Relating Improvement in Gastrointestinal (CFAbd‐Score © ) and Sinonasal (SNOT) Symptoms During Therapy With Elexacaftor/Tezacaftor/Ivacaftor in CF Patients

BACKGROUND: For people with cystic fibrosis (pwCF) carrying susceptible mutations, elexacaftor/tezacaftor/ivacaftor (ETI) has changed the course of their lives. Organ manifestations critically affecting both respiratory and digestive tracts have been found to improve considerably. Consequently, ETI-associated reductions in sinonasal symptoms (SNS) deriving from the upper respiratory tract are consistently reported. However, although substantial ETI-related declines in the burden of abdominal symptoms (AS) have been reported using the CFAbd-Score, their correlation with SNS changes has not been studied. AIMS: Assessing correlations between ETI-related changes in pwCF SNS and AS. METHODS: The German adapted version of the Sinonasal-Outcome-Test 20 (SNOT-20-GAV) and the CFAbd-Score, the first CF-specific gastrointestinal (GI) patient-reported outcome measure developed and validated following FDA guidelines, were simultaneously administered. PwCF completing both paired questionnaires, at least once before and after ETI initiation, were included. RESULTS: In two German CF-centers, n = 31 pwCF (18 f, mean-age 13 years) were included, completing n = 106 paired questionnaires. During ETI therapy, significant decreases (p < 0.05) were observed for the mean total CFAbd-Score (10.9→5.8pts[-47%]) as well as all sub-scores ('pain': -61%, 'disorders of bowel movement': -56%, 'GERD': -54%, 'disorders of appetite': -50% and 'QoL-impairment':-67%). Analogously, SNS significantly improved (total SNOT: 10.1→3.4pts[-66%] and its 3 domains: primary and secondary nasal symptoms, and SNS-related QoL [-68%/-81%/-54%]). However, the correlation between changes in symptoms related to upper-respiratory and GI tracts was only modest. CONCLUSION: The burden of symptoms captured with the CFAbd-Score and the SNOT-20-GAV significantly and markedly decreased after ETI initiation. The modest association between changes in both organ-specific symptom scores supports the previously reported individualized electrophysiological responses observed in nasal-potential and intestinal-current measurements.