Hemlibra (emicizumab)
An approved treatment for Hemophilia A.
The same compound appears under different names depending on the context. Here is how to identify Emicizumab wherever you encounter it, plus the key facts at a glance.
- Generic name
- Emicizumab
- Brand name
- Hemlibra
- Development code
- ACE910
- Drug class
- Bispecific antibody
- Manufacturer
- Roche / Genentech
- How it's taken
- Given as a subcutaneous injection.
A breakthrough antibody treatment that bridges clotting factors IXa and X together, mimicking the job of the missing Factor VIII. Given as a subcutaneous injection, it dramatically reduces bleeding in hemophilia A patients with and without inhibitors.
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Where Emicizumab fits
Standard prophylactic therapy for hemophilia A (with or without inhibitors). Transformed hemophilia care by replacing frequent IV infusions with subcutaneous injections as infrequently as monthly.
How Emicizumab works
In hemophilia A, the body can't make enough Factor VIII, a protein needed to form blood clots. Emicizumab is a specially designed antibody with two arms that grab onto two different clotting proteins (Factor IXa and Factor X) and brings them together, doing the same job that Factor VIII normally does. This restores the clotting cascade and prevents bleeds.
Mechanism: Bispecific antibody that mimics the function of clotting Factor VIII
Side effects and safety
Common side effects include injection site reactions, headache, and joint pain. Hemlibra has a boxed warning: thrombotic microangiopathy (damage to small blood vessels that can harm the kidneys) and blood clots have happened in people on Hemlibra who were given activated prothrombin complex concentrate (aPCC), on average more than 100 U/kg per 24 hours for 24 hours or more. If aPCC must be used, doctors should use caution and monitor closely; the risk can last up to 6 months after the last Hemlibra dose. Hemlibra also affects some blood clotting lab tests (such as aPTT and one-stage factor VIII assays), so tell every lab and care team that you take it. The label also warns that some people develop antibodies to Hemlibra that can make it stop working, so tell your doctor if you have more breakthrough bleeds.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Emicizumab
Given as a subcutaneous injection. Loading dose of once weekly for 4 weeks, then maintenance dosing options of once weekly, every 2 weeks, or every 4 weeks. Can be self-administered at home after training.
Availability and cost
Only available as the brand-name product.
Bispecific monoclonal antibody mimicking the function of Factor VIIIa. Subcutaneous injection (weekly to monthly) revolutionized hemophilia A prophylaxis by replacing the need for frequent IV factor infusions.
Help paying for Hemlibra
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
HEMLIBRA Co-pay Assistance Program: eligible commercially insured patients could pay as little as $0 per treatment, up to $15,000 per calendar year. Excludes Medicare, Medicaid, TRICARE.
For: private insurance · source - Free medicine program
Genentech Patient Foundation gives free HEMLIBRA to eligible uninsured patients or insured patients without coverage, with incomes under $150,000; other income-based criteria apply.
For: no insurance, underinsured · source - Other support
Referrals to independent co-pay assistance foundations, which may help commercially or publicly insured patients.
For: private insurance, Medicare, Medicaid · source
Good to know: Free drug comes from the separate Genentech Patient Foundation (888-941-3331); both a patient consent form and a prescriber form are required. Local Account and Community Managers (Genentech employees) also offer support.
- From a charity · Hemophilia Federation of AmericaHelping Hands Program fundOpen
Pays for: Emergency living expenses ($250 prepaid card, once per year; referral through HTC or member organization; does not cover medical bills, copays or premiums), up to $250 per year.
The foundation says: “The Helping Hands program is now open on a limited basis for 2026. Due to funding constraints, a maximum of 20 requests will be approved…” - From a charity · TotalAssist (formerly PAN Foundation)Hemophilia fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $12,500 per year. Requires health insurance (any kind).
- From a charity · The Assistance FundHemophilia fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”
Clinical trial results
In HAVEN 1 (patients with Factor VIII inhibitors), weekly Hemlibra cut treated bleeds by 87% compared with no prophylaxis. In HAVEN 3 (patients without inhibitors), weekly and every-2-week dosing cut treated bleeds by 96% and 97% compared with no prophylaxis. Effective in patients with and without Factor VIII inhibitors.
