How is Obizur (factor VIII) produced?

Obizur (factor VIII) is made in a laboratory using [recombinant technology](https://www.genome.gov/genetics-glossary/Recombinant-DNA-Technology). This process involves making clotting factor VIII in a specific type of [genetically-engineered](https://www.genome.gov/genetics-glossary/Genetic-Engineering) hamster cell. Obizur (factor VIII) isn't made from human blood, so it [can't spread](https://www.cdc.gov/hemophilia/treatment/?CDC_AAref_Val=https://www.cdc.gov/ncbddd/hemophilia/treatment.html) viruses found in human blood to you. But because the manufacturing process involves the use of hamster cells, you might be at risk for allergic reactions to Obizur (factor VIII) if you have an allergy to hamsters.

Can Obizur (factor VIII) be used to prevent bleeding episodes?

No. Obizur (factor VIII) is approved to control bleeding episodes that require hospitalization. Other factor VIII products like [Alphanate](https://www.goodrx.com/alphanate/what-is) can help prevent bleeding episodes from happening in the first place. Your provider will determine which product is best for your condition.

What's the difference between acquired and congenital hemophilia A?

Obizur (factor VIII) is FDA-approved to treat bleeding episodes in adults with __acquired hemophilia A__ (AHA), an [autoimmune blood problem](https://rarediseases.org/rare-diseases/acquired-hemophilia/) that happens when the body's immune system mistakenly attacks its own clotting factors (most often factor VIII). On the other hand, __congenital hemophilia A__ is a [genetic condition](https://www.bleeding.org/bleeding-disorders-a-z/types/hemophilia-a), meaning people can inherit the problem from their parents. Although they both involve clotting factor VIII and can cause bleeding, acquired and congenital hemophilia A can be pretty different. People are often diagnosed with congenital hemophilia A early in life, whereas AHA typically occurs in older adults. In addition, bleeding typically happens in the joints, muscles, and soft tissue for congenital hemophilia A, while bleeding in the joints isn't common for AHA.

Obizur

coagulation factor VIII

Used for Hemophilia

Obizur (factor VIII) is a clotting factor replacement that's infused through the veins to treat bleeding episodes in adults with an autoimmune blood condition called acquired hemophilia A. It's typically given at a hospital that's designated as a hemophilia treatment center. How long your treatment is depends on things like your health status and how serious your bleed is. Obizur (factor VIII) doesn't treat the inherited form of this blood condition (congenital hemophilia A) like other similar medications do. Obizur (factor VIII) doesn't have many known side effects.

Reviewed by:

Allison Gourley, PharmD

Kristianne Hannemann, PharmD

Last reviewed on December 19, 2023

What is Obizur (factor VIII)?

What is Obizur (factor VIII) used for?

Bleeding in adults with acquired hemophilia A (AHA)

How Obizur (factor VIII) works

Obizur (factor VIII) is a coagulation (clotting) factor replacement for adults with acquired hemophilia A who have problems with their clotting factor VIII (FVIII). Clotting factors are proteins in the blood that help control bleeding.

Obizur (factor VIII) works by temporarily replacing factor FVIII in the blood. As a result, the medication helps control bleeds in people who have low levels of functioning factor VIII that's naturally found in the blood.

Are you looking for information on Novoseven RT (factor VIIa) or Alphanate (factor VIII / von Willebrand factor complex) instead?

Drug facts

Common Brands	Obizur
Drug Class	Coagulation factor replacement
Controlled Substance Classification	Not a controlled medication
Generic Status	No lower-cost generic available
Availability	Prescription only

Common Brands

Obizur

Drug Class

Coagulation factor replacement

Controlled Substance Classification

Not a controlled medication

Generic Status

No lower-cost generic available

Availability

Prescription only

Side effects of Obizur (factor VIII)

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

See Risks and Warnings.

Obizur (factor VIII) serious side effects

Contact your healthcare provider immediately if you experience any of the following.

