Key takeaways

  • Kesimpta is a medication used to treat relapsing forms of multiple sclerosis (MS) and clinically isolated syndrome (CIS).
  • Kesimpta comes as a solution inside single-dose prefilled injection pens or syringes. The drug is given as an injection under the skin.
  • Kesimpta may cause side effects. Mild side effects of the drug include headache and injection site reactions. More serious side effects include an increased risk of infection and allergic reaction.

The active ingredient in Kesimpta is ofatumumab, which is a biologic drug. Kesimpta belongs to a group of drugs called monoclonal antibodies.

Kesimpta is prescribed to treat relapsing forms of MS. With relapsing forms of MS, you experience relapses, which are periods of new or worsening symptoms.

What are the symptoms of MS?

MS is a chronic (long-term) condition that affects the brain and spinal cord. The immune system causes MS by mistakenly attacking the protective layer wrapped around nerve fibers. This layer is called myelin. When the immune system attacks myelin, it causes inflammation and lesions in the nervous system. This interferes with how well the brain can communicate with the rest of the body.

Symptoms of MS can include:

  • difficulty walking
  • fatigue (low energy)
  • vision problems, such as blurry vision
  • problems with speech, such as slurred speech or changes in your speech volume
  • pain
  • tremors

Who is Kesimpta prescribed for?

Kesimpta is prescribed to treat the following types of MS in adults:

Kesimpta is also prescribed to treat clinically isolated syndrome (CIS). With CIS, you have an episode of MS-like symptoms that last 24 hours or longer. CIS is often classified as a type of MS, but it may or may not develop into MS.

MS symptoms occur when your immune system mistakenly attacks myelin, which is a protective layer wrapped around your nerve fibers. This action causes inflammation and lesions in your nervous system, interfering with how well your brain communicates with the rest of your body.

Kesimpta is a type of drug called a monoclonal antibody. It specifically targets and blocks a certain protein in your immune system. By blocking this protein, Kesimpta suppresses your immune system. This can reduce inflammation in your nervous system and relieve MS symptoms. It can also prevent your immune system from attacking myelin, which can slow or prevent MS from worsening.

Talk with your doctor or pharmacist if you’d like to learn more about how Kesimpta works to treat MS.

Is Kesimpta used in children?

No, Kesimpta is not used in children. It’s only approved for treating relapsing forms of MS in adults. To learn more about MS treatment options for children, talk with your child’s doctor.

Using Kesimpta for multiple sclerosis or clinically isolated syndrome may cause side effects in some people. Kesimpta’s side effects can be mild or serious.

The following lists include some of the main side effects that have been reported in people using Kesimpta. For information about other possible side effects of this medication, talk with your doctor or pharmacist.

You can also learn more about this drug’s side effects from Kesimpta’s prescribing information.

What are Kesimpta’s mild side effects?

Kesimpta may cause mild side effects in some people. These include:

In many cases, mild side effects from the drug can be temporary. Some side effects may be easy to manage, too. But if side effects last for a longer time, or if they bother you or become severe, talk with your doctor or pharmacist.

What are Kesimpta’s serious side effects?

In rare cases, using Kesimpta may lead to serious side effects. Examples include:

Call your doctor right away if you have any serious side effects while using Kesimpta. If the side effects seem life threatening or you think you’re having a medical emergency, call 911 or your local emergency number immediately.

Allergic reaction

For some people, Kesimpta can cause an allergic reaction. This side effect was not reported in the drug’s studies. However, allergic reaction has been reported since Kesimpta became available to prescribe.

In general, symptoms of an allergic reaction can be mild or serious.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should continue Kesimpta treatment.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Kesimpta, they may have you switch to a different treatment.

Before you use Kesimpta, there’s some important information to keep in mind. The drug may not be a safe option for you if you have certain medical conditions or other factors that affect your health.

If any of the following medical conditions or other health factors apply to you, talk with your doctor before using Kesimpta.

