Natalizumab

Natalizumab is a prescription medication used to treat multiple sclerosis and Crohn's disease. Natalizumab belongs to a group of drugs called immunomodulators. It is thought to work by stopping certain cells of the immune system from reaching the brain and spinal cord or digestive tract and causing damage.

This medication comes in an injectable form to be given once every four weeks through a needle placed in a vein (IV infusion).

Common side effects include headache, tiredness, and joint pain. Because natalizumab can cause serious side effects, this medication is only available through a special program called the Touch program.

Natalizumab is a prescription medicine used to treat adults with relapsing forms of Multiple Sclerosis (MS) and adults with moderate to severe Crohn's disease.

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

Natalizumab may be found in some form under the following brand names:

• Tysabri

Natalizumab can cause serious side effects. See "Drug Precautions" section.

Other side effects with natalizumab include:

• headache
• tiredness
• urinary tract infection
• joint pain
• lung infection
• depression
• pain in your arms and legs
• diarrhea
• vaginitis
• rash
• nose and throat infections
• stomach area pain

This is not a complete list of natalizumab side effects. Ask your doctor or pharmacist for more information.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• azathioprine (Imuran)
• cyclophosphamide (Cytoxan)
• methotrexate (Rheumatrex, Trexall)
• mitoxantrone
• mycophenolate mofetil (CellCept)
• adalimumab (Humira)
• cyclosporine (Gengraf, Neoral, Sandimmune)
• etanercept (Enbrel)
• glatiramer (Copaxone)
• infliximab (Remicade)
• interferon beta (Avonex, Betaseron, Rebif)
• mercaptopurine (Purinethol)
• dexamethasone (Decadron, Dexone)
• methylprednisolone (Medrol)
• prednisolone
• prednisone (Deltasone)
• sirolimus (Rapamune)
• tacrolimus (Prograf)
• "live" vaccines

This is not a complete list of natalizumab drug interactions. Ask your doctor or pharmacist for more information.

Natalizumab increases your chance of getting a rare brain infection that usually causes death or severe disability called progressive multifocal leukoencephalopathy (PML). 

• Your chance of getting PML may be higher if you are also being treated with other medicines that can weaken your immune system, including other treatments for Multiple Sclerosis (MS) and Crohn's disease (CD). You should not take certain medicines that weaken the immune system at the same time you are taking Natalizumab. Even if you use Natalizumab alone to treat your MS or CD, you can still get PML.
• Your chance of getting PML increases if you have been exposed to John Cunningham Virus (JCV). JCV is a common virus that is harmless in most people but can cause PML in people who have weakened immune systems, such as people taking Natalizumab. Most people who are exposed to JCV do not know it or have any symptoms. This exposure usually happens in childhood.
  • If you have been exposed to JCV, your chance of getting PML increases even more if:
    • you have received Natalizumab for a long time, especially longer than 2 years
    • you have received certain medicines that can weaken your immune system before you start receiving Natalizumab
• Your risk of getting PML is greatest if you have all 3 risk factors listed above. Your doctor should discuss the risks and benefits of Natalizumab treatment with you before you decide to receive Natalizumab.
• Your doctor should monitor youfor any new signs or symptoms that may be suggestive of PML for approximately six months after you have stopped using Natalizumab.
• For 6 months after you stop taking Natalizumab, it is important that you call your doctor right away if you get any new or worsening medical problems (such as a new or sudden change in your thinking, eyesight, balance, or strength or other problems) that have lasted over several days. Tell all of your doctors that you are getting treatment with Natalizumab.

Other serious side effects with Natalizumab include:

• Infections. Natalizumab may increase your chance of getting an unusual or serious infection because Natalizumab can weaken your immune system.
• Allergic reactions. Symptoms can include:
  • hives
  • itching
  • trouble breathing
  • chest pain
  • dizziness
  • wheezing
  • chills
  • rash
  • nausea
  • flushing of skin
  • low blood pressure

Tell your doctor or nurse right away if you have any symptom of an allergic reaction, even if it happens after you leave the infusion center. You may need treatment if you are having an allergic reaction.

