B-cell therapy uses drugs called monoclonal antibodies to attack white blood cells known as B cells that cause nerve damage. The FDA has approved two such drugs for MS.

Ocrelizumab (Ocrevus) treats relapsing forms of MS, including:

  • Clinically isolated syndrome
  • Relapsing-remitting MS
  • Active secondary progressive MS in adults
  • Primary progressive MS in adults

 It may lower relapses and slow the disease.

Ofatumumab (Kesimpta) also treats relapsing forms of MS, including:

  • Clinically isolated syndrome
  • Relapsing-remitting MS
  • Active secondary progressive MS in adults

You may have fewer relapses, and the progression of your MS may slow down.

These drugs are new versions of the cancer medication rituximab (Rituxan). Rituximab isn’t approved to treat MS, but doctors sometimes prescribe it as an "off-label" treatment.  

How You Get B-Cell Therapy

You get each type of B-cell therapy in a slightly different way.

You get ocrelizumab in a hospital or clinic through an IV -- what doctors call an infusion. You get the first dose in two infusions

spread 2 weeks apart. After that, you need one infusion every 6 months. Treatment sessions may last 3 to 4 hours, so bring something to pass the time.

Ofatumumab comes in a prefilled syringe or injector pen you use at home. You inject the medicine in your belly or thigh. Your doctor will show you how. If you don’t like to give yourself shots, ask someone else to help. You start with one shot a week for 3 weeks. Then you switch to one shot each month.

With rituximab, you'd get the medication through an IV in a doctor’s office. You’d get two doses, 2 weeks apart. Then, every 6 months, you’d have two more doses, 2 weeks apart.

B-Cell Therapy Side Effects

Before you start B-cell therapy, you’ll get blood tests for hepatitis B and other infections. If you've had hepatitis B in the past, it could come back if you take these treatments.

Ocrelizumab can lead to an allergic reaction. Doctors call it an infusion reaction. It usually happens during your first treatment. You might have:

  • Itching
  • Rash
  • Nausea
  • Hives
  • Headache  

These symptoms are usually mild, but they can be severe. You’ll get meds before your injection to help with side effects. And a nurse will watch closely for problems during and after your treatment.

You may have a reaction to ofatumumab, also. Where the shot goes in your skin, you may have:

  • Redness
  • Swelling
  • Pain

Ofatumumab also can cause:

  • A fever
  • Headache
  • Body aches
  • Tired feeling
  • Colds
  • Runny nose
  • Sinus infections

Rituximab also can cause infusion reactions. You might have itching, swelling, or a rash where the injection goes in.

Other common side effects are:

  • Diarrhea
  • Headache
  • Nausea
  • Muscle spasms
  • Insomnia

With any of these treatments, you could be more prone to infections like colds, bronchitis, and herpes. So it’s important to take steps to stay healthy.

Some researchers believe that these treatments can also give you a slightly higher chance of some cancers, especially breast cancer. But experts aren't sure of the connection.

In very rare cases, they may lead to progressive multifocal leukoencephalopathy (PML), a rare brain infection that can be fatal.

B-Cell Therapy Cost

B-cell therapy is very expensive. Be sure to find out if your insurance covers B-cell therapy and how much of the bill it pays.

WebMD Medical Reference

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