The aim of the proposed trial in assessment of effects of Kalydeco™ treatment on sinonasal involvement in CF patients with at least one mutation of G551D receiving a new therapy with the CFTR potentiator. The focus will be given on changes in epithelial lining fluid inflammatory markers from CF upper airways sampled by nasal lavage.

The program is subdivided into a part A assessing inflammatory markers in NL and sinonasal symptoms longitudinally from pre-treatment to months with the new therapy.

Part B will only be performed in a smaller subgroup and assess inflammatory markers in NL every second day in the first month of treatment and then every week until the end of month 3 with Kalydeco™ therapy.

Enrollment of Patients In this longitudinal trial, 10 CF patients with a G551D mutation, newly receiving ivacaftor 150 mg bid, as approved (1), were included in the Jena (Germany) and Innsbruck (Austria) University CF centers. Inclusion criteria were: CF patients' age ≥ 6 years with a diagnosis confirmed by two positive sweat tests and/or detection of two disease-causing CFTR mutations; one of them being G551D. Patients were required to strictly follow the procedures defined in the SOPs and they and/or their parents gave informed written consent prior to enrolment. Exclusion criteria were: inability to perform NL in a standardized manner as described below, contraindication for ivacaftor, pregnancy or breast-feeding, and participation in another clinical study within 30 days prior to study drug administration. Nasal Lavage Patients were thoroughly trained to perform NL in standardized home-based conditions (Figures 1A-C) by using the instructionvideo from our publication in Journal of Immunological Methods 2014 (14) and an illustrated SOP sheet. The pooled native NLF was transferred into disposed reaction tubes containing 15 μL of protease inhibitor (Figures 1D, E) and, within 30 minutes after sampling, stored in a freezer below -18°C until transfer on ice to the centers. Here, the vials were directly stored at - 80°C until performance of laboratory analyses. Prior to the initiation of ivacaftor therapy, NL was collected at least once a week (mean: 5.5 ± 3.9 samplings/patient) during a mean time of 30.3 ± 19.7 days. During the first month of therapy (days 0-30), NL was collected every second day and once/week from month two onward (mean: 25.9 ± 4.1 samplings/patient). Follow-up range after initiation of ivacaftor: 2.3-16.1 months, (median: 5.7 months). Assessment of Inflammatory Mediators Concentrations of IL-1b, IL-6, and IL-8 were measured in undiluted NL fluid using Milliplex® MAP Kits (Human High Sensitivity HS TCMAG-28K, Merck Millipore; Darmstadt, Germany) and a Bio-Plex® 200 system (Bio-Rad; Hercules, California, USA) according to the manufacturer's instructions. Measurements of Neutrophil Elastase (NE) were performed using Human PMN Elastase ELISA (DEH3311, Demeditec Diagnostics GmbH; Kiel, Germany) and read by a FLUOstar Galaxy spectrometer (BMG LABTECH GmbH; Offenburg, Germany). As specified by the manufacturer, lower detection limits were 0.12 pg/mL (IL-1b), 0.13 pg/mL (IL-6), 0.12 pg/mL (IL-8), and 0.2 ng/mL (NE). Statistical Analyses Descriptive statistics were used to describe clinical characteristics of the study population. Linear mixed-effects models were performed to analyze overall trends of inflammatory markers. To smooth effects caused by outliers in inflammatory marker values, individual changes regarding cumulative periods for each patient were determined by calculating medians for the time periods before and after treatment initiation (i.e. regarding periods of 4, 8 and 12 weeks during treatment as shown in Figure 2). The resulting individual patients' medians were used to calculate medians and interquartile ranges (IQR) of the entire cohort at the end of the above-mentioned time periods. Wilcoxon signedrank test (two-tailed) was applied to determine changes in the aforementioned inflammatory mediators, sweat test, FEV1 and their statistical significance (using p<0.05) during the new therapy. All statistical analyses were performed with IBM SPSS 19 (SPSS Inc., Chicago, IL, USA); figures were created with GraphPad Prism (GraphPad Software Inc., La Jolla, CA, USA).

Inclusion Criteria:

• G551D and Kalydeco therapy

Exclusion Criteria:

• no G551D

CF patients with G551D mutation receiving Kalydeco