Development history
Approved November 2017 for hemophilia A with inhibitors, expanded October 2018 to all hemophilia A patients. Transformed hemophilia care by offering the first non-factor replacement prophylaxis option.
Explore Hemophilia A trials
Other Hemophilia A treatments
Emicizumab in Trial Friend News and Guides
Common questions about Emicizumab
▸What is Emicizumab (Hemlibra)?
A breakthrough antibody treatment that bridges clotting factors IXa and X together, mimicking the job of the missing Factor VIII. Given as a subcutaneous injection, it dramatically reduces bleeding in hemophilia A patients with and without inhibitors.
▸How does Emicizumab work?
In hemophilia A, the body can't make enough Factor VIII, a protein needed to form blood clots. Emicizumab is a specially designed antibody with two arms that grab onto two different clotting proteins (Factor IXa and Factor X) and brings them together, doing the same job that Factor VIII normally does. This restores the clotting cascade and prevents bleeds.
▸What are the side effects of Emicizumab?
Common side effects include injection site reactions, headache, and joint pain. Hemlibra has a boxed warning: thrombotic microangiopathy (damage to small blood vessels that can harm the kidneys) and blood clots have happened in people on Hemlibra who were given activated prothrombin complex concentrate (aPCC), on average more than 100 U/kg per 24 hours for 24 hours or more. If aPCC must be used, doctors should use caution and monitor closely; the risk can last up to 6 months after the last Hemlibra dose. Hemlibra also affects some blood clotting lab tests (such as aPTT and one-stage factor VIII assays), so tell every lab and care team that you take it. The label also warns that some people develop antibodies to Hemlibra that can make it stop working, so tell your doctor if you have more breakthrough bleeds.
▸How is Emicizumab taken?
Given as a subcutaneous injection. Loading dose of once weekly for 4 weeks, then maintenance dosing options of once weekly, every 2 weeks, or every 4 weeks. Can be self-administered at home after training.
▸Is Emicizumab FDA approved?
Yes, Emicizumab (Hemlibra) is FDA approved (2017) for the treatment of Hemophilia A.
▸How did emicizumab change hemophilia A treatment?
Emicizumab transformed hemophilia A care by replacing frequent intravenous factor infusions with subcutaneous injections as infrequently as once monthly. Before its approval in 2017, patients needed IV infusions multiple times per week. It was also the first non-factor replacement prophylaxis option.
▸Can emicizumab be used with other clotting treatments?
Caution is required. Combining emicizumab with activated prothrombin complex concentrate (aPCC) carries a serious risk of thrombotic microangiopathy and blood clots. aPCC should be avoided whenever possible during emicizumab treatment. Other bypass agents should be used at the lowest effective dose.
▸What dosing options are available for emicizumab?
After a 4-week loading phase of weekly injections, patients can choose maintenance dosing of once weekly, every 2 weeks, or every 4 weeks. The flexibility in scheduling is a major convenience advantage for patients and families.
▸Does emicizumab work for hemophilia B?
No. Emicizumab specifically mimics the function of Factor VIII by bridging Factors IXa and X together. It only treats hemophilia A (Factor VIII deficiency). Hemophilia B patients should discuss other non-factor options like fitusiran, concizumab, or marstacimab with their hematologist.
▸What percentage of patients achieve zero bleeds on emicizumab?
Results vary by trial and dosing schedule. In HAVEN 1 (patients with inhibitors), weekly Hemlibra cut treated bleeds by 87% compared with no prophylaxis. In HAVEN 3 (patients without inhibitors), treated bleeds fell by 96% with weekly dosing and 97% with every-2-week dosing compared with no prophylaxis. Ask your hematologist what zero-bleed rates were seen for your schedule.
▸Is emicizumab effective in patients with Factor VIII inhibitors?
Yes. Emicizumab was first approved for hemophilia A patients with inhibitors in November 2017, then expanded to all hemophilia A patients in October 2018. Because it mimics Factor VIII's function through a completely different protein structure, pre-existing Factor VIII inhibitors do not affect it.
▸What patient support programs exist for emicizumab?
HEMLIBRA Access Solutions through Genentech provides copay assistance for commercially insured patients, referrals to copay foundations, and the Genentech Patient Foundation may provide medication at no cost for uninsured patients.