Rationale: Lumacaftor/ivacaftor (LUM/IVA) was shown to be safe and well tolerated in children 2 through 5 years of age with cystic fibrosis (CF) homozygous for F508del-CFTR in a Phase 3 open-label study. Improvements in sweat chloride concentration, markers of pancreatic function, and lung clearance index2.5 (LCI2.5), along with increases in growth parameters, suggested the potential for early disease modification with LUM/IVA treatment. Objective: To further assess the effects of LUM/IVA on CF disease progression in children 2 through 5 years of age using chest magnetic resonance imaging (MRI). Methods: This Phase 2 study had two parts: a 48-week, randomized, double-blind, placebo-controlled treatment period in which children 2 through 5 years of age with CF homozygous for F508del-CFTR received either LUM/IVA or placebo (Part 1) followed by an open-label period in which all children received LUM/IVA for an additional 48 weeks (Part 2). The results from Part 1 are reported. The primary endpoint was absolute change from baseline in chest MRI global score at Week 48. Secondary endpoints included absolute change in LCI2.5 through Week 48 and absolute changes in weight-for-age, stature-for-age, and body mass index-for-age z-scores at Week 48. Additional endpoints included absolute changes in sweat chloride concentration, fecal elastase-1 levels, serum immunoreactive trypsinogen, and fecal calprotectin through Week 48. The primary endpoint was analyzed using Bayesian methods, where the actual Bayesian posterior probability of LUM/IVA being superior to placebo in the chest MRI global score at Week 48 was calculated using a vague normal prior distribution; secondary and additional endpoints were analyzed using descriptive summary statistics. Results: Fifty-one children were enrolled and received LUM/IVA (n = 35) or placebo (n = 16). For the change in chest MRI global score at Week 48, the Bayesian posterior probability of LUM/IVA being better than placebo (treatment difference, <0; higher score indicates greater abnormality) was 76%; the mean treatment difference was -1.5 (95% credible interval, -5.5 to 2.6). Treatment with LUM/IVA also led to within-group numerical improvements in LCI2.5, growth parameters, and biomarkers of pancreatic function as well as greater decreases in sweat chloride concentration compared with placebo from baseline through Week 48. Safety data were consistent with the established safety profile of LUM/IVA. Conclusions: This placebo-controlled study suggests the potential for early disease modification with LUM/IVA treatment, including that assessed by chest MRI, in children as young as 2 years of age. Clinical trial registered with www.clinicaltrials.gov (NCT03625466).

Rationale: We previously reported that ivacaftor was safe and well tolerated in cohorts aged 12 to <24 months with cystic fibrosis and gating mutations in the ARRIVAL study; here, we report results for cohorts aged 4 to <12 months.Objectives: To evaluate the safety, pharmacokinetics, and pharmacodynamics of ivacaftor in infants aged 4 to <12 months with one or more gating mutations.Methods: ARRIVAL is a single-arm phase 3 study. Infants received 25 mg or 50 mg ivacaftor every 12 hours on the basis of age and weight for 4 days in part A and 24 weeks in part B.Measurements and Main Results: Primary endpoints were safety (parts A and B) and pharmacokinetics (part A). Secondary/tertiary endpoints (part B) included pharmacokinetics and changes in sweat chloride levels, growth, and markers of pancreatic function. Twenty-five infants received ivacaftor, 12 in part A and 17 in part B (four infants participated in both parts). Pharmacokinetics was consistent with that in older groups. Most adverse events were mild or moderate. In part B, cough was the most common adverse event (n = 10 [58.8%]). Five infants (part A, n = 1 [8.3%]; part B, n = 4 [23.5%]) had serious adverse events, all of which were considered to be not or unlikely related to ivacaftor. No deaths or treatment discontinuations occurred. One infant (5.9%) experienced an alanine transaminase elevation >3 to ≤5× the upper limit of normal at Week 24. No other adverse trends in laboratory tests, vital signs, or ECG parameters were reported. Sweat chloride concentrations and measures of pancreatic obstruction improved.Conclusions: This study of ivacaftor in the first year of life supports treating the underlying cause of cystic fibrosis in children aged ≥4 months with one or more gating mutations.Clinical trial registered with clinicaltrials.gov (NCT02725567).

