Hympavzi 150 mg solution for injection in Pre-filled pen – patient leaflet, side effects, dosage

1. What Hympavzi is and what it is used for

Hympavzi contains the active substance marstacimab. Marstacimab is a monoclonal antibody, a type of protein designed to recognise and attach to a specific target in the body called tissue factor pathway inhibitor (TFPI).

Hympavzi is a medicine used to prevent or reduce bleeding in patients 12 years of age and older, weighing at least 35 kg, with:

• severe haemophilia A (congenital factor VIII deficiency, when the

  factor VIII blood level is less than 1%) who have not developed factor VIII inhibitors, or

  • severe haemophilia B (congenital factor IX deficiency, when the

    factor IX blood level is less than 1%) who have not developed factor IX inhibitors.

Haemophilia A is an inherited bleeding disorder caused by a lack of factor VIII. Haemophilia B is an inherited bleeding disorder caused by lack of factor IX. Factor VIII and factor IX are proteins required for blood to clot and stop any bleeding. Some patients with haemophilia can develop factor VIII or factor IX inhibitors (antibodies in the blood that act against replacement factor VIII or factor IX medicines and prevent them from working properly).

The active substance in Hympavzi, marstacimab, recognises and attaches to TFPI, a protein that prevents blood from clotting too much. By attaching to TFPI, marstacimab decreases how well it works, which promotes the formation of thrombin (a protein that plays a crucial role in blood clotting when there is an injury or damage to the body). This helps to increase clotting and stop bleeding in patients with haemophilia.

2. What you need to know before you use Hympavzi

Do not use Hympavzi

• if you are allergic to marstacimab or any of the other ingredients of this

  medicine (listed in section 6). If you are not sure if you are allergic, talk to your doctor, pharmacist or nurse before using Hympavzi.

Warnings and precautions

Talk to your doctor before using Hympavzi.

Before you start using Hympavzi, it is very important to talk to your doctor about using other factor VIII and factor IX products (products that help blood clot but work in a different way from Hympavzi) while using Hympavzi. You may need to use other factor VIII or factor IX products to treat episodes of breakthrough bleeding while using Hympavzi. Carefully follow your healthcare provider’s instructions regarding when and how to use these factor VIII or factor IX products while using Hympavzi.

Blood clots (thromboembolic events)

Hympavzi increases how easily your blood clots and may cause blood clots in the blood vessels (so called thromboembolic events). Blood clots may be life-threatening. Tell your doctor if you have a history of blood clots or if you have a condition which increases your risk of blood clots. This includes if you:

• have a history of coronary artery disease (heart disease caused by

  narrowing or blockage of blood vessels supplying the heart muscle)

• have a history of ischaemic disease (reduced blood flow due to

  narrowed or blocked blood vessels)

• have a history of blood clots in veins or arteries

• have a genetic condition that increases your risk for blood clotting

  (such as Factor V Leiden)

• are bedridden, immobilised or off your feet for a long time
• are obese (overweight)
• are a smoker
• currently have serious infections
• currently have sepsis (blood poisoning)
• currently have trauma or crush injuries
• currently have cancer

Stop using Hympavzi, and talk to a doctor immediately if you notice any symptoms of a possible blood clot including the following side effects:

• swelling or pain in arms or legs

• redness or discolouration in your

  arms or legs

• shortness of breath
• pain in chest or upper back
• fast heart rate

• coughing up blood

  • feeling faint
  • headache
  • numbness in your face
  • eye pain or swelling
  • trouble seeing

Allergic reactions

Symptoms of allergic reaction have been seen in people using Hympavzi. Stop using Hympavzi and get medical help right away if you get any symptoms of a possible severe allergic reaction including the following:

• rash, hives, generalised itching

• swelling of the face, lips, tongue

  or throat

  • difficulty breathing or

    swallowing

  • dizziness

Children below the age of 12 years

Hympavzi should not be used in children less than 1 year of age, and is not recommended for individuals below 12 years of age. The safety and benefits of this medicine are not yet known in this population.

Other medicines and Hympavzi

Tell your doctor or pharmacist if you are using, have recently used or might use any other medicines.

Pregnancy, contraception and breast-feeding

If you are able to get pregnant, you should use an effective method of contraception (birth control) during treatment with Hympavzi and for at least 1 month after the last injection.

If you are pregnant, think you may be pregnant or are planning to have a baby, ask your doctor for advice before using this medicine. Your doctor will consider the benefit of you using Hympavzi against the risk to your unborn baby.

If you are breast-feeding, ask your doctor for advice on whether to stop breast-feeding or stop using Hympavzi. Your doctor will consider the benefit of you using Hympavzi against the benefits for your nursing infant. Driving and using machines

Hympavzi has no or limited effect on the ability to drive or use machines. Hympavzi contains polysorbate 80

This medicine contains 0.2 mg of polysorbate 80 in each mL. Polysorbates may cause allergic reactions. Tell your doctor if you have any known allergies. Hympavzi contains sodium

This medicine contains less than 1 mmol sodium (23 mg) per 1 mL, that is to say essentially ‘sodium-free’.

3. How to use Hympavzi

Your treatment will be started under the supervision of a doctor qualified to care for patients with haemophilia. Always use this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure.

Your healthcare provider will provide instructions for stopping your current treatment when switching from factor- or non-factor-based medicines to Hympavzi. Contact your healthcare provider if you are not sure what to do. If you are severely ill or need to undergo major surgery, tell your healthcare provider that you are using Hympavzi.

Keeping a record

Each time you use Hympavzi, record the name and batch number of the medicine.

How Hympavzi is given

• Hympavzi is given as an injection under the skin (subcutaneous injection).

  Do not inject it into a vein or muscle.

• For a more comfortable injection, Hympavzi may be allowed to warm at

  room temperature in the carton away from direct sunlight for about 15 to 30 minutes prior to use. Hympavzi should not be warmed in any other way. For example, do not warm in hot water or a microwave. Before you use the pen for the first time, your doctor, nurse or pharmacist will show you and/or your caregiver how to inject Hympavzi. If you inject Hympavzi yourself or if your caregiver injects it, you or your caregiver must carefully read and follow the detailed instructions for use on the reverse side of this leaflet.

Where to inject Hympavzi

• Your doctor or nurse will show you and/or your caregiver which areas

  of the body should be injected with Hympavzi. The best place to give Hympavzi is the belly area (abdomen) or thigh. Injections to the buttocks should be given by a caregiver, doctor, nurse or pharmacist only.

• Change the site of injection on your body each time an injection is given.

• If more than one injection is required to deliver a complete dose, each

  injection should be given at a different injection site.

  • If you are using other medicines that must be injected under the skin,

    these injections should be given at a different injection site. How much Hympavzi to use

Your treatment will start with a loading dose which will then be followed by a maintenance dose given every week:

• Loading dose (a higher starting dose to quickly build up levels in the

  body): The recommended dose is 300 mg.

• Maintenance dose: The recommended dose is 150 mg.

You should use this medicine once a week (any time of day) on the same day each week.

You should record which day of the week you use Hympavzi to help you remember to inject this medicine once a week.

Depending on how you respond to Hympavzi, your doctor may change your maintenance dose as needed, up to a maximum of 300 mg weekly. Use in adolescents

Hympavzi can be used in adolescents 12 years of age and older. An adolescent can self-inject the medicine provided the adolescent’s doctor or nurse and the parent or caregiver agree and the patient is trained to do so. If you use more Hympavzi than you should

If you have used more Hympavzi than you are supposed to, tell your doctor immediately. You may be at risk of developing side effects such as blood clots and require medical attention. Always use Hympavzi exactly as your doctor has told you, and check with your doctor, pharmacist or nurse if you are not sure.

If you forget to use Hympavzi

• If you forget your scheduled dose, inject the forgotten dose as soon as

  possible before the day of the next scheduled dose. Then continue to inject the medicine as scheduled. Do not inject a double dose to make up for a forgotten dose.

• If you forget two scheduled doses in a row (that is if it has been more than

  13 days since your last injection), contact your doctor as soon as possible and ask what to do.

• If you are not sure what to do, ask your doctor, pharmacist or nurse. If you stop using Hympavzi

Do not stop using Hympavzi without talking to your doctor. If you stop using Hympavzi, you may no longer be protected against bleeding. If you have any further questions on the use of this medicine, ask your doctor, pharmacist or nurse.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Serious side effects

Hympavzi may cause a rash (seen in up to 1 in 100 people), which may be severe. Contact your doctor immediately if you have a severe rash; some rashes may be serious. Do not use Hympavzi again until you have talked with your doctor about your rash.

Hympavzi may cause blood clots (thromboembolism) (seen in up to 1 in 100 people). Stop using Hympavzi and contact your doctor immediately if you notice any signs or symptoms of a possible blood clot. Please refer to section 2 “What you need to know before you use Hympavzi” for a list of possible symptoms of a blood clot (thromboembolic event).

