OC 06.4 - Safety and Efficacy of Direct Oral Anticoagulants in Pediatric Oncology Patients: Real-World Experience from two Quaternary Care Pediatric Centers

Saturday, June 22, 2024

13:45 – 14:00 ICT

Room: 111 A-C

Presenting Author(s)

Vilmarie Rodriguez, MD, MS

Director Thrombosis and Anticoagulation Program
Nationwide Children's Hospital/The Ohio State University
Columbus, Ohio, United States

Co-Author(s)

JS

Joseph Stanek, MS

MS
Hematology-Oncology/BMT Nationwide Children’s Hospital, Columbus OH
Columbus, Ohio, United States
NY

Nicholas Yeager, MD

MD
Nationwide Children's Hospital/The Ohio State University
Columbus, Ohio, United States
ED

Emily Drake

APN
Dana Farber/Boston Children’s Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School
Boston, Massachusetts, United States
LV

Lynda M. Vrooman, MD

MD
Dana Farber/Boston Children’s Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School
Boston, Massachusetts, United States
LS

Lewis B. Silverman

MD
Dana Farber/Boston Children’s Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School
Boston, Massachusetts, United States
Riten Kumar, MD, MSc

Department of Pediatrics
Dana Farber/Boston Children’s Cancer and Blood Disorders Center; Harvard Medical School
Boston, Massachusetts, United States

Background: Direct oral anticoagulants (DOACs) (rivaroxaban, apixaban) are currently the guideline-endorsed treatment recommendation in adults with cancer-associated thrombosis. Despite safety and efficacy demonstrated in the treatment and prophylaxis of venous thrombo-embolism (VTE) in children, limited data are available in the pediatric oncology population.

Aims: To describe the safety and efficacy of DOAC in pediatric oncology patients.

Methods: We performed a retrospective chart review at two quaternary care pediatric centers. Permission from the Institutional Review Board was obtained at both centers. Children and young adults (ages 0-22) years with a cancer diagnoses between 1/1/2019 and 07/31/2023, who received a DOAC for VTE treatment, primary, and/or secondary VTE prophylaxis were eligible. Bleeding and thrombosis outcomes were classified according to International Society of Thrombosis and Haemostasis (ISTH) criteria. Standard statistical methods were used to summarize data.

Results: 51 patients (n=27 female) met eligibility criteria. Median age at VTE diagnosis was 14.4 (0-22.5) years (Table 1). Twenty-eight patients (54.9%) had leukemia/lymphoma while the remaining had solid tumors. 25 patients (49.1%) had catheter-associated thrombosis. Median duration of DOAC therapy/prophylaxis was 187 (range 15-824) days. Symptomatic thrombus recurrence was reported in 4 (7.8%) patients, three while on prophylactic doses of rivaroxaban (n=2) and apixaban (n=1). Major bleeding was reported in 3 (5.9%), and clinically relevant non-major bleeding (CRNM) in 10 (19.6%) patients (Table 2). Seven deaths were reported, though none were attributed to bleeding or progressive thrombosis.

Conclusion(s): Bleeding rates in our cohort are higher than those reported in a subgroup analysis of oncology patients enrolled in the EINSTEIN-Jr study. VTE recurrence rates were observed primarily in patients secondary prophylaxis suggesting the need to continue therapeutic doses especially in patients deemed to be at high risk for VTE recurrence. Prospective cohort studies can help clarify optimal anticoagulation strategy in this high-risk cohort.