Tysabri 2007
Tysabri, an MS Medication, Has Been Back for Nearly a Year
Tysabri, a highly effective but potentially life-threatening MS medication, has been back on the market for almost a year. No new PML cases have emerged.
Tysabri History
Tysabri, one of the FDA-approved medications for multiple sclerosis, has a controversial history. The drug, infused for one hour once monthly, has been considered "heaven sent" by thousands of people who have had no luck with standard MS disease-modifying medications (Copaxone, Rebif, Avonex, or Betaseron.) In clinical trials, things went well and people found definite relief from symptoms as well as lowered MS relapse rates. But soon after Tysabri was released in November of 2004, two MS clinical trial patients and one Crohn's disease patient contracted PML, a deadly neurological virus. One of the MS patients and the Crohn's patient soon died. Tysabri was quickly pulled from the market in February of 2005.
An investigation into the deaths of said clinical trial patients ensued. A common thread seemed to be that all three people who had contracted PML had used another immunosuppressant drug concurrently with the Tysabri, thereby drastically lowering their immune system response against other illnesses. The two MS patients were reported to be on one of the CRAB drugs.
Tysabri Reintroduction
After many pleas from multiple sclerosis patients to reconsider Tysabri, the FDA reintroduced the drug to the market in July of 2006. Very rigorous criteria was set in place to screen potential Tysabri recipients. Patients could not have already weakened immune systems, could not take other immunosuppressive drugs while on Tysabri, and shouldn't have responded to other available MS treatments. Tysabri would only be available at registered infusion sites and patients and prescribing doctors needed to be enrolled in the "TOUCH" program, closely monitoring patients' progresses and responses to Tysabri.
Tysabri Today
It is coming up on a year since Biogen, Tysabri's creator, reintroduced the controversial medication to the market. Very recently, Biogen updated the public about Tysabri's year back in the game. No new cases of PML have occured since rerelease in July of 2006. Tysabri has now been in the MS world, both for clinical trial patients and world-wide consumers, for more than three years. At least 10,000 patients receive Tysabri infusions world-wide. To date, Tysabri has shown to effectively reduce (by approx. 67%) the number of MS patient relapses. Although controversial, Tysabri has a higher effectiveness rate (nearly double) than that of any of the CRAB drugs.
Tysabri Chemistry/ Side-effects
- Tysabri is a monoclonal antibody which prevents immune cells from attacking myelin in the brain and spinal cord.
- Tysabri is administered once a month by infusion.
- Tysabri is not an interferon and so it may have different side-effects such as lower digestive tract infections or stomach pain.
- Tysabri can increase your risk of developing infections because it is an immunosuppressive drug.
- Lastly, because Tysabri is a relatively new drug, long-term side-effects are not known. Risk for PML is raised by taking Tysabri. This drug is considered for people who have not responded to other therapies. For further reference: http://www.nationalmssociety.org and http://www.elan.com.
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