Antithrombin-directed RNA Interaction
Qfitlia
The FDA lists this product in 2 strengths and forms.
Indications
QFITLIA is indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients aged 12 years and older with hemophilia A or B with or without factor VIII or IX inhibitors. QFITLIA is an antithrombin-directed small interfering ribonucleic acid indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients aged 12 years and older with hemophilia A or B with or without factor VIII or IX inhibitors.
( 1 )
Contraindications
None. None ( 4 )
Warnings and precautions
Hepatotoxicity: Obtain liver tests at baseline and then monthly for at least 6 months after initiating QFITLIA and after dose increases, and periodically thereafter. Liver test elevations may require QFITLIA interruption or discontinuation ( 5.3 ).
5.1Thrombotic Events
Serious thrombotic events have been reported in QFITLIA-treated patients. Thrombotic events were reported in 2.6% of patients receiving the 80 mg once monthly dose (2.3 events per 100 person-years), including a fatal event of cerebral venous sinus thrombosis. The 80 mg once monthly dose is not approved or recommended for use. Thrombotic events were reported in 1.4% of patients receiving QFITLIA prophylaxis using the antithrombin-based dose regimen (AT-DR) that targeted AT activity 15-35% (0.8 events per 100 person-years).
Participants with established thrombophilia or a history of thrombosis were generally excluded from studies with QFITLIA. The risk of thrombosis is greater in patients with persistent AT activity <15%, with comorbidities that predispose to thrombosis, when bleed management guidelines are not followed in the post-operative setting, when there is an indwelling venous catheter, and with use of the 80 mg once monthly (non-AT-based) dose.
Treatment of breakthrough bleeding episodes with CFC or BPA at a dose greater or more frequent than recommended may also increase thrombotic risk [see Dosage and Administration (2.3) ] . The decision to utilize higher dosing regimens of CFC or BPA in the setting of inadequate hemostasis requires an assessment of the benefits and risks and close clinical monitoring. Monitor AT activity using an FDA-cleared test and target AT activity 15–35% to reduce the risk of thrombosis [see Dosage and Administration (2.1 , 2.2) and Warnings and Precautions (5.1) ] .



