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Emicizumab Side Effects

Medically reviewed by Last updated on Feb 5, 2024.

Applies to emicizumab: subcutaneous solution.


Subcutaneous route (Solution)

Warning: Thrombotic Microangiopathy and ThromboembolismCases of thrombotic microangiopathy and thrombotic events were reported when on average a cumulative amount of greater than 100 units/kg/24 hours of activated prothrombin complex concentrate was administered for 24 hours or more to patients receiving emicizumab-kxwh prophylaxis. Monitor for the development of thrombotic microangiopathy and thrombotic events if aPCC is administered. Discontinue aPCC and suspend dosing of emicizumab-kxwh if symptoms occur.

Serious side effects of Emicizumab

Along with its needed effects, emicizumab may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking emicizumab:

Incidence not known

Other side effects of Emicizumab

Some side effects of emicizumab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to emicizumab: subcutaneous solution.


The most common adverse reactions were injection site reactions, antibody formation, headache, injection site erythema, and arthralgia.[Ref]


Common (1% to 10%): Thrombotic microangiopathy, thrombotic events

Frequency not reported: Superficial thrombophlebitis[Ref]


Very common (10% or more): Injection site reactions (22%), injection site erythema (11%)

Common (1% to 10%): Injection site pain, injection site pruritus[Ref]

Nervous system

Very common (10% or more): Headache (15%)[Ref]


Very common (10% or more): Arthralgia (10%)

Common (1% to 10%): Myalgia

Uncommon (0.1% to 1%): Rhabdomyolysis, serum creatine kinase elevated[Ref]


Common (1% to 10%): Diarrhea[Ref]


Very common (10% or more): Antibody formation (up to 22%)[Ref]


Common (1% to 10%): Pyrexia[Ref]


Frequency not reported: Skin necrosis[Ref]


1. Product Information. Hemlibra (emicizumab). Genentech. 2017.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.