Cystic fibrosis is an autosomal recessive disease caused by mutations in the CFTR gene that lead to progressive respiratory decline. Some mutant CFTR proteins show residual function and respond to ...the CFTR potentiator ivacaftor in vitro, whereas ivacaftor alone does not restore activity to Phe508del mutant CFTR.
We conducted a randomized, double-blind, placebo-controlled, phase 3, crossover trial to evaluate the efficacy and safety of ivacaftor alone or in combination with tezacaftor, a CFTR corrector, in 248 patients 12 years of age or older who had cystic fibrosis and were heterozygous for the Phe508del mutation and a CFTR mutation associated with residual CFTR function. Patients were randomly assigned to one of six sequences, each involving two 8-week intervention periods separated by an 8-week washout period. They received tezacaftor-ivacaftor, ivacaftor monotherapy, or placebo. The primary end point was the absolute change in the percentage of predicted forced expiratory volume in 1 second (FEV
) from the baseline value to the average of the week 4 and week 8 measurements in each intervention period.
The number of analyzed intervention periods was 162 for tezacaftor-ivacaftor, 157 for ivacaftor alone, and 162 for placebo. The least-squares mean difference versus placebo with respect to the absolute change in the percentage of predicted FEV
was 6.8 percentage points for tezacaftor-ivacaftor and 4.7 percentage points for ivacaftor alone (P<0.001 for both comparisons). Scores on the respiratory domain of the Cystic Fibrosis Questionnaire-Revised, a quality-of-life measure, also significantly favored the active-treatment groups. The incidence of adverse events was similar across intervention groups; most events were mild or moderate in severity, with no discontinuations of the trial regimen due to adverse events for tezacaftor-ivacaftor and few for ivacaftor alone (1% of patients) and placebo (<1%).
CFTR modulator therapy with tezacaftor-ivacaftor or ivacaftor alone was efficacious in patients with cystic fibrosis who were heterozygous for the Phe508del deletion and a CFTR residual-function mutation. (Funded by Vertex Pharmaceuticals and others; EXPAND ClinicalTrials.gov number, NCT02392234 .).
Combination treatment with the cystic fibrosis transmembrane conductance regulator (CFTR) modulators tezacaftor (VX-661) and ivacaftor (VX-770) was designed to target the underlying cause of disease ...in patients with cystic fibrosis.
In this phase 3, randomized, double-blind, multicenter, placebo-controlled, parallel-group trial, we evaluated combination therapy with tezacaftor and ivacaftor in patients 12 years of age or older who had cystic fibrosis and were homozygous for the CFTR Phe508del mutation. Patients were randomly assigned in a 1:1 ratio to receive either 100 mg of tezacaftor once daily and 150 mg of ivacaftor twice daily or matched placebo for 24 weeks. The primary end point was the absolute change in the percentage of the predicted forced expiratory volume in 1 second (FEV
) through week 24 (calculated in percentage points); relative change in the percentage of the predicted FEV
through week 24 (calculated as a percentage) was a key secondary end point.
Of the 510 patients who underwent randomization, 509 received tezacaftor-ivacaftor or placebo, and 475 completed 24 weeks of the trial regimen. The mean FEV
at baseline was 60.0% of the predicted value. The effects on the absolute and relative changes in the percentage of the predicted FEV
in favor of tezacaftor-ivacaftor over placebo were 4.0 percentage points and 6.8%, respectively (P<0.001 for both comparisons). The rate of pulmonary exacerbation was 35% lower in the tezacaftor-ivacaftor group than in the placebo group (P=0.005). The incidence of adverse events was similar in the two groups. Most adverse events were of mild severity (in 41.8% of patients overall) or moderate severity (in 40.9% overall), and serious adverse events were less frequent with tezacaftor-ivacaftor (12.4%) than with placebo (18.2%). A total of 2.9% of patients discontinued the assigned regimen owing to adverse events. Fewer patients in the tezacaftor-ivacaftor group than in the placebo group had respiratory adverse events, none of which led to discontinuation.
The combination of tezacaftor and ivacaftor was efficacious and safe in patients 12 years of age or older who had cystic fibrosis and were homozygous for the CFTR Phe508del mutation. (Funded by Vertex Pharmaceuticals; EVOLVE ClinicalTrials.gov number, NCT02347657 .).
Cystic fibrosis: a clinical view Castellani, Carlo; Assael, Baroukh M.