Other side effects

Tell your doctor, nurse or pharmacist if you get any of these side effects. Very common (may affect more than 1 in 10 people)

• a reaction in the area where the injection is given (including itching,

  swelling, redness, pain, bruising, hardening)

Common (may affect up to 1 in 10 people)

• headache
• high blood pressure

• itching (pruritus)

  Reporting of side effects

  If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

5. How to store Hympavzi

Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the pre-filled pen label and carton after EXP. The expiry date refers to the last day of that month.

Store in a refrigerator (2 °C - 8 °C). Do not freeze.

Keep the pre-filled pen in the original carton in order to protect from light.

Hympavzi may be removed from the refrigerator and stored in its original carton for up to 7 days at room temperature (up to 30 °C). Do not return Hympavzi to the refrigerator after storing at room temperature. If Hympavzi has been at room temperature for more than 7 days, throw it away, even if it contains unused medicine. Do not shake.

Remove Hympavzi from the refrigerator prior to use. For a more comfortable injection, Hympavzi may be allowed to warm at room temperature in the carton for about 15 to 30 minutes away from direct sunlight prior to use.

Before using the medicine, check the solution for particles or discolouration. Do not use if you notice that the medicine is cloudy, dark yellow, or contains flakes or particles.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information

What Hympavzi contains

• The active substance is marstacimab.
• The other ingredients are disodium edetate, L-histidine, L-histidine monohydrochloride, polysorbate 80 (E 433), sucrose, water for injections (see section 2 “Hympavzi contains polysorbate 80” and “Hympavzi contains sodium”).

What Hympavzi looks like and contents of the pack

Hympavzi is a clear and colourless to light yellow solution for injection (injection) in a pre-filled pen.

Each pack of Hympavzi contains 1 pre-filled pen.

Marketing Authorisation Holder

Pfizer Limited

Ramsgate Road

Sandwich

Kent

CT13 9NJ

United Kingdom

Manufacturer

Pfizer Manufacturing Belgium NV

Rijksweg 12

2870 Puurs-Sint-Amands

Belgium

This leaflet was last revised in 09/2025

For any information about this medicine, please contact: Medical Information, Pfizer Ltd, Walton Oaks, Dorking Road, Tadworth, Surrey, KT20 7NS.

Telephone 01304 616161.

Ref 2_0

076

PAA238644

• Each Hympavzi pre-filled pen is a single-dose pre-filled pen (called “pen” in this ‘Instructions for Use’). The Hympavzi pre-filled pen contains 150 mg of Hympavzi for injection under the skin (subcutaneously). ● Do not inject Hympavzi into a vein or muscle.
• Do not shake Hympavzi.

• To help you remember when to inject Hympavzi, you can mark your calendar ahead of time. Call your doctor, nurse or pharmacist if you or your caregiver have any questions about the right way to inject Hympavzi.

  How To Store Hympavzi

  • Check the expiry date (EXP) printed on the pen label. ● Do not use if the expiry date has passed.

Getting Ready

Step

• Choose an injection site on your stomach area (abdomen) or thigh unless a different site has been suggested by your doctor, nurse or pharmacist. Hympavzi may also be injected into your buttocks by a doctor, nurse, pharmacist or caregiver only. Keep at least 5 cm away from your belly button. ● Change the injection site each time you give yourself an injection of

  Hympavzi. 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 if convenient. ● Allow the site to 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 muscle.
• Do not inject Hympavzi through your clothes.
• Store unused Hympavzi in the refrigerator between 2 °C to 8 °C. Do not freeze Hympavzi. Store Hympavzi in its original carton to protect from direct light.
• If necessary, Hympavzi may be stored in its original carton at room temperature up to 30 °C for up to 7 days. Do not use Hympavzi if it has been out of the refrigerator for longer than 7 days. Throw away (dispose of) any Hympavzi that has been kept at room temperature for longer than 7 days. ● Do not use past the expiry date printed on the Hympavzi pre-filled pen. ● Keep Hympavzi and all medicines out of the reach of children.

Gather the following supplies on a clean flat surface:

• 1 Hympavzi pre-filled pen.
• 1 alcohol swab (not included).
• 1 cotton ball or gauze pad (not included).

