Last reviewed 2026-04-20 · How we verify

Hemlibra (EMICIZUMAB)

Hemlibra works by binding to and activating factor IXa, a protein involved in blood clotting, to bypass the need for factor VIII.

Hemlibra (emicizumab) is a biologic medication developed by Genentech Inc, targeting coagulation factor IX to treat Hereditary factor VIII deficiency disease. It was FDA-approved in 2017 and remains a patented product. Hemlibra works by mimicking the function of factor VIII, a protein necessary for blood clotting, thereby preventing bleeding episodes in patients with this condition. Key safety considerations include the risk of thrombotic events and potential interactions with other medications. As a biologic, Hemlibra requires careful administration and monitoring.

At a glance

Mechanism of action

HEMLIBRA bridges activated factor IX and factor to restore the function of missing activated factor VIII that is needed for effective hemostasis.

Approved indications

• Hereditary factor VIII deficiency disease

Boxed warnings

• WARNING: THROMBOTIC MICROANGIOPATHY AND THROMBOEMBOLISM 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 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. WARNING: THROMBOTIC MICROANGIOPATHY and THROMBOEMBOLISM See full prescribing information for complete boxed warning. 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.

Common side effects

• Injection site reaction
• Headache
• Arthralgia
• Pyrexia
• Diarrhea
• Thrombotic microangiopathy
• Skin necrosis
• Superficial thrombophlebitis
• Rhabdomyolysis
• Neutralizing anti-emicizumab-kxwh antibodies

Key clinical trials

• A Study to Assess the Efficacy and Safety of Emicizumab in Participants With Type 3 Von Willebrand Disease (PHASE3)
• A Clinical Study to Evaluate the Effects of NXT007 Compared to Emicizumab Prophylaxis in People With Hemophilia A (PHASE3)
• Real-World Joint Outcomes After Selective Transition to Low-Dose Emicizumab in Pediatric Hemophilia A (PHASE2,PHASE3)
• Incidence of Ultrasonographically Detected Articular Damage in Initially Healthy Joints of Patients With Hemophilia A Receiving Prophylactic Treatment With Emicizumab
• SAFE Study: Safety of aPCC Following Emicizumab Prophylaxis (PHASE3)
• A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Subcutaneous Emicizumab in Participants From Birth to 12 Months of Age With Hemophilia A Without Inhibitors (PHASE3)
• A Study to Evaluate Overall Health, Physical Activity, and Joint Outcomes in Participants With Severe or Moderate Hemophilia A Without Factor VIII Inhibitors on Emicizumab Prophylaxis (PHASE4)
• A Study to Evaluate the Safety, Efficacy, Pharmacokinetics and Pharmacodynamics of Emicizumab in Participants With Mild or Moderate Hemophilia A Without FVIII Inhibitors (PHASE3)

Primary sources

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