Eculizumab injection is used to treat paroxysmal nocturnal hemoglobinuria (PNH: a type of anemia in which too many red blood cells are broken down in the body, so there are not enough healthy cells to bring oxygen to all parts of the body). Eculizumab injection is also used to treat atypical hemolytic uremic syndrome (aHUS; an inherited condition in which small blood clots form in the body and may cause damage to the blood vessels, blood cells, kidneys, and other parts of the body). Eculizumab injection is also used to treat a certain form of myasthenia gravis (MG; a disorder of the nervous system that causes muscle weakness). It is also used to treat neuromyelitis optica spectrum disorder (NMOSD; an autoimmune disorder of the nervous system that affects eye nerves and the spinal cord) in certain adults. Eculizumab injection is in a group of medications called monoclonal antibodies. It works by blocking the activity of the part of the immune system that may damage blood cells in people with PNH and that causes clots to form in people with aHUS. It also works by blocking the activity of the part of the immune system that may damage certain parts of the central nervous system in people with NMOSD or by disrupting communication between nerves and muscles in people with MG.

Receiving eculizumab injection may increase the risk that you will develop a meningococcal infection (an infection that may affect the covering of the brain and spinal cord and/or may spread through the bloodstream) during your treatment or for some time afterward. Meningococcal infections may cause death in a short period of time. You will need to receive a meningococcal vaccine at least 2 weeks before you begin your treatment with eculizumab injection to decrease the risk that you will develop this type of infection. If you have received this vaccine in the past, you may need to receive a booster dose before you begin your treatment. If your doctor feels that you need to begin treatment with eculizumab injection right away, you will receive your meningococcal vaccine as soon as possible.

Even if you receive the meningococcal vaccine, there is still a risk that you may develop meningococcal disease during or after your treatment with eculizumab injection. If you experience any of the following symptoms, call your doctor immediately or get emergency medical help: headache that comes along with nausea or vomiting, fever, a stiff neck, or a stiff back; fever of 103°F (39.4°C) or higher; rash and fever; confusion; muscle aches and other flu-like symptoms; or if your eyes are sensitive to light.

Tell your doctor if you have fever or other signs of infection before you begin your treatment with eculizumab injection. Your doctor will not give you eculizumab injection if you already have a meningococcal infection.

Your doctor will give you a patient safety card with information about the risk of developing meningococcal disease during or for a period of time after your treatment. Carry this card with you at all times during your treatment and for 3 months after your treatment. Show the card to all healthcare providers who treat you so that they will know about your risk.

A program called Soliris REMS has been set up to decrease the risks of receiving eculizumab injection. You can only receive eculizumab injection from a doctor who has enrolled in this program, has talked to you about the risks of meningococcal disease, has given you a patient safety card, and has made sure that you received a meningococcal vaccine.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with eculizumab injection and each time you receive an injection. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) or the manufacturer's website to obtain the Medication Guide.

Talk to your doctor about the risks of receiving eculizumab injection.

Eculizumab injection comes as a solution (liquid) to be injected intravenously (into a vein) over at least 35 minutes by a doctor or nurse in a medical office. It is usually given to adults once a week for 5 weeks and then once every other week. Children may receive eculizumab injection on a different schedule, depending on their age and body weight. Extra doses of eculizumab injection are also given before or after certain other treatments for PNH , aHUS, MG, or NMOSD.

Your doctor will probably start you on a low dose of eculizumab injection and increase your dose after 4 weeks.

Eculizumab injection may cause serious allergic reactions. Your doctor will watch you carefully while you are receiving eculizumab injection and for 1 hour after you receive the medication. Your doctor may slow or stop your infusion if you have an allergic reaction. If you experience any of the following symptoms, tell your doctor immediately: chest pain; feeling faint; rash; hives; swelling of the eyes, face, lips, tongue, or throat; hoarseness; or difficulty breathing or swallowing.

Before receiving eculizumab injection,

• tell your doctor and pharmacist if you are allergic to eculizumab injection, any other medications, or any of the ingredients in eculizumab injection. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had any other medical condition(s).
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while receiving eculizumab injection, call your doctor.
• if your child will be treated with eculizumab injection, your child should be vaccinated against Streptococcus pneumoniae and Haemophilus influenza type b (Hib) before beginning treatment. Talk to your child's doctor about giving your child these vaccinations and any other vaccinations your child needs.
• if you are being treated for PNH, you should know that your condition may cause too many red blood cells to break down after you stop receiving eculizumab injection. Your doctor will monitor you carefully and may order laboratory tests during the first 8 weeks after you finish your treatment. Call your doctor right away if you develop any of the following symptoms: confusion, chest pain, difficulty breathing, or any other unusual symptoms.
• if you are being treated for aHUS, you should know that your condition may cause blood clots to form in your body after you stop receiving eculizumab injection. Your doctor will monitor you carefully and may order laboratory tests during the first 12 weeks after you finish your treatment. Call your doctor right away if you develop any of the following symptoms: sudden trouble speaking or understanding speech; confusion; sudden weakness or numbness of an arm or leg (especially on one side of the body) or of the face; sudden trouble walking, dizziness, loss of balance or coordination; fainting; seizures; chest pain; difficulty breathing; swelling in the arms or legs; or any other unusual symptoms.

If you miss an appointment to receive a dose of eculizumab injection, call your doctor right away.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Unless your doctor tells you otherwise, continue your normal diet.

Eculizumab injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• runny nose
• pain or swelling in the nose or throat
• cough
• difficulty falling asleep or staying asleep
• excessive tiredness
• dizziness
• muscle or joint pain
• back pain
• pain in the arms or legs
• sores in the mouth
• diarrhea
• nausea
• vomiting
• stomach pain
• painful or difficult urination

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment :

• fever
• swelling of the arms, hands, feet, ankles, or lower legs
• fast heartbeat
• weakness
• pale skin
• shortness of breath

Eculizumab injection may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to eculizumab injection.

Ask your pharmacist any questions you have about eculizumab injection.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.