• 1 sharps disposal container for pen disposal (not included).EXP date

  Unlocked needle guard

  Needle

  (inside needle guard)

  Window

  Dose strength

  Plunger

  Locked needle

  guard Yellow bar in window HYMPAVZI Pre-filled Pen BEFORE use:

  HYMPAVZI Pre-filled Pen AFTER use:

  Step

  LOT:

  EXP.: YYYY MMM DD

  LOT:

  EXP.: YYYY MMM DD

  Step

  2 Check Date (EXP) Check Medicine

  Thigh

  Buttocks:

  Doctor, nurse, pharmacist or caregiver only Stomach Area

  (Abdomen):

  Keep at least 5 cm

  away from your

  belly button

  Step

  4 Choose and Clean Injection Site Step

  5 Twist Off Cap

  Important Information

This ‘Instructions for Use’ contains information on how to inject Hympavzi. Read this ‘Instructions for Use’ carefully before using Hympavzi pre-filled pen and each time you get a refill prescription as there may be new information. Your doctor, nurse or pharmacist should show you or your caregiver how to prepare and inject a dose of Hympavzi the right way before you use it for the first time.

Do not inject yourself or someone else until you have been shown how to inject Hympavzi.

• Put the used pen in a sharps disposal container as instructed by your doctor, nurse or pharmacist and in accordance with local health and safety laws.
• Do not throw away (dispose of) pens in the household waste. Inject Medicine

1...2...3...4...5 Push down firmly Count

Keep pushing

1^st click Step

6

2^nd click

Step

10

Step

9

Step

8

Step

7 Remove Pen Check Window After Care Disposal

• Remove the pen from your skin.

  • If you see a small drop of medicine on your skin, wait a little longer before

    removing the pen when you give your next injection.

Note: After you remove the pen from your skin, the needle will be automatically covered and the needle guard locked in place.

The pen cannot be reused.

• Press lightly on the injection site for a few seconds with a clean cotton ball or gauze pad if you see a drop of blood.

• Do not rub the area.

  Note: If bleeding does not stop, please contact your doctor, nurse or pharmacist. Remove the pen from its carton and keep out of direct

sunlight.

• Make sure the name Hympavzi appears on the carton

  and pen label.

• Check the pen for any visible damage such as cracks

  or leaks.

• Wash and dry your hands.
• Do not remove the cap until you are ready to inject.

• Throw away (dispose of) the pen if it is damaged, or

  if the pen or the carton containing the pen has been

  dropped.

• Do not use the pen if:

  • it has been stored in direct light. Exposure to room

    light during dose preparation and injection is

    acceptable.

  • it has been frozen or thawed or it has been out of

    the refrigerator for more than 7 days.

• Do not shake the pen. Shaking can damage

  Hympavzi.

  Note: For a more comfortable injection, allow the pen

  to warm up to room temperature in the carton for

  about 15 to 30 minutes away from direct sunlight.

  Do not use any other methods to warm up the pen,

  such as warming the pen in a microwave or hot water.

  • Twist and pull off the cap. ● Put the cap into a sharps disposal container right away. You will not need it again.

Note:

• It is normal to see a few drops of medicine at the needle tip.
• The needle cover will stay inside the cap after cap removal.

Caution: Handle the pen with care as it contains a needle. Do not put, or press your hand over the needle guard. Doing so may result in a needle injury.

• Push the pen down firmly against your skin at a 90° angle and keep pushing until the injection is complete (Step 7). You will hear the 1st click when the injection starts. ● Keep pushing the pen firmly against your skin while the yellow bar moves across the window. You will hear a 2nd click when the injection is almost complete. ● Count slowly to 5 after you hear the 2nd click to make sure you get a full dose.

  Do not remove the pen from your skin until you have counted slowly to 5 after you hear the 2nd click and until the yellow marker completely fills the window.

  Note: The needle goes into your skin as you push the pen down. Your doctor, nurse or pharmacist may suggest gently pinching your skin while you inject.

  Note: If you do not hear a click when pushing the pen against your skin, try pushing down harder. If you still cannot start the injection, get a new Hympavzi pre-filled pen.

  Caution: If you change your mind where to inject after inserting the needle into your skin, you will need to throw away (dispose of) the pen and get a new Hympavzi pre-filled pen. Cap

Needle

cover

INSTRUCTIONS FOR USE

• Look carefully at the medicine through the window on the pen.

  • The medicine should be clear and colourless to light yellow.
  • Do not use the pen if the medicine is cloudy, dark yellow, or contains flakes or particles.

Note: It is normal to see air bubbles in the window.

If you have any questions about the medicine, contact your doctor, nurse or

pharmacist.

• Check the window to make

  sure all the medicine has

  been injected.

  If the yellow bar is not in the position shown, this means you have not received a full

  dose. Call your doctor, nurse or pharmacist for help.

  Do not inject another dose.

Supplies Needed For Hympavzi Injection

Hympavzi® 150 mg solution for injection in pre-filled pen

PAA238644