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Questions and Answers on Natalizumab (marketed as
Tysabri)
1. What action is the FDA taking with Tysabri today?
The Food and Drug Administration (FDA) today approved an
application for resumed marketing of Tysabri (natalizumab) with a
special restricted distribution program. Tysabri is a monoclonal
antibody, for the treatment of patients with relapsing forms of
multiple sclerosis (MS). Tysabri is indicated for use as monotherapy,
because we don't know enough about how its use with other immune
modifying drugs could impact risk. It is also meant for patients
who have not responded adequately to, or cannot tolerate, other
treatments for MS.
2. Why was marketing of Tysabri previously halted?
Tysabri, which was initially approved by the FDA in November, 2004, was withdrawn by the manufacturer in February 2005 after three patients in the drug’s clinical trials developed progressive multifocal leukoencephalopathy (PML), a serious viral infection of the brain. In addition, FDA put clinical trials of the drug on hold in February, 2005 based on this information.
3. Why is this product being allowed to go on the market?
FDA allowed a clinical trial of Tysabri to resume in February, 2006, following a reexamination of the patients who had participated in the previous clinical trials, confirming that there were no additional cases of PML. In March, 2006, FDA consulted 2006 with its Advisory Committee on drugs for peripheral and central nervous systems about the possibility of making Tysabri available to appropriate MS patients while decreasing the possibility of patients developing PML. The Advisory Committee recommended a risk-minimization program with mandatory patient registration and periodic follow-up to identify as early as possible any cases of PML that do occur and to try to determine the reason the infection occurs. In response, the manufacturer, Biogen-Idec submitted to the agency a Risk Management Plan, called the TOUCH Prescribing Program, to help ensure safe use of the product.
4. What are the risks?
Tysabri increases the chance of patients getting a rare brain infection that usually causes death or severe
disability. This infection is called progressive multifocal leukoencephalopathy (PML). PML usually happens in people with weakened immune systems.
- No one can predict who will get PML.
- There is no known treatment, prevention, or cure for PML.
- A patient’s chance of getting PML may be higher if he or she is also being treated with other medicines that can weaken the immune system, including other MS treatments.
- Even if Tysabri is used alone to treat MS, it is not known if the chance of getting PML will be lower. It is also not known if treatment for a long period of time with Tysabri can increase the chance of getting PML.
- Other serious side effects include allergic reactions, which usually occur within 2 hours of the infusion, but can happen at any time after receiving Tysabri.
- Tysabri may also increase the chance of getting an unusual or
serious infection.
5. How can consumers get the product?
Tysabri is available only through a Risk Management Plan, called the TOUCH Prescribing Program. In order to receive Tysabri, patients must talk to their doctor and understand the risks and benefits of Tysabri and agree to all of the instructions in the TOUCH Prescribing Program.
6. What are the main features of the Risk Management Plan?
- The drug will only be prescribed, distributed, and infused by prescribers,
infusion centers and pharmacies registered with the program.
- Tysabri will only be administered to patients who are enrolled in the program.
- Prior to initiating the therapy, health care professionals are to obtain the patient’s Magnetic Resonance Imaging (MRI) scan to help differentiate potential future multiple sclerosis symptoms from PML.
- Patients on Tysabri are to be evaluated 3 and 6 months after the first infusion and every 6 months after that, and their status will be reported regularly to Biogen Idec.
7. Who will manage the program?
Biogen Idec Inc., the company that manufactures Tysabri, and Elan Pharmaceticals Inc., the company that distributes Tysabri, will manage the program.
8. How will FDA evaluate the program?
Biogen Idec and Elan Pharmaceuticals will be monitoring the conduct of the program continuously. Periodically they will submit reports to FDA about the functioning of the program. Biogen Idec and Elan Pharmaceuticals will also submit to FDA proposals for any changes in the program to help ensure safe use of the product.
9. How can consumers get additional information?
Consumers who would like more information or have any questions can talk with their healthcare provider. Consumers can also call 1-800-456-2255 or visit www.TYSABRI.com.
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Date created: June 5, 2006 |