Allergic reaction: swelling underneath the skin around the eyes, mouth, or throat (angioedema); hives; chest tightness; shortness of breath; wheezing; low blood pressure

Source: DailyMed

The following Obizur (factor VIII) side effects have also been reported

Side effects that you should report to your care team as soon as possible:

Allergic reactions or angioedema—skin rash, itching or hives, swelling of the face, eyes, lips, tongue, arms, or legs, trouble swallowing or breathing

Pros and cons of Obizur (factor VIII)

Pros

Works well to treat bleeding episodes in adults with acquired hemophilia A
Only medication that directly replaces FVIII approved for the treatment of bleeding in AHA
Few known side effects
Provider can tailor additional doses based on your response to treatment and your FVIII levels (no "one-size-fits-all")

Cons

Can't give to yourself at home
Can't use to prevent bleeding episodes from happening (can only treat current bleeding episodes)
Not for people with allergy to hamsters; can cause allergic reactions since it's lab-made using genetically-engineered hamster cells
Unknown if safe during pregnancy or while breastfeeding

Pharmacist tips for Obizur (factor VIII)

During treatment, your provider will check that your bleeding is improving. Your provider will also check your blood work to make sure that Obizur (factor VIII) is helping to bring your factor VIII levels back to normal.
Let your provider know right away if you have any problems or allergic reactions after your Obizur (factor VIII) infusion. These reactions can include chest tightness, trouble breathing, wheezing, itchy skin, hives, or lightheadedness. Your provider will probably need to stop the infusion and treat your symptoms right away.

Common questions about Obizur

Obizur is made in a laboratory using recombinant technology. This process involves making clotting factor VIII in a specific type of genetically-engineered hamster cell. Obizur isn't made from human blood, so it can't spread viruses found in human blood to you. But because the manufacturing process involves the use of hamster cells, you might be at risk for allergic reactions to Obizur if you have an allergy to hamsters.

Your healthcare provider will inject Obizur into your vein. Your dose and how often you need infusions of the medication will depend on things like your weight, how serious your bleed is, and how you're responding to treatment.

No. Obizur is approved to control bleeding episodes that require hospitalization. Other factor VIII products like Alphanate can help prevent bleeding episodes from happening in the first place. Your provider will determine which product is best for your condition.

No. Obizur is typically given at a hospital that's specifically designated as a hemophilia treatment center. In addition, a trained healthcare provider must help prepare the medication and infuse it through your vein. The treatment center and your providers will have resources readily available to check how well Obizur is working to help control your bleed.

Although Obizur is FDA-approved for treating acquired hemophilia A (AHA), researchers from a small study have seen some benefit of using the medication off-label to treat the inherited form of this blood condition called congenital hemophilia A. There will need to be more studies done to confirm its use for congenital hemophilia A before the FDA says the medication is safe and works well enough for it. Speak with your provider to learn about the differences between AHA and congenital hemophilia and treatment options available for your hemophilia condition.

Obizur is FDA-approved to treat bleeding episodes in adults with acquired hemophilia A (AHA), an autoimmune blood problem that happens when the body's immune system mistakenly attacks its own clotting factors (most often factor VIII). On the other hand, congenital hemophilia A is a genetic condition, meaning people can inherit the problem from their parents. Although they both involve clotting factor VIII and can cause bleeding, acquired and congenital hemophilia A can be pretty different. People are often diagnosed with congenital hemophilia A early in life, whereas AHA typically occurs in older adults. In addition, bleeding typically happens in the joints, muscles, and soft tissue for congenital hemophilia A, while bleeding in the joints isn't common for AHA.

Risks and warnings for Obizur (factor VIII)

Obizur (factor VIII) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Allergic reaction

Risk factors: Hamster allergy

Rarely, Obizur (factor VIII) can cause allergic reactions, which can be serious. Sometimes, these reactions can lead to life-threatening situations like anaphylaxis, which can include the closing of the throat. Get medical help right away if you experience chest tightness, shortness of breath, wheezing, swelling, or rash.

