Hympavzi

Hympavzi is used to prevent or reduce the frequency of bleeding episodes in adults or children 6 years and older with hemophilia A (with or without factor VIII inhibitors) or hemophilia B (with or without factor IX inhibitors). It is administered subcutaneously once weekly using a Hympavzi prefilled pen or a prefilled syringe.

Hympavzi’s mechanism of action involves targeting the Kunitz 2 domain of tissue factor pathway inhibitor (TFPI), a natural anticoagulation protein that prevents the formation of blood clots. Hympavzi represents a new management option for hemophilia A and B, particularly for those who develop inhibitors to FVIII and FIX. Factor replacement therapies, which replace missing clotting factors, may still be required to manage breakthrough bleeding episodes. Hympavzi belongs to the drug class called tissue factor pathway inhibitor (TFPI) antagonists.

Hympavzi gained FDA approval on October 11, 2024. Hympavzi is the first anti-TFPI approved in the U.S. for hemophilia A or B and the first to be administered SC via a pre-filled, auto-injector pen or syringe.

See the detailed “Instructions for Use” in the Hympavzi Package Insert for information on how to inject a dose of Hympavzi, and how to properly throw away (dispose of) a used Hympavzi prefilled syringe or Hympavzi prefilled pen (autoinjector)

• Use Hympavzi exactly as prescribed by your healthcare provider.
• Your healthcare provider will provide instructions for stopping (discontinuing) your current treatment when switching from factor- or non-factor-based medicines to Hympavzi. Follow these instructions closely.
• Hympavzi comes in two different strengths in a single-dose prefilled syringe or single-dose prefilled pen.
• Hympavzi is given as an injection under your skin (subcutaneous injection) by you or your caregiver.
• People 12 years of age and older, or their caregiver, may inject Hympavzi if your healthcare provider decides that it is appropriate. Your healthcare provider should show you or your caregiver how to inject Hympavzi before the first injection.
• Do not inject yourself or someone else until you have been shown how to inject Hympavzi.

Inject Hympavzi 1 time a week on the same day each week. Inject Hympavzi at any time of day.

• Choose an injection site on your stomach area (abdomen) or thigh unless a different site has been suggested by your healthcare provider. Hympavzi may also be injected into your upper arms by a healthcare provider or caregiver only. Keep at least 2 inches away from your belly button.
• Change (rotate) the injection site each time you give yourself an injection of Hympavzi and away from any other medicine given under your skin. You may use the same area of your body but be sure to choose a different injection site in that area.
• Clean the injection site with soap and water, or an alcohol swab.
• Allow the site to air dry. Do not touch, fan, or blow on the cleaned injection site.
• Do not inject Hympavzi into bony areas or areas on your skin that are bruised, red, sore (tender), or hard. Avoid injecting into areas with scars or stretch marks.
• Do not inject Hympavzi into a vein or through your clothes.

Your healthcare provider will provide information on the treatment of breakthrough bleeding during your treatment with Hympavzi. Do not use Hympavzi to treat breakthrough bleeding.

Before you start using Hympavzi, it is very important to talk to your healthcare provider about using factor VIII and factor IX products or bypassing agents (these are products that help blood clot but work in a different way than Hympavzi).

Your healthcare provider may prescribe factor VIII, factor IX medicines, or bypassing agents to treat episodes of breakthrough bleeding during your treatment with Hympavzi. Carefully follow your healthcare provider’s instructions carefully regarding when to use these medicines and the prescribed dose during your treatment with Hympavzi. Do not use additional doses of Hympavzi to treat breakthrough bleeds.

Before using Hympavzi, tell your healthcare provider about all of your medical conditions, including if you:

• have a planned surgery. Your healthcare provider may stop Hympavzi before your surgery. Talk to your healthcare provider about when to stop using Hympavzi and when to start it again if you have a planned surgery
• have a severe short-term (acute) illness such as an infection or injury
• have been told that you are at risk for blood clots
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

Pregnancy

Hympavzi may harm your unborn baby. For females who can become pregnant:

• Your healthcare provider will do a pregnancy test before you start treatment with Hympavzi
• You should use effective birth control (contraception) during treatment with Hympavzi and for 2 months after the last dose of Hympavzi.
• Tell your healthcare provider right away if you become pregnant or think that you may be pregnant during treatment with Hympavzi.

Breastfeeding

It is not known if Hympavzi passes into your breast milk.

Common Side Effects

The most common side effects of Hympavzi are:

• swelling, hardening, redness, bruising, bleeding, and pain at the injection site
• joint pain
• diarrhea
• headache
• itching
• fever
• rash.

