Anne Munck

Lumacaftor–Ivacaftor in Patients with Cystic Fibrosis Homozygous for Phe508del CFTR

BACKGROUND Cystic fibrosis is a life-limiting disease that is caused by defective or deficient cystic fibrosis transmembrane conductance regulator (CFTR) protein activity. Phe508del is the most common CFTR mutation. METHODS We conducted two phase 3, randomized, double-blind, placebo-controlled studies that were designed to assess the effects of lumacaftor (VX-809), a CFTR corrector, in combination with ivacaftor (VX-770), a CFTR potentiator, in patients 12 years of age or older who had cystic fibrosis and were homozygous for the Phe508del CFTR mutation. In both studies, patients were randomly assigned to receive either lumacaftor (600 mg once daily or 400 mg every 12 hours) in combination with ivacaftor (250 mg every 12 hours) or matched placebo for 24 weeks. The primary end point was the absolute change from baseline in the percentage of predicted forced expiratory volume in 1 second (FEV1) at week 24. RESULTS A total of 1108 patients underwent randomization and received study drug. The mean baseline FEV1 was 61% of the predicted value. In both studies, there were significant improvements in the primary end point in both lumacaftor-ivacaftor dose groups; the difference between active treatment and placebo with respect to the mean absolute improvement in the percentage of predicted FEV1 ranged from 2.6 to 4.0 percentage points (P<0.001), which corresponded to a mean relative treatment difference of 4.3 to 6.7% (P<0.001). Pooled analyses showed that the rate of pulmonary exacerbations was 30 to 39% lower in the lumacaftor-ivacaftor groups than in the placebo group; the rate of events leading to hospitalization or the use of intravenous antibiotics was lower in the lumacaftor-ivacaftor groups as well. The incidence of adverse events was generally similar in the lumacaftor-ivacaftor and placebo groups. The rate of discontinuation due to an adverse event was 4.2% among patients who received lumacaftor-ivacaftor versus 1.6% among those who received placebo. CONCLUSIONS These data show that lumacaftor in combination with ivacaftor provided a benefit for patients with cystic fibrosis homozygous for the Phe508del CFTR mutation. (Funded by Vertex Pharmaceuticals and others; TRAFFIC and TRANSPORT ClinicalTrials.gov numbers, NCT01807923 and NCT01807949.).

Consensus on the use and interpretation of cystic fibrosis mutation analysis in clinical practice

It is often challenging for the clinician interested in cystic fibrosis (CF) to interpret molecular genetic results, and to integrate them in the diagnostic process. The limitations of genotyping technology, the choice of mutations to be tested, and the clinical context in which the test is administered can all influence how genetic information is interpreted. This paper describes the conclusions of a consensus conference to address the use and interpretation of CF mutation analysis in clinical settings. Although the diagnosis of CF is usually straightforward, care needs to be exercised in the use and interpretation of genetic tests: genotype information is not the final arbiter of a clinical diagnosis of CF or CF transmembrane conductance regulator (CFTR) protein related disorders. The diagnosis of these conditions is primarily based on the clinical presentation, and is supported by evaluation of CFTR function (sweat testing, nasal potential difference) and genetic analysis. None of these features are sufficient on their own to make a diagnosis of CF or CFTR-related disorders. Broad genotype/phenotype associations are useful in epidemiological studies, but CFTR genotype does not accurately predict individual outcome. The use of CFTR genotype for prediction of prognosis in people with CF at the time of their diagnosis is not recommended. The importance of communication between clinicians and medical genetic laboratories is emphasized. The results of testing and their implications should be reported in a manner understandable to the clinicians caring for CF patients.

Efficacy and Safety of Ivacaftor in Patients Aged 6 to 11 Years with Cystic Fibrosis with a G551D Mutation

RATIONALE 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. OBJECTIVES 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. METHODS 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. MEASUREMENTS AND MAIN RESULTS 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. CONCLUSIONS 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).

