Lumacaftor/ivacaftor initiation in two liver transplantation patients under tacrolimus and antifungal azoles

The ageing of people living with cystic fibrosis: what to expect now?

The prognosis of people with cystic fibrosis (pwCF) has improved dramatically with the introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulators (CFTRm). The ageing of the cystic fibrosis (CF) population is changing the disease landscape with the emergence of different needs and increasing comorbidities related to both age and long-term exposure to multiple treatments including CFTRm. Although the number of pwCF eligible for this treatment is expected to increase, major disparities in care and outcomes still exist in this population. Moreover, the long-term impact of the use of CFTRm is still partly unknown due to the current short follow-up and experience with their use, thus generating some uncertainties. The future spread and initiation of these drugs at an earlier stage of the disease is expected to reduce the systemic burden of systemic inflammation and its consequences on health. However, the prolonged life expectancy is accompanied by an increasing burden of age-related comorbidities, especially in the context of chronic disease. The clinical manifestations of the comorbidities directly or indirectly associated with CFTR dysfunction are changing, along with the disease dynamics and outcomes. Current protocols used to monitor slow disease progression will need continuous updates, including the composition of the multidisciplinary team for CF care, with a greater focus on the needs of the adult population.

Higher doses of fluconazole are needed to ensure target attainment in critically ill adults on continuous Veno-venous hemodialysis

BACKGROUND

Critically ill patients undergoing Continuous Renal Replacement Therapy (CRRT) are treated with higher doses of fluconazole based on the literature recommendations. However, clinical follow-up data demonstrating the effectiveness of this approach are lacking.

PURPOSE

A retrospective cohort study was conducted to evaluate whether target attainment was achieved with higher doses of fluconazole. Additionally, the study focused on identifying factors that may contribute to variability in fluconazole exposure in these patients.

METHODS

Critically ill patients undergoing Continuous Veno-Venous Hemodialysis (CVVHD) who received either standard or higher doses of intravenous fluconazole were included. Evaluation of target attainment was conducted for each dose regimen.

RESULTS

Administering higher doses resulted in target attainment in 100 % of the patients, indicating that starting with at least 400 mg twice daily is an adequate dosing guideline. In this study, only the dose of fluconazole was found to significantly influence target attainment (p < 0.001), with no other predefined factors identified as having a significant impact.

CONCLUSION

According to the results of the study, increasing the fluconazole dose to at least 400 mg twice daily is sufficient to reach the desired target in critically ill patients undergoing CVVHD.

Subtherapeutic triazole concentrations as result of a drug-drug interaction with lumacaftor/ivacaftor

Lumacaftor/ivacaftor (Orkambi®, LUM/IVA) is indicated for the treatment of cystic fibrosis (CF) patients aged ≥ 2 years with homozygous F580del mutation in the CFTR gene. Triazole fungal agents are used to treat fungal disease in CF. The use of triazoles is limited by pharmacokinetic challenges, such as drug-drug interactions. The most notable drug-drug interaction between triazoles and LUM/IVA is due to strong induction of CYP3A4 and UGT by LUM. In this real-world retrospective observational study, we described the effect of LUM/IVA on the trough concentration of triazoles. Concomitant use of LUM/IVA with itraconazole, posaconazole or voriconazole resulted in subtherapeutic triazole levels in 76% of the plasma samples. In comparison, in patients with triazole agents without LUM/IVA only 30.6% of the plasma samples resulted in subtherapeutic concentrations. Subtherapeutic plasma concentrations of triazoles should be considered in CF patients on LUM/IVA and further research is warranted for other dosing strategies and alternative antifungal therapy.

Evaluation of the drug-drug interaction between triazole antifungals and cystic fibrosis transmembrane conductance regulator modulators in a real-life cohort

Limited data on the clinical management of drug-drug interactions between triazoles and Cystic Fibrosis transmembrane conductance regulator (CFTR) modulators are available. We retrospectively evaluated azole target attainment and dose adaptations in patients from two Dutch CF centres concomitantly receiving triazoles and CFTR modulators. In total, 21 patients with 59 triazole trough concentrations were evaluated. Subtherapeutic concentrations were frequently observed, especially for itraconazole and voriconazole. Of the investigated antifungal agents, posaconazole appears the most preferable option. Our results emphasize the importance of adequate management of this interaction and underpin the added value of therapeutic drug monitoring of triazoles in this population.

Unmet challenges in cystic fibrosis treatment with modulators

INTRODUCTION

'Highly effective' modulator therapies (HEMTs) have radically changed the Cystic Fibrosis (CF) therapeutic landscape.

AREAS COVERED

A comprehensive search strategy was undertaken to assess impact of HEMT in life of pwCF, treatment challenges in specific populations such as very young children, and current knowledge gaps.

EXPERT OPINION

HEMTs are prescribed for pwCF with definite genotypes. The heterogeneity of variants complicates treatment possibilities and around 10% of pwCF worldwide remains ineligible. Genotype-specific treatments are prompting theratyping and personalized medicine strategies. Improvement in lung function and quality of life increase survival rates, shifting CF from a pediatric to an adult disease. This implies new studies addressing long-term efficacy, side effects, emergence of adult co-morbidities and possible drug-drug interactions. More sensitive and predictive biomarkers for both efficacy and toxicity are warranted. As HEMTs cross the placenta and are found in breast milk, studies addressing the potential consequences of treatment during pregnancy and breastfeeding are urgently needed. Finally, although the treatment and expected outcomes of CF have improved dramatically in high- and middle-income countries, lack of access in low-income countries to these life-changing medicines highlights inequity of care worldwide.

Use of CFTR modulators in special populations, part 3: Solid organ transplant

BACKGROUND

Solid organ transplant (SOT) recipients with cystic fibrosis (CF) may benefit from the pulmonary and extrapulmonary benefits associated with CF transmembrane conductance regulator modulators. Nevertheless, evolution of modulator safety and efficacy data prompts consideration.

METHODS

The search terms "transplant" AND "ivacaftor"(IVA) OR "lumacaftor"(LUM) OR "tezacaftor" (TEZ) OR "elexacaftor" (ELX) were utilized to conduct a scoping review of English articles from the period of January 1, 2012 to December 31, 2022. Search results from PubMed and Embase databases were reviewed by title and abstract for relevance. Included studies reported efficacy and safety outcomes of modulators in SOT recipients.

RESULTS

One hundred thirty-six patients from one cohort study (90 lung transplant recipients) and eight case reports and series (29 lung transplant recipients, 16 liver transplant recipients and one lung/liver transplant patient) were included. Post-modulator initiation, 33 patients did not necessitate tacrolimus dose adjustments, 10 required dose uptitration, and 43 required dose reductions. Moreover, LUM/IVA use with azole antifungals may lead to subtherapeutic levels but opposing effects sustained tacrolimus levels. Liver transplant recipients were more likely to experience elevations in transaminases requiring pharmacologic or medical interventions. Majority of patients experienced improvements in pulmonary function, fasting blood glucose, hemoglobin, body mass index, and rhinosinusitis symptoms. However, intolerance or lack of benefit prompted discontinuation of ELX/TEZ/IVA in over 40% of lung-transplant recipients in one study.

CONCLUSION

Modulator therapy has been reported to produce pulmonary and extra-pulmonary benefits in the CF population with SOT. Considerations for modulator therapy initiation ought to include modulator pharmacokinetics, concomitant medications, and transplant type due to the complex nature of SOT recipients.

Novel Applications of Biomarkers and Personalized Medicine in Cystic Fibrosis

As routine care in cystic fibrosis (CF) becomes increasingly personalized, new opportunities to further focus care on the individual have emerged. These opportunities are increasingly filled through research in tools aiding drug selection, drug monitoring and titration, disease-relevant biomarkers, and evaluation of therapeutic benefits. Herein, we will discuss such research tools presently being translated into the clinic to improve the personalization of care in CF.

Ivacaftor-elexacaftor-tezacaftor and tacrolimus combination in cystic fibrosis

The CFTR modulator combination elexacaftor/tezacaftor/ivacaftor (ETI) is a genetic mutation-targeted treatment in cystic fibrosis that results in profound improvements in clinical outcomes. Each of the compounds are substrates of CYP3A4/5, the cytochrome P450 enzyme family for which tacrolimus is also a substrate. The use of these compounds in an individual with a solid organ transplant has not been previously studied and there is potential for a drug interaction. In this report, we describe a pediatric liver transplant recipient with clinical decline related to cystic fibrosis who improved substantially with ETI, without significant impact on the systemic exposure of either ETI or tacrolimus.

CFTR modulator use in post lung transplant recipients

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulator therapy has previously been contraindicated in solid organ transplant recipients. This was due to lack of data and concern for interactions with immunosuppressive drug regimens. However, in post-lung transplant recipients, CFTR modulators may improve extrapulmonary manifestations of cystic fibrosis without impacting graft function or immunosuppressive drug levels. Herein, we present our single center experience with the use of elexacaftor/tezacaftor/ivacaftor, Trikafta, in adult post-lung transplant recipients.

Survival Benefits Following Liver Transplantation: A Matched-pair Analysis in Pediatric Patients With Cystic Fibrosis

OBJECTIVES

Cystic fibrosis-related liver disease (CFLD) with consecutive cirrhosis is the third most common cause of death in CF patients. The aim of this study was to identify the potential long-term benefits of liver transplantation (LTx) in a match-control comparison.

METHODS

Retrospective single-center data analysis of all pediatric LTx for CFLD between 1998 and 2014. A control group was selected from the local CF patient registry. Data were collected from case report forms and included clinical and laboratory data, lung function tests, the indication for LTx, and details of surgical procedures.

RESULTS

At our institution, 23 patients with severe CFLD median age 13.8 years (range 8.7-17.4; 16 boys) underwent LTx between 1998 and 2014. In all patients, normalization of hepatic CF manifestations were achieved after LTx. But obviously there was no significant positive influence on nutritional status. Signs of posttransplant liver steatosis were documented by ultrasound in 17 patients. Liver biopsies after LTx were performed in 19 patients, in 42% (n = 8) of these biopsies a fatty degeneration was observed. Five patients died after LTx, none because of primary hepatic dysfunction (1 because of posttransplant proliferative disorder, 4 because of infection). Analysis of matched control pairs revealed that liver function, anthropometry, pulmonary function, and life expectancy of CFLD patients with LTx are comparable with matched CF peers without CFLD.

CONCLUSIONS

Isolated LTx normalizes the hepatic manifestation of CF disease. LTx enables children and adolescents with severe CFLD to have a comparable prognosis in terms of growth, life expectancy, and lung function as CF patients without advanced liver involvement. Our data clarifies the long-term perspectives of affected patients.

To treat or not to treat: CFTR modulators after lung transplantation

Evidence for the extrapulmonary benefits of (CFTR) modulators is rapidly expanding. The use of CFTR modulators in CF patients who have undergone lung transplantation is not clear without guidance published in the medical literature to assist clinicians in the care of these patients. We discuss the potential benefits of CFTR modulators and provide insight into their use based on our experience in a small cohort of CF LTx recipients. We present pros and cons of CFTR modulator therapy for LTx recipients with CF. CFTR modulators should be considered in CF patients after lung transplantation for the time being until further research defines how to best use these therapies in transplant recipients.

Cystic fibrosis foundation consensus statements for the care of cystic fibrosis lung transplant recipients

Cystic fibrosis (CF) is the indication for transplantation in approximately 15% of recipients worldwide, and Cystic Fibrosis Lung Transplant Recipients (CFLTRs) have excellent long-term outcomes. Yet, CFLTRs have unique comorbidities that require specialized care. The objective of this document is to provide recommendations to CF and lung transplant clinicians for the management of perioperative and underlying comorbidities of CFLTRs and the impact of transplantation on these comorbidities. The Cystic Fibrosis Foundation (CFF) organized a multidisciplinary committee to develop CF Lung Transplant Clinical Care Recommendations. Three workgroups were formed to develop focused questions. Following a literature search, consensus recommendations were developed by the committee members based on literature review, committee experience and iterative revisions, and in response to public comment. The committee formulated 32 recommendation statements in the topics related to infectious disease, endocrine, gastroenterology, pharmacology, mental health and family planning. Broadly, the committee recommends close coordination of care between the lung transplant team, the cystic fibrosis care center, and specialists in other disciplines with experience in the care of CF and lung transplant recipients. These consensus statements will help lung transplant providers care for CFLTRs in order to improve post-transplant outcomes in this population.

A current review of the safety of cystic fibrosis transmembrane conductance regulator modulators

WHAT IS KNOWN AND OBJECTIVE

Treatment with cystic fibrosis transmembrane conductance regulator (CFTR) modulators has led to improved clinical outcomes and an increase in lifespans of cystic fibrosis (CF) patients. As CF patients continue to live longer, they are at risk for developing adverse drug reactions associated with polypharmacy and CFTR modulators.

COMMENT

The authors aim to describe safety concerns of the current combination CFTR modulators, based upon a literature review, including notable safety concerns and recommendations for drug-drug interactions.

WHAT IS NEW AND CONCLUSION

Cystic fibrosis transmembrane conductance regulator agents are generally well tolerated with low discontinuation rates when compared to placebo. Elevations in liver enzymes and drug-drug interactions are the most notable safety concerns. Additionally, lumacaftor/ivacaftor has shown more respiratory-related adverse events and drug-drug interactions compared to elexacaftor/tezacaftor/ivacaftor and tezacaftor/ivacaftor. Postmarketing studies are needed to determine long-term safety concerns.

Cystic fibrosis year in review 2019: Section 1 CFTR modulators

During the year 2019, research and case reports/series in the field of cystic fibrosis (CF) were in abundance. To adequately address the large body of CF research published during 2019, the CF year in review will be divided into three sections. This report is the first section, focusing specifically on new research related to cystic fibrosis transmembrane conductance regulator modulator therapy. Additional sections will concentrate on pulmonary and infections research and the multisystem effects of CF. It is an exciting time to be providing care for patients and their families with CF with all the exciting new discoveries that will be shared in these reviews.

Tezacaftor and ivacaftor for the treatment of cystic fibrosis

Introduction: Cystic fibrosis (CF) is a complex, multi-system, genetic disease affecting over 70,000 people worldwide. The underlying defect is a mutation in the CFTR gene. Dysfunctional CFTR protein results in abnormal anion movement across epithelial membranes in affected organs. There has been a paradigm shift in CF treatment over the last decade with the advent of CFTR modulation, treatments which target this underlying genetic defect and have the potential to change the course of CF clinical disease.Areas covered: Available CFTR modulators in current clinical practice are reviewed in this article, with a direct comparison and summary of relevant pivotal clinical trials. The approval of ivacaftor and subsequent development of lumacaftor and tezacaftor dual combinations represents an exciting development in CF management in recent years.Expert opinion: Tezacaftor/ivacaftor (tez/iva) appears to have a more favorable adverse event and drug-drug interaction profile than lumacaftor/ivacaftor. Tez/iva has been approved, alongside Phe508del, for a large number of 'residual function' CFTR mutations, with some based on response to in vitro culture. Dual therapy with tez/iva has paved the way for triple CFTR modulation currently in clinical trials with an ultimate view to provide modulation therapy to the majority of CF genotypes in the future.