Long-term tezacaftor/ivacaftor safety and efficacy in people with cystic fibrosis and an F508del-CFTR mutation: 96-week, open-label extension of the EXTEND trial.

BACKGROUND: Study 661-110 (EXTEND) is a phase 3, open-label, three-part rollover study designed to assess the long-term safety and efficacy of tezacaftor/ivacaftor (TEZ/IVA) in participants aged ≥12 years homozygous for F508del (F/F) or heterozygous for F508del and a residual function mutation (F/RF). TEZ/IVA was shown to be safe and efficacious for up to 120 weeks in Part A. Here we report results from Part B, which evaluated safety and efficacy for an additional 96 weeks. METHODS: Part B enrolled participants aged ≥12 years with CF and F/F or F/RF genotypes who completed TEZ/IVA treatment in either Study 661-110 Part A, Study 661-112 (F/F), or Study 661-114 (F/F). Participants received TEZ 100 mg/IVA 150 mg fixed-dose combination once daily (morning) and IVA 150 mg once daily (evening) for 96 weeks. Safety endpoints included adverse events (AEs) and serum liver function tests. Efficacy endpoints included absolute change from baseline in percent predicted forced expiratory volume in 1 second (ppFEV1) and pulmonary exacerbation (PEx) rate. RESULTS: 464 participants were enrolled from Part A (n=377) and other eligible studies (n=87); 463 received ≥1 dose of TEZ/IVA. Overall, 92.2% had ≥1 AE, 0.9% had AEs leading to treatment discontinuation, and 29.4% reported serious AEs. The most common AEs, which were generally consistent with common manifestations of CF, included infective PEx of CF, cough, nasopharyngitis, hemoptysis, and headache. Lung function was maintained over 96 weeks in both genotype groups. PEx rates per year were comparable with Part A. CONCLUSIONS: TEZ/IVA was generally safe and well tolerated over a further 96 weeks; safety data were consistent with Part A. Improvements in ppFEV1 and PEx rates were maintained for an additional 96 weeks in Part B.

A Phase 3, Open-Label Study of Lumacaftor/Ivacaftor in Children 1 to Less Than 2 Years of Age with Cystic Fibrosis Homozygous for F508del-CFTR.

Rationale: Previous phase 3 trials showed that treatment with lumacaftor/ivacaftor was safe and efficacious in people aged ⩾2 years with cystic fibrosis (CF) homozygous for the F508del mutation in CFTR (CF transmembrane conductance regulator) (F/F genotype). Objectives: To assess the safety, pharmacokinetics, and pharmacodynamics of lumacaftor/ivacaftor in children aged 1 to <2 years with the F/F genotype. Methods: This open-label, phase 3 study consisted of two parts (part A [n = 14] and part B [n = 46]) in which two cohorts were enrolled on the basis of age (cohort 1, 18 to <24 mo; cohort 2, 12 to <18 mo). For the 15-day treatment period in part A, the lumacaftor/ivacaftor dose was based on weight at screening. Pharmacokinetic data from part A were used to determine dose-based weight boundaries for part B (24-wk treatment period). Measurements and Main Results: The primary endpoint of part A was pharmacokinetics, and the primary endpoint for part B was safety and tolerability. Secondary endpoints for part B were absolute change in sweat chloride concentration from baseline at Week 24 and pharmacokinetics. Analysis of pharmacokinetic data from part A confirmed the appropriateness of part B dosing. In part B, 44 children (95.7%) had adverse events, which for most were either mild (52.2% of children) or moderate (39.1% of children) in severity. The most common adverse events were cough, infective pulmonary exacerbation of CF, pyrexia, and vomiting. At Week 24, mean absolute change from baseline in sweat chloride concentration was -29.1 mmol/L (95% confidence interval, -34.8 to -23.4 mmol/L). Growth parameters (body mass index, weight, length, and associated z-scores) were normal at baseline and remained normal during the 24-week treatment period. Improving trends in some biomarkers of pancreatic function and intestinal inflammation, such as fecal elastase-1, serum immunoreactive trypsinogen, and fecal calprotectin, were observed. Conclusions: Lumacaftor/ivacaftor was generally safe and well tolerated in children aged 1 to <2 years with the F/F genotype, with a pharmacokinetic profile consistent with studies in older children. Efficacy results, including robust reductions in sweat chloride concentration, suggest the potential for CF disease modification with lumacaftor/ivacaftor treatment. These results support the use of lumacaftor/ivacaftor in this population. Clinical trial registered with www.clinicaltrials.gov (NCT03601637).

A Phase 3, open-label, 96-week trial to study the safety, tolerability, and efficacy of tezacaftor/ivacaftor in children ≥ 6 years of age homozygous for F508del or heterozygous for F508del and a residual function CFTR variant.

