Fitusiran

Brand Names: Qfitlia

Drug Class: Antithrombin-directed RNA Interaction

Overview

11 DESCRIPTION QFITLIA injection contains fitusiran, an antithrombin-directed double-stranded small interfering ribonucleic acid (siRNA), which is covalently linked to a ligand containing a triantennary N-acetylgalactosamine (GalNAc) moiety. The molecular formula of fitusiran sodium is C 520 H 636 F 21 N 175 Na 43 O 309 P 43 S 6 and the molecular weight is 17,193 Da.

Mechanism of Action

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action QFITLIA is a double-stranded siRNA that causes degradation of AT messenger RNA (mRNA) through RNA interference, reducing plasma AT levels. 12.2 Pharmacodynamics In clinical studies with QFITLIA in hemophilia patients, the primary pharmacodynamic (PD) measure was plasma AT activity. Lower AT activity levels were associated with lower annualized bleeding rates (ABR); however, persistent AT activity

Indications

  • 1 INDICATIONS AND USAGE 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 )

Common Doses

  • 50 mg
  • 20 mg
  • 10 mg
  • 1 mL

Dosage

2 DOSAGE AND ADMINISTRATION For subcutaneous use only. Starting dose: 50 mg once every 2 months ( 2.1 ). Monitor AT activity using an FDA-cleared test. Maintain AT activity between 15–35% by adjusting the dose and/or frequency of administration ( 2.2 ). See Full Prescribing Information for important preparation and administration instructions ( 2.4 ). 2.1 Recommended Dosage For subcutaneous use only. Use of QFITLIA is recommended under the supervision of a healthcare professional experienced in the treatment of hemophilia or bleeding disorders.

Black Box Warning

WARNING: THROMBOTIC EVENTS AND ACUTE AND RECURRENT GALLBLADDER DISEASE WARNING: THROMBOTIC EVENTS and ACUTE AND RECURRENT GALLBLADDER DISEASE See full prescribing information for complete boxed warning. Thrombotic Events Serious thrombotic events have occurred in QFITLIA-treated patients with risk factors including persistent antithrombin (AT) activity less than 15%, QFITLIA 80 mg once monthly dosing, an indwelling venous catheter, and the post-operative setting when bleed management guidelines were not followed.

Contraindications

  • 4 CONTRAINDICATIONS None. None ( 4 )

Side Effects

  • 6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Thrombotic Events [see Boxed Warning and Warnings and Precautions (5.1) ] Acute and Recurrent Gallbladder Disease [see Boxed Warning and Warnings and Precautions (5.2) ] Hepatotoxicity [see Warnings and Precautions (5.3) ] Common adverse reactions (incidence >10%) are viral infection, nasopharyngitis, and bacterial infection ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Genzyme Corporation 1-800-745-4447 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.

Interactions

  • 7 DRUG INTERACTIONS 7.1 Hypercoagulability with Concomitant Use of CFC or BPA QFITLIA prophylaxis leads to increased thrombin generation with additive increase in peak thrombin when used concomitantly with CFC or BPA [see Boxed Warning , Dosage and Administration (2.3) and Warnings and Precautions (5.1) ] .