An analysis including pediatric patients with cancer-associated venous thromboembolism (VTE) suggested that anticoagulant therapy using rivaroxaban or standard treatment approaches appeared safe and efficacious. Results of this study were reported recently in the journal Blood Advances.
“The results of our analyses suggest that anticoagulant therapy with either rivaroxaban or standard anticoagulants in children with cancer-associated VTE is safe, efficacious, and associated with complete or partial vein recanalization in almost 85% of the children,” the study investigators wrote in their report.
VTE often arises in adult patients with cancer and cancer-associated VTE treatment may be impacted by polypharmacy use and associated drug interactions. However, less has been known about management of pediatric cancer-associated VTE.
This study was a subgroup analysis of the phase 3 EINSTEIN-Jr trial (ClinicalTrials.gov Identifier: NCT02234843). The EINSTEIN-Jr trial examined use of oral rivaroxaban in comparison with standard anticoagulant therapy in children with acute VTE. The subgroup analysis focused on outcomes for pediatric patients with cancer-associated VTE after a treatment duration of 3 months.
Children received either rivaroxaban adjusted for bodyweight, or standard anticoagulation involving agents such as heparin or vitamin K antagonist treatment. Outcomes of interest related to symptomatic recurrent VTEs, bleeding events, and VTE imaging at baseline and 3 months, with pharmacokinetic parameters also being assessed.
This subgroup analysis included 56 pediatric patients with cancer-associated VTE, of whom 40 were in the rivaroxaban-treated arm and 16 were in the standard treatment arm. Patients with cancer-associated VTE represented 11.2% of the population of 500 children enrolled in the EINSTEIN-Jr trial.
Median follow-up occurred at 91 days (interquartile range, 85-95). By 3 months, no children had experienced symptomatic recurrent VTE or major bleeding. Imaging conducted at 3 months revealed that 38.5% of evaluable children had complete vein recanalization, and 46.2% of evaluable children had partial vein recanalization. In the rivaroxaban group, there was 1 patient who experienced clinically relevant nonmajor bleeding, and 1 child was reported to have died from progression of a malignancy.
There were 70 interruptions of anticoagulant therapy overall, and these occurred among 46.4% of the patients. Interruptions lasted for a mean individual total of 5.8 days and occurred for reasons of thrombocytopenia, lumbar puncture, invasive procedure, or minor/clinically relevant nonmajor bleed.
The study investigators concluded that in this analysis anticoagulation using rivaroxaban or standard therapies showed safety and efficacy and was linked to a lower clot burden in most patients, even in the presence of treatment interruptions. “Rivaroxaban exposures were within the adult exposure range despite substantial polypharmacy use,” the study investigators also noted in their report, based on pharmacokinetic analyses they performed.
Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.
Palumbo JS, Lensing AWA, Brandão LR, et al. Anticoagulation in pediatric cancer–associated venous thromboembolism: a subgroup analysis of EINSTEIN-Jr. Blood Adv. 2022;6(22):5821-5828. doi:10.1182/bloodadvances.2022008160