Dawnzera

Pronunciation: dawn-ZAIR-ah
Generic name: donidalorsen
Dosage form: subcutaneous injection ( 80 mg/0.8 mL)

Medically reviewed by Melisa Puckey, BPharm. Last updated on Aug 22, 2025.

What is Dawnzera?

Dawnzera (donidalorsen) is a prescription medicine used to prevent hereditary angioedema in adult and pediatric patients 12 years of age and older. It helps reduce the risk of sudden, unpredictable episodes of severe swelling in the limbs, face, abdomen, and throat, which may be life-threatening.

Dawnzera injection can be self-administered at home once every 4 to 8 weeks using an autoinjector.  

Dawnzera is an RNA-targeted medicine that works by reducing the production of prekallikrein (PKK), a plasma protein that has an important role in the inflammatory pathway that leads to HAE attacks.  By reducing prekallikrein, Dawnzera helps to prevent hereditary angioedema attacks. Dawnzera's mechanism of action is as a prekallikrein-directed antisense oligonucleotide.

Dawnzera FDA approval was granted on August 21, 2025, to Ionis after positive results from Phase 3 OASIS-HAE study (NCT05139810). 

How well does Dawnzera work?

HAE attack rate compared to placebo (4 weekly dose): 

• Dawnzera patients had an 81% reduction in the HAE attack rate over 24 weeks, compared to placebo
• Dawnzera patients had an 87% reduction of the HAE attack rate from week 5 to 25, compared to placebo (administered every 4 weeks).

Average HAE attack rate (4 weekly dose):

• 0.44 attacks for Dawnzera patients (mean attacks per 4 weeks)
• 2.26 attacks for the placebo group (mean attacks per 4 weeks)

Quality of Life (Angioedema‑QoL):

• Dawnzera improved Quality of Life score by 18.6 points more than placebo (score range 0–100; higher = worse QoL) 

The OASIS-HAE clinical trial results were published in The New England Journal of Medicine, “Efficacy and Safety of Donidalorsen for Hereditary Angioedema”.

Side effects

Common Dawnzera side effects 

Common side effects include injection site reactions, upper respiratory tract infection, urinary tract infection, and abdominal discomfort.

Serious side effects

Dawnzera can cause serious side effects, including serious allergic reactions. Stop using this medicine and call your healthcare provider or go to your nearest emergency room right away if you have symptoms of a serious allergic reaction. Symptoms of a serious allergic reaction may include:

• Rash
• Trouble breathing
• Fainting, dizziness, feeling lightheaded (low blood pressure)
• Swelling of your face, lips, or tongue
• Chest pain
• Itching

These are not the only possible side effects of this injection. Tell your healthcare provider if you have any side effect that bothers you or that do not go away while using this medicine.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

Before using this medicine

Before using this injection, tell your healthcare provider about all your medical conditions, including if you:

• Pregnant or plan to become pregnant, as it is not known if this medicine can harm your unborn baby. Tell your healthcare provider if you become pregnant during treatment with this medicine.
• Breastfeeding or plan to breastfeed, as it is not known if Dawnzera passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby while using this medicine.

Do not use this medicine if you have had a serious allergic reaction, including anaphylaxis, to the active ingredient donidalorsen or any of the inactive ingredients in this medicine. 

How should I use this medicine?

• Dawnzera can be self-administered as an injection under your skin (subcutaneous) in your stomach area (abdomen) or the front of your upper legs (thighs). Only a healthcare provider or caregiver may give you an injection in the back of your upper arm. 
• Dawnzera is given one time every 4 weeks or one time every 8 weeks, depending on your prescribed dosing frequency.
• Use this injection exactly as your healthcare provider tells you to take it.
• Read the detailed Instructions for Use that comes with your single-dose autoinjector.
• Your healthcare provider will show you and your caregiver how to inject Dawnzera the first time.

Dawnzera dose information

The recommended dosage of Dawnzera is 80 mg administered subcutaneously every 4 weeks. 

A dosage of 80 mg administered subcutaneously every 8 weeks may be considered.

What happens if I miss a dose?

If you have missed a dose of your injection, administer the missed dose as soon as possible. Then inject this medicine on the regular dosing schedule from the date of the most recently injected dose.

Preparing and injecting Dawnzera

Step 1. Prepare the autoinjector

• Take the autoinjector out of the refrigerator 30 minutes before your injection.
• Keep it in the original carton while it warms to room temperature.
• Do not use other heat sources (microwave, hot water, etc.) to warm it up.

Step 2. Check the medicine

• Look at the expiration date and do not use if expired.
• Check the medicine through the viewing window:
• It should be clear and colorless to yellow.
• Some small air bubbles are normal.
• Do not use the autoinjector if:
• The clear cap is missing or loose.
• The device looks damaged.
• Do not use if cloudy, discolored, or contains particles.

Step 3. Choose your injection site

• Inject into the stomach (at least 2 inches away from the belly button) or the front of the thigh.
• A caregiver or healthcare provider may inject into the back of the upper arm.
• Do not inject into skin that is bruised, red, hard, scarred, or damaged.

Step 4. Wash and clean

• Wash your hands with soap and water.
• Clean the injection site with an alcohol wipe (circular motion).
• Let the skin air dry. Do not touch the area again before injecting.

Injecting Dawnzera

Step 5. Remove the clear cap

• Hold the autoinjector in the middle, with the clear cap pointing away.
• Pull the clear cap straight off (do not twist).
• Throw it away in the trash or sharps container.
• Do not recap and do not press the orange needle shield with your hands.
• Only remove the cap right before injection.

Step 6. Give the injection

1. Hold the autoinjector in one hand and place the orange needle shield flat against your skin at a 90° angle.
2. Push firmly until you hear a click (injection starts). You may hear a second click — this is normal.
3. Hold the device in place for 10 seconds to ensure the full dose is delivered. Do not move, twist, or tilt the autoinjector during the injection.

Step 7. Finish and dispose of autoinjector

• Check the viewing window: the orange plunger rod should fill the window.
• If it hasn’t, you may not have received the full dose. Contact your healthcare provider.
• Lift the autoinjector straight up. The needle shield will lock in place automatically.
• A small amount of blood or fluid at the site is normal. Apply a cotton ball or gauze, then cover with a small bandage if needed.
• The autoinjector contains one single dose. Do not reuse. Dispose of it in a sharps container.

 Always follow your healthcare provider’s instructions. If something doesn’t look right or you have concerns, contact them before using Dawnzera.

For more detailed instructions, see the Package Insert.

Interactions

Other drugs may interact with this medicine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Storage

• Store in the refrigerator between 36°F to 46°F (2°C to 8°C) in the original carton.
• This injection  may be stored at room temperature up to 86°F (30°C) in the original carton for up to 6 weeks. If not used within 6 weeks, throw away injection..
• Do not freeze.
• Do not expose the autoinjector to heat.
• Protect from direct light.

Keep all medicines out of the reach of children.

Ingredients

Active ingredient: donidalorsen 

Inactive ingredients: disodium hydrogen phosphate; sodium chloride; sodium dihydrogen phosphate; water for injection; and may include hydrochloric acid or sodium hydroxide. Phosphorous and sodium.

Company 

Dawnzera Ionis Pharmaceuticals Inc.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer