Pronunciation: ZIL-ue-KOE-plan
Brand name: Zilbrysq
Dosage form: subcutaneous injection (16.6 mg/0.416 mL, 23 mg/0.574 mL, 32.4 mg/0.81 mL)
Drug class: Selective immunosuppressants

Medically reviewed by Melisa Puckey, BPharm. Last updated on Nov 28, 2024.

What is Zilucoplan?

Zilucoplan is used to treat myasthenia gravis (MG) in adults to help improve symptoms for patients who are AChR antibody positive (AChR-Ab+). Zilucoplan’s brand name is Zilbrysq. It is a once-daily, under-the-skin injection that can be self-administered by MG patients. Zilucoplan works by blocking a protein (C5) in the immune system that is involved with the symptoms of generalized myasthenia gravis. Zilucoplan is from the class of medicines called complement inhibitors and is a C5 inhibitor.

Zilucoplan FDA approval

Zilucoplan FDA approval was granted on October 17, 2023, to treat adult patients with generalized myasthenia gravis (gMG) that is anti-acetylcholine receptor (AChR) antibody positive. Zilucoplan approval was based on positive results from the phase 3 12-week Zilucoplan Clinical Trial called RAISE (NCT04115293). This clinical trial showed rapid and clinically meaningful improvements in symptoms of MG, compared to a placebo, measured using the MG-ADL score.

What is myasthenia gravis?

Myasthenia gravis is a long-term (chronic) autoimmune disease that causes muscle weakness, leading to symptoms of double vision, drooping eyelids, trouble talking, breathing, and trouble walking. Myasthenia gravis is caused by antibodies from your immune blocking or attacking receptors between nerves and muscles, which makes it harder for the muscles to contract. Many patients with myasthenia gravis have antibodies that attack the nicotinic acetylcholine receptors (AChR); these patients are called AChR antibody positive (AChR-Ab+).

Usually, the first and main symptom of MG is painless weakness of specific muscles that gets worse towards the end of the day. It may also become worse during physical activity and then improve after rest. MG symptoms often start with eye weakness; then, over a period of time, they may progress to a severe generalized form, with weakness in arms and legs or in muscles involved in swallowing and breathing.

The complement system is part of the immune system that becomes activated in MG, damaging the neuromuscular junction and causing symptoms of MG.

How does zilucoplan work?

Zilucoplan injection reduces complement-mediated damage to the junction between the nerves and muscles through its targeted mechanism of action of inhibiting complement component 5. The complement system is part of the immune system and, when activated, drives myasthenia gravis. By zilucoplan blocking the complement system, it helps improve myasthenia gravis symptoms.

Zilucoplan mechanism of action (MOA) is suppressing the C5 protein in the immune complement system. This stops C5b-9 from being made and deposited at the neuromuscular junction. It is thought that the decrease in C5b-9 deposited at the neuromuscular junction causes generalized myasthenia gravis symptoms to improve. Zilucoplan is a C5 inhibitor.

Zilucoplan injection is not a monoclonal antibody, so it can be used with intravenous immunoglobulin and plasma exchange without needing supplemental dosing.

How well does zilucoplan work?

In phase 3 12-week Zilucoplan Clinical Trial (RAISE), zilucoplan injection was effective in significantly improving symptoms in people with MS. Zilucoplan reduced the MG-ADL score by 4.39 points, whereas the placebo group only saw a reduction of 2.30 points. This means that the zilucoplan injection led to a 2.09-point greater reduction in the MG-ADL score compared to the placebo.

The severity of MG is measured using the Myasthenia Gravis–Activities of Daily Living (MG-ADL) score, which is the result of 8 questions related to symptoms and the ability to do functional activities related to daily living. The total score ranges from 0 (no symptoms) to 24 (severe symptoms). In clinical trials, the MG-ADL score is measured at the start of the trial, and the end of the trial. A decrease in MD-ADL score means there has been an improvement in MG symptoms.

Zilucoplan side effects

Common zilucoplan side effects

Common zilucoplan side effects include:

• pain, bruising, swelling, or irritation at the site of the injection;
• cold symptoms such as stuffy nose, sneezing, sore throat; or diarrhea.