Treatment of early Pseudomonas aeruginosa infection in patients with cystic fibrosis: the ELITE trial

Rationale Antibiotic therapy for early Pseudomonas aeruginosa infection in patients with cystic fibrosis (CF) is effective, but the optimal therapeutic regimen and duration for early treatment remains unclear. The EarLy Inhaled Tobramycin for Eradication (ELITE) study was designed to assess the efficacy and safety of two regimens (28 and 56 days) of tobramycin inhalation solution (TIS) 300 mg/5 ml twice daily for the treatment of early onset P aeruginosa infection in patients with CF. Methods In this open-label randomised multicentre study, patients with CF (aged ≥6 months) with early P aeruginosa infection were treated for 28 days with TIS twice daily administered by the PARI LC PLUS (PARI GmbH, Starnberg, Germany) jet nebuliser. After 28 days, patients were randomised 1:1 to either stop TIS (n=45) or to receive a further 28 days of TIS (n=43). The primary endpoint was the median time to recurrence of P aeruginosa (any strain). Secondary endpoints included the proportion of patients free of P aeruginosa infection 1 month after cessation of therapy and safety assessments. Results The median time to recurrence of P aeruginosa (any strain) was similar between the two groups. In total, 93% and 92% of the patients were free of P aeruginosa infection 1 month after the end of treatment and 66% and 69% remained free at the final visit in the 28-day and 56-day groups, respectively. TIS was well tolerated. Conclusions Treatment with TIS for 28 days is an effective and well tolerated therapy for early P aeruginosa infection in patients with CF. Trial registration number NCT00391976.

European Cystic Fibrosis Society Standards of Care: Best Practice guidelines.

Specialised CF care has led to a dramatic improvement in survival in CF: in the last four decades, well above what was seen in the general population over the same period. With the implementation of newborn screening in many European countries, centres are increasingly caring for a cohort of patients who have minimal lung disease at diagnosis and therefore have the potential to enjoy an excellent quality of life and an even greater life expectancy than was seen previously. To allow high quality care to be delivered throughout Europe, a landmark document was published in 2005 that sets standards of care. Our current document builds on this work, setting standards for best practice in key aspects of CF care. The objective of our document is to give a broad overview of the standards expected for screening, diagnosis, pre-emptive treatment of lung disease, nutrition, complications, transplant/end of life care and psychological support. For comprehensive details of clinical care of CF, references to the most up to date European Consensus Statements, Guidelines or Position Papers are provided in Table 1. We hope that this best practice document will be useful to clinical teams both in countries where CF care is developing and those with established CF centres.

European best practice guidelines for cystic fibrosis neonatal screening

There is wide agreement on the benefits of NBS for CF in terms of lowered disease severity, decreased burden of care, and reduced costs. Risks are mainly associated with disclosure of carrier status and diagnostic uncertainty. When starting a NBS programme for CF it is important to take precautions in order to minimise avoidable risks and maximise benefits. In Europe more than 25 screening programmes have been developed, with quite marked variation in protocol design. However, given the wide geographic, ethnic, and economic variations, complete harmonisation of protocols is not appropriate. There is little evidence to support the use of IRT alone as a second tier, without involving DNA mutation analysis. However, if IRT/DNA testing does not lead to the desired specificity/sensitivity ratio in a population, a screening programme based on IRT/IRT may be used. Sweat chloride concentration remains the gold standard for discriminating between NBS false and true positives, but age-related changes in sweat chloride should be taken into account. CF phenotypes associated with less severe disease often have intermediate or normal sweat chloride concentrations. Programmes should include arrangements for counselling and management of infants where the diagnosis is not clear-cut. All newborns identified by NBS should be managed according to internationally accepted guidelines. CF centre care and the availability of necessary medication are essential prerequisites before the introduction of NBS programmes. Clear explanation to families of the process of screening and of implications of normal and abnormal results is central to the success of CF NBS programmes. Effective communication is especially important when parents are told that their child is affected or is a carrier. When establishing a NBS programme for CF, attention should be given to ensuring timely and appropriate processing of results, to minimise potential stress for families.