Cellular and molecular life sciences : CMLS,
01/2017, Letnik:
74, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Cystic fibrosis (CF), a monogenic disease caused by mutations in the CFTR gene on chromosome 7, is complex and greatly variable in clinical expression. Airways, pancreas, male genital system, ...intestine, liver, bone, and kidney are involved. The lack of CFTR or its impaired function causes fat malabsorption and chronic pulmonary infections leading to bronchiectasis and progressive lung damage. Previously considered lethal in infancy and childhood, CF has now attained median survivals of 50 years of age, mainly thanks to the early diagnosis through neonatal screening, recognition of mild forms, and an aggressive therapeutic attitude. Classical treatment includes pancreatic enzyme replacement, respiratory physiotherapy, mucolitics, and aggressive antibiotic therapy. A significant proportion of patients with severe symptoms still requires lung or, less frequently, liver transplantation. The great number of mutations and their diverse effects on the CFTR protein account only partially for CF clinical variability, and modifier genes have a role in modulating the clinical expression of the disease. Despite the increasing understanding of CFTR functioning, several aspects of CF need still to be clarified, e.g., the worse outcome in females, the risk of malignancies, the pathophysiology, and best treatment of comorbidities, such as CF-related diabetes or CF-related bone disorder. Research is focusing on new drugs restoring CFTR function, some already available and with good clinical impact, others showing promising preliminary results that need to be confirmed in phase III clinical trials.
Ivacaftor (VX-770), a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, has been shown to improve lung function, pulmonary exacerbation rate, respiratory symptoms, and weight ...gain compared with placebo in patients with cystic fibrosis aged 12 years or older with a G551D-CFTR mutation.
This randomized, double-blind, placebo-controlled trial evaluated ivacaftor in patients with cystic fibrosis aged 6-11 years with a G551D-CFTR mutation on at least one allele.
Patients were randomly assigned to receive ivacaftor administered orally at 150 mg (n = 26) or placebo (n = 26) every 12 hours for 48 weeks in addition to existing prescribed cystic fibrosis therapies.
Despite near-normal mean baseline values in FEV1, patients receiving ivacaftor had a significant increase in percent predicted FEV1 from baseline through Week 24 versus placebo group (treatment effect, 12.5 percentage points; P < 0.001). Effects on pulmonary function were evident by 2 weeks, and a significant treatment effect was maintained through Week 48. Patients treated with ivacaftor gained, on average, 2.8 kg more than those receiving placebo at Week 48 (P < 0.001). The change from baseline through Week 48 in the concentration of sweat chloride, a measure of CFTR activity, with ivacaftor was -53.5 mmol/L (P < 0.001) versus placebo. The incidence of adverse events was similar in the two groups.
In patients who are younger and healthier than those in previously studied populations, ivacaftor demonstrated a significant improvement in pulmonary function, weight, and CFTR activity compared with placebo. Clinical trial registered with www.clinicaltrials.gov (NCT00909727).
Summary Cystic fibrosis is a common life-limiting autosomal recessive genetic disorder, with highest prevalence in Europe, North America, and Australia. The disease is caused by mutation of a gene ...that encodes a chloride-conducting transmembrane channel called the cystic fibrosis transmembrane conductance regulator (CFTR), which regulates anion transport and mucociliary clearance in the airways. Functional failure of CFTR results in mucus retention and chronic infection and subsequently in local airway inflammation that is harmful to the lungs. CFTR dysfunction mainly affects epithelial cells, although there is evidence of a role in immune cells. Cystic fibrosis affects several body systems, and morbidity and mortality is mostly caused by bronchiectasis, small airways obstruction, and progressive respiratory impairment. Important comorbidities caused by epithelial cell dysfunction occur in the pancreas (malabsorption), liver (biliary cirrhosis), sweat glands (heat shock), and vas deferens (infertility). The development and delivery of drugs that improve the clearance of mucus from the lungs and treat the consequent infection, in combination with correction of pancreatic insufficiency and undernutrition by multidisciplinary teams, have resulted in remarkable improvements in quality of life and clinical outcomes in patients with cystic fibrosis, with median life expectancy now older than 40 years. Innovative and transformational therapies that target the basic defect in cystic fibrosis have recently been developed and are effective in improving lung function and reducing pulmonary exacerbations. Further small molecule and gene-based therapies are being developed to restore CFTR function; these therapies promise to be disease modifying and to improve the lives of people with cystic fibrosis.
We recently established conditions allowing for long-term expansion of epithelial organoids from intestine, recapitulating essential features of the in vivo tissue architecture. Here we apply this ...technology to study primary intestinal organoids of people suffering from cystic fibrosis, a disease caused by mutations in CFTR, encoding cystic fibrosis transmembrane conductance regulator. Forskolin induces rapid swelling of organoids derived from healthy controls or wild-type mice, but this effect is strongly reduced in organoids of subjects with cystic fibrosis or in mice carrying the Cftr F508del mutation and is absent in Cftr-deficient organoids. This pattern is phenocopied by CFTR-specific inhibitors. Forskolin-induced swelling of in vitro-expanded human control and cystic fibrosis organoids corresponds quantitatively with forskolin-induced anion currents in freshly excised ex vivo rectal biopsies. Function of the CFTR F508del mutant protein is restored by incubation at low temperature, as well as by CFTR-restoring compounds. This relatively simple and robust assay will facilitate diagnosis, functional studies, drug development and personalized medicine approaches in cystic fibrosis.