Other zilucoplan side effects

You may get infections more easily, even serious or fatal infections. Call your doctor right away if you have signs of infection such as:

• fever, chills, sore throat;
• mouth sores, red or swollen gums;
• pale skin, easy bruising, unusual bleeding;
• chest discomfort, wheezing, dry cough or hack, rapid weight loss;
• signs of meningitis - headache, neck stiffness, increased sensitivity to light, nausea, vomiting, confusion, drowsiness; or
• pancreatitis with symptoms of severe pain in your upper stomach spreading to your back, nausea or vomiting

Get emergency medical help if you have signs of an allergic reaction including symptoms of hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Also, see the Warnings section.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

Warnings

Zilucoplan affects part of your immune system and may lower the ability of your immune system to fight certain infections, therefore increasing your chance of getting serious and life-threatening meningococcal infections.

• Meningococcal infections may become life-threatening or fatal if not recognized and treated early. You must complete or update two types of meningococcal vaccines (for both serogroup B infections and serogroup A, C, W, and Y infections) at least 2 weeks before your first dose of this medicine, if you have not already had these vaccines.
• If your healthcare provider decides that urgent treatment with zilucoplan is needed, you should receive meningococcal vaccination(s) as soon as possible.
• If you have not completed or updated vaccinations for meningococcal infections at least 2 weeks before your first zilucoplan dose and therapy must be started right away, you must also receive antibiotics.
• If you had a meningococcal vaccine in the past, you might need additional vaccination before starting this medicine. Your healthcare provider will decide if you need additional meningococcal vaccination.
• Meningococcal vaccines do not prevent all meningococcal infections. Call your healthcare provider or get emergency medical care right away if you get any of these signs and symptoms of a meningococcal infection: headache with nausea or vomiting, confusion, headache and fever, muscle aches with flu-like symptoms, headache with a stiff neck or stiff back, eyes sensitive to light, fever, and fever with a rash.

Your healthcare provider will give you a Patient Safety Card about the risk of meningococcal infection. Carry it with you at all times during treatment and for 2 months after your last dose. Your risk of meningococcal infection may continue for several weeks after your last dose of this medicine. It is important to show this card to any healthcare provider who treats you. This will help them diagnose and treat you quickly.

Zilucoplan is only available through a program called the Zilbrysq REMS. Before you can receive this medicine, your healthcare provider must:

• enroll in the Zilbrysq REMS.
• counsel you about the risk of meningococcal infection.
• give you the Patient Guide, including information about the signs and symptoms of meningococcal infection.
• give you a Patient Safety Card about your risk of meningococcal infection, as discussed above.
• make sure you are vaccinated with two types of meningococcal vaccine and, if needed, get revaccinated with the meningococcal vaccine. Ask your healthcare provider if you are unsure if you need to be revaccinated.

Zilucoplan may also increase the risk of other types of serious infections. This injection may increase your chance of getting Streptococcus pneumoniae and Haemophilus influenzae type b. Your healthcare provider will tell you if you should receive the Streptococcus pneumoniae and Haemophilus influenzae type b vaccinations.

Certain people may have an increased risk of gonorrhea infection. Talk to your healthcare provider about whether you are at risk for gonorrhea infection, about gonorrhea prevention, and about regular testing.

Call your healthcare provider right away if you have new signs or symptoms of infection.

Zilucoplan contraindications

Zilucoplan is contraindicated in patients who have a Neisseria meningitidis infection.

Before taking this medicine

Before you start using zilucoplan, tell your doctor if you have any signs of infection such as fever, chills, cough, body aches, tiredness, open sores or skin wounds, diarrhea, stomach pain, weight loss, painful urination, or coughing up blood.

You should not use zilucoplan if you have meningitis, an infection caused by a bacteria called Neisseria meningitidis.

Tell your doctor if you have ever had:

• active or recent infection; or
• pancreas problems.

Using zilucoplan may increase your risk of getting certain bacterial infections such as pneumonia, gonorrhea (a sexually transmitted disease), or a bloodstream infection. Ask your doctor about your individual risk and how to prevent an infection.

