This medication is used to treat multiple sclerosis (MS). Ofatumumab belongs to a class of medications known as monoclonal antibodies. This medication is not a cure for MS but it is thought to help by preventing immune system cells (lymphocytes) from attacking the nerves in your brain and spinal cord. It helps decrease the number of episodes of disease worsening (relapses) and may prevent or delay disability.

Read the Medication Guide and Instructions for Use provided by your pharmacist before you start using ofatumumab and each time you get a refill. Ask your health care professional how to prepare and use this medication. If you have any questions, ask your doctor or pharmacist.

Before starting treatment with this medication, your doctor will test you for hepatitis B. If needed, treatment for hepatitis B or other infections should be done before receiving this medication.

Inject this medication under the skin as directed by your doctor. The first 3 doses are usually given 1 week apart. Later (maintenance) doses are usually given every 4 weeks. The injection is given in the abdomen, thigh, or upper arm. The dosage and treatment schedule are based on your medical condition and response to treatment.

Take the medication out of the refrigerator 15 to 30 minutes before you inject it to allow it to reach room temperature. Do not warm up this medication any other way (for example, do not heat it in the microwave or place it in hot water). Do not shake the medication. Before using, check this product for particles or discoloration. If either is present, do not use the liquid. Before injecting each dose, clean the skin you are going to inject into (the injection site) with rubbing alcohol. Change the injection site each time to lessen injury under the skin. Do not inject into moles, scars, stretch marks, or skin that is tender, bruised, red, scaly, or hard. To lessen bruising, do not rub the injection site after a shot. Learn how to store and discard medical supplies safely.

Use this medication regularly to get the most benefit from it. To help you remember, mark your calendar with a reminder.

Tell your doctor if your condition does not get better or if it gets worse.

Redness, swelling, itching, or pain at the injection site may occur. Other common injection side effects include fever, headache, muscle ache, chills, and tiredness. These side effects usually lessen after the first few injections. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills, cough).

This drug may cause serious (possibly fatal) liver disease. Also, if you have a current or past infection with hepatitis B, this drug may cause the infection to return or worsen. This may occur during treatment or after treatment is finished. Before starting treatment with this medication, your doctor may order a test to see if you have hepatitis B infection. Get medical help right away if you have any symptoms of liver damage, such as:

• nausea/vomiting that doesn't stop
• loss of appetite
• stomach/abdominal pain
• yellowing eyes/skin
• dark urine

This medication may increase your risk of getting a rare but very serious (possibly fatal) brain infection (progressive multifocal leukoencephalopathy-PML). Get medical help right away if you have any of these side effects:

• clumsiness
• loss of coordination/balance
• weakness
• sudden change in your thinking (such as confusion, difficulty concentrating, memory loss)
• difficulty talking/walking
• seizure
• vision changes

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using ofatumumab, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• past/current/recent infections
• liver disease (especially hepatitis B)
• immune system problems

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Ofatumumab can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.

Tell your doctor your vaccine history and ask if you need to get any vaccines before starting treatment with this medication. Your doctor may direct you to have any required vaccines at least 2 to 4 weeks before starting this medication. Tell your health care professional that you are using ofatumumab before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using ofatumumab. Ofatumumab may harm an unborn baby. Ask about reliable forms of birth control while using this medication and for 6 months after the last dose. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are:

• other drugs that weaken the immune system/increase the risk of infection (such as natalizumab, rituximab)

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Lab and/or medical tests (such as complete blood count, liver function, immunoglobulin levels, tests for hepatitis B) should be done before you start using this medication and while you are using it. Keep all medical and lab appointments.

It is important to use each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Store in the refrigerator. Do not freeze. Keep the medication in the original package to protect from light. This medication may also be stored at room temperature if needed. If the medication is stored at room temperature, discard after 7 days. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).