Side Effect Reporting

You may report side effects to the FDA at (800) FDA-1088 or
You may also report side effects to Genentech at (888) 835-2555.

Support & Resources


HEMLIBRA is indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients ages newborn and older with hemophilia A with or without factor VIII inhibitors.

Important Safety Information


Cases of thrombotic microangiopathy and thrombotic events were reported when on average a cumulative amount of >100 U/kg/24 hours of activated prothrombin complex concentrate (aPCC) was administered for 24 hours or more to patients receiving HEMLIBRA prophylaxis. Monitor for the development of thrombotic microangiopathy and thrombotic events if aPCC is administered. Discontinue aPCC and suspend dosing of HEMLIBRA if symptoms occur.

Warnings and Precautions

Thrombotic Microangiopathy (TMA) and Thromboembolism Associated With HEMLIBRA and aPCC

In clinical trials, TMA was reported in 0.8% of patients (3/391) and thrombotic events were reported in 0.5% of patients (2/391). In patients who received at least one dose of aPCC, TMA was reported in 8.1% of patients (3/37) and thrombotic events were reported in 5.4% of patients (2/37). Patients with TMA presented with thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury, without severe deficiencies in ADAMTS13.

Consider the benefits and risks if aPCC must be used in a patient receiving HEMLIBRA prophylaxis. Due to the long half-life of HEMLIBRA, the potential for an interaction with aPCC may persist for up to 6 months after the last dose. Monitor for the development of TMA and/or thromboembolism when administering aPCC. Immediately discontinue aPCC and interrupt HEMLIBRA prophylaxis if clinical symptoms, imaging, or laboratory findings consistent with TMA and/or thromboembolism occur, and manage as clinically indicated. Consider the benefits and risks of resuming HEMLIBRA prophylaxis following complete resolution of TMA and/or thrombotic events on a case-by-case basis.


Treatment with HEMLIBRA may induce anti-drug antibodies. Anti-emicizumab-kxwh antibodies were reported in 5.1% of patients (34/668) treated with HEMLIBRA in clinical trials. Most patients with anti-emicizumab-kxwh antibodies did not experience a change in HEMLIBRA plasma concentrations or an increase in bleeding events; however, in uncommon cases (incidence <1%), the presence of neutralizing antibodies with decreasing plasma concentration may be associated with loss of efficacy.

Monitor for clinical signs of loss of efficacy (eg, increase in breakthrough bleeding events) and if observed, promptly assess the etiology and consider a change in treatment if neutralizing anti-emicizumab-kxwh antibodies are suspected.

Laboratory Coagulation Test Interference

HEMLIBRA affects intrinsic pathway clotting-based laboratory tests, including activated clotting time (ACT); activated partial thromboplastin time (aPTT); and all assays based on aPTT, such as one-stage, factor VIII (FVIII) activity. Intrinsic pathway clotting-based laboratory tests should not be used.

Results affected by HEMLIBRA: aPTT; Bethesda assays (clotting-based) for FVIII inhibitor titers; one-stage, aPTT-based single-factor assays; aPTT-based Activated Protein C Resistance (APC-R); ACT.

Most Common Adverse Reactions

The most common adverse reactions (incidence ≥10%) are injection site reactions, headache, and arthralgia.

Drug Interactions

Clinical experience suggests that a drug interaction exists with HEMLIBRA and aPCC.

Pregnancy, Lactation, Females and Males of Reproductive Potential

Women of childbearing potential should use contraception while receiving HEMLIBRA. HEMLIBRA should be used during pregnancy only if the potential benefit for the mother outweighs the risk to the fetus. Consider developmental/health benefits, clinical need, and potential adverse effects on the breastfed child and mother.

You may report side effects to the FDA at (800) FDA-1088 or You may also report side effects to Genentech at (888) 835-2555.

Please see the HEMLIBRA full Prescribing Information for additional Important Safety Information, including Boxed WARNING.