients.

Effect of nebulised recombinant DNase on neutrophil elastase load in cystic fibrosis

BACKGROUND

DNA released by degenerating inflammatory neutrophils contributes to mucous plugging of airways in patients with cystic fibrosis. Neutrophil elastase, a major effector of tissue destruction in the lungs of patients with cystic fibrosis, is a highly cationic molecule which is bound and inhibited by negatively charged polyanions such as mucin and DNA in purulent sputum. Thus, the solubilisation of DNA in the airways by aerosolised recombinant DNase may remove a source of neutrophil elastase inhibition, effectively increasing elastase load. The aim of this study was to assess the effect of rhDNase therapy on neutrophil elastase load in patients with cystic fibrosis.

METHODS

Blood and sputum were collected from 15 patients with cystic fibrosis before initiation of nebulised DNase therapy and at 12 weeks following therapy. The long term effects of continuous rhDNase administration were evaluated at 52 weeks for 11 of these patients. Plasma was analysed for neutrophil elastase, interleukin (IL)-8 and neutrophil elastase in complex with alpha 1-protease inhibitor (alpha 1PI). Sputum was assessed for neutrophil elastase, IL-8, and active elastase. At each visit spirometric measurements were carried out.

RESULTS

Sputum elastase activity decreased at 12 weeks and was maintained at 52 weeks when a decline in total plasma elastase was also observed. Although, as expected, there was a correlation between plasma levels of total elastase and neutrophil elastase/alpha 1PI complex, the decrease in the levels of the complex at 52 weeks did not reach statistical significance.

CONCLUSIONS

This study indicates that prolonged daily administration of rhDNase results in a reduction in elastase load in patients with cystic fibrosis.

Referral for lung transplantation: experience of a Birmingham Adult Cystic Fibrosis Centre between 1987 and 1994

BACKGROUND

Whilst much is known of the outcome of lung transplantation for patients with cystic fibrosis, less is known about those patients who are either not referred for transplantation or who die before a donor is available. The referral practice and outcome of all the cystic fibrosis patients in one clinic was documented, whether or not they were assessed for lung transplantation. The results give a perspective on the impact of the current transplantation programmes on the adult cystic fibrosis population as a whole.

METHODS

A retrospective study was made of patient deaths and referrals for lung transplantation between 1987 and 1994 from the Adult Cystic Fibrosis Clinic at Birmingham Heartlands Hospital.

RESULTS

The Birmingham Heartlands Adult Cystic Fibrosis Clinic has managed 192 patients since its beginning and currently cares for 141 patients. Since 1987 there have been 16 deaths in patients with cystic fibrosis who were considered unsuitable for lung transplantation. Of 49 patients referred for lung transplantation, 47 were accepted on to a provisional or active waiting list. The mean (SE) age at referral was 23.9 (0.7) years and mean (SE) forced expiratory volume in one second (FEV1) was 0.87 (0.04) 1. Fourteen patients died whilst awaiting transplantation and 19 received donor lungs. There have been 10 deaths in the transplanted group. Survival following transplantation was 58% at one year and 52% at two years.

CONCLUSION

Most of the deaths that occurred in the Cystic Fibrosis Clinic were in patients who either were not considered suitable for transplantation or were still awaiting transplantation. Whilst lung transplantation is the focus for many adults with cystic fibrosis, lack of donor organs has limited the impact of transplant programmes on the clinic.