Make sure you are current on all vaccines that protect against serious bacterial infections including meningitis, at least 2 weeks before you start using zilucoplan. If you were vaccinated in the past, Your doctor will determine if you need additional vaccinations.

Pregnancy

Tell your healthcare provider if you are pregnant or plan to become pregnant , as It is not known if zilucoplan will harm your unborn baby.

Breastfeeding

Tell your healthcare provider if you are breastfeeding or plan to breastfeed as it is not known if zilucoplan passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you are using this medicine.

How should I use zilucoplan?

Your doctor or healthcare provider will give you the detailed Instructions for Use that come with your injection. This has information on how to prepare and use this medicine and how to throw away the used prefilled syringes properly. Use this medicine exactly as prescribed by your healthcare provider after proper training on how to prepare and inject zilucoplan.

Zilucoplan instructions

• Zilucoplan is given as a daily injection under the skin (subcutaneous) using a prefilled syringe. The daily dose should be administered at approximately the same time each day.
• Zilucoplan is injected into areas of the abdomen, thighs, or back of the upper arms that are not tender, bruised, red, or hard. You should not inject into skin areas with scars or stretch marks. Only a caregiver can give zilucoplan in the upper, outer arm.
• Rotate injection sites for each administration.
• Prepare an injection only when you are ready to give it and make sure you understand how to use, store, and throw away zilucoplan. Call your pharmacist if the medicine looks cloudy, has changed colors or has particles in it.
• Take the medicine out of the refrigerator and let it reach room temperature for 30 to 45 minutes before using. Do not warm the medicine with hot water, sunlight, or a microwave.

Your healthcare provider will decide the total daily dose depending on your body weight.

Each prefilled syringe is for single-use only. Throw away the prefilled syringe after each use. Do not reuse.

Zilucoplan Dosing Information

The recommended adult Zilucoplan dosing is based on actual body weight.
Zilucoplan dose:

• Less than 56kg = 16.mg once daily
• 56 kg to less than 77 kg = 23 mg once daily
• 77 kg and above = 32.4 mg once daily.

What strengths is zilucoplan available as?

Zilbrysq brand is available as prefilled syringes as 16.6 mg/0.416 mL, 23 mg/0.574 mL, or 32.4 mg/0.81 mL.

What should I do if I miss a dose?

If you miss your zilucoplan dose, inject a dose as soon as possible. Then, inject your next dose at your regular scheduled time. Do not inject more than 1 dose each day. Call your healthcare provider if you are not sure what to do.

Interactions

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

Click on the link below for more information on interactions with this medicine.

Zilucoplan Package Insert

Review the Zilucoplan Package Insert (Zilbrysq Package Insert) for more detailed information about this medicine. Discuss any medical questions you have with your doctor or other health care provider. This is not all the information you need to know about this medicine for safe and effective use, and it does not take the place of talking to your doctor about your treatment.

Zilucoplan Package Insert is sometimes called Zilucoplan Prescribing Information (PI) or Zilucoplan FDA label.

Storage

Pharmacy Prior to Dispensing

• Prefilled syringes refrigerated at 2°C to 8°C (36°F to 46°F) in the original carton until dispensing.
• Do not freeze.

Storage for Patients or Caregivers After Dispensing

• Store at 2°C to 8°C (36°F to 46°F) until expiration date on the carton.
• Store up to 30°C (86°F) for up to 3 months after removing from refrigerator or until expiration date on the carton, whichever occurs first. Write the date removed from the refrigerator in the space provided on the carton.
• Do not freeze.
• Store prefilled syringes in the original carton to protect them from light until time of use.

Zilucoplan Ingredients

Active ingredient: zilucoplan.

Zilbrysq Inactive ingredients: dibasic sodium phosphate, anhydrous, monobasic sodium phosphate, monohydrate, sodium chloride, and water for injection.

UCB zilucoplan 

UCB Zilucoplan (Zilbrysq) is Manufactured for: UCB, Inc., Smyrna, GA 30080 

Further information

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

Medical Disclaimer