ReFacto® Antihemophilic Factor (Recombinant) is a purified protein produced by recombinant DNA technology for use in therapy of factor VIII deficiency. ReFacto (antihemophilic factor) is a glycoprotein with an approximate molecular mass of 170 kDa consisting of 1438 amino acids. It has an amino acid sequence that is comparable to the 90 + 80 kDa form of factor VIII, and post-translational modifications that are similar to those of the plasma-derived molecule. ReFacto (antihemophilic factor) has in vitro functional characteristics comparable to those of endogenous factor VIII.

ReFacto (antihemophilic factor) is produced by a genetically engineered Chinese hamster ovary (CHO) cell line. The CHO cell line secretes B-domain deleted recombinant factor VIII into a defined cell culture medium that contains human serum albumin and recombinant insulin, but does not contain any proteins derived from animal sources. The protein is purified by a chromatography purification process that yields a high-purity, active product. The potency expressed in international units (IU) is determined using the European Pharmacopoeial chromogenic assay against the WHO standard. The specific activity of ReFacto (antihemophilic factor) is 9110-13700 IU per milligram of protein. ReFacto (antihemophilic factor) is not purified from human blood and contains no preservatives or added human or animal components in the final formulation.

ReFacto (antihemophilic factor) is formulated as a sterile, nonpyrogenic, lyophilized powder preparation for intravenous (IV) injection. It is available in single-use vials containing the labeled amount of factor VIII activity (IU). Each vial contains nominally 250, 500, 1000 or 2000 IU of ReFacto (antihemophilic factor) per vial. The formulated product is a clear colorless solution upon reconstitution and contains sodium chloride, sucrose, L-histidine, calcium chloride, and polysorbate 80.

SIDE EFFECTS: Flushing of the face, headache, nausea, and fast heartbeat may sometimes occur and can be lessened by giving this medication more slowly. Burning/redness/irritation at the injection site, fever, and chills may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing, chest discomfort/tightness.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before using this medication, tell your doctor or pharmacist if you are allergic to any antihemophilic factor (factor VIII) products; or to animal proteins (e.g., mouse, hamster, cow); or if you have any other allergies. This product may contain inactive ingredients (such as natural rubber/latex found in the packaging of some brands), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history.

Manufacturers of some brands of this medication recommend that you monitor your heartbeat during treatment. If your heart starts to beat faster, it is recommended that you give this medication more slowly or temporarily stop the infusion until your heart rate returns to normal. Consult your doctor for more details.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.