Tysabri Infusion and Pml Danger

I am both surprised and shocked by the press release surrounding the latest disease modifying drug (DMD) TYSABRI. I am surprised that Biogen, the drug’s manufacturer, is hoping to provide a test capable of alerting a Tysabri user to the potential risk of developing a brain infection as a result of taking the drug. I am shocked,(in a good way) because if the test proves effective, it will make Tysabri a drug I can consider using once every 4 weeks instead of Copaxone, which I now self-inject daily. That is, if the test assures me I don't have to worry about subjecting myself to PML.

The screening tool could be marketed as early as 2011 if clinical trials involving 9,000 people, set to start this year, show a low rate of false findings.

Presently, everyone who agrees to be given Tysabri in the form of a IV, has the slight risk of getting the JC virus that causes progressive multifocal leukoencephalopathy, or PML, a brain-cell destroyer that can lead to disability and death. Some people with MS have died from this infection others have had to recover from the infection which can be more crippling then the MS it is suppose to modify.

If a potential user takes the guess work out of the process by being screened ahead of time, there would be more people with MS who could take the drug and significantly reduce worrying about contracting PML. Of course, if the screening shows you are likely to develop PML, you simply forgo TYSABRI all together.

The company has reported 42 PMLcases. Tysabri was removed from the market on Feb. 28, 2005, after three patients developed PML, and two died. It has since been approved again and is mostly recommended now only after other drugs fail, or if reactions to the other drugs make sustained use unlikely.

Interestingly 61 percent of 285 neurologists surveyed by RBC Capital Markets in San Francisco said Tysabri’s ability to slow MS progression would make it their first choice if they could assess the risk of PML.

.Reaction Closer to Home

From my own personal experience, my neurologist has had only positive results with Tysabri. No patients have developed PML or had to be taken off the drug. The last time we spoke about it, he had full confidence in its ability to treat MS effectively.

Tysabri is administered via an IV solution, much like solu-medrol steroids. After the IV is administered and the patient has waited the required amount of time to insure no adverse reactions the patient is free to leave the facility until the next scheduled IV dosage is given.

Because of the dangers, Tysabri users are closely monitored and tested. Close adherence to the guidelines are a must for any MS patient who agrees to begin using Tysabri.

“PML occurs when a common germ, called JC virus, mutates, then evades the body’s immune defenses and penetrates the brain, causing irreversible damage. Researchers theorize that Tysabri may subdue defenses meant to keep the virus out of the brain.”

“The test is designed to detect the presence of an antibody to the JC virus in the blood of patients, signaling that the patient has been infected.

With a false-negative rate of 2 percent, patients who are free of the virus would lower their risk of getting the brain disorder PML to 1 in 25,000 for the first three years of their Tysabri therapy”

What makes TYSABRI different?

1. TYSABRI works in a different way.TYSABRI is an antibody, not an interferon (AVONEX^®(interferon beta-1a), Betaseron^®(interferon beta-1b), Rebif^® (interferon beta-1a)) or glatiramer acetate(Copaxone^®)^†
   • TYSABRI is thought to inhibit white blood cells from getting into the brain and attacking nerves
   • Keeping these cells from attacking nerves is believed to result in fewer brain lesions that cause multiple sclerosis symptoms
   • The way in which TYSABRI works has been studied, but the exact way that TYSABRI works is not fully known
2. TYSABRI is taken differently than other multiple sclerosis medicines. With TYSABRI:
   • You can avoid the hassles of self-injection
   • You only have to think about taking your MS treatment once every 4 weeks

Imagine how you would feel if you decided to try Tysabri, only to end up being the one out of a thousand that actually ends up developing PML. Best described as a brain infection, PML, if serious enough, can cripple both mind and body.

Currently doctors have become more skilled at picking up the infection and treating it more swiftly. However weighing the pros and cons still puts Tysabri on the short end of the stick. Understandably, many-MS patients and neurologists alike-are just not willing to take the risk, so Tysabri goes unprescribed and under-utilized.

However, if the manufacturers are able to come up with a reliable test that accurately tells me I am not likely to get PML, I will be happy to trade in my daily injections for a once-a-month IV infusion.

Oral medication (a pill) is also still in the pipeline, so between the two, I am hoping to be off the daily injection ride within the next year or two.

I will be monitoring the PML screening Biogen plans to put in place and I hope it turns out to be something that truly works.

What has the outcome been for those who have accepted the risks involved and have been using Tysabri for weeks or years?

It is always encouraging to read or listen to a successful outcome. So, to present a well-rounded view of the drug, I have included a Youtube Video of "Vern