Background
The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gating mutation
G551D
prevents sufficient ion transport due to reduced channel-open probability. Ivacaftor, an oral CFTR ...potentiator, increases the channel-open probability.
Aim
To further analyze improvements in weight and body mass index (BMI) in two studies of ivacaftor in patients aged ≥6 years with CF and the
G551D
mutation.
Methods
Patients were randomized 1:1 to ivacaftor 150 mg or placebo every 12 h for 48 weeks. Primary end point (lung function) was reported previously. Other outcomes included weight and height measurements and CF Questionnaire-Revised (CFQ-R).
Results
Studies included 213 patients (aged ≤ 20 years,
n
= 105; aged > 20 years,
n
= 108). In patients ≤20 years, adjusted mean change from baseline to week 48 in body weight was 4.9 versus 2.2 kg (ivacaftor vs. placebo,
p
= 0.0008). At week 48, change from baseline in mean weight-for-age
z
-score was 0.29 versus −0.06 (
p
< 0.0001); change in mean BMI-for-age
z
-score was 0.26 versus −0.13 (
p
< 0.0001). In patients >20 years, adjusted mean change from baseline to week 48 in body weight was 2.7 versus −0.2 kg (
p
= 0.0003). Mean BMI change at week 48 was 0.9 versus −0.1 kg/m
2
(
p
= 0.0003). There was no linear correlation evident between changes in body weight and improvements in lung function or sweat chloride. Significant CFQ-R improvements were seen in perception of eating, body image, and sense of ability to gain weight.
Conclusions
Nutritional status improved following treatment with ivacaftor for 48 weeks.
Many diseases are driven by proteins that are aberrantly ubiquitinated and degraded. These diseases would be therapeutically benefited by targeted protein stabilization (TPS). Here we present ...deubiquitinase-targeting chimeras (DUBTACs), heterobifunctional small molecules consisting of a deubiquitinase recruiter linked to a protein-targeting ligand, to stabilize the levels of specific proteins degraded in a ubiquitin-dependent manner. Using chemoproteomic approaches, we discovered the covalent ligand EN523 that targets a non-catalytic allosteric cysteine C23 in the K48-ubiquitin-specific deubiquitinase OTUB1. We showed that a DUBTAC consisting of our EN523 OTUB1 recruiter linked to lumacaftor, a drug used to treat cystic fibrosis that binds ΔF508-cystic fibrosis transmembrane conductance regulator (CFTR), robustly stabilized ΔF508-CFTR protein levels, leading to improved chloride channel conductance in human cystic fibrosis bronchial epithelial cells. We also demonstrated stabilization of the tumor suppressor kinase WEE1 in hepatoma cells. Our study showcases covalent chemoproteomic approaches to develop new induced proximity-based therapeutic modalities and introduces the DUBTAC platform for TPS.
Origins of cystic fibrosis lung disease Stoltz, David A; Meyerholz, David K; Welsh, Michael J
The New England journal of medicine,
2015-Jan-22, Letnik:
372, Številka:
4
Journal Article
A fixed-dose combination tablet of the cystic fibrosis transmembrane conductance regulator (CFTR) corrector tezacaftor and the CFTR potentiator ivacaftor with the next-generation CFTR corrector ...elexacaftor (hereafter referred to as elexacaftor/ivacaftor/tezacaftor) Trikafta™ has been developed by Vertex Pharmaceuticals Inc. to treat patients with the most common cystic fibrosis mutation (F508del). Its use has been associated with statistically significant and/or clinically meaningful improvements in lung function and respiratory-related quality of life compared with comparator regimens (placebo or ivacaftor/tezacaftor) in multinational phase II and III studies, and in October 2019 elexacaftor/ivacaftor/tezacaftor was approved by the US FDA for the treatment of cystic fibrosis in patients aged ≥ 12 years who have ≥ 1 F508del mutation in the CFTR gene. A regulatory assessment for elexacaftor/ivacaftor/tezacaftor as a treatment for cystic fibrosis is underway in the EU. This article summarizes the milestones in the development of elexacaftor/ivacaftor/tezacaftor leading to this first approval for the treatment of cystic fibrosis in patients aged ≥ 12 years who have ≥ 1 F508del mutation in the CFTR gene.
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