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New Clues to Link Between MS Drug Tysabri and Rare Brain Disease

Posted 25 Mar 2014 by Drugs.com

TUESDAY, March 25, 2014 – Researchers report that they think they have figured out why patients who take the multiple sclerosis drug Tysabri face a high risk of developing a rare, and sometimes fatal, brain infection. A common virus that can cause the brain disease progressive multifocal leukoencephalopathy (PML) likes to infect and hide in certain blood cells that are triggered to mobilize by Tysabri, the study authors explained. Even more troubling, the researchers discovered that current tests may be missing some who harbor the virus. "Right now, the risk of PML in patients treated with [Tysabri] for more than two years is about one in 75 patients. That's a very high risk," said study author Eugene Major, a senior investigator at the U.S. National Institute of Neurological Disorders and Stroke (NINDS) in Bethesda, Md. "We need to be able to understand why this therapy puts patients ... Read more

Related support groups: Multiple Sclerosis, Tysabri, Natalizumab

Study Shows MS Patients at Most Risk for Drug-Linked Brain Illness

Posted 16 May 2012 by Drugs.com

WEDNESDAY, May 16 – Drug company researchers say they've determined which multiple sclerosis patients are most vulnerable to developing a rare brain infection while taking a powerful drug called Tysabri (natalizumab). Even the multiple sclerosis patients at highest risk of developing the brain infection face low odds of getting it while on Tysabri, but the infection can be deadly. "Now we can identify which risk group each patient is in. This will help doctors and patients make better decisions," said Dr. Gary Bloomgren, lead author of a study released Wednesday and vice president of drug safety at Biogen Idec, which makes the drug. About 100,000 patients have taken Tysabri at least once. The drug, which is used mainly to delay the progression of multiple sclerosis, has been on the market since 2006. It originally went on the market in 2005 but was removed due to medical problems that ... Read more

Related support groups: Multiple Sclerosis, Tysabri, Natalizumab

FDA Medwatch Alert: Tysabri (natalizumab): Drug Safety Communication - New Risk Factor for Progressive Multifocal Leukoencephalopathy (PML)

Posted 23 Jan 2012 by Drugs.com

ISSUE: FDA notified healthcare profesisonals that testing positive for anti-JC virus (JCV) antibodies has been identified as a risk factor for progressive multifocal leukoencephalopathy (PML). PML is a rare but serious brain infection associated with use of Tysabri (natalizumab) for the treatment of multiple sclerosis (MS) or Crohn's disease. A patient's anti-JCV antibody status may be determined using an anti-JCV antibody detection test that has been analytically and clinically validated, and has been ordered by a healthcare professional. The Stratify JCV Antibody ELISA test2 was cleared by FDA on January 20, 2012. Testing positive for anti-JCV antibodies means that a person has been exposed to JCV in the past. BACKGROUND: Tysabri (natalizumab) is in a class of medications called immunomodulators. It works by stopping certain cells of the immune system from causing damage to the body. ... Read more

Related support groups: Tysabri, Natalizumab

First Test Approved to Help Detect Risk of Rare Brain Infection

Posted 22 Jan 2012 by Drugs.com

FRIDAY, Jan. 20 – The first test to help determine the risk of a rare brain infection among users of the drug Tysabri has been approved by the U.S. Food and Drug Administration. Tysabri (natalizumab) is commonly prescribed to treat multiple sclerosis or Crohn's disease. A relatively small number of users have developed a rare brain infection called progressive multifocal leukoencephalopathy (PML). The newly approved Stratify JCV Antibody ELISA test, combined with other clinical data, can help doctors evaluate the risk of developing PML among people who take Tysabri to treat MS or Crohn's, the FDA said in a news release. There is "no treatment, prevention or cure for PML, and no certain way to predict who will develop it," the agency stressed. But it said risk factors for PML include the presence of antibodies for the John Cunningham virus, a normally harmless germ except among people ... Read more

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FDA Medwatch Alert: Tysabri (natalizumab): Update of Healthcare Professional Information

Posted 2 May 2011 by Drugs.com

[UPDATED Posted 04/22/2011] FDA has updated the Tysabri (natalizumab) Prescribing Information to give new information about the size of the risk of progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection, associated with use of Tysabri for the treatment of multiple sclerosis (MS) and Crohn's disease. The update includes new safety information about patients who have taken other drugs that suppress the immune system, who may be at a higher risk for PML. Tysabri, in a class of medications called immunomodulators, has been approved by the FDA for the treatment of relapsing forms of multiple sclerosis since November 2004 and for the treatment of moderately to severely active Crohn's disease since January 2008. The revised label includes a table summarizing rates of PML with Tysabri use according to the number of infusions (how long the drug is taken or duration o ... Read more

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Scientists Find Clue to Dangerous Side Effect of MS Drug

Posted 25 Jan 2010 by Drugs.com

WEDNESDAY, Sept. 9 – Scientists may have discovered part of the reason why Tysabri, a drug used to treat multiple sclerosis, may lead to the development of a rare but potentially deadly brain disease in some patients. The drug seems to rouse the typically dormant JC virus from its slumber, allowing it to cross into the brain. Although this finding may lead to a way of predicting who is at risk for the brain infection – called progressive multifocal leukoencephalopathy (PML) – at this point, the implications are still unclear. "We don't know what this means until we find out over time whether or not people actually do get PML," said Patricia O'Looney, vice president of biomedical research at the National Multiple Sclerosis Society in New York City. "But it certainly is exploring a key question." The study authors also warned against coming to premature conclusions. "We don't advocate ... Read more

Related support groups: Multiple Sclerosis, Tysabri

FDA Medwatch Alert: Tysabri (natalizumab)

Posted 25 Aug 2008 by Drugs.com

[Posted 08/25/2008] FDA informed healthcare professionals of two new cases of progressive multifocal leukoencephalopathy (PML) in European patients receiving Tysabri monotherapy for multiple sclerosis for more than one year. PML, which is usually fatal, is a known risk of Tysabri treatment, but previous cases in patients with multiple sclerosis were seen in combination with other immunomodulatory therapies. Approximately 39,000 patients have received treatment with Tysabri worldwide, with approximately 12,000 patients receiving treatment for a least one year. No new cases have been seen in the US, where about 7,500 patients have received the drug for greater than one year and approximately 3,300 patients have received the drug for at least one and one-half years. In the U.S., Tysabri is available only to patients with relapsing multiple sclerosis or Chron's disease who are enrolled in ... Read more

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FDA Medwatch Alert: Tysabri (natalizumab)

Posted 27 Feb 2008 by Drugs.com

[Posted 02/27/2008] Biogen Idec, Elan and FDA notified healthcare professionals of reports of clinically significant liver injury, including markedly elevated serum hepatic enzymes and elevated total bilirubin, occurred as early as six days after the first dose of Tysabri. The combination of transaminase elevations and elevated bilirubin without evidence of obstruction is recognized as an important predictor of severe liver injury that may lead to death or the need for a liver transplant in some patients. Tysabri should be discontinued in patients with jaundice or other evidence of significant liver injury. Physicians should inform patients that Tysabri may cause liver injury.[February, 2008 - Letter - Biogen Idec, Elan] Read more

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FDA Medwatch Alert: Tysabri (natalizumab)

Posted 5 Jun 2006 by Drugs.com

[UPDATE 07/21/2006] Dear Healthcare Provider Letter issued. [Posted 06/05/2006] FDA notified healthcare professionals of the resumed marketing, with a special restricted distribution program of Tysabri (natalizumab), a monoclonal antibody for the treatment of patients with relapsing forms of multiple sclerosis. Tysabri was initially approved by the FDA in November 2004, but 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. Tysabri will be available only through the 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.   [July 2006 - ... Read more

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FDA Medwatch Alert: Tysabri (natalizumab)

Posted 28 Feb 2005 by Drugs.com

[02/28/2005] FDA issued a public health advisory to inform patients and health care providers about the suspended marketing of Tysabri (natalizumab) due to two serious adverse events reported with its use. FDA received reports of one confirmed, fatal case and one possible case of progressive multifocal leukoencephalopathy (PML) in patients receiving Tysabri for multiple sclerosis. Although the relationship between Tysabri and PML is not known at this time, because of the rare, serious and often fatal nature of PML, FDA announced the following, effective immediately: - Biogen Idec is voluntarily suspending marketing of Tysabri.- Biogen Idec is suspending dosing of Tysabri in clinical trials and is notifying patients and investigators of the possible association between Tysabri and PML. Patients being treated with Tysabri should contact their physician to discuss appropriate alternative ... Read more

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Tysabri May Treat Myelin Sheath Damage From MS

Posted 28 Apr 2009 by Drugs.com

TUESDAY, April 28 – The drug Tysabri (natalizumab) appears to regenerate and stabilize damage done to the myelin sheath in people with multiple sclerosis (MS), a study from drug makers Biogen Idec and Elan Corp shows. MS is nervous system disease that affects the brain and spinal cord. Symptoms experienced by MS patients are caused by damage to the myelin sheath that surrounds and protects nerve cells. In this study, researchers used advanced MRI technology to measure lesions and normal brain tissue in patients who took either Tysabri, interferon beta-1a, or no drugs. After 12 months of follow-up, the 62 patients who took Tysabri showed remyelination when compared to the 26 who took inteferon beta-1a or the 22 patients in the control group. The findings were presented Tuesday at the annual meeting of the American Academy of Neurology, in Seattle. "What we have seen in these MRI data ... Read more

Related support groups: Multiple Sclerosis, Tysabri

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