Neutrophil migration and activation are essential for defense against pathogens. However, this process may also lead to collateral tissue injury. We used microRNA overexpression as a platform and discovered protein-coding genes that regulate neutrophil migration. Here we show that miR-99 decreased the chemotaxis of zebrafish neutrophils and human neutrophil-like cells. In zebrafish neutrophils, miR-99 directly targets the transcriptional factor RAR-related orphan receptor alpha (roraa). Inhibiting RORα, but not the closely related RORγ, reduced chemotaxis of zebrafish and primary human neutrophils without causing cell death, and increased susceptibility of zebrafish to bacterial infection. Expressing a dominant-negative form of Rorα or disrupting the roraa locus specifically in zebrafish neutrophils reduced cell migration. At the transcriptional level, RORα regulates transmembrane signaling receptor activity and protein phosphorylation pathways. Our results, therefore, reveal previously unknown functions of miR-99 and RORα in regulating neutrophil migration and anti-microbial defense.

In two pivotal phase 3 trials, up to 24 weeks of treatment with elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was efficacious and safe in patients with cystic fibrosis (CF) ≥12 years of age who have at least one F508del allele. The aim of this study is to assess long-term safety and efficacy of ELX/TEZ/IVA in these patients.

Rationale: Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) has been shown to be safe and efficacious in people with cystic fibrosis (pwCF) aged 2 years and older with at least one F508del-CFTR allele or more. After U.S. approval in 2019, reports emerged of depression-related adverse events in pwCF treated with ELX/TEZ/IVA. Objectives: To review available evidence on depression-related events in pwCF treated with ELX/TEZ/IVA in the context of background epidemiology in pwCF. Methods: Safety data from 14 ELX/TEZ/IVA clinical trials and 10 trials of CF transmembrane conductance regulator (CFTR) modulators in which placebo was administered, along with data from CF registries in the United States and Germany and cumulative postmarketing adverse event data from 61,499 pwCF who initiated ELX/TEZ/IVA after initial approval in the United States (October 2019) through October 2022, were reviewed and used to calculate exposure-adjusted rates of depression-related adverse events and prevalence of depression. In addition, a scientific literature review was conducted to identify ELX/TEZ/IVA publications reporting depression-related events or changes in depressive symptoms after treatment initiation. Measurements and Main Results: In clinical trials, the exposure-adjusted rate of any depression-related adverse event was 3.32/100 person years (PY) in the pooled ELX/TEZ/IVA group (n = 1,711) and 3.24/100 PY in the pooled placebo group (n = 1,369). The exposure-adjusted rates of suicidal ideation and suicide attempt were also similar between the pooled ELX/TEZ/IVA group and pooled placebo group (ideation: 0.23/100 PY vs. 0.28/100 PY; attempt: 0.08/100 PY vs. 0.14/100 PY). In the postmarketing setting, the exposure-adjusted reporting rates of depression-related events were low in context of the background prevalence in pwCF (all depression-related events: 1.29/PY; suicidal ideation: 0.12/100 PY; and suicide attempt: 0.05/100 PY). Assessments of individual case reports were confounded by preexisting mental health conditions, intercurrent psychosocial stressors (including coronavirus disease [COVID-19] lockdowns), and the heterogeneous and fluctuating nature of depression. Data from CF registries in the United States and Germany showed that patterns of depression prevalence in pwCF exposed to ELX/TEZ/IVA did not change after treatment initiation. Published studies utilizing the nine-item Patient Health Questionnaire did not show evidence of worsening depression symptoms in pwCF treated with ELX/TEZ/IVA. Conclusions: Our review of data from clinical trials, postmarketing reports, an ongoing registry-based ELX/TEZ/IVA postauthorization safety study, and peer-reviewed literature suggests that depression symptoms and depression-related events reported in pwCF treated with ELX/TEZ/IVA are generally consistent with background epidemiology of these events in the CF population and do not suggest a causal relationship with ELX/TEZ/IVA treatment.

