Impact of Elexacaftor/Tezacaftor/Ivacaftor on Healthcare Resource Utilization and Associated Costs Among People With Cystic Fibrosis in the US: A Retrospective Claims Analysis.

INTRODUCTION: Cystic fibrosis (CF) is a life-limiting genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) is a CFTR modulator (CFTRm) that targets the underlying cause of CF. Based on safety and efficacy demonstrated in clinical trials, ELX/TEZ/IVA is approved in the US for the treatment of CF in people aged ≥ 2 years who have ≥ 1 F508del-CFTR mutation or a CFTR mutation that is responsive to ELX/TEZ/IVA based on in vitro data. While ELX/TEZ/IVA demonstrated unprecedented improvements in lung function and dramatic reductions in pulmonary exacerbations (PEx) and associated hospitalizations in clinical trials, a limited number of studies have examined the impact of ELX/TEZ/IVA on healthcare resource utilization (HCRU) and associated costs in a real-world setting. The aim of this retrospective study was to evaluate changes in PEx, HCRU, and associated non-CFTRm healthcare costs following initiation of ELX/TEZ/IVA among people with CF aged ≥ 12 years in the US. METHODS: We evaluated the rates of PEx, HCRU, and associated costs before and after initiation of ELX/TEZ/IVA in people with CF aged ≥ 12 years using data from the Merative MarketScan® Commercial Claims and Encounters Database and the Merative Multi-State Medicaid Database from April 21, 2019 to December 31, 2020. Because the study period included time following the onset of the COVID-19 pandemic, we limited our primary analysis to the period prior to the pandemic (October 21, 2019 to March 12, 2020). Outcomes following the onset of the pandemic (March 13 to December 31, 2020) were examined in an exploratory analysis. RESULTS: In both commercially insured and Medicaid-insured people with CF, ELX/TEZ/IVA was associated with reductions in PEx, hospitalizations, and associated costs prior to the COVID-19 pandemic, and these reductions were maintained following the onset of the pandemic. CONCLUSIONS: These findings suggest that ELX/TEZ/IVA reduces the burden and costs associated with PEx and hospitalizations in people with CF.

Safety and Tolerability of Difelikefalin for the Treatment of Moderate to Severe Pruritus in Hemodialysis Patients: Pooled Analysis From the Phase 3 Clinical Trial Program.

Rationale & Objective: We report a pooled safety analysis of intravenous difelikefalin in participants with moderate to severe chronic kidney disease-associated pruritus (CKD-aP) treated by hemodialysis in 4 phase 3 clinical studies. Study Design: KALM-1 and KALM-2 were randomized, double-blind, placebo-controlled, pivotal phase 3 studies; CLIN3101 (52 weeks) and CLIN3105 (12 weeks) were open-label studies. Setting & Participants: Adults with moderate to severe CKD-aP treated by hemodialysis in North America, Europe, and the Asia-Pacific region. Intervention: At least 1 intravenous placebo or difelikefalin dose of 0.5 mcg/kg for up to 64 weeks. Outcomes: Safety. Results: Safety analyses were conducted with 848 participants in the placebo-controlled cohort (424 participants each in the difelikefalin and placebo groups) and in 1,306 participants in the all-difelikefalin-exposure cohort. In the placebo-controlled cohort, the most commonly reported treatment-emergent adverse events (TEAEs), occurring in ≥2% of participants receiving difelikefalin and with a ≥1% higher incidence than placebo, were diarrhea (9.0% and 5.7%, respectively); dizziness (6.8% and 3.8%, respectively); nausea (6.6% and 4.5%, respectively); gait disturbances, including falls (6.6% and 5.4%, respectively), hyperkalemia (4.7% and 3.5%, respectively); headache (4.5% and 2.6%, respectively); somnolence (4.2% and 2.4%, respectively); and mental status changes (3.3% and 1.4%, respectively). These were mostly mild or moderate, with few leading to discontinuation. Incidence rates of TEAEs, serious TEAEs, and discontinuations because of TEAEs did not increase with long-term exposure. Three participants (0.7%) in the difelikefalin group and 5 participants (1.2%) in the placebo group died during the study. Limitations: Pooled data from studies with different designs. Conclusions: Intravenous difelikefalin demonstrated an acceptable safety profile, was generally well tolerated with long-term use, and may address the unmet treatment need for patients with CKD-aP treated by hemodialysis. Funding: Cara Therapeutics, Inc. Trial Registration: KALM-1 is registered as NCT03422653, KALM-2 as NCT03636269, CLIN3101 as NCT03281538, and CLIN3105 as NCT03998163.

Effect of difelikefalin, a selective kappa opioid receptor agonist, on respiratory depression: A randomized, double-blind, placebo-controlled trial.

Difelikefalin, a selective kappa opioid receptor agonist designed to limit central nervous system (CNS) penetration, is under development for the treatment of pruritus. Its hydrophilic, small-peptidic structure limits CNS entry, minimizing potential CNS-mediated adverse events (AEs). This study assessed the effect of difelikefalin on key relevant measures of respiratory depression in healthy volunteers. This single-center, randomized, double-blind, placebo-controlled, three-way crossover study enrolled healthy, nonsmoking volunteers. Subjects were randomized to 1 of 3 treatment sequences of difelikefalin (1.0 or 5.0 mcg/kg i.v.) or placebo on sequential days with an intervening 24 (±2) h washout period. The primary end points included incidence of increased end-tidal carbon dioxide (ETCO2 ) greater than or equal to 10 mm Hg versus baseline or a level greater than 50 mm Hg sustained greater than or equal to 30 seconds, and incidence of reduction in saturation of peripheral oxygen (SpO2 ) to less than 92% sustained greater than or equal to 30 seconds. Secondary end points included incidence of reduced respiratory rate and other safety assessments. Fifteen subjects were randomized and completed the study. No subject on placebo or difelikefalin met the increased ETCO2 or reduced SpO2 primary end point criteria for respiratory depression. All respiratory measures in each group remained near baseline values during 4-h postdose observations. No subject met the reduced respiratory rate criterion or experienced clinically significant changes in ETCO2 , SpO2 , or respiratory rate. The most commonly reported treatment-emergent AEs (TEAEs; ≥20% of subjects) were paresthesia, hypoesthesia, and somnolence in the difelikefalin arms. All TEAEs were mild and resolved without intervention. Difelikefalin 1.0 and 5.0 mcg/kg i.v. did not produce respiratory depression.