Elexacaftor/tezacaftor/ivacaftor-real-world clinical effectiveness and safety. A single-center Portuguese study

Progress of personalized medicine of cystic fibrosis in the times of efficient CFTR modulators

BACKGROUND

Cystic fibrosis (CF) is a systemic disorder of exocrine glands that is caused by mutations in the CFTR gene.

MAIN BODY

The basic defect in people with CF (pwCF) leads to impaired epithelial transport of chloride and bicarbonate that can be assessed by CFTR biomarkers, i.e. the β-adrenergic sweat rate and sweat chloride concentration (SCC), chloride conductance of the nasal respiratory epithelium (NPD), urine secretion of bicarbonate, intestinal current measurements (ICM) of chloride secretory responses in rectal biopsies and in bioassays of chloride transport in organoids or cell cultures. CFTR modulators are a novel class of drugs that improve defective posttranslational processing, trafficking and function of mutant CFTR. By April 2025, triple combination therapy with the CFTR potentiator ivacaftor (IVA) and the CFTR correctors elexacaftor (ELX) and tezacaftor (TEZ) has been approved in Europe for the treatment of all pwCF who do not carry two minimal function CFTR mutations. Previous phase 3 and post-approval phase 4 studies in pwCF who harbour one or two alleles of the major mutation F508del consistently reported significant improvements of lung function and anthropometry upon initiation of ELX/TEZ/IVA compared to baseline. Normalization of SCC, NPD and ICM correlated with clinical outcomes on the population level, but the restoration of CFTR function was diverse and not predictive for clinical outcome in the individual patient. Theratyping of non-F508del CF genotypes in patient-derived organoids and cell cultures revealed for most cases clinically meaningful increases of CFTR activity upon exposure to ELX/TEZ/IVA. Likewise, every second CF patient with non-F508del genotypes improved in SCC and clinical outcome upon exposure to ELX/TEZ/IVA indicating that triple CFTR modulator therapy is potentially beneficial for all pwCF who do not carry two minimal function CFTR mutations. This group who is not eligible for CFTR modulators may opt for gene addition therapy in the future, as the first-in-human trial with a recombinant lentiviral vector is underway.

FUTURE DIRECTIONS

The upcoming generation of pwCF will probably experience a rather normal life in childhood and adolescence. To classify the upcoming personal signatures of CF disease in the times of efficient modulators, we need more sensitive CFTR biomarkers that address the long-term course of airway and gut microbiome, host defense, epithelial homeostasis and multiorgan metabolism.

Elexacaftor/tezacaftor/ivacaftor, a game-changer in cystic fibrosis: The Portuguese experience

BACKGROUND

Phase 3 trials of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) combination treatment in people with cystic fibrosis (CF) with ≥1 F508del-CFTR allele showed profound short-term effects on lung function, weight, and pulmonary exacerbations (PEx). The authors conducted a 12-month study to add evidence on the real-world long-term effectiveness and safety of CFTR modulator therapy with ELX/TEZ/IVA in Portuguese CF adult population.

METHODS

Ambispective, multicentre, observational, real-life study involving all the Portuguese CF Reference Centres. Adult patients on treatment with ELX/TEZ/IVA combination outside clinical trials were included. Demographics, efficacy, and safety variables on the first 12 months of treatment were compared with the pre-treatment year.

RESULTS

132 adult people with CF were included, of which 119 completed 12 months treatment (mean duration of treatment 21.5 months). Mean age was 31.7 ± 11.0 years, 53 % patients were homozygous for the F508del variant, baseline sweat chloride was 86.7 ± 25.9 mmol/L and pre-treatment percent-predicted FEV1 was 77.9 ± 19.7 %. At 1 year, mean absolute change from baseline in FEV1 was +0.46L (95 % CI: 0.37, 0.55; p < 0.001) and +13.9 percentage points (95 % CI: 11.5, 16.2; p < 0.001). PEx episodes decreased by 78 % (p < 0.001) and hospitalizations for PEx decreased by 91.4 % (p < 0.001). Body mass index (BMI) increased 1.2 kg/m2 (95 % CI: 0.9, 1.5; p < 0.001). Mean sweat chloride variation was -44.5 mmol/L (95 % CI: -49.8, -39.2; p < 0.001). No correlation was found between sweat chloride and lung function (r = -0.116, p = 0.335). There were no major safety concerns. Of note, headache was reported in 7.6 % and neuropsychiatric manifestations occurred in 12.6 % treated patients, being anxiety and depressive disorders the most common.

CONCLUSIONS

ELX/TEZ/IVA treatment in Portuguese adults with CF was associated with significant improvement in lung function, a drop in PEx and PEx-related hospitalizations and increase in BMI at 12 months and was well tolerated. These results add knowledge to our understanding of clinical benefits and tolerability of ELX/TEZ/IVA. Careful evaluation of adverse effects of ELX/TEZ/IVA therapy and its determinants, mainly concerning mental health, are a research priority.

Efficacy and safety profile of elexacaftor-tezacaftor-ivacaftor triple therapy on cystic fibrosis: a systematic review and single arm meta-analysis

Background: Elexacaftor-Tezacaftor-Ivacaftor (ELE/TEZ/IVA) is believed to be an effective and well-tolerated treatment for cystic fibrosis (CF), but the exact efficacy and safety profile are still unknown. Objective: This study aimed to clarify the extent of functional restoration when patients are given with triple combination treatment and demonstrate the prevalence of adverse events, to evaluate the overall profile of ELE/TEZ/IVA on CF. Methods: A literature search was conducted in PubMed, Web of Science and Cochrane Library. Random effects single-arm meta-analysis was performed to decipher the basal characteristics of CF, the improvement and safety profile after ELE/TEZ/IVA treatment. Results: A total 53 studies were included in this analysis. For all the patients in included studies. 4 weeks after ELE/TEZ/IVA treatment, the increasement of percentage of predicted Forced Expiratory Volume in the first second (ppFEV1) was 9.23% (95%CI, 7.77%-10.70%), the change of percentage of predicted Forced Vital Capacity (ppFVC) was 7.67% (95%CI, 2.15%-13.20%), and the absolute change of Cystic Fibrosis Questionnaire-Revised (CFQ-R) score was 21.46 points (95%CI, 18.26-24.67 points). The Sweat chloride (SwCl) was significantly decreased with the absolute change of -41.82 mmol/L (95%CI, -44.38 to -39.25 mmol/L). 24 weeks after treatment, the increasement of ppFEV1 was 12.57% (95%CI, 11.24%-13.90%), the increasement of ppFVC was 10.44% (95%CI, 7.26%-13.63%), and the absolute change of CFQ-R score was 19.29 points (95%CI, 17.19-21.39 points). The SwCl was significantly decreased with the absolute change of -51.53 mmol/L (95%CI, -56.12 to -46.94 mmol/L). The lung clearance index2.5 (LCI2.5) was also decreased by 1.74 units (95%CI, -2.42 to -1.07 units). The body mass index increased by 1.23 kg/m2 (95%CI, 0.89-1.57 kg/m2). As for adverse events, 0.824 (95%CI, 0.769-0.879) occurred during ELE/TEZ/IVA period, while the incidence of severe adverse events was 0.066 (95%CI, 0.028-0.104). Conclusion: ELE/TEZ/IVA is a highly effective strategy and relatively safe for CF patients and needs to be sustained to achieve better efficacy. Systematic Review Registration: Identifier: CRD42023441840.