WS18.3 A combination of CFTR functional tests supporting drug development and diagnosis: the contribution of intestinal epithelial organoids

S30 Oral Presentations / Journal of Cystic Fibrosis 15 (2016) S1–S50 al. Nature Med. 2013). This functional assay might be an ideal drugscreening platform to evaluate efficacy of old and new compounds to restore CFTR function in the genetic background of individual patients. Our objective was to prospectively evaluate the correlation between the in vitro efficacy of a selected CFTR-modulating drug in the organoid model and the corresponding in vivo treatment effect. Methods: We treated 19 CF patients with different CFTR-mutations based on their in vitro organoid responses. Patients with S1251N (n = 16) received either curcumin + genistein or VX770, patients with G1249R (n = 2) or R347P (n = 1) received VX770 during 4–8 weeks. The primary outcome to evaluate the in vivo treatment effect was change in %FEV1. The in vivo treatment effect was compared to the forskolin-induced organoid swelling response of each patient group. Results: Mean improvement in %FEV1 after 4–8 weeks treatment was 5.36% (range −1.00%, 12.50%). The change in %FEV1 was highly correlated to the forskolin-induced swelling responses in organoids (Pearson correlation R = 0.9639, p = 0.0361). Conclusion: In CF patients with different CFTR-mutations the in vitro efficacy of CFTR-modulating drugs in the intestinal organoid model highly correlates with the in vivo pulmonary outcomes. These data suggest that the intestinal organoid model can help to select effective CFTR-targeting treatment and to predict pulmonary treatment outcomes. WS18.3 A combination of CFTR functional tests supporting drug development and diagnosis: the contribution of intestinal epithelial organoids S. Caldrer1 , S. Vercellone1 , A. Sandri2 , C. Sorio1 , L. Rodella3 , F. Catalano3 , A. Cerofolini3 , F. Lombardo3 , M. Buffelli4 , H. de Jonge5 , B. Assael2 , P. Melotti2 . 1 University of Verona, Medicine, Verona, Italy; 2 Cystic Fibrosis Centre, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; 3 Endoscopic Surgery Unit, AOUI Verona, Verona, Italy; 4 University of Verona, Neurologic Science, Verona, Italy; 5 Erasmus University Medical Center, Gastroenterology & Hepatology, Rotterdam, Netherlands Objectives: In vivo and ex vivo measurements of CFTR function in human cells and tissues can be used for screening and monitoring new therapies and phenotyping of controversial CFTR genotypes. A technique enabling intestinal stem cells to expand into closed organoids containing crypt-like structures and an internal lumen lined by differentiated cells, was developed (Sato et al., 2011, Dekkers et al., 2013) and was set up in our laboratory. Methods: We analyzed intestinal organoids from 10 non-CF and 9 CF subjects by measuring the forskolin induced swelling (FIS) using a slight modification of the protocol described by Dekkers et al., Nat Med, 2013. Results: In non-CF organoids swelling was completely blocked by the CFTR (inh)-172 and significantly enhanced following treatment with the potentiator Ivacaftor (VX770). Swelling rates in CF organoids were variable, dependent on the CFTR mutation. Remarkably, in organoids from a CF patient carrying the W1282X/R117H CFTR genotype we observed swelling following exposure for 24 h to Ataluren (PTC124). Conclusion: This study explored the possibility to build a biobank of organoids suitable for functional assays to support diagnosis and predict response to CF-targeted drugs. As shown here for FIS, and elsewhere for other CFTR assays, we could demonstrate partial restoration of CFTR activity in response to a CFTR potentiator, corrector and a premature termination corrector. In our Centre we aim at combining CFTR functional tests covering multiple tissues and cell types for individualized approaches for CF diagnosis, drug development and monitoring of new therapies targeting the basic defect. Acknowledgement: FFC grants #: 4/2013, 3/2014, 03/2015; LIFC VR WS18.4 Intestinal current measurement as outcome marker for clinical trials: the ECFS CTN certification process and central reading core facility S. Scheinert1 , H. de Jonge2 , I. Bronsveld3 , L. Nährlich4 , P. Melotti5 , S. van Koningsbruggen-Rietschel6 , I. Sermet-Gaudelus7 , K. Hayes8 , N. Derichs1 . 