The effect of discontinuing hypertonic saline or dornase alfa on mucociliary clearance in elexacaftor/tezacaftor/ivacaftor treated people with cystic fibrosis: The SIMPLIFY-MCC Study

Many people with CF (pwCF) desire a reduction in inhaled treatment burden after initiation of elexacaftor/tezacaftor/ivacaftor. The randomized, open-label SIMPLIFY study showed that discontinuing hypertonic saline (HS) or dornase alfa (DA) was non-inferior to continuation of each treatment with respect to change in lung function over a 6-week period. In this SIMPLIFY substudy, we used gamma scintigraphy to determine whether discontinuation of either HS or DA was associated with deterioration in the rate of in vivo mucociliary clearance (MCC) in participants ≥12 years of age. While no significant differences in MCC endpoints were associated with HS discontinuation, significant improvement in whole and peripheral lung MCC was observed after discontinuing DA. These results suggest that pwCF on ETI with mild lung disease do not experience a subclinical deterioration in MCC that could later impact health outcomes after discontinuing HS, and in fact may benefit from improved MCC after stopping DA treatment.

Safety, tolerability, and effect of a single aural dose of Dornase alfa at the time of ventilation tube surgery for otitis media: A Phase 1b double randomized control trial

BACKGROUND

One third of children require repeat ventilation tube insertion (VTI) for otitis media. Disease recurrence is associated with persistent middle ear bacterial biofilms. With demonstration that Dornase alfa (a DNase) disrupts middle ear effusion biofilms ex vivo, we identified potential for this as an anti-biofilm therapy to prevent repeat VTI. First, safety and tolerability needed to be measured.

METHODS

This was a phase 1B double-blinded randomized control trial conducted in Western Australia. Children between 6 months and 5 years undergoing VTI for bilateral middle ear effusion were recruited between 2012 and 2014 and followed for two years. Children's ears were randomized to receive either Dornase alfa (1 mg/mL) or 0.9 % sodium chloride (placebo) at time of surgery. Children were followed up at 2 weeks post-VTI and at 3-monthly intervals for 2 years. Outcomes assessed were: 1) safety and tolerability, 2) otorrhoea frequency, 3) blocked or extruded ventilation tube (VT) frequency, 4) time to blockage or extrusion, 5) time to infection recurrence and/or need for repeat VTI.

RESULTS

Sixty children (mean age 2.3 years) were enrolled with 87 % reaching study endpoint. Treatment did not change otorrhoea frequency. Hearing improved in all children following VTI, with no indication of ototoxicity. Dornase alfa had some effect on increasing time until VT extrusion (p = 0.099); and blockage and/or extrusion (p = 0.122). Frequency of recurrence and time until recurrence were similar. Fourteen children required repeat VTI within the follow-up period.

CONCLUSION

A single application of Dornase alfa into the middle ear at time of VTI was safe, non-ototoxic, and well-tolerated.

TRIAL REGISTRATION

ACTRN12623000504617.

Bladder cancer patients have increased NETosis and impaired DNaseI-mediated NET degradation that can be therapeutically restored in vitro

Background

Neutrophils, key players of the immune system, also promote tumor development through the formation of neutrophil extracellular traps (NETs) in a process called NETosis. NETs are extracellular networks of DNA, histones and cytoplasmic and granular proteins (calprotectin, myeloperoxidase, elastase, etc.) released by neutrophils upon activation. NETs regulate tumor growth while promoting angiogenesis and invasiveness, and tumor cells also stimulate NETosis. Although NETosis seems to be increased in cancer patients, an increase of NETs in plasma may also be mediated by an impaired degradation by plasma DNaseI, as evidenced in several immunological disorders like lupus nephritis. However, this has never been evidenced in bladder cancer (BC) patients. Herein, we aimed to evaluate the occurrence of increased NETosis in plasma and tumor tissue of BC patients, to ascertain whether it is mediated by a reduced DNaseI activity and degradation, and to in vitro explore novel therapeutic interventions.

Methods

We recruited 71 BC patients from whom we obtained a plasma sample before surgery and a formalin-fixed paraffin embedded tumor tissue sample, and 64 age- and sex-matched healthy controls from whom we obtained a plasma sample. We measured NETs markers (cell-free fDNA, calprotectin, nucleosomes and neutrophil elastase) and the DNaseI activity in plasma with specific assays. We also measured NETs markers in BC tissue by immunofluorescence. Finally, we evaluated the ability of BC and control plasma to degrade in vitro-generated NETs, and evaluated the performance of the approved recombinant human DNaseI (rhDNaseI, Dornase alfa, Pulmozyme^®, Roche) to restore the NET-degradation ability of plasma. In vitro experiments were performed in triplicate. Statistical analysis was conducted with Graphpad (v.8.0.1).

