A dose-ranging study of ticagrelor in children aged 3-17 years with sickle cell disease: A 2-part phase 2 study.

Antiplatelet treatment is a potential therapeutic approach for sickle cell disease (SCD). Ticagrelor inhibits platelet aggregation and is approved for adults with acute coronary syndrome and following myocardial infarction. HESTIA1 (NCT02214121) was a 2-part, phase 2 dose-finding study generating ticagrelor exposure, platelet inhibition, and safety data in children with SCD (3-17 years). In part A (n = 45), patients received 2 ticagrelor single doses, 0.125-2.25 mg/kg (washout ≥7 days), then 7 days of twice-daily (bid) dosing with 0.125, 0.563, or 0.75 mg/kg. In the 4-week blinded Part B extension (optional), patients received ticagrelor (0.125, 0.563, or 0.75 mg/kg bid; n = 16) or placebo (n = 7). Platelet reactivity decreased from baseline to 2 hours postdosing, and returned to near baseline after 6 hours postdosing. Dose-dependent platelet inhibition was seen with ticagrelor; mean relative P2Y12 reaction unit inhibition 2 hours after a single dose ranged from 6% (0.125 mg/kg) to 73% (2.25 mg/kg). Ticagrelor plasma exposure increased approximately dose proportionally. No patients experienced a hemorrhagic event during treatment. No differences were seen between groups in pain ratings and analgesic use during Part B. Ticagrelor was well tolerated with no safety concerns, no discontinuations due to adverse events (AEs), and reported AEs were mainly due to SCD. In conclusion, a dose-exposure-response relationship for ticagrelor was demonstrated in children with SCD for the first time. These data are important for future pediatric studies of the efficacy and safety of ticagrelor in SCD.

Epithelial Thickness is a Marker of Gastroesophageal Reflux Disease.

BACKGROUND & AIMS: Histologic criteria have been refined for the diagnosis of gastroesophageal reflux disease (GERD). We aimed to evaluate these criteria for the assessment of GERD and to measure interassessor agreement. METHODS: We performed a post hoc analysis of data from the Diamond study (NCT 00291746), conducted in Europe and Canada on adults with frequent upper gastrointestinal symptoms who had not taken a proton pump inhibitor in the previous 2 months. GERD was diagnosed based on the presence of 1 or more of the following: reflux esophagitis, pathologic esophageal acid exposure, and/or positive symptom-acid association probability. Nonerosive reflux disease was defined as the presence of pathologic esophageal acid exposure and/or a positive symptom-acid association probability, but no reflux esophagitis. Biopsies collected from 336 patients from 0.5 cm and 2.0 cm above the Z line were evaluable; they were analyzed independently at pathology centers in Germany and Italy (biopsies from 258 and 195 patients, respectively). The primary outcomes were the accuracy of histologic criteria for the diagnosis of GERD, defined by endoscopy and pH monitoring, and interassessor agreement on histologic criteria. RESULTS: At the assessment site for basal cell layer thickness, total epithelial thickness was the best-performing criterion for diagnosis of investigation-defined GERD; it also identified nonerosive reflux disease, reflux esophagitis, and pathologic esophageal acid exposure at 0.5 cm and 2.0 cm above the Z line. Basal cell layer thickness and presence of dilated intercellular spaces did not identify patients with GERD. Among the criteria tested, the best agreement between assessments carried out at the 2 pathology centers was for total epithelial thickness at 0.5 cm and 2.0 cm above the Z line. CONCLUSIONS: Based on an analysis of 336 patients with frequent upper gastrointestinal symptoms, total epithelial thickness is a robust histologic marker for GERD.

Development Strategy and Relative Bioavailability of a Pediatric Tablet Formulation of Ticagrelor.

BACKGROUND AND OBJECTIVE: Ticagrelor is a P2Y12 receptor inhibitor approved as an antiplatelet drug for patients with acute coronary syndrome or a history of myocardial infarction. Ticagrelor is also being investigated for the reduction of vaso-occlusive crises in pediatric patients with sickle cell disease. A pediatric formulation suitable for this age range was developed; the development strategy is described. Primary objectives were determining the relative bioavailability of ticagrelor pediatric tablets and granules for oral suspension to the adult immediate-release tablet, and the pediatric tablets taken whole and dispersed/suspended in water to the granules for oral suspension. Bioequivalence between the pediatric tablet taken whole or suspended in water was also assessed. Secondary objectives were comparing the formulations' safety and tolerability. METHODS: We conducted a randomized, four-period, cross-over, single-dose study. Pharmacokinetic parameters were assessed for ticagrelor and its active metabolite AR-C124910XX. Bioequivalence was concluded if the 90% confidence intervals of the maximum plasma concentration and area under the plasma concentration-time curve ratios were contained completely within the 80.00-125.00% limits for ticagrelor/AR-C124910XX. RESULTS: Forty-four healthy adults (95% white; 57% male) were included. Similar bioavailability of ticagrelor (and AR-C124910XX) was demonstrated for all comparisons tested. Ticagrelor pediatric tablets taken whole were bioequivalent to pediatric tablets suspended in water. The plasma concentration-time profiles for ticagrelor and AR-C124910XX were similar, showing rapid ticagrelor absorption and AR-C124910XX formation. All formulations were well tolerated. CONCLUSION: Similar bioavailability of a new pediatric dispersible tablet formulation of ticagrelor for use across a wide age range of pediatric patients was demonstrated compared with other oral ticagrelor formulations. CLINICALTRIALS. GOV IDENTIFIER: NCT03126695. EUDRACT: 2017-000371-93.

Effect of CYP2C19 polymorphism on the pharmacokinetics of rosuvastatin in healthy Taiwanese subjects.

CYP2C19 contributes to N-desmethyl rosuvastatin formation in "in vitro" models. Approximately 80% of Taiwanese are CYP2C19 extensive metabolizers (EMs, CYP2C19*1/*1, *1/*2, or *1/*3). We studied the potential effect of CYP2C19 genotypes on rosuvastatin pharmacokinetics in healthy Taiwanese subjects following single and multiple daily oral doses of rosuvastatin calcium (20 mg). Geometric mean ratios for poor metabolizers (PMs): EMs for rosuvastatin were 0.974 and 0.872 for area under the curve and maximum plasma concentration on day 1 (1.01 and 0.965 on day 17) and for N-desmethyl rosuvastatin, 1.21 and 1.07 on day 1 (1.14 and 1.09 on day 17), respectively. Changes of lipid profiles from baseline to day 18 for PMs and EMs were -52.4% and -53.3% (low-density lipoprotein cholesterol), and -34.2% and -30.0% (total cholesterol), respectively. Rosuvastatin was generally well-tolerated by both PMs and EMs. These results suggest that CYP2C19 polymorphism does not affect rosuvastatin pharmacokinetics in healthy Taiwanese in a clinically meaningful way.

Efficacy and safety of rosuvastatin therapy in children and adolescents with familial hypercholesterolemia: Results from the CHARON study.

OBJECTIVE: Heterozygous familial hypercholesterolemia (HeFH) is an autosomal dominant disorder leading to premature atherosclerosis. Guidelines recommend initiating statins early to reduce low-density lipoprotein cholesterol (LDL-C). Studies have evaluated rosuvastatin in children aged ≥10 years, but its efficacy and safety in younger children is unknown. METHODS: Children with HeFH and fasting LDL-C >4.92 mmol/L (190 mg/dL) or >4.10 mmol/L (>158 mg/dL) with other cardiovascular risk factors received rosuvastatin 5 mg daily. Based on LDL-C targets (<2.85 mmol/L [<110 mg/dL]), rosuvastatin could be uptitrated to 10 mg (aged 6-9 years) or 20 mg (aged 10-17 years). Treatment lasted 2 years. Changes in lipid values, growth, sexual maturation, and adverse events (AEs) were assessed. RESULTS: The intention-to-treat analysis included 197 patients. At 24 months, LDL-C was reduced by 43, 45, and 35% vs baseline in patients aged 6-9, 10-13, and 14-17 years, respectively (P < .001 for all groups). Most AEs were mild. Intermittent myalgia was reported in 11 (6%) patients and did not lead to discontinuation of rosuvastatin treatment. Serious AEs were reported by 9 (5%) patients, all considered unrelated to treatment by the investigators. No clinically important changes in hepatic biochemistry were reported. Rosuvastatin treatment did not appear to adversely affect height, weight, or sexual maturation. CONCLUSIONS: In HeFH patients aged 6-17 years, rosuvastatin 5-20 mg over 2 years significantly reduced LDL-C compared with baseline. Treatment was well tolerated, with no adverse effects on growth or sexual maturation.