BACKGROUND: Two previous Phase 3 studies ("parent studies") showed that tezacaftor/ivacaftor was generally safe and efficacious for up to 24 weeks in children 6 through 11 years of age with cystic fibrosis (CF) and F508del/F508del (F/F) or F508del/residual function (F/RF) genotypes. We assessed the safety and efficacy of tezacaftor/ivacaftor in an open-label, 96-week extension study. METHODS: This was a Phase 3, 2-part, multicenter, open-label, extension study in children 6 through 11 years of age at treatment initiation (Study VX17-661-116; NCT03537651). The primary endpoint was safety and tolerability. Secondary endpoints were absolute change from baseline in lung clearance index2.5 (LCI2.5), sweat chloride (SwCl) concentration, Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain score, and body mass index (BMI). RESULTS: One-hundred thirty children enrolled and received ≥ 1 dose of tezacaftor/ivacaftor; 109 completed treatment. Most (n = 129) had ≥ 1 treatment-emergent adverse event (TEAE), the majority of which were mild or moderate in severity and generally consistent with common manifestations of CF. Exposure-adjusted TEAE rates were similar to or lower than those in the parent studies. Five (3.8%) had TEAEs leading to treatment discontinuation. Efficacy results from the parent studies were maintained, with improvements in lung function, SwCl concentration, CFQ­R respiratory domain score, and BMI observed from parent study baseline to Week 96. CONCLUSIONS: Tezacaftor/ivacaftor is generally safe and well tolerated, and treatment effects are maintained for up to 120 weeks. These results support long-term use of tezacaftor/ivacaftor in children ≥ 6 years of age with CF and F/F or F/RF genotypes.

Long-term safety and efficacy of tezacaftor-ivacaftor in individuals with cystic fibrosis aged 12 years or older who are homozygous or heterozygous for Phe508del CFTR (EXTEND): an open-label extension study.

BACKGROUND: Tezacaftor-ivacaftor is an approved cystic fibrosis transmembrane conductance regulator (CFTR) modulator shown to be efficacious and generally safe and well tolerated over 8-24 weeks in phase 3 clinical studies in participants aged 12 years or older with cystic fibrosis homozygous for the Phe508del CFTR mutation (F/F; study 661-106 [EVOLVE]) or heterozygous for the Phe508del CFTR mutation and a residual function mutation (F/RF; study 661-108 [EXPAND]). Longer-term (>24 weeks) safety and efficacy of tezacaftor-ivacaftor has not been assessed in clinical studies. Here, we present results of study 661-110 (EXTEND), a 96-week open-label extension study that assessed long-term safety, tolerability, and efficacy of tezacaftor-ivacaftor in participants aged 12 years or older with cystic fibrosis who were homozygous or heterozygous for the Phe508del CFTR mutation. METHODS: Study 661-110 was a 96-week, phase 3, multicentre, open-label study at 170 clinical research sites in Australia, Europe, Israel, and North America. Participants were aged 12 years or older, had cystic fibrosis, were homozygous or heterozygous for Phe508del CFTR, and completed one of six parent studies of tezacaftor-ivacaftor: studies 661-103, 661-106, 661-107, 661-108, 661-109, and 661-111. Participants received oral tezacaftor 100 mg once daily and oral ivacaftor 150 mg once every 12 h for up to 96 weeks. The primary endpoint was safety and tolerability. Secondary endpoints were changes in lung function, nutritional parameters, and respiratory symptom scores; pulmonary exacerbations; and pharmacokinetic parameters. A post-hoc analysis assessed the rate of lung function decline in F/F participants who received up to 120 weeks of tezacaftor-ivacaftor in studies 661-106 (F/F) and/or 661-110 compared with a matched cohort of CFTR modulator-untreated historical F/F controls from the Cystic Fibrosis Foundation Patient Registry. Primary safety analyses were done in all participants from all six parent studies who received at least one dose of study drug during this study. This study was registered at ClinicalTrials.gov (NCT02565914). FINDINGS: Between Aug 31, 2015, to May 31, 2019, 1044 participants were enrolled in study 661-110 from the six parent studies of whom 1042 participants received at least one dose of study drug and were included in the safety set. 995 (95%) participants had at least one TEAE; 22 (2%) had TEAEs leading to discontinuation; and 351 (34%) had serious TEAEs. No deaths occurred during the treatment-emergent period; after the treatment-emergent period, two deaths occurred, which were both deemed unrelated to study drug. F/F (106/110; n=459) and F/RF (108/110; n=226) participants beginning tezacaftor-ivacaftor in study 661-110 had improvements in efficacy endpoints consistent with parent studies; improvements in lung function and nutritional parameters and reductions in pulmonary exacerbations observed in the tezacaftor-ivacaftor groups in the parent studies were generally maintained in study 661-110 for an additional 96 weeks. Pharmacokinetic parameters were also similar to those in the parent studies. The annualised rate of lung function decline was 61·5% (95% CI 35·8 to 86·1) lower in tezacaftor-ivacaftor-treated F/F participants versus untreated matched historical controls. INTERPRETATION: Tezacaftor-ivacaftor was generally safe, well tolerated, and efficacious for up to 120 weeks, and the safety profile of tezacaftor-ivacaftor in study 661-110 was consistent with cystic fibrosis manifestations and with the safety profiles of the parent studies. The rate of lung function decline was significantly reduced in F/F participants, consistent with cystic fibrosis disease modification. Our results support the clinical benefit of long-term tezacaftor-ivacaftor treatment for people aged 12 years or older with cystic fibrosis with F/F or F/RF genotypes. FUNDING: Vertex Pharmaceuticals Incorporated.