PT - JOURNAL ARTICLE AU - Castellani, C AU - Simmonds, NJ AU - Colombo, C AU - Kinnman, N AU - DeSouza, C AU - Thorat, T AU - Chew, M AU - Chandarana, K AU - van der Ent, K TI - S61 Respiratory microbiology outcomes from an observational study of ivacaftor in people with cystic fibrosis and non-G551D gating mutations (VOCAL) AID - 10.1136/thorax-2021-BTSabstracts.67 DP - 2021 Nov 01 TA - Thorax PG - A41--A41 VI - 76 IP - Suppl 2 4099 - http://thorax.bmj.com/content/76/Suppl_2/A41.1.short 4100 - http://thorax.bmj.com/content/76/Suppl_2/A41.1.full SO - Thorax2021 Nov 01; 76 AB - Introduction and Objectives Certain respiratory pathogens are associated with reduced lung function and disease progression in people with cystic fibrosis (pwCF). We report respiratory microbiology results from a Phase 4 observational study (NCT02445053) assessing real-world effectiveness of ivacaftor (IVA) in pwCF with non-G551D gating mutations (G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P or G1349D).Methods PwCF aged ≥6 years in Italy, the Netherlands and the UK who were IVA-naïve or on IVA for ≤18 months at enrolment were eligible. Data were recorded for 12 months pre-IVA and up to 48 months after enrolment. Microbiology cultures were taken via sputum, throat or oropharyngeal swabs.Results 65 of 73 (89%) completed the study; mean IVA exposure was 49.5 months (range, 2–64). Mean (standard deviation) baseline age and percent predicted forced expiratory volume in 1 second were 26.9 (13.5) years and 64.83 (23.61), respectively. In the 12 months pre-IVA, 279 cultures were obtained from 69 pwCF and 182 cultures in 64 pwCF at year 4 following IVA treatment. Prevalence of P. aeruginosa, A. fumigatus and S. maltophilia was 55.1%, 30.4% and 11.6%, respectively, in the 12 months pre-IVA and was reduced to 52.9%, 18.6% and 7.1% in year 1 and 41.5%, 16.9% and 4.6% in year 2 on IVA. Sustained or further reductions were observed through 48 months of treatment. Prevalence of other pathogens was variable or too low to evaluate. 70% of pwCF were on chronic oral and/or inhaled antibiotics pre-IVA vs 68% at 48 months. Use of other chronic inhaled therapies was stable throughout the study.Conclusions Lower prevalence of P. aeruginosa, A. fumigatus and S. maltophilia was observed with prolonged IVA treatment for up to 48 months in real-world settings. Chronic medication use remained stable.Please refer to page A189 for declarations of interest related to this abstract.