Efficacy and safety of ivacaftor in patients with cystic fibrosis and a non-G551D gating mutation

BACKGROUND Ivacaftor is used to treat patients with CF and a G551D gating mutation; the KONNECTION study assessed the efficacy and safety of ivacaftor in patients with CF and a non-G551D gating mutation. METHODS Patients with CF ≥6-years- old with non-G551D gating mutations received ivacaftor 150mg q12h or placebo for 8weeks in this 2-part, double-blind crossover study (Part 1) with a 16-week open-label extension (Part 2). The primary efficacy outcome was absolute change in FEV1 through 8 and 24weeks of ivacaftor treatment; secondary outcomes were changes in BMI, sweat chloride, and CFQ-R and safety through 8 and 24weeks of treatment. RESULTS Eight weeks of ivacaftor resulted in significant improvements in percent predicted FEV1, BMI, sweat chloride, and CFQ-R scores that were maintained through 24weeks. Ivacaftor was generally well tolerated. CONCLUSIONS Ivacaftor was efficacious in a group of patients with CF who had selected non-G551D gating mutations.

Age-Related Prevalence and Distribution of Nontuberculous Mycobacterial Species among Patients with Cystic Fibrosis

ABSTRACT We studied the prevalence and species distribution of nontuberculous mycobacteria (NTM) in relation to age in 385 patients with cystic fibrosis (CF) (mean age ± standard deviation [range], 12.0 ± 6.1 [1 to 24] years; sex ratio, 0.53) attending three Parisian centers. The overall prevalence of NTM in sputum was 8.1% (31 out of 385). The following NTM were isolated (n = 33): Mycobacterium abscessus (n = 13, 39.4%), Mycobacterium avium complex (MAC) (n = 7, 21.2%), Mycobacterium gordonae (n = 6, 18.2%), and other (n = 7, 21.2%). Sixteen patients met the American Thoracic Society microbiological criteria for NTM infection, including 11 patients positive for M. abscessus, 4 for MAC, and 1 for MAC and Mycobacterium kansasii. The overall prevalence of NTM was significantly lower in patients under 15 years old than for patients equal to or more than 15 years old (4.8 versus 14.9%, respectively; P = 0.001). M. abscessus was isolated at all ages, while MAC was not recovered before 15 years (prevalence of 0.0 and 5.2% in patients aged 1 to 14 and 15 to 24, respectively; P = 0.001).

Outcome of cystic fibrosis-associated liver cirrhosis: management of portal hypertension.

BACKGROUND/AIM Variceal bleeding is the most severe complication in patients with cystic fibrosis-associated liver cirrhosis, who often do not have severe respiratory failure. The advent of liver transplantation has broadened the treatment options. The purpose of this study was to report our experience with the management of portal hypertension. METHODS Clinical and biochemical features, outcome of liver disease and management of portal hypertension were analyzed retrospectively in 44 children with cystic fibrosis-associated liver cirrhosis. RESULTS The mean age at diagnosis of liver cirrhosis was 9 years. Eighty-six per cent of the children developed esophageal varices, 50% of whom bled early in their second decade. Injection sclerotherapy of esophageal varices did not prevent recurrence of bleeding in five of seven children. Elective surgical portosystemic shunting was successfully performed in nine of 11 patients considered being at high risk of bleeding or with recurrent bleeding episodes but without severe pulmonary failure and liver dysfunction, allowing prolonged post-operative survival up to 15 years. Two of three children who underwent isolated liver transplantation for severe portal hypertension died post-operatively. CONCLUSIONS Management emphasis in cystic fibrosis patients with liver cirrhosis should be on control of bleeding and variceal decompression. These results suggest that surgical portosystemic shunting may be considered to relieve portal hypertension in patients without progressive liver failure and severe lung disease as an alternative to liver transplantation. With this policy, patients may be stabilized for many years until progression of liver or lung diseases indicates liver or lung-liver transplantation.

A European consensus for the evaluation and management of infants with an equivocal diagnosis following newborn screening for cystic fibrosis

Screening newborns for cystic fibrosis (CF) is considered to be an ethical undertaking in regions with a significant incidence of the condition. Current screening protocols result in recognition of infants with an equivocal diagnosis. A survey of European practice suggested inconsistencies in the evaluation and management of these infants. We have undertaken a consensus process using a modified Delphi method. This has enabled input of CF specialists from a wide geographical area to a rigorous process that has provided a clear pathway to a consensus statement. A core group produced 21 statements, which were modified over a series of three rounds (including a meeting arranged at the European CF Conference). A final document of 19 statements was produced, all of which achieved a satisfactory level of consensus. The statements cover four themes; sweat testing, further assessments and investigations, review arrangements and database. This consensus document will provide guidance to CF specialists with established screening programmes and those who are in the process of implementing newborn screening in their region.