Serious side effects and warnings

Hympavzi may cause the following serious side effects:

• Blood clots (thromboembolic events). Hympavzi may increase your risk for blood clots (thromboembolic events) in blood vessels of your arm, leg, lung, or head, which may be life-threatening. Get medical help right away if you develop any of these signs or symptoms of blood clots: swelling or pain in arms or legs redness or discoloration in your arms or legs shortness of breath pain in the chest or upper back fast heart rate cough up blood feel faint headache numbness in your face eye pain or swelling trouble seeing.
• Allergic reactions, including rash and itching, have happened in people treated with Hympavzi. Stop using Hympavzi and get medical help right away if you develop any of the following symptoms of a severe allergic reaction: swelling of your face, lips, mouth, or tongue trouble breathing wheezing dizziness or fainting fast heartbeat or pounding in your chest sweating.

Hympavzi may harm an unborn baby. Pregnant women should not take Hympavzi, and females with childbearing potential should use effective contraception during treatment with Hympavzi and for 2 months after the last dose.

Hympavzi can raise certain blood clotting markers. These changes are temporary and have not raised safety concerns, but the markers may not reliably indicate a blood clot in patients taking Hympavzi.

It is not known if Hympavzi is safe and effective in people receiving ongoing Immune Tolerance Induction (ITI).

It is not known if Hympavzi is safe and effective in children younger than 6 years old.

These are not all of the possible side effects of Hympavzi. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Dose of Hympanzi for Hemophilia A or B for Adults and Children 12 years and older

• Your first dose (loading dose) of Hympavzi is 300 mg (two 150 mg injections). Then you will inject a weekly (maintenance) dose as prescribed by your healthcare provider.

Missed dose

• If you miss a maintenance dose of 150 mg of Hympavzi: Give the dose as soon as possible before the day of your next scheduled dose, and then continue with your usual weekly dosing schedule. You may inject your next dose at your regularly scheduled time or continue dosing based on the new day you injected your missed dose. In case you are not sure when to inject Hympavzi, call your healthcare provider. If more than 13 days have passed since your last dose was given, you will need to restart with a loading dose. Call your healthcare provider right away for dosing instructions.
• If you miss 1 or more doses of the maintenance dose of 300 mg of Hympavzi: Give a dose as soon as possible, and then continue with your usual weekly dosing schedule. You may inject your next dose at your regularly scheduled time or continue dosing based on the new day you injected your missed dose. In case you are not sure when to inject Hympavzi, call your healthcare provider.

Overdose:

• If you inject too much Hympavzi, call your healthcare provider or the Poison Help Line at 1-800-222-1222 or go to the nearest hospital emergency room right away.

Dose of Hympanzi for Hemophilia A or B for Children 6 to 12 years

• Your first dose (loading dose) of Hympavzi is 150 mg (one 150 mg injection or two 75 mg injections) as prescribed by your healthcare provider. Then you will inject a weekly (maintenance) dose as prescribed by your healthcare provider.

Missed dose:

• If you miss a maintenance dose of 75 mg of Hympavzi: Give the dose as soon as possible before the day of your next scheduled dose, and then continue with your usual weekly dosing schedule. You may inject your next dose at your regularly scheduled time or continue dosing based on the new day you injected your missed dose. In case you are not sure when to inject Hympavzi, call your healthcare provider. If more than 13 days have passed since your last dose was given, you will need to restart with a loading dose. Call your healthcare provider right away for dosing instructions.
• If you miss 1 or more doses of the maintenance dose of 150 mg of Hympavzi: Give a dose as soon as possible, and then continue with your usual weekly dosing schedule. You may inject your next dose at your regularly scheduled time or continue dosing based on the new day you injected your missed dose. In case you are not sure when to inject Hympavzi, call your healthcare provider.

Overdose:

• If you inject too much Hympavzi, call your healthcare provider or the Poison Help Line at 1-800-222-1222 or go to the nearest hospital emergency room right away.

Tell your healthcare provider about all the medicines you take, including prescription medicines, over-the-counter medicines, vitamins, and herbal supplements. Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.

Store Hympavzi in a refrigerator at 36°F to 46°F (2°C to 8°C) in the original carton to protect it from light.

If needed, Hympavzi may be stored one time at room temperature up to 86°F (30°C) in its original carton for up to 7 days.

• Do not return Hympavzi to the refrigerator after storing it at room temperature.
• Throw away (dispose of) Hympavzi that has been left out of the refrigerator for more than 7 days.

Do not freeze or shake Hympavzi. Keep out of the reach of children.

Active ingredient: marstacimab-hncq

Inactive ingredients: edetate disodium, histidine, L-histidine monohydrochloride, polysorbate 80, sucrose, and water for injection.

Hympavzi is available as 150 mg/mL and 75 mg/0.5 mL single-dose prefilled pens or prefilled syringes.

Hympavzi (marstacimab-hncq) is manufactured by Pfizer Inc., New York, NY 10001.