People with myasthenia gravis may need to use many different medicines to manage their symptoms. In recent years, a new group of medicines called complement inhibitors have been approved to treat this condition. Although all of these medicines are injected into the body, Zilbrysq is a complement inhibitor that can be given as an injection at home.
How Does Zilbrysq Work for Myasthenia Gravis?
Myasthenia gravis (MG) is a type of autoimmune condition, which means that the body’s immune cells attack its own healthy cells. In MG, the immune system attacks a receptor on the cells in the neuromuscular junction, which is the place where the nerves and the muscles meet. The receptor that the body attacks, called the acetylcholine receptor, sends important signals to the muscles to tell them to move and function. MG slows down these signals, causing the muscles to quickly become weak and tired.
Each person with MG will have a different experience depending on which part of the body is affected. Some people with MG have symptoms that start suddenly, while other people have symptoms that slowly get worse over a few years. In some cases, this condition will go into “remission,” which means that symptoms go away for some length of time.
Here are some of the symptoms caused by MG:
- It can affect the neck, arms, and legs, causing issues with walking, using the arms and hands normally, or even holding the head up.
- It can affect the eye muscles, causing people to see double or have droopy eyelids.
- It can affect the face and mouth, causing slurred speech, trouble chewing or swallowing, or changes in the voice or facial expressions.
- About one-fifth (20%) of people with this condition will experience a medical emergency called a “myasthenic crisis” where it becomes difficult or impossible to breathe. Some myasthenic crises have no cause, while others are caused by “triggers” such as infections, stress, or exposure to certain medicines.
The key to treating MG is to help the body to keep sending signals through the acetylcholine receptor. Anticholinesterase medicines, such as pyridostigmine (Mestinon), can help increase these signals by increasing the amount of a substance called acetylcholine in the body. Oral corticosteroids such as prednisone are also often used to help control symptoms. Medicines that suppress the overactive immune system (immunosuppressants) can also be helpful. Some people may receive other injections or undergo surgery to help treat this condition.
In recent years, new medicines called complement inhibitors have been approved to treat MG. The active ingredient in Zilbrysq, zilucoplan, is a complement inhibitor. It works by blocking the complement pathway, which plays an important role in the way that the immune system attacks the acetylcholine receptor in people with MG. Blocking this pathway slows down the attacks from the immune system, allowing the body to send stronger signals to the muscles.
Can Anyone With Myasthenia Gravis Use Zilbrysq?
Zilbrysq is approved for use in people with MG who have a certain type of antibody in their blood called the anti-acetylcholine receptor antibody. Although most (80%-90%) people with MG have this antibody, not everyone does, so it is important to confirm that this antibody is present. Zilbrysq may not help people who do not have this antibody.
How Do I Use It?
Zilbrysq is a liquid injected under the skin once every day. It can be injected into the thigh, stomach, or outer area of the upper arm. This medicine is stored in the refrigerator. To make the injection more pleasant, each dose should sit at room temperature for about 30-45 minutes before use.
Zilbrysq comes in a prefilled syringe with a needle. Your health care provider will show you how to inject the medicine before you use it the first time. Your prescription will also come with “Instructions for Use,” which explain how to prepare and give a dose. It is important to inject the medicine properly so that you get the right dose. Ask your pharmacist or other healthcare provider if you are unsure how to use Zilbrysq.
Is There Anything I Need to Know Before Starting This Medicine?
This medicine can increase the risk of certain serious infections, including meningococcal infections. To help reduce the risk of this happening, Zilbrysq is only available through a special program called the Zilbrysq REMS program. You and your health care provider must both enroll in this program before you can start using this medicine.
As part of the program, your health care provider will talk to you about meningococcal infections, including how to prevent them, how to recognize the symptoms, and the importance of getting medical help right away when you get sick. To help reduce the risk of infection, they will ensure that you have received your meningococcal vaccines at least 2 weeks before starting Zilbrysq. If you need to start Zilbrysq right away and have not yet gotten your vaccines, you will need to take antibiotics until the vaccines start working. Your health care provider will also provide you with a Patient Safety Card about this risk that you can show to any other health care providers that treat you. You should carry this card with you at all times while you are using Zilbrysq and for 2 months after you stop using it.
How Was It Studied?
One study was done to see if Zilbrysq was safe and effective in adults with MG. All of the people in this study had the anti-acetylcholine receptor antibody (AchR) in their blood, and the average age was 53. A little more than half (57%) of the people in this study were female. Most (74%) were White, about 12% were Asian, 7% were Black, and less than 1% were American Indian or Alaskan Native. About 7% of the people in this study identified as Hispanic or Latino.
Here is some important information about the treatments that people were using when the study started.
- Most people (85%) were using an anticholinesterase medicine.
- About two-thirds (63%) were taking an oral corticosteroid every day.
- About half (53%) were taking an immunosuppressive medicine.
Zilbrysq was compared with a placebo, and no one knew whether they were receiving the medicine or the placebo. Anyone who was already using other medicines for MG before the study started was told to keep taking these medicines during the study.
This study measured efficacy by measuring each person’s symptoms on two different scales:
- The MG Activities of Daily Living (MG-ADL) scale, which asks a person to rate how much their condition affects their ability to do certain things, including talking, chewing, swallowing, breathing, seeing clearly, and brushing their teeth and hair. The score can range from 0 to 24, and a higher score means that symptoms are more severe.
- The Quantitative MG (QMG) score, which asks health care providers to rate a person’s muscle function for the muscles in the face, eyes, throat, arms, hands, and legs. The score can range from 0 to 39, and a higher score means that symptoms are more severe.
What Benefits Were Seen in These Studies?
Improvement in symptoms. After three months, scores on the MG-ADL, which were rated by the people in the study, improved by a greater amount in the people who used Zilbrysq than the people who used a placebo. The people who used Zilbrysq also had their scores on the QMG, which were rated by a health care provider, improve by a greater amount than the people who used placebo. This means that the symptoms that were rated by the people in the study, as well as their specialists, improved more in the people using Zilbrysq than in people using a placebo.
How Quickly Will Zilbrysq Work for Myasthenia Gravis?
If Zilbrysq is working, your symptoms will start to improve within the first week of using the medicine. Most people see the greatest improvements during the first month. Do not stop using this or any other medicines for MG without talking to your health care provider first, even if your symptoms have gotten better. Your symptoms may get worse again if you stop or change any of your medicines.
Tell your health care provider if your symptoms do not seem to be improving after one to two months of using Zilbrysq. They may discuss other options for treating your condition.
How Can I Prevent or Manage Side Effects?
Zilbrysq can cause a skin reaction at the injection site, which may involve redness, itching, and swelling. One way to reduce these reactions is to inject the drug into a different part of the body each time, which is called “rotating” the injection site. For example, Zilbrysq can be injected into different parts of the thigh, stomach, or outer area of the upper arms. Don’t inject the drug into skin that is already tender, damaged, bruised, swollen, or scarred.
People who use Zilbrysq may be more likely to have certain bacterial infections, especially infections in the nose, throat, or lungs. Some of these infections can be prevented with vaccines. Before you start Zilbrysq, speak with your health care professional about whether you are due for any vaccines. You can also help to prevent infections by reducing your exposure to germs by washing your hands and avoiding people who are sick.
Zilbrysq may increase your risk for a type of sexually transmitted disease (STD) called gonorrhea. To help reduce the risk of this infection, it is important to follow safe sex practices, such as using a condom, and ensure that you and your partner(s) get tested regularly. Speak with your health care provider about the best ways to prevent this condition and when to get tested.
Some people who use Zilbrysq might develop pancreatic cysts and pancreatitis. Before you start using this medicine, your health care provider will check your blood for certain enzymes found in the pancreas. Call your health care provider right away if you have any symptoms, such as severe pain in the upper part of your belly that travels to your back.
These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. If you experience anything that you think may be caused by Zilbrysq, you can also report side effects to the FDA at 800-FDA-1088.
Are There Any Interactions With Other Medicines?
There are no known interactions between Zilbrysq and other medicines. But it is still important for your health care provider to be aware of all the prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, or other supplements you take or have recently taken.
Are There Any Special Steps Required to Get This Medicine?
Zilbrysq is a type of medicine called a “specialty” medicine. This means that you can only get it from a specialty pharmacy and that it may require prior authorization from your insurance company.
Is There a Coupon Card Available?
The manufacturer has a program that can help to answer any questions you may have about this medicine, including help with covering the cost of the medicine. You can find out more at www.ucbonward.com/ZILBRYSQ.
