Fesilty

Fesilty is a human blood coagulation factor used to treat acute bleeding episodes in adults and children with congenital fibrinogen deficiency, including hypo- or afibrinogenemia.

• Fesilty is not indicated for dysfibrinogenemia.

Fesilty is administered intravenously by a healthcare provider, and the dose depends on body weight and target fibrinogen levels.

Fesilty gained FDA approval on December 16, 2025.

Fesilty is administered intravenously by a healthcare provider using an infusion pump.

• The infusion rate should not exceed 5 mL/min in adults and children 6 years and older.

Before receiving Fesilty, tell your healthcare provider about all your medical conditions, including if you:

• Have allergies to Fesilty or any of its ingredients (arginine hydrochloride, polysorbate 80, sodium 110 citrate dihydrate, trehalose dihydrate)
• Have a history of severe allergic reactions (including anaphylaxis)
• Have had blood clots or are at risk for blood clots (thrombosis)
• Have any history of heart or blood vessel problems
• Have ever reacted to any blood products or plasma-derived products
• Are pregnant or planning to become pregnant
• Are breastfeeding or planning to breastfeed.

Common side effects

The most common side effects of Fesilty are:

• Pain in extremity
• Back pain
• Hypersensitivity reactions
• Pyrexia
• Thrombosis
• Increased fibrin D dimer
• Headache
• Vomiting.

Serious side effects and warnings

Fesilty can cause the following serious side effects.

Allergic Reactions

Hypersensitivity reactions have occurred in patients receiving Fesilty. Should symptoms occur, your healthcare provider will discontinue Fesilty. Watch for signs of an allergic reaction and call your doctor right away if you experience:

• Hives or skin rash
• Chest tightness
• Wheezing or trouble breathing
• Dizziness or low blood pressure
• Severe allergic reaction (anaphylaxis).

Blood Clots

Blood clots can occur with Fesilty. Contact your doctor immediately if you notice:

• Unexplained chest pain or leg pain
• Swelling in your legs or arms
• Coughing up blood
• Shortness of breath or rapid breathing
• Stroke symptoms or sudden weakness.

Risk of Infection

Fesilty is made from donated human blood plasma, which means there's a small risk it could transmit infections or disease-causing agents. While this risk is very low due to careful donor screening, plasma testing, and virus removal during manufacturing, you should report any concerning symptoms to your doctor.

If you experience any unusual symptoms after taking Fesilty, contact your healthcare provider right away.

To report suspected side effects, contact Grifols Therapeutics LLC at 1-800-520-2807 or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Fesilty contains fibrinogen, a plasma protein essential for blood clotting. During coagulation, thrombin converts fibrinogen into fibrin, which forms a stable clot reinforced by Factor XIII. Fibrinogen also enables platelet aggregation by binding to platelet surface receptors, creating a platelet plug.

In patients with congenital fibrinogen deficiency, Fesilty, administered intravenously, replaces missing fibrinogen, which, together with platelets, achieves hemostasis and stops bleeding.

Fesilty (fibrinogen, human) belongs to the drug class called human blood coagulation factors.

Dose of Fesilty for Congenital Fibrinogen Deficiency

The dose is calculated individually based on body weight (BW). The target fibrinogen levels are:

• Minor bleeding: 100 mg/dL
• Major bleeding: 150 mg/dL

Dosing When Fibrinogen Level is Known

• Adults and children ≥ 6 years: [Target level – Measured level] ÷ 1.8
• Children < 6 years: [Target level – Measured level] ÷ 1.6

Dosing When Fibrinogen Level is Unknown

• All patients, regardless of age: 70 mg/kg body weight

Monitoring and Frequency

• Monitor fibrinogen levels regularly
• Adjust dosing frequency and duration based on bleeding severity and patient condition

Infusion Rates

• Adults and children ≥ 6 years: 5 mL/min
• Children 4 to < 6 years: 1.0 mL/min
• Children 2 to < 4 years: 0.75 mL/min
• Infants 28 days to < 2 years: 0.30 mL/min
• Newborns (0-27 days): 0.10 mL/min

Active: fibrinogen, human - chmt

Inactive: arginine hydrochloride, polysorbate 80, sodium 110 citrate dihydrate, trehalose dihydrate

Fesilty is a sterile white powder for intravenous injection.

• Supplied as approximately 1 gram of human fibrinogen per vial and one 50 mL vial of sterile water.
• The exact fibrinogen amount is printed on each vial label and carton.

Manufactured by Biotest AG, 63303 Dreieich, Germany. Manufactured for Grifols Therapeutics LLC, Research Triangle Park, NC 27709 USA, US License No. 1871.

• What is Acquired Fibrinogen Deficiency (AFD)?