  • if you have ever had hepatitis B
  • if you have any active infection (currently causing symptoms)
  • if you have a scheduled vaccination or have recently received a vaccination
  • if you have a weakened immune system
  • if you are pregnant or breastfeeding, or planning to become pregnant or breastfeed
  • if you consume alcohol
  • if you’ve had an allergic reaction to the drug or any of its ingredients

Here are answers to some frequently asked questions about Kesimpta.

Is Kesimpta chemotherapy?

No, Kesimpta is not chemotherapy. Chemotherapy refers to aggressive treatments used for cancer and certain other conditions. It works by destroying rapidly growing cells in the body.

Kesimpta is a type of drug called a monoclonal antibody. It works by targeting and blocking specific proteins in your immune system that are thought to play a role in causing MS symptoms.

Unlike Kesimpta, chemotherapy does not work by targeting specific proteins in the immune system. Instead, chemotherapy targets all cells in the body that grow rapidly. This includes cancer cells, but it can also affect noncancerous cells such as hair cells and skin cells.

To learn more about how Kesimpta works, including how it compares with chemotherapy drugs, talk with your doctor or pharmacist.

How does Kesimpta compare with Ocrevus?

Like Kesimpta, Ocrevus is a monoclonal antibody drug prescribed to treat certain types of MS. But these medications do have some differences.

Kesimpta and Ocrevus are both prescribed to treat relapsing forms of MS. But unlike Kesimpta, Ocrevus is also approved to treat primary progressive multiple sclerosis.

Kesimpta is given as an injection under the skin. You can give yourself injections at home after your doctor or pharmacist shows you how to do so.

Ocrevus is given as an intravenous (IV) infusion by your doctor or another healthcare professional. You’ll need to go to a clinic or your doctor’s office to receive Ocrevus doses, or you may be able to receive Ocrevus infusions at home.

To learn more about how Kesimpta and Ocrevus compare, talk with your doctor or pharmacist.

The price of Kesimpta depends on several factors. These can include your treatment plan, your insurance plan, the pharmacy you use, and your location.

Kesimpta is a brand-name biologic drug that is not available as a biosimilar. Brand-name biologic drugs usually cost more than biosimilars.

Here are some key details on how Kesimpta is used to treat MS.

What is the usual dosage for Kesimpta?

The usual dosage for Kesimpta is 20 milligrams (mg). You can give yourself injections at home after your doctor or pharmacist shows you how to do so. You’ll typically receive this drug once weekly for your first 3 weeks of treatment. After that, you’ll skip injecting Kesimpta for 1 week before you switch to a dosage of 20 mg once per month.

How do you use Kesimpta?

Kesimpta comes as a solution inside single-dose prefilled injection pens or syringes. The drug is given as an injection under the skin.

When you’re first prescribed Kesimpta, your doctor or pharmacist will show you or a caregiver how to give injections at home. The drug manufacturer also provides step-by-step instructions on how to inject Kesimpta.

How often should I inject Kesimpta?

When you’re first prescribed Kesimpta, you’ll likely inject the drug once weekly for 3 weeks. Then you’ll skip receiving Kesimpta for 1 week before you switch to a dosage of 20 mg once per month.

Once you’re receiving Kesimpta on a monthly basis, try to give yourself the drug on the same day each month. This helps keep a steady level of the drug in your system, which helps it work effectively for your condition.

If you’re prescribed Kesimpta, you may wonder how effective it is at treating your condition.

Clinical trials found Kesimpta effective for treating relapsing forms of MS. Your doctor or pharmacist may be able to provide more details. Or you can read Kesimpta’s prescribing information to learn more.

The American Academy of Neurology’s guidelines for treating MS do not specifically mention Kesimpta. But they do recommend using a disease-modifying therapy (DMT) to treat relapsing forms of MS. Kesimpta is considered a DMT because it can help slow the worsening of your MS symptoms over time. Your doctor can provide more information on how they’ll determine which DMT may be best for you.

To learn more about Kesimpta’s effectiveness, talk with your doctor.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.