Facts About Tysabri and PML
Tysabi patients have been developing progressive multifocal leukoencephalopathy (PML), a rare brain infection which can cause difficulty with walking and other movements, decline in mental function, and problems with vision and speaking. The symptoms of PML may begin gradually, usually worsen rapidly, and can vary depending on which part of the brain is infected. PML is often fatal, and there is no known cure.
Tysabri has been prescribed for patients with Multiple Sclerosis and Crohn's disease. Both of these conditions are tragic and debilitating, but the treatment shouldn't be worse than the disease.
Tysabri and PML
Tysabri was approved for patients with Multiple Sclerosis and Crohn’s disease in November of 2004, and then withdrawn from the market in February 2005 after reports of patients who had taken Tysabri being diagnosed with, and subsequently dying form, progressive multifocal leukoencephalopathy. The FDA put a temporary hold on the drug, only to resume clinical trials of Tysabri in February of 2006.
Tysabri in the News
- Biogen: 5 More Cases Of Brain Infection In Tysabri Patients
- Tysabri (Natalizumab): Update of Healthcare Professional Information
- F.D.A. Panel Recommends M.S. Drug Despite Lethal Risk
- Tysabri May Cause Liver Damage, Health Officials Say
- The Tricky Biology Behind Tysabri
- FDA sees risks linked to the drug Tysabri
- Drug Makers Report Cases of Brain Disease
- New Brain Illnesses in Patients on Tysabri
- Biogen: 5 More Cases Of Brain Infection In Tysabri Patients
- Tysabri Lawsuits
Tysabri was allowed back on the market in June 2006 with increased restrictions and enhanced safety warnings, including a black box warning about the dangers of PML.
- According to the FDA, the risk for developing progressive multifocal leukoencephalopathy from taking Tysabri increases with the number of Tysabri infusions received.
- In September of 2009, the Los Angeles Times reported that questions continued to be raised about Tysabri, and 12 new cases of PML in Tysabri patients had emerged since the drug was allowed back on the market.
- In January, 2010, the FDA knew of 31 confirmed Tysabri-induced cases of PML worldwide, including eight patients in the United States who died from PML after taking Tysabri.
- In August of 2010, a report in the Wall Street Journal reported that Biogen had been informed that there were now 63 known cases of Tysabri-induced PML.
Tysabri has been a highly profitable drug for Biogen, with 48,800 patients on Tysabri paysing as much as $28,000 per year for the treatment. Biogen has been aggressively marketing Tysabri, to the point that the company received a warning letter from the FDA about its marketing of Tysabri, which the FDA called false and misleading, and which minimized important risks associated with the drug.
How does Tysabri Cause PML?
Neither the exact way Tysabri acts on MS patients nor the way it causes PML are fully understood. Scientists think that Tysabri seems to affect Multiple Sclerosis patients by acting on T-Cells, a part of the body’s immune system. In MS patients, these T-Cells malfunction and actually attack the patient’s own nervous system. Tysabri prevents T-Cells from performing their full function in an attempt to halt this damage. Tysabri’s effect on the immune system may be the mechanism that also makes Tysabri patients prarticularly vulnerbale to PML. PML is caused by a common virus that as many as 80% of the people on the planet have been exposed to. Normally, the body’s immune system can easily fight off this virus. But when Tysabri interferes with the function of T-Cells, it seems to make the body much more vulnerable to infection by the virus that causes PML.
Further Risks of Tysabri
Tysbari carries further risks than just PML. In the years since Tysabri has been on the market, there have been further warnings issued by the FDA about Tysabri, including the possibility of liver damage and immune function disorders.
- In February of 2008, the FDA announced it was adding a further warning to the Tysabri label stating that Tysabri can cause liver damage, and that this liver damage can begin within six days of taking the first dose.
- In February of 2010, The FDA released a warning about the possible occurrence of Immune Reconstitution Inflammatory Syndrome (IRIS) in patients who have developed PML and stopped using Tysabri. IRIS is a rare condition characterized by that can affect people with compromised immune systems that can cause a patient’s symptoms to worsen after return of immune function.
Tysabri Lawsuits
Individuals and families who have been harmed by the dangerous side effects of Tysabri are beginning to file lawsuits to seek compensation for their injuries. If you have been diagnosed with progressive multifocal leukoencephalopathy as a result of taking Tysabri, the law firm of Blizzard & Nabers will work with you to file a Tysabri lawsuit. Our firm specializes in pharmaceutical law. For more than 25 years, our attorneys have successfully represented our clients and stood up for the rights of people harmed by pharmaceutical companies and dangerous drugs. We are a nationwide law firm serving clients from all over the country. We handle all Tysabri-related injury cases on a contingency basis.
To learn more, or for a free case review from an experienced Tysabri attorney, please contact us by email or call us at 1-800-349-0127.
