Background: Cystic fibrosis (CF) is a rare hereditary disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Recent therapies enable effective restoration of CFTR function of the most common F508delCFTRmutation. This shifts the unmet clinical need towards people with rareCFTRmutations such as nonsense mutations, of which G542X and W1282X are most prevalent. CFTR function measurements in patient-derived cell-based assays played a critical role in preclinical drug development for CF and may play an important role to identify new drugs for people with rareCFTRmutations.Methods: Here, we miniaturised the previously described forskolin-induced swelling (FIS) assay in intestinal organoids from a 96-well to a 384-well plate screening format. Using this novel assay, we tested CFTR increasing potential of a 1400-compound Food and Drug Administration (FDA)-approved drug library in organoids from donors with W1282X/W1282XCFTRnonsense mutations.Results: The 384-well FIS assay demonstrated uniformity and robustness based on coefficient of variation and Z’-factor calculations. In the primary screen, CFTR induction was limited overall, yet interestingly, the top five compound combinations that increased CFTR function all contained at least one statin. In the secondary screen, we indeed verified that four out of the five statins (mevastatin, lovastatin, simvastatin and fluvastatin) increased CFTR function when combined with CFTR modulators. Statin-induced CFTR rescue was concentration-dependent and W1282X-specific.Conclusions: Future studies should focus on elucidating genotype specificity and mode-of-action of statins in more detail. This study exemplifies proof of principle of large-scale compound screening in a functional assay using patient-derived organoids.

Background Understanding molecular pathogenesis of head and neck squamous cell carcinomas (HNSCC) has considerably improved in the last decades. As a result, novel therapeutic strategies have evolved, amongst which are epidermal growth factor receptor (EGFR)-targeted therapies. With the exception of cetuximab, targeted therapies for HNSCC have not yet been introduced into clinical practice. One important aspect of new treatment regimes in clinical practice is presence of robust biomarkers predictive for therapy response. Methods We performed a systematic search in PubMed, Embase and the Cochrane library. Articles were included if they investigated a biomarker for targeted therapy in the EGFR-PI3K-AKT-mTOR-pathway. Results Of 83 included articles, 52 were preclinical and 33 were clinical studies (two studies contained both a preclinical and a clinical part). We classified EGFR pathway inhibitor types and investigated the type of biomarker (biomarker on epigenetic, DNA, mRNA or protein level). Conclusion Several EGFR-PI3K-AKT-mTOR-pathway inhibitor biomarkers have been researched for HNSCC but few of the investigated biomarkers have been adequately confirmed in clinical trials. A more systematic approach is needed to discover proper biomarkers as stratifying patients is essential to prevent unnecessary costs and side effects.

As life expectancy for people with cystic fibrosis continues to improve due to advances in care and CFTR modulator therapies, age-related comorbidities are emerging as new clinical challenges. This short review summarizes insights from a symposium focusing on ageing and CF at the 20th ECFS Basic Science Conference in March 2025 in Pisa, Italy. Mechanisms of ageing and their involvement in CF disease are first outlined. We then highlight two age-associated comorbidities in CF, cardiovascular disease and colorectal cancer, and outline future research directions to clarify how CF-specific and general ageing mechanisms intersect. Understanding these processes will be crucial for tailoring long-term care strategies in the ageing CF population.

Cystic fibrosis (CF) results from pathogenic CFTR variants that impair epithelial chloride and bicarbonate transport. CFTR modulators such as elexacaftor/tezacaftor/ivacaftor (ETI) have transformed CF care, and the next-generation regimen vanzacaftor/tezacaftor/deutivacaftor (VTD) has recently been introduced on the market. VTD offers once-daily dosing and expanded regulatory approval, yet its functional advantages remain not fully characterized across a broad set of genotypes. Consequently, we set out to compare CFTR functional rescue of ETI and VTD in primary patient-derived intestinal organoids (PDIOs) harbouring a broad range of CFTR variants. We evaluated ETI and VTD efficacy in 62 PDIO lines representing 42 rare CFTR genotypes and reference groups (p.Phe508del/p.Phe508del, p.Phe508del/class I, class I/class I). CFTR rescue was assessed by CFTR function by steady-state lumen area quantification and forskolin-induced swelling assays and CFTR maturation via western blot. Across rare variants, CFTR functional rescue by ETI and VTD strongly correlated, with modest but consistent VTD advantages in a subset of folding-defective genotypes (e.g., p.Val520Phe). Three PDIOs showed disproportionately high responses to VTD. VTD increased CFTR maturation more effectively than ETI, yet demonstrated similar acute effects on CFTR function. VTD provides modest genotype-specific functional advantages and enhanced CFTR maturation but is largely comparable to ETI across rare variants. PDIO-based screenings performed in this study underline again their potential for theratyping, which is particularly critical for guiding decisions on accessibility for rare variants in an era with a variety of modulators, and combinations thereof.

Cystic Fibrosis Screen Positive Inconclusive Diagnosis/CFTR-related Metabolic Syndrome (CFSPID/CRMS) presents a significant clinical challenge due to its variable diagnostic outcomes and uncertain disease progression. Current diagnostic strategies, including sweat chloride testing and genetic analysis fall short in delivering clear guidance for clinical decision-making and risk assessment. Here, we comment on the potential of CFTR functional tests in patient-derived intestinal organoids (PDIOs) to enhance early risk stratification in CFSPID/CRMS cases. Using four hypothetical cases based on real-world data, we illustrate diverse clinical trajectories: diagnosis of cystic fibrosis (CF), reclassification as a CFTR-related disorder (CFTR-RD), non-CF designation, and persistent diagnostic uncertainty. Organoid-based assays—such as forskolin-induced swelling (FIS), steady-state lumen area (SLA) analysis, and rectal organoid morphology analysis (ROMA)—offer functional insights into CFTR activity and drug responsiveness. Compared to existing CFTR functional tests, such as Intestinal Current Measurement (ICM) and Nasal Potential Difference (NPD), these assays are more accessible, highly reproducible, and when needed support personalized medicine approaches. PDIO-based assays could help identify infants at high risk of disease progression, facilitating earlier interventions while minimizing unnecessary follow-ups for those unlikely to develop CF-related symptoms. Although not yet widely implemented, these assays hold promise for refining CFSPID diagnostics and management. Future research should focus on establishing standardized protocols allowing validation of clinical utility.