Rationale: Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was shown to be efficacious and safe in patients ≥12 years of age with cystic fibrosis and at least one F508del-CFTR (cystic fibrosis transmembrane conductance regulator) allele, but it has not been evaluated in children <12 years of age. Objectives: To assess the safety, pharmacokinetics, and efficacy of ELX/TEZ/IVA in children 6 through 11 years of age with F508del-minimal function or F508del-F508del genotypes. Methods: In this 24-week open-label phase 3 study, children (N = 66) weighing <30 kg received 50% of the ELX/TEZ/IVA adult daily dose (ELX 100 mg once daily, TEZ 50 mg once daily, and IVA 75 mg every 12 h) whereas children weighing ⩾30 kg received the full adult daily dose (ELX 200 mg once daily, TEZ 100 mg once daily, and IVA 150 mg every 12 h). Measurements and Main Results: The primary endpoint was safety and tolerability. The safety and pharmacokinetic profiles of ELX/TEZ/IVA were generally consistent with those observed in older patients. The most commonly reported adverse events included cough, headache, and pyrexia; in most of the children who had adverse events, these were mild or moderate in severity. Through Week 24, ELX/TEZ/IVA treatment improved the percentage of predicted FEV1 (10.2 percentage points; 95% confidence interval [CI], 7.9 to 12.6), Cystic Fibrosis Questionnaire-Revised respiratory domain score (7.0 points; 95% CI, 4.7 to 9.2), lung clearance index2.5 (-1.71 units; 95% CI, -2.11 to -1.30), and sweat chloride (-60.9 mmol/L; 95% CI, -63.7 to -58.2); body mass index-for-age z-score increased over the 24-week treatment period when compared with the pretreatment baseline. Conclusions: Our results show ELX/TEZ/IVA is safe and efficacious in children 6 through 11 years of age with at least one F508del-CFTR allele, supporting its use in this patient population. Clinical trial registered with www.clinicaltrials.gov (NCT03691779).

Rationale: The triple-combination regimen elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was shown to be safe and efficacious in children aged 6 through 11 years with cystic fibrosis and at least one F508del-CFTR allele in a phase 3, open-label, single-arm study. Objectives: To further evaluate the efficacy and safety of ELX/TEZ/IVA in children 6 through 11 years of age with cystic fibrosis heterozygous for F508del and a minimal function CFTR mutation (F/MF genotypes) in a randomized, double-blind, placebo-controlled phase 3b trial. Methods: Children were randomized to receive either ELX/TEZ/IVA (n = 60) or placebo (n = 61) during a 24-week treatment period. The dose of ELX/TEZ/IVA administered was based on weight at screening, with children <30 kg receiving ELX 100 mg once daily, TEZ 50 mg once daily, and IVA 75 mg every 12 hours, and children ⩾30 kg receiving ELX 200 mg once daily, TEZ 100 mg once daily, and IVA 150 mg every 12 hours (adult dose). Measurements and Main Results: The primary endpoint was absolute change in lung clearance index2.5 from baseline through Week 24. Children given ELX/TEZ/IVA had a mean decrease in lung clearance index2.5 of 2.29 units (95% confidence interval [CI], 1.97-2.60) compared with 0.02 units (95% CI, -0.29 to 0.34) in children given placebo (between-group treatment difference, -2.26 units; 95% CI, -2.71 to -1.81; P < 0.0001). ELX/TEZ/IVA treatment also led to improvements in the secondary endpoint of sweat chloride concentration (between-group treatment difference, -51.2 mmol/L; 95% CI, -55.3 to -47.1) and in the other endpoints of percent predicted FEV1 (between-group treatment difference, 11.0 percentage points; 95% CI, 6.9-15.1) and Cystic Fibrosis Questionnaire-Revised Respiratory domain score (between-group treatment difference, 5.5 points; 95% CI, 1.0-10.0) compared with placebo from baseline through Week 24. The most common adverse events in children receiving ELX/TEZ/IVA were headache and cough (30.0% and 23.3%, respectively); most adverse events were mild or moderate in severity. Conclusions: In this first randomized, controlled study of a cystic fibrosis transmembrane conductance regulator modulator conducted in children 6 through 11 years of age with F/MF genotypes, ELX/TEZ/IVA treatment led to significant improvements in lung function, as well as robust improvements in respiratory symptoms and cystic fibrosis transmembrane conductance regulator function. ELX/TEZ/IVA was generally safe and well tolerated in this pediatric population with no new safety findings.

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).