Real-world safety and effectiveness of elexacaf tor/tezacaf tor/ivacaf tor in people with cystic fibrosis: Interim results of a long-term registry-based study

Background: Phase 3 clinical trials showed elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was safe and efficacious in people with cystic fibrosis (CF) with & GE;1 F508del-CFTR allele. To assess long-term effects of ELX/TEZ/IVA under real-world conditions of use, a 5-year observational registry-based study is being conducted. We report interim results from the first 2 years of follow-up. Methods: The study included people with CF in the US Cystic Fibrosis Foundation Patient Registry (CFFPR) who initiated ELX/TEZ/IVA between October 2019 and December 2020. Pulmonary exacerbations (PEx), percent predicted forced expiratory volume in 1 second (ppFEV 1 ), hospitalizations, bacterial pathogens, body mass index (BMI), CF complications and comorbidities, and liver function tests (LFTs) after treatment initiation were compared with the 5-year pre-treatment period. Death and lung transplantation were assessed relative to 2019 CFFPR data. Results: 16,116 people with CF were included (mean treatment duration 20.4 months). Among those with 5 years of pre-treatment data, mean PEx/patient/year declined to 0.18 (95% CI: 0.17, 0.19) in Years 1 and 2 post-treatment from 0.86 (95% CI: 0.83, 0.88) in the baseline year (79% reduction), after a continued increase observed pre-treatment. Similarly, a decline in mean hospitalizations/patient/year was observed in Year 1 that was sustained in Year 2 (74% reduction from baseline year). The mean absolute change in ppFEV 1 from baseline was + 8.2 percentage points (95% CI: 8.0, 8.4) in Year 1 and + 8.9 percentage points (95% CI: 8.7, 9.1) in Year 2, after a continued decline observed pre-treatment. Positive bacterial cultures decreased for all evaluated pathogens, and mean BMI increased by 1.6 kg/m 2 (95% CI: 1.5, 1.6) by Year 2. No new safety concerns were identified based on evaluation of CF complications, comorbidities, and LFTs. The annualized rates of death (0.47% [95% CI: 0.39, 0.551) and lung transplantation (0.16% [95% CI: 0.12, 0.221) were considerably lower than reported in 2019 (1.65% and 1.08%, respectively). Conclusions: ELX/TEZ/IVA treatment was associated with sustained improvements in lung function, reduced frequency of PEx and all-cause hospitalization, increased BMI, and lower prevalence of positive bacterial cultures. Additionally, there was a 72% lower rate of death and 85% lower rate of lung transplantation relative to the year before ELX/TEZ/IVA availability. These results, from the largest cohort of ELX/TEZ/IVA-treated people to date, extend our understanding of the broad clinical benefits of ELX/TEZ/IVA. & COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Automated summary

The ELX/TEZ/IVA treatment showed sustained improvements in lung function, reduced frequency of pulmonary exacerbations and hospitalizations, increased body mass index, and decreased prevalence of positive bacterial cultures among cystic fibrosis patients. Additionally, there were significantly lower rates of death and lung transplantation compared to the year before ELX/TEZ/IVA was available.