Effects of Sildenafil on CFTR-dependent Ion Transport Activity
| Status: | Completed |
|---|---|
| Conditions: | Pulmonary |
| Therapuetic Areas: | Pulmonary / Respiratory Diseases |
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 3/21/2019 |
| Start Date: | October 2015 |
| End Date: | May 2017 |
Phase II Study of the Effects of Sildenafil on CFTR-dependent Ion Transport Activity
Dehydrated airway surfaces resulting from sodium hyperabsorption and lack of chloride
secretion are critical to the pathology that leads to the morbidity and mortality from Cystic
Fibrosis (CF) lung disease. Previously published work in CF cell lines has demonstrated that
by increasing cGMP and restoring inhibition of ENaC, sodium hyperabsorption may be reversed
following administration of a phosphodiesterase inhibitor (PDEi,) such as sildenafil.
Additionally it has been shown in CF cell lines and animal models, that phosphodiesterase
inhibitors/analogues can enhance chloride secretion and/or correct surface localization of
ΔF508 CFTR. The goal of this project is to translate the results of this work from the
laboratory into a clinical trial in patients with CF using an FDA-approved therapy. The
Specific Aims of this project are to: 1) Evaluate the effect of systemically administered
phosphodiesterase inhibitors on ion transport in CF by measurement of Na+ and Cl- conductance
by NPD and Na+ and Cl- concentration in sweat utilizing pilocarpine iontophoresis 2) To
establish appropriate dosing of sildenafil in CF by performing a dose-escalation study during
which patients are carefully monitored for side effects, plasma sildenafil levels are
obtained and outcome measures are compared based on the dose of sildenafil administered. The
results of this study in conjunction with those from an ongoing study examining the role of
sildenafil as an anti-inflammatory in CF will aid in establishing safety, pharmacokinetics
and mechanism of action of sildenafil in the treatment of CF lung disease.
secretion are critical to the pathology that leads to the morbidity and mortality from Cystic
Fibrosis (CF) lung disease. Previously published work in CF cell lines has demonstrated that
by increasing cGMP and restoring inhibition of ENaC, sodium hyperabsorption may be reversed
following administration of a phosphodiesterase inhibitor (PDEi,) such as sildenafil.
Additionally it has been shown in CF cell lines and animal models, that phosphodiesterase
inhibitors/analogues can enhance chloride secretion and/or correct surface localization of
ΔF508 CFTR. The goal of this project is to translate the results of this work from the
laboratory into a clinical trial in patients with CF using an FDA-approved therapy. The
Specific Aims of this project are to: 1) Evaluate the effect of systemically administered
phosphodiesterase inhibitors on ion transport in CF by measurement of Na+ and Cl- conductance
by NPD and Na+ and Cl- concentration in sweat utilizing pilocarpine iontophoresis 2) To
establish appropriate dosing of sildenafil in CF by performing a dose-escalation study during
which patients are carefully monitored for side effects, plasma sildenafil levels are
obtained and outcome measures are compared based on the dose of sildenafil administered. The
results of this study in conjunction with those from an ongoing study examining the role of
sildenafil as an anti-inflammatory in CF will aid in establishing safety, pharmacokinetics
and mechanism of action of sildenafil in the treatment of CF lung disease.
Inclusion Criteria:
1. Confirmed diagnosis of CF based on the following criteria: Positive sweat chloride
≥60mEq/liter (by pilocarpine iontophoresis) and genotype with two F508del CFTR
mutations, and accompanied by one or more clinical features consistent with the CF
phenotype
2. Male or female subjects ≥ 18 years of age
3. FEV1 ≥ 50% predicted (Hankinson)
4. Clinically stable without evidence of acute upper or lower respiratory tract infection
or current pulmonary exacerbation within the 14 days prior to the screening visit
5. Ability to reproducibly perform spirometry (according to ATS criteria)
6. Ability to understand and sign a written informed consent or assent and comply with
the requirements of the study
7. Willing and able to perform nasal potential difference testing
8. No changes in use of nasal medications within 2 weeks of screening visit
9. If on Orkambi, has been on stable Orkambi dose for at least 4 weeks at day 1.
Exclusion Criteria:
1. History of hypersensitivity to sildenafil
2. Use of an investigational agent within the 4-week period prior to Visit 1 (Day 0)
3. Breastfeeding, pregnant, or verbal expression of unwillingness to practice an
acceptable birth control method (abstinence, hormonal or barrier methods, partner
sterilization or intrauterine device) during participation in the study
4. History of significant hepatic (SGOT or SGPT > 3 times the upper limit of normal at
screening, documented biliary cirrhosis, or portal hypertension), cardiovascular
(history of aortic stenosis, coronary artery disease, pulmonary hypertension with
right ventricular systolic pressure >55 mmHg or life-threatening arrhythmia),
neurological (history of stroke), hematologic (history of bleeding diathesis),
ophthalmologic (history of retinal impairment or non-arteritic ischemic optic
neuritis) or renal impairment (creatinine >1.8 mg/dL.)
5. Inability to swallow pills
6. Previous lung transplantation
7. Use of concomitant nitrates, α-blocker, or Ca channel blocker
8. Use of concomitant medications known to be potent inhibitors of CYP3A4 (e.g.
ketoconazole, itraconazole, ritonavir, clarithromycin, erythromycin, rifampin,
verapamil)
9. Presence of a condition or abnormality that in the opinion of the investigator would
compromise the safety of the subject or the quality of the data
10. Weight less than 40 kg
11. History of sputum or throat swab culture yielding Burkholderia cepacia within 2 years
of screening
12. History of nasal disease or nasal surgery that would, in the opinion of the
investigator, impede accurate measurements of NPD
13. Use of anticoagulant medication (e.g. heparin, coumadin)
14. Resting room air oxygen saturation <93%
15. Use of nighttime oxygen
15) History of migraine headaches 16) Baseline BP of < 90/50 mm Hg
We found this trial at
1
site
1400 Jackson St
Denver, Colorado 80206
Denver, Colorado 80206
(303) 388-4461
Principal Investigator: Jennifer L Taylor-Cousar, MD
National Jewish Health National Jewish Health is known worldwide for treatment of patients with respiratory,...
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