FondaKIDS III: A long‐term retrospective cohort study of fondaparinux for treatment of venous thromboembolism in children

Abstract

Background The incidence of venous thromboembolism (VTE) and use of anticoagulation are rising in children, but treatment options remain limited. As a newer anticoagulant, fondaparinux may be a safe and effective alternative with the benefit of once‐daily dosing, but there is relatively little data supporting its use. Procedure This retrospective cohort study describes the long‐term dosing, efficacy, and safety of fondaparinux for treatment of VTE in children at a single institution. The study included children <18 years old treated with fondaparinux for VTE between 2008 and 2018. Descriptive statistics were used to present the findings. Results A total of 277 patients were identified and analyzed in this study. Seventy‐six percent of patients reached therapeutic levels with 0 or 1 dose adjustments over a median treatment duration of 93 days. Of the patients included in the efficacy analysis, 91% of patients had improvement in their clot status, including 69% (160/233) with complete resolution and 22% (53/233) with partial resolution. Twenty‐six patients (11%) had VTE recurrence, but only seven (3%) of the new thrombi developed while on fondaparinux. Major bleeding occurred in seven patients (2.5%), primarily in patients with underlying medical conditions with increased bleeding risk. Minor bleeding occurred in 53 patients (19%). Conclusions This study demonstrates the stable long‐term pediatric dosing of fondaparinux with similar efficacy and safety when compared to other anticoagulants. Given its advantages, fondaparinux can be considered a reasonable alternative for treatment of VTE in children.

Implications of the first FDA‐approved anticoagulant in pediatrics: One ship has sailed but the next ones are at the dock

“…This is not the case, however, for fondaparinux which has been in regulatory limbo with respect to pediatric use for nearly 15 years. This, despite the fact that there is more published data on fondaparinux than dalteparin including a similarly (to dalteparin) designed, prospective, dose-finding, pharmacokinetic, efficacy and safety study, [4][5][6]…”

“…This is not the case, however, for fondaparinux which has been in regulatory limbo with respect to pediatric use for nearly 15 years. This, despite the fact that there is more published data on fondaparinux than dalteparin including a similarly (to dalteparin) designed, prospective, dose‐finding, pharmacokinetic, efficacy and safety study, 4–6 and the fact that the pharmaceutical companies (the compound has changed hands a few times) have been in discussions with the FDA repeatedly. Unlike with dalteparin, the FDA has placed numerous and pointless hurdles upon the responsible pharmaceutical companies for capricious reasons succeeding only in potentially putting children at increased risk of harm by, for example, requiring a dose‐finding study when the dose of fondaparinux is already well established.…”

Implications of the first FDA-approved anticoagulant in pediatrics: One ship has sailed but the next ones are at the dock – Highlight On [PBC-19-1346.R2]

“…This is not the case, however, for fondaparinux which has been in regulatory limbo with respect to pediatric use for nearly 15 years. This, despite the fact that there is more published data on fondaparinux than dalteparin including a similarly (to dalteparin) designed, prospective, dose-finding, pharmacokinetic, efficacy and safety study [6][7][8], and the fact that the Pharma companies (the compound has changed hands a few times) have been in discussions with the FDA repeatedly. Unlike with dalteparin, the FDA has placed numerous and pointless hurdles upon the responsible Pharma for capricious reasons succeeding only in potentially putting children at increased risk of harm by, for example, requiring a dose-finding study when the dose of fondaparinux is already well-established.…”

Fondaparinux for treatment of venous thromboembolism: Will it survive a test of time?

“…In this issue of Pediatric Blood and Cancer , Shen et al share their experience of using fondaparinux in children with VTE, FondaKIDS III study 3 . FondaKIDs study, 4 the first one in this series, was a safety, dose‐finding study, while FondaKIDS II study 5 provided long‐term dosing, efficacy, and safety in 35 children over a 5‐year period.…”

“…FondaKIDs study, 4 the first one in this series, was a safety, dose‐finding study, while FondaKIDS II study 5 provided long‐term dosing, efficacy, and safety in 35 children over a 5‐year period. FondaKIDS III study is the extension of FondaKIDS II study 3 . This retrospective cohort study included 277 children over a 10‐year period.…”