Abstract Number: PB1132
Meeting: ISTH 2020 Congress
Background: Extended half-life FVIII and FIX concentrates as well as disruptive therapies such as monoclonal antibodies mimicking the action of FVIII have recently been extensively validated and are increasingly adopted by the hemophilia community. However, female carriers with clotting factor deficiency have been excluded from these trials and have very limited or no access to these innovative therapies.
Aims: Multiple research initiatives have shown that a significant proportion of carriers present with clotting factor FVIII or FIX deficiency, mostly in the mild hemophilia range. While DDAVP represents a treatment of choice for carriers of HA with mild FVIII deficiency, mainly if not exclusively short-acting concentrates are used in most carriers with FIX deficiency and severe to moderate FVIII deficiency requiring replacement.
Methods: We here report our experience with new treatments in carriers with clotting factor deficiency. Five carriers with FIX deficiency ranging from 1 to 27 % were treated with EHL-FIX for surgery (n=3) (mastectomy, tonsillectomy, uterine curettage, one bolus required), vaginal delivery (n=1) (1 bolus pre-delivery and one on day 4) or prophylactically (n=1) (infusions every 14 days).
Results: There was no immediate or delayed postoperative bleeding complication and prophylaxis was very effective with a spontaneous joint bleeding rate of 0. One carrier of HA with severe FVIII deficiency secondary to double inheritance of the int22 inversion was recently started on replacement with Hemlibra (6 mg/kg ¼ weeks) with an excellent haemostatic control and tolerance.
Conclusions: New therapies should be considered in carriers with clotting factor deficiency requiring replacement therapy for invasive procedures or prophylaxis. Although very little experience in this setting has been reported so far, initiatives should be encouraged to collect data and promote access to innovative therapies in carriers.
To cite this abstract in AMA style:Hermans C, Lambert C. Extended Half-life FIX and Disruptive Therapies in Carriers with FVIII and FIX Deficiencies: Preliminary Experience [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/extended-half-life-fix-and-disruptive-therapies-in-carriers-with-fviii-and-fix-deficiencies-preliminary-experience/. Accessed January 21, 2022.
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