HEMLIBRA® interferes with certain laboratory assays 1

Some currently available tests were not designed for use with HEMLIBRA

Coagulation test results affected by HEMLIBRA

  • Activated partial thromboplastin time (aPTT)
  • One-stage, aPTT-based, single-factor assays (ie, FVIII activity)
  • Bethesda assays (clotting-based) for FVIII inhibitor titers
  • aPTT-based activated protein C resistance (APC-R)
  • Activated clotting time (ACT)

When talking to patients and caregivers:

EXPLAIN that HEMLIBRA interferes with some laboratory tests

ENCOURAGE them to update emergency medical information

DISCUSS advising other healthcare providers about the possibility of false readings prior to blood tests or medical procedures

Download our Laboratory Monitoring Guide to see how to select appropriate laboratory assays while using HEMLIBRA.

Measuring HEMLIBRA hemostatic activity

In clinical trials, HEMLIBRA clinical outcomes were achieved without the use of assays to inform treatment decisions or make dosing adjustments.

Measuring FVIII activity

Chromogenic FVIII activity tests containing bovine proteins CAN BE USED to measure endogenous or infused FVIII activity.*

  • Assays utilizing bovine proteins do not detect HEMLIBRA and cannot be used to measure its activity

*Chromogenic FVIII activity tests may be manufactured with either human or bovine coagulation proteins.

Measuring FVIII inhibitors

The chromogenic Bethesda assay (CBA) CAN BE USED to measure FVIII inhibitors.

  • While clotting-based Bethesda assays will give a false reading, chromogenic Bethesda assays made with bovine proteins can be used to measure FVIII inhibitors

Your local or other selected laboratory can tell you if bovine protein–based chromogenic assays are available.

FVIII=factor VIII.


Treating Breakthrough Bleeds

Guidelines for addressing breakthrough bleeds