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Background and Objective: There is an unmet need for a safer anticoagulant since bleeding remains a concern with currently approved anticoagulants. Coagulation factor XI (FXI) is an attractive anticoagulant drug target with limited a role in physiological hemostasis. The objective of this study was to evaluate the safety, pharmacokinetics, and pharmacodynamics of SHR2285, a novel small molecule FXIa inhibitor, in healthy Chinese volunteers. Methods: The study consisted of single ascending doses part (part 1: 25–600 mg) and multiple ascending doses part (part 2: 100, 200, 300, and 400 mg). In both parts, subjects were randomized in a 3:1 ratio to receive SHR2285 or placebo orally. Blood, urine and feces samples were collected to describe its pharmacokinetic and pharmacodynamic profile. Results: In total, 103 healthy volunteers completed the study. SHR2285 was well tolerated. SHR2285 was absorbed rapidly with median time to maximum plasma concentration (Tmax) of 1.50 to 3.00 h. The geometric median half-life (t1/2) of SHR2285 varied from 8.74 to 12.1 h across 25–600 mg single dose. Total systemic exposure of metabolite SHR164471 was approximately 1.77- to 3.61-fold that of the parent drug. The plasma concentration of SHR2285 and SHR164471 reached steady state by the morning of Day 7, with low accumulation ratio (0.956–1.20 and 1.18–1.56, respectively). The increase in pharmacokinetic exposure of SHR2285 and SHR164471 was less than dose proportional. Food has minimal effect on the pharmacokinetics of SHR2285 and SHR164471. SHR2285 produced an exposure-dependent prolongation of activated partial thromboplastin time (APTT) and a decrease in FXI activity. The maximum FXI activity inhibition rate (geometric mean) at steady state was 73.27%, 85.58%, 87.77% and 86.27% for 100–400 mg, respectively. Conclusions: SHR2285 was generally safe and well tolerated in healthy subjects across a wide range of doses. SHR2285 exhibited a predictable pharmacokinetic profile and an exposure-related pharmacodynamic profile. ClinicalTrials.gov Identifier NCT04472819; registered on July 15, 2020. [ABSTRACT FROM AUTHOR]

Background: Data available for pharmacokinetics (PK)/pharmacodynamics (PD) of ticagrelor and significant endogenous/exogenous factors or biomarkers related to bleeding events in both healthy and clinical patients are limited. Objective: Based on PK and PD data from multicenter healthy subjects and patients, we aimed to establish an integrated approach towards population PK (pop PK) and the PD model of ticagrelor. Methods: This study was conducted as a multicenter, prospective clinical registration study involving both healthy subjects and clinical patients. The integrated Pharmacokinetic/pharmacodynamic (PK/PD) models were characterized based on PK/PD [ticagrelor concentration, aggregation baseline (BASE), P2Y12 response unit (PRU) and inhibition rate (INHIBIT)] data from 175 healthy volunteers. The model was corrected by sparse PD (BASE, PRU and INHIBIT) data from 208 patients with acute coronary syndrome (ACS). The correlations between PD biomarkers and clinically relevant bleedings in 1 year were explored. Results: A one-compartment, linear model with first-order absorption was adopted as PK model. Food status (FOOD) and body weight (WT) significantly influenced clearance and improved the fitting degree of the PK model, while SEX was selected as the covariates of the PD model. For patients taking ticagrelor 90 mg, the peak value [mean (95% CI)] of PRU was 355.15 (344.24–366.06) and the trough value was 3.64 (3.14–4.15). The PRU mean parameters were basically within the expected range (80–200) of the literature suggestions. Conclusion: A fixed dose of ticagrelor, without adjusting the dosing regimen other than covariates of FOOD/WT/SEX, could be used in patients with acute coronary syndromes, and the standard regimen could be used in Chinese patients from the perspective of exposure. [ABSTRACT FROM AUTHOR]

Introduction: To identify the potential factors responsible for the individual variability of dabigatran, we investigated the genetic variations associated with clinical outcomes and pharmacodynamics (PD) in Chinese patients with nonvalvular atrial fibrillation (NVAF). Materials and methods: Chinese patients with NVAF taking dabigatran etexilate with therapeutic doses were enrolled. The primary (bleeding events) and secondary (thromboembolic and major adverse cardiac events) outcomes for a 2‐year follow‐up were evaluated. Peak and trough PD parameters (anti‐FIIa activity, activated partial thromboplastin time and prothrombin time) were detected. Whole‐exome sequencing, genome‐wide sequencing and candidate gene association analyses were performed. Results: There were 170 patients with NVAF treated with dabigatran (110 mg twice daily) who were finally included. Two single‐nucleotide polymorphisms (SNPs) were significantly related with bleeding, which include UBASH3B rs2276408 (odds ratio [OR] = 8.79, 95% confidence interval [CI]: 2.99–25.83, p = 7.77 × 10−5 at sixth month visit) and FBN2 rs3805625 (OR = 8.29, 95% CI: 2.87–23.89, p = 9.08 × 10−5 at 12th month visit), as well as with increased trends at other visits (p <.05). Furthermore, minor allele carriers of 16 new SNPs increased PD levels, and those of one new SNP decreased PD values (p < 1.0 × 10−5). Lastly, 33 new SNPs were found to be associated with bleeding and PD among 14 candidate genes. Unfortunately, the low number of secondary outcomes precluded further association analyses. Conclusions: Genetic variations indeed affected bleeding and PD in Chinese patients with NVAF treated with dabigatran. The functions of these suggestive genes and SNPs might further be explored and verified in more in vivo and in vitro investigations. [ABSTRACT FROM AUTHOR]