Results

NETosis occurs in BC tissue, more profusely in the muscle-invasive subtype (P<0.01), that with the worst prognosis. Compared to controls, BC patients had increased NETosis and a reduced DNaseI activity in plasma (P<0.0001), which leads to an impairment to degrade NETs (P<0.0001). Remarkably, this can be therapeutically restored with rhDNaseI to the level of healthy controls.

Conclusion

To the best of our knowledge, this is the first report demonstrating that BC patients have an increased NETosis systemically and in the tumor microenvironment, in part caused by an impaired DNaseI-mediated NET degradation. Remarkably, this defect can be therapeutically restored in vitro with the approved Dornase alfa, thus Pulmozyme^® could become a potential therapeutic tool to locally reduce BC progression.

Use of dornase alfa in pediatric patients without cystic fibrosis

OBJECTIVES

Literature regarding clinical benefits of dornase alfa (DNase) in pediatric patients without cystic fibrosis is lacking. In December 2020, the study institution implemented restrictions to limit DNase use in this patient population. The primary objective was adherence to DNase ordering restrictions. Secondary objectives included length of stay, respiratory function, and use of inhaled mucolytic agents.

METHODS

This single-center retrospective chart review included patients less than 18 years of age who received DNase one year prior to through one year after order restriction implementation. Data collected included patient demographics and respiratory clinical parameters. Dosing regimens for DNase, n-acetylcysteine, and hypertonic saline were collected, as well as changes in length of stay (LOS) and adherence to ordering restrictions.

RESULTS

Of 101 total DNase orders, 45 were placed after implementation of ordering restrictions and 16 (36%) met all ordering criteria. Hospital and intensive care unit (ICU) LOS after implementation of restrictions were not significantly different (p = 0.767 and p = 0.219, respectively). There was no significant change in patients' mean oxygenation index (p = 0.252) or FiO2% (p = 0.113) 24 hours after DA administration.

CONCLUSION

Respiratory function did not significantly change after DNase administration. Implementing restrictions on DNase did not impact intensive care unit or hospital LOS. Adherence to DNase ordering restrictions could be improved.

Resolution of lobe collapse in a child with cystic fibrosis with Mycobacterium abscessus using serial intrabronchial rhDNase

An eight-year-old girl with cysticfibrosis (CF) developed a left upper lobe collapse failing to resolve withinitial conventional antibiotic treatment, mucolytics and intensifiedphysiotherapy. Mycobacterium abscessus was isolated from her sputum. Bronchoscopy revealed thick viscousmucus plugging of the left upper lobe bronchus with complete obliteration.Three bronchoscopies with saline lavage and Dornase alfa, a rhDNase, at the endof each procedure resulted in removal of this mucus plug and the re-inflationof the affected lobe, with clinical and radiological resolution. The use of flexible bronchoscopy as a 'secondary' treatment with 0.9% saline lavage and instillation of rhDNase isdescribed sparsely in the literature. This is the first reported successfultherapeutic resolution of a lung collapse in a CF patient with Mycobacteriumabscessus, with sequential therapeutic bronchoscopies with instillation ofDornase alfa. This should be considered for lobar collapse in CF not respondingto the standard therapeutic regime.

Hypertonic saline in people with cystic fibrosis: review of comparative studies and clinical practice

Cystic fibrosis (CF) is a multisystem disorder, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. These cause a reduced secretion of chloride, a marked absorption of sodium and, therefore, of water, through the epithelium, resulting in the formation of thickened secretions in organs such as lung or pancreas. These viscous secretions lead to airway obstruction, chronic infection and inflammation resulting in progressive lung damage, bronchiectasis and eventual respiratory failure. Although the average life expectancy has increased over the last 30 years, lung disease is the most common cause of death in people with CF. For these reasons, the improvement of sputum clearance is a major therapeutic aim in CF and early initiation of airway clearance is widely recommended and implemented. Symptomatic mucolytic therapy today is mainly based on inhalation of DNase, hypertonic saline or mannitol, in combination with physiotherapy. Mucolytic agents break down the gel structure of mucus and therefore decrease its elasticity and viscosity, reducing the pulmonary exacerbation frequency and to improve and stabilize lung function. Nevertheless, high quality studies comparing these mucolytic drugs are still few, and the individual experiences of patients and caregivers explain the high variability of their use globally. This review will summarize the current knowledge on hypertonic saline in the treatment of CF lung disease. Furthermore, we report the real-world prescription of inhaled mucolytic agents in CF.