Development of antibodies

There's a chance that Obizur (factor VIII) can stop working well for you even though it worked well when you first started treatment. In a clinical study, nearly 1 out of 4 (26%) people who were treated with Obizur (factor VIII) developed inhibitory antibodies to the medication. These antibodies are proteins that can attach to the medication and make it work less well.

Your provider will keep track of how well Obizur (factor VIII) seems to be working for you during treatment. If you seem to stop responding to the medication, your provider might suspect that you've developed antibodies against the medication and might treat your bleeding another way.

Obizur (factor VIII) dosage

Typical dosage for Obizur (factor VIII)

This medication is given as an infusion through the veins (intravenously or IV). It must be given by a healthcare provider in a hospital or emergency care setting that's designated as a hemophilia treatment center.

Your provider will calculate your starting dose based on your body weight; the typical starting dose is 200 units/kg of weight.

Any following doses of Obizur (factor VIII) are given every 4 to 12 hours. How often the medication is given depends on how serious your bleed is, your response to the medication, and the FVIII levels in your blood (to make sure they're reaching a particular range that's safe for you).

Obizur (factor VIII) contraindications

Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Obizur (factor VIII) will not be safe for you to take.

Allergies to hamsters
Congenital hemophilia A with inhibitors

What are alternatives to Obizur (factor VIII)?

There are a number of medications that your doctor can prescribe in place of Obizur (factor VIII). Compare a few possible alternatives below.

Obizur (factor VIII)

Used for:

Bleeding in adults with acquired hemophilia A (AHA)

View prices

Factor VIII / VWF complex

Used for:

To treat or prevent bleeds in people with certain types of von Willebrand disease (VWD) and hemophilia A

View prices

Factor VIIa

Used for:

Sevenfact:

To treat or control bleeding in people with hemophilia A or hemophilia B with inhibitors

Novoseven RT:

To treat active bleeds or to prevent bleeding episodes during surgery in people with the following conditions:

Hemophilia A and B with inhibitors
Acquired hemophilia
Congenital Factor VII (FVII) deficiency
Glanzmann thrombasthenia where platelet transfusions didn't work well

$11,903.45Lowest GoodRx priceView prices

References

Best studies we found

bleedingdisorders.com. (n.d.). A quick look at bleeding disorders & coagulation.

Centers for Disease Control and Prevention. (n.d.). Division of Blood Disorders Gateway.

Centers for Disease Control and Prevention. (2022). Treatment of hemophilia.

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

What is Obizur (factor VIII)?

What is Obizur (factor VIII) used for?

How Obizur (factor VIII) works

Are you looking for information on Novoseven RT (factor VIIa) or Alphanate (factor VIII / von Willebrand factor complex) instead?

Drug facts

Side effects of Obizur (factor VIII)

Common Side Effects

Obizur (factor VIII) serious side effects

The following Obizur (factor VIII) side effects have also been reported

Pros and cons of Obizur (factor VIII)

Pros

Cons

Pharmacist tips for Obizur (factor VIII)

Common questions about Obizur

How is Obizur produced?

How do you administer Obizur?

Can Obizur be used to prevent bleeding episodes?

Am I able to use Obizur at home to treat my bleeding episodes?

Can Obizur be used in people with congenital hemophilia A?

What's the difference between acquired and congenital hemophilia A?

Risks and warnings for Obizur (factor VIII)

Allergic reaction

Development of antibodies

Obizur (factor VIII) dosage

Typical dosage for Obizur (factor VIII)

Obizur (factor VIII) contraindications

What are alternatives to Obizur (factor VIII)?

References

View All References (9)

Common questions about Obizur

How is Obizur produced?

How do you administer Obizur?

Can Obizur be used to prevent bleeding episodes?

Am I able to use Obizur at home to treat my bleeding episodes?

Can Obizur be used in people with congenital hemophilia A?

What's the difference between acquired and congenital hemophilia A?