Proven Safety

Established Hemophilia Treatment Product Safety1

Incidence of inhibitor development

  • In minimally treated and previously untreated patients, the incidence of inhibitor development with Helixate FS was 15% (N=61)
  • In previously treated patients, one patient had a pre-existing inhibitor. In the other 72 patients, no de novo inhibitors were observed
  • In the Joint Outcome Study, which was conducted to demonstrate the effectiveness of routine prophylaxis for prevention of joint damage in children, the incidence of new inhibitor development was 12.5% (N=65)
    • High-titer inhibitor detected in two patients being treated with prophylaxis were removed from the study (N=32)
  • Postmarketing registries in previously untreated patients have shown inhibitor development rates of 31-50% which is comparable to previously reported inhibitor rates for FVIII products. Some of these registries showed a trend towards an increased risk of inhibitor development in PUPs as compared to another rFVIII product.

Next: Proven Recombinant Technology»

Reference: 1.
DiMichele D. Inhibitors in Hemophilia: A Primer. 4th ed. Montreal: World Federation of Hemophilia; 2008. Treatment of Hemophilia; no 7.

Important Safety Information

You should not use Helixate FS if you are allergic to rodents (like mice and hamsters) or are allergic to any ingredients in Helixate FS.

Tell your healthcare provider if you have been told you have heart disease or are at risk for heart disease.

You could have an allergic reaction to Helixate FS. Call your healthcare provider right away and stop treatment if you get rash or hives, itching, tightness of the chest or throat, difficulty breathing, light-headed, dizziness, nausea or a decrease in blood pressure.

Your body can make antibodies, called "inhibitors," against Helixate FS, which may stop Helixate FS from working properly. Consult with your healthcare provider to make sure you are carefully monitored with blood tests for the development of inhibitors to factor VIII.

Other common side effects of Helixate FS are local injection-site reactions (pain, swelling, irritation at infusion site) and infections from implanted injection device. Tell your healthcare provider about any side effect that bothers you or does not go away.

Call your healthcare provider right away if bleeding is not controlled after using Helixate FS.


Helixate FS, Antihemophilic Factor (Recombinant), is medicine used to replace the clotting factor (factor VIII or antihemophilic factor) that is missing in people with hemophilia A.

Helixate FS is used to treat and control bleeding in adults and children with hemophilia A. Your healthcare provider may give you Helixate FS when you have surgery. Helixate FS can reduce the number of bleeding episodes in adults and children when used regularly (prophylaxis), and can reduce the risk of joint damage in children without preexisting joint damage when used regularly.

Helixate FS is not used to treat von Willebrand disease.

Please see the full Prescribing Information for HELIXATE FS, including approved patient labeling.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.