rivaroxaban and Anemia

Rivaroxaban has been shown to be efficacious for treatment of venous thromboembolism in adults, and has a reduced risk of bleeding compared with standard anticoagulants. We aimed to develop paediatric rivaroxaban regimens for the treatment of venous thromboembolism in children and adolescents.. In this phase 2 programme, we did three studies to evaluate rivaroxaban treatment in children younger than 6 months, aged 6 months to 5 years, and aged 6-17 years. Our studies used a multicentre, single-arm design at 54 sites in Australia, Europe, Israel, Japan, and north America. We included children with objectively confirmed venous thromboembolism previously treated with low-molecular weight heparin, fondaparinux, or a vitamin K antagonist for at least 2 months or, in children who had catheter-related venous thromboembolism for at least 6 weeks. We administered rivaroxaban orally in a bodyweight-adjusted 20 mg-equivalent dose, based on physiologically-based pharmacokinetic modelling predictions and EINSTEIN-Jr phase 1 data in young adults, in either a once-daily (tablets; for those aged 6-17 years), twice-daily (in suspension; for those aged 6 months to 11 years), or three times-daily (in suspension; for those younger than 6 months) dosing regimen for 30 days (or 7 days for those younger than 6 months). The primary aim was to define rivaroxaban treatment regimens that match the target adult exposure range. The principal safety outcome was major bleeding and clinically relevant non-major bleeding. Analyses were per-protocol. The predefined efficacy outcomes were symptomatic recurrent venous thromboembolism, asymptomatic deterioration on repeat imaging at the end of the study treatment period. These trials are registered at ClinicalTrials.gov, numbers NCT02564718, NCT02309411, and NCT02234843.. Between Feb 11, 2013, and Dec 20, 2017, we enrolled 93 children (ten children younger than 6 months; 15 children aged 6 months to 1 year; 25 children aged 2-5 years; 32 children aged 6-11 years; and 11 children aged 12-17 years) into our study. 89 (96%) children completed study treatment (30 days of treatment, or 7 days in those younger than 6 months), and 93 (100%) children received at least one dose of study treatment and were evaluable for the primary endpoints. None of the children had a major bleed, and four (4%, 95% CI 1·2-10·6) of these children had a clinically relevant non-major bleed (three children aged 12-17 years with menorrhagia and one child aged 6-11 years with gingival bleeding). We found no symptomatic recurrent venous thromboembolism in any patients (0%, 0·0-3·9). 24 (32%) of 75 patients with repeat imaging had their thrombotic burden resolved, 43 (57%) patients improved, and eight (11%) patients were unchanged. No patient deteriorated. We confirmed therapeutic rivaroxaban exposures with once-daily dosing in children with bodyweights of at least 30 kg and with twice-daily dosing in children with bodyweights of at least 20 kg and less than 30 kg. Children with low bodyweights (<20 kg, particularly <12 kg) showed low exposures so, for future studies, rivaroxaban dosages were revised for these weight categories, to match the target adult exposure range. 61 (66%) of 93 children had adverse events during the study. Pyrexia was the most common adverse event (ten [11%] events), and anaemia and neutropenia or febrile neutropenia were the most frequent grade 3 or worse events (four [4%] events each). No children died or were discontinued from rivaroxaban because of adverse events.. Treatment with bodyweight-adjusted rivaroxaban appears to be safe in children. The treatment regimens that we confirmed in children with bodyweights of at least 20 kg and the revised treatment regimens that we predicted in those with bodyweights less than 20 kg will be evaluated in the EINSTEIN-Jr phase 3 trial in children with acute venous thromboembolism.. Bayer AG, Janssen Research and Development.

Topics: Adolescent; Anemia; Anticoagulants; Body Weight; Child; Child, Preschool; Drug Administration Schedule; Drug Dosage Calculations; Factor Xa; Female; Half-Life; Hemorrhage; Humans; Infant; Male; Neutropenia; Prothrombin Time; Rivaroxaban; Treatment Outcome; Venous Thromboembolism

A high risk of gastrointestinal bleeding has been reported with the use of some direct oral anticoagulants (DOACs). This risk may be of particular concern in individuals with associated anaemia. The aim of this study is to investigate potential differences in the risks of gastrointestinal bleeding and stroke among the four available DOACs in patients with atrial fibrillation (AF) and moderate or severe anaemia.. All Danish patients diagnosed with incident AF who had a baseline haemoglobin measurement and subsequently initiated DOAC therapy between 2012 and 2021 were identified through administrative registries. Only patients with moderate or severe anaemia (N = 7269) were included and evaluated regarding the risk of hospitalization for gastrointestinal bleeding and stroke. Standardized absolute 1-year risks of stroke and gastrointestinal bleeding were calculated from multivariable Cox regression analyses. DOACs were compared pairwise RESULTS: Compared with apixaban, both dabigatran and rivaroxaban were associated with a significantly increased risk of gastrointestinal bleeding with standardized 1-year risk ratios of 1.73 (95 % confidence interval [CI], 1.10-2.35) and 1.56 (95 % CI, 1.18-1.93), respectively, while no significant difference was seen in the comparison of apixaban with edoxaban 1.32 (95 % CI, 0.41-2.32). No significant differences in gastrointestinal bleeding were observed with pairwise comparisons of dabigatran, rivaroxaban and edoxaban. Finally, no significant difference in stroke risk among the four DOACs was observed.. In AF patients with moderate or severe anaemia, apixaban was associated with a significantly lower risk of gastrointestinal bleeding than dabigatran and rivaroxaban. No significant difference in stroke risk was observed across all four available DOACs.

Topics: Administration, Oral; Anemia; Anticoagulants; Atrial Fibrillation; Dabigatran; Gastrointestinal Hemorrhage; Humans; Pyridones; Rivaroxaban; Stroke

Results from the J-ROCKET AF study revealed that rivaroxaban was non-inferior to warfarin with respect to the principal safety outcomes in patients with non-valvular atrial fibrillation. This subgroup analysis evaluated whether non-major clinically relevant bleeding (NMCRB) could be a predictive factor for major bleeding (MB). Other predictive factors for MB were also obtained in both rivaroxaban and warfarin treatment groups.. The temporal incidence of MB was compared between the rivaroxaban and warfarin treatment groups. Assessment was made whether MB events were often preceded by NMCRB. Univariate and multivariate analyses were carried out to identify any independent predictive factors for MB in both treatment groups.. The incidences of MB and NMCRB were 18.04% (138/639 patients) in the rivaroxaban arm, and 16.42% in the warfarin arm (124/639 patients). NMCRB preceded MB in only four patients in each treatment group (rivaroxaban: 4/117 and warfarin: 4/98). Multivariate analysis identified predictive factors for bleeding events: anemia with warfarin treatment and concomitant use of antiplatelet agents with rivaroxaban treatment.. Results from this subgroup analysis, particularly the fact that there was no repeated or sequential pattern between NMCRB and MB occurrences in both treatment groups, suggests that NMCRB might not be a predictive factor for MB. On the contrary, anemia and concomitant use of antiplatelet therapy were likely predictive factors for bleeding with warfarin and rivaroxaban treatment, respectively.

Topics: Aged; Anemia; Anticoagulants; Atrial Fibrillation; Female; Hemorrhage; Humans; Japan; Male; Multivariate Analysis; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Rivaroxaban; Stroke; Warfarin