Withdrawal of dornase alfa increases ventilation inhomogeneity in children with cystic fibrosis

BACKGROUND

The lung clearance index (LCI) is increasingly used as an outcome in clinical trials of patients with mild cystic fibrosis (CF) lung disease. Yet, understanding the impact of standard CF respiratory therapy on LCI is needed. We assessed to what degree withdrawal of nebulised dornase alfa affected LCI in school-age children with CF not receiving CFTR modulators or hydrator therapy.

METHODS

A single-centre, randomised, controlled, parallel group study to determine effects of one month's withdrawal of nebulised dornase alfa (intervention) in 5-18 years old children with CF. Remaining chronic maintenance therapy stayed unchanged. Outcome measures were assessed at two visits one month apart. Primary outcome was absolute change in LCI. Secondary outcomes were FEV₁, FEF_25-75 and CF Questionnaire-revised (CFQ-R) respiratory symptom score. Possible harmful effects were assessed by comparing the occurrence of pulmonary exacerbations between groups.

RESULTS

Twenty-eight children (median age 10.4 [interquartile range: 7.6; 13.5] years) with CF received standard care (n = 14) or intervention (n = 14). Compared with the control group, LCI increased (worsened) 1.74 (95% confidence interval: 0.62; 2.86) during withdrawal of dornase alfa, while FEV₁ (-6.8% predicted) and FEF_25-75 (-13.1% predicted) decreased significantly. Change in CFQ-R respiratory symptom score and the occurrence of pulmonary exacerbations did not differ significantly between groups.

CONCLUSIONS

One month's withdrawal of dornase alfa caused increasing ventilation inhomogeneity and deteriorating FEV₁ and FEF_25-75 in school-age children with mild CF. Hence, adherence to dornase alfa optimally needs to be addressed when using LCI and spirometric parameters as endpoints, even in short-term clinical trials.

Nebulized in-line endotracheal dornase alfa and albuterol administered to mechanically ventilated COVID-19 patients: a case series

Background

Mechanically ventilated patients with COVID-19 have a mortality of 24–53%, in part due to distal mucopurulent secretions interfering with ventilation. DNA from neutrophil extracellular traps (NETs) contribute to the viscosity of mucopurulent secretions and NETs are found in the serum of COVID-19 patients. Dornase alfa is recombinant human DNase 1 and is used to digest DNA in mucoid sputum. Here, we report a single-center case series where dornase alfa was co-administered with albuterol through an in-line nebulizer system.

Methods

Demographic and clinical data were collected from the electronic medical records of five mechanically ventilated patients with COVID-19—including three requiring veno-venous extracorporeal membrane oxygenation—treated with nebulized in-line endotracheal dornase alfa and albuterol, between March 31 and April 24, 2020. Data on tolerability and response were analyzed.

Results

The fraction of inspired oxygen requirements was reduced for all five patients after initiating dornase alfa administration. All patients were successfully extubated, discharged from hospital and remain alive. No drug-associated toxicities were identified.

Conclusions

Results suggest that dornase alfa will be well-tolerated by patients with severe COVID-19. Clinical trials are required to formally test the dosing, safety, and efficacy of dornase alfa in COVID-19, and several have been recently registered.

Efficacy and safety of aerosolized intra-tracheal dornase alfa administration in patients with SARS-CoV-2-induced acute respiratory distress syndrome (ARDS): a structured summary of a study protocol for a randomised controlled trial

OBJECTIVES

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) may trigger severe pneumonia in coronavirus disease of 2019 (COVID-19) patients through release of damage-associated molecular patterns (DAMPs) and recruitment of neutrophils in the lungs. Activated neutrophils induce inflammation and severe alveolar injury by releasing neutrophil extracellular traps (NETs). The backbones of many DAMPs and NETs are made of extracellular, cell-free DNA decorated with highly toxic compounds such as elastase, myeloperoxidase and citrullinated histones. Dornase alfa is a FDA-approved recombinant human DNAse 1 for the treatment of cystic fibrosis, which cleaves extracellular DNA and may break up cell-free DNA, loosening sticky mucus in the distal airways and reducing NETs-induced toxicity on alveolar pneumocytes. The COVIDornase trial intends to define the impact of aerosolized intra-tracheal dornase alfa administration on the severity and progression of acute respiratory distress syndrome (ARDS) in COVID-19 patients. This drug might make lung mucus thinner and looser, promoting improved clearance of secretions and reduce extracellular double-stranded DNA-induced hyperinflammation in alveoli, preventing further damage to the lungs.

TRIAL DESIGN

COVIDornase is a prospective, randomized, controlled, 2-arm (1:1 ratio), multicentric, open-label clinical trial.

PARTICIPANTS

The study will recruit mechanically ventilated patients hospitalized in the intensive care unit (ICU) in the recruiting centres (at the time of writing: The Rothschild foundation hospital in Paris, the Strasbourg university hospitals, and Metz-Thionville hospital) who have been diagnosed with COVID-19 and meet ARDS criteria.

INCLUSION CRITERIA

- Adult patient (age ≥ 18 years old); - Hospitalized in ICU; - With severe COVID-19 pneumonia and ARDS according to Berlin criteria (PaO2/FiO2 < 300 and PEEP > 5 cmH2O); - Intubated for less than 8 days; - With an anticipated duration of mechanical ventilation > 48 hours; - Carrier of an arterial catheter; - For whom 4 PaO2/FiO2 values over the preceding 24 hours are available; NON-INCLUSION CRITERIA: - Known hypersensitivity to dornase alfa or any of its excipients; - Pregnant or breastfeeding status; - Patient under legal protection.

INTERVENTION AND COMPARATOR

Intervention 1, Study group Dornase alfa (Pulmozyme®, Roche, Switzerland) will be administered by aerosol, at a dose of 2500 IU twice daily, 12 hours apart, for 7 consecutive days, using a vibrating mesh nebulizer (Aerogen Solo®, Aerogen, Ireland). The remainder of the management will be performed in accordance with good clinical practice, including mechanical ventilation (protective ventilation, PEEP > 5 cmH2O, tracheal balloon pressure check every 4 hours or automatic device, 30° head of the bed elevation, tidal volume 6-8mL/kg, plateau pressure < 30 cmH2O), neuromuscular blockers if necessary, prone position if PaO2/FiO2 < 150, early enteral nutrition, glycemic control and a sedation protocol based on the RASS score. Intervention 2, Comparator Patients will receive usual care in accordance with good practice (as detailed above), without aerosols.

MAIN OUTCOMES

The primary outcome is the occurrence of at least one grade improvement between D0 (inclusion) and D7 in the ARDS scale severity (Berlin criteria). For instance from "severe" to "moderate" or from "moderate" to "mild".

RANDOMISATION

All consecutive patients meeting the inclusion criteria will be randomised 1:1 using an eCRF-based, computer-generated randomisation table, either to the dornase alfa arm or to the control arm. An interim analysis will be performed after inclusion of 20 patients. Inclusions may be stopped at the interim analysis per data safety and monitoring board (DSMB) advice, if statistical analyses conclude on the futility or efficacy of the intervention or by other DSMB decision.

BLINDING (MASKING)

The participants and caregivers will not be blinded to study group assignment. Those assessing the outcomes will be blinded to study group assignment.

NUMBERS TO BE RANDOMISED (SAMPLE SIZE)

Fifty patients will be randomized to each group, 100 patients in total.

TRIAL STATUS

Protocol version number 2, April 29th, 2020. Recruitment is ongoing. The trial started recruitment on the 21st April 2020. We estimate recruitment will finish August 21st 2020.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.gov on 21 April 2020, updated on 8 May 2020. Trial registration number is NCT04355364.

FULL PROTOCOL

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated. This Letter serves as a summary of the key elements of the full protocol.

Randomized trial of efficacy and safety of dornase alfa delivered by eRapid nebulizer in cystic fibrosis patients

BACKGROUND

Dornase alfa administered via jet nebulizer is indicated as a chronic respiratory medication for cystic fibrosis (CF) patients. Efficacy and safety of dornase alfa via an electronic nebulizer with vibrating membrane technology have not been formally assessed in randomized clinical trials.

METHODS

87 CF patients (≥6 years) were randomized in a crossover study to receive dornase alfa 2.5 mg/d in 2-week periods with the Pari eRapid and Pari LC Plus jet nebulizers. The primary end point was comparison of forced expiratory volume in the first second. Safety, quality of life, and treatment satisfaction/preference were also compared between devices.

RESULTS

Lung function was equivalent between nebulizers. Most domain scores from the Cystic Fibrosis Questionnaire-Revised and Treatment Satisfaction Questionnaire for Medication instruments were similar but patients strongly preferred the eRapid. Mean patient-reported administration times were shorter with the eRapid vs the LC Plus (2.7 vs 10.2 min). Adverse events were similar between devices.

CONCLUSIONS

Administration of dornase alfa via the eRapid nebulizer resulted in comparable efficacy and safety, shorter nebulization times, and higher patient preference.

Model of mucociliary clearance in cystic fibrosis lungs

Mucus clearance is a primary innate defense mechanism in the human airways. Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by dehydration of airway surface liquid and impaired mucociliary clearance. As a result, microorganisms are not efficiently removed from the airways, and patients experience chronic pulmonary infections and inflammation. We propose a new physiologically based mathematical model of muco-ciliary transport consisting of the two major components of the mucociliary clearance system: (i) periciliary liquid layer (PCL) and (ii) mucus layer. We study mucus clearance under normal conditions and in CF patients. Restoring impaired clearance of airway secretions in one of the major goals of therapy in patients with CF. We consider the action of the aerosolized and inhaled medication dornase alfa, which reduces the viscosity of cystic fibrosis mucus, by selectively cleaving the long DNA strands it contains. The results of the model simulations stress the potential relevance of the location of the drug deposition in the central or peripheral airways. Mucus clearance was increased in case the drug was primarily deposited peripherally, i.e. in the small airways.

Sinonasal inhalation of dornase alfa administered by vibrating aerosol to cystic fibrosis patients: a double-blind placebo-controlled cross-over trial

BACKGROUND

Chronic rhinosinusitis significantly impairs CF patients' quality of life and overall health. The Pari-Sinus™ device delivers vibrating aerosol effectively to paranasal sinuses. After a small pilot study to assess sinonasal inhalation of dornase alfa and placebo (isotonic saline) on potential sinonasal outcome measures, we present the subsequent prospective double-blind placebo-controlled crossover-trial.

METHODS

23 CF patients were randomised to inhale either dornase alfa or isotonic saline for 28 days with the Pari-Sinus™ and after 28 days (wash-out) crossed over to the alternative treatment. The primary outcome parameter was primary nasal symptom score in the disease-specific quality of life Sino-Nasal Outcome-Test-20 (SNOT-20: nasal obstruction/sneezing/runny nose/thick nasal discharge/reduced smelling).

RESULTS

Primary nasal symptoms improved significantly with dornase alfa compared with no treatment, while small improvements with isotonic saline did not reach significance. SNOT-20 overall scores improved significantly after dornase alfa compared with isotonic saline (p=0.017). Additionally, sinonasal dornase alfa but not isotonic saline significantly improved pulmonary function (FEF75-25: p=0.021).

CONCLUSION

Vibrating sinonasal inhalation of dornase alfa reduces rhinosinusitis symptoms in CF.

Physicochemical compatibility and stability of nebulizable drug admixtures containing Dornase alfa and tobramycin

The objective of this in-vitro study was to determine whether admixtures of the inhalation solutions Pulmozyme(®) (Dornase alfa) and either Bramitob(®) or Tobi(®) (both containing Tobramycin) are physicochemically compatible and to analyze the aerodynamic parameters of these admixtures. After mixing, test solutions were stored at room temperature and under ambient light conditions over a period of 24 h. Tobramycin concentrations were determined by using a fluorescence immunoassay. Stability of dornase alfa was determined by size-exclusion high performance liquid chromatography, ultraviolet spectroscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis and tentacle strong cation-exchange chromatography. In addition, pH values and osmolality of the admixtures were measured and test solutions were visually examined for any changes up to 24 h. Aerosols of Pulmozyme(®)/Bramitob(®) or Pulmozyme(®)/TOBI(®) admixtures were generated with the PARI eFlow(®) rapid and aerodynamic particle sizing was performed via cascade impaction with the Next Generation Pharmaceutical Impactor. The stability tests revealed that neither the stability of tobramycin nor the stability of dornase alfa was affected by mixing the inhalation products. Cascade impaction showed no relevant changes in particle size distribution, Mass Median Aerodynamic Diameter, Geometric Standard Deviation and Fine Particle Fraction in comparison to aerodynamic parameters of the unmixed solutions. Thus, admixtures of Pulmozyme(®) and either Bramitob(®) or TOBI(®) can be designated as compatible for a 24 h period and simultaneous inhalation is feasible.