• Liver damage. Natalizumab may cause liver damage. Symptoms can include:
  • yellowing of the skin and eyes (jaundice)
  • nausea
  • vomiting
  • unusual darkening of the urine
  • feeling tired or weak

Call your doctor right away if you have symptoms of liver damage.

Natalizumab is available only through a restricted distribution program called the TOUCH Prescribing Program.

Natalizumab is only:

• prescribed by doctors who are enrolled in the TOUCH Prescribing Program
• infused at an infusion center that is enrolled in the TOUCH Prescribing Program
• given to patients who are enrolled in the TOUCH Prescribing Program

In order to receive Natalizumab, you must talk to your doctor and understand the benefits and risks of Natalizumab and agree to all of the instructions in the TOUCH Prescribing Program.

• If you take Natalizumab, it is important that you call your doctor right away if you get any new or worsening medical problems (such as a new or sudden change in your thinking, eyesight, balance, or strength or other problems) that have lasted over several days. Tell all of your doctors that you are getting treatment with Natalizumab.

Who should not receive Natalizumab?

Do not receive Natalizumab if you:

• have PML
• are allergic to Natalizumab

Natalizumab is not recommended if you:

• have a medical condition that can weaken your immune system such as HIV infection or AIDS, leukemia or lymphoma, or an organ transplant, and others.
• are taking medicines that can weaken your immune system. Talk with your doctor about all of the medicines you take or have taken.

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of natalizumab there are no specific foods that you must exclude from your diet when receiving natalizumab.

Before receiving natalizumab, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• have any new or worsening medical problems (such as a new or sudden change in your thinking, eyesight, balance, or strength or other problems) that have lasted several days
• have had hives, itching or trouble breathing during or after an infusion of natalizumab
• have a fever or infection (including shingles or any unusually long lasting infection)
• are pregnant or breastfeeding

Tell your doctor about all of the medicines you are taking, including prescription and non-prescription medicines, vitamins and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Natalizumab falls into category C. In animal studies, pregnant animals were given this medication and had some babies born with problems. No well-controlled studies have been done in humans. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.

Natalizumab has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from natalizumab, a choice should be made whether to stop nursing or to stop use of this medication. The importance of the drug to the mother should be considered.

• Natalizumab is given once every four weeks through a needle placed in a vein (IV infusion), in a hospital or medical setting.
• The IV infusion usually takes about one hour.
• Following each dose, you will be monitored for side effects and allergic reactions to the medication.
• You must follow all the instructions of the TOUCH Prescribing Program. Before you can begin to receive natalizumab, your doctor or nurse will:
  • explain the TOUCH Prescribing Program to you
  • have you sign the TOUCH Prescriber/Patient Enrollment Form
• Before every natalizumab infusion you will be asked a series of questions to confirm that natalizumab is still right for you.
• Call your doctor who prescribes natalizumab right away to report any medical problems that keep getting worse and last several days.

The recommended dose of natalizumab for multiple sclerosis and Crohn's disease is 300 mg intravenous infusion over one hour every four weeks.

Natalizumab is usually administered by a healthcare provider in a medical setting making it unlikely for an overdose to occur. However, if overdose is suspected, seek emergency medical attention.

WARNING: PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY

Natalizumab increases the risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain that usually leads to death or severe disability. Cases of PML have been reported in patients taking natalizumab who were recently or concomitantly treated with immunomodulators or immunosuppressants, as well as in patients receiving natalizumab as monotherapy.

• Because of the risk of PML, natalizumab is available only through a special restricted distribution program called the TOUCH Prescribing Program. Under the TOUCH Prescribing Program, only prescribers, infusion centers, and pharmacies associated with infusion centers registered with the program are able to prescribe, distribute, or infuse the product. In addition, natalizumab must be administered only to patients who are enrolled in and meet all the conditions of the TOUCH Prescribing Program.
• Healthcare professionals should monitor patients on natalizumab for any new sign or symptom that may be suggestive of PML. Natalizumab dosing should be withheld immediately at the first sign or symptom suggestive of PML. For diagnosis, an evaluation that includes a gadolinium-enhanced magnetic resonance imaging (MRI) scan of the brain and, when indicated, cerebrospinal fluid analysis for JC viral DNA are recommended.