1 Charité-Universitätsmedizin Berlin, Berlin, Germany; 2 Erasmus University Rotterdam, Rotterdam, Netherlands; 3 UMC, Utrecht, Netherlands; 4 Universitätsklinikum Giessen, Giessen, Germany; 5 University of Verona, Verona, Italy; 6 University of Cologne, Cologne, Germany; 7 Necker Hospital, Paris, France; 8 ECFS Clinical Trials Network Standardisation Committee, London, United Kingdom Background: Multiple CFTR modulators are under development for mutation-specific CF therapy. CFTR biomarkers play an important role for the effect evaluation in clinical trials. Intestinal current measurement (ICM), precisely determining ex vivo CFTR function in human rectal biopsies, has been standardized in an ECFS ICM SOP prepared by the ECFS Diagnostic Network Working Group and ECFS Clinical Trials Network (CTN) standardisation committee. Objectives and Methods: To ensure high quality of standard and multicentre comparability of results in ICM centres, several ICM SOP hands-on training workshops at the CFTR biomarker center Berlin and subsequently at the trainees institution have been provided since 2012. The ECFS CTN has developed a certification process and setup of an ICM central reading core facility. ICM recordings from the applying centre were centrally reviewed by two independent ICM SOP investigators, and a systematic scoring and quality check was performed. Results: A total of 280 rectal biopsies from 7 European ICM sites (n = 5 non-CF healthy control and n = 5 PI-CF patients per site) have been submitted for certification so far and were centrally evaluated, resulting in a success rate of 82% interpretable biopsies. Known differences in CFTR function between PI-CF and non-CF could be confirmed in a multicenter setting. Conclusions: A growing network of European ICM sites has successfully performed standardisation of ICM for use as outcome parameter in clinical trials. The ECFS CTN and the ICM central reading core facility are prepared to implement ICM as CFTR biomarker in upcoming early clinical trials with next generation CFTR modulators. WS18.5 Nasal potential difference and sweat chloride responses to ivacaftor correlate in three patients with non-p.Gly551Asp gating mutations M. Shteinberg1,2 , M. Wilschanski3 , G. Livnat1,2 . 1 Carmel Medical Center, Haifa, Israel; 2 Technion-Israel Institute of Technology, The B. Rappaport Faculty of Medicine, Haifa, Israel; 3 Hadassah-Hebrew University Medical Center, Cystic Fibrosis Center, Jerusalem, Israel Objectives: Ivacaftor, a CFTR potentiator, has been consistently found to lower sweat chloride in patients with cystic fibrosis (CF) carrying gating mutations. Nasal potential difference (NPD) measurement, a method developed for the diagnosis of CF, was also found to reflect CFTR function in patients with classic and non-classic CF. In clinical trials involving patients with the p.Gly551Asp mutation, ivacaftor has been found to normalize NPD measurements. This finding has not been reported in patients carrying other gating mutations responsive to ivacaftor. Methods: Sweat Chloride and NPD were measured in three patients with CFTR gating mutations before and after commencing treatment with ivacaftor. Results: Two siblings aged 13 and 12 carrying the p.Ser549Asn mutation, and a 37 year old man homozygous for the p.Gly1244Glu mutations, commenced treatment with ivacaftor. During treatment, sweat chloride decreased and NPD approached normal tracing for the two children who had also an impressive clinical improvement (NPD exponent decreased from 0.86 and 1.33 to 0.37 and 0.69, respectively). The adult patient, who had undergone an ileal resection with ileostomy and has an enterocuteneous fistula, did not respond clinically to ivacaftor. Sweat Chloride and NPD measurements did not change on ivacaftor treatment in this patient, with an NPD exponent of 1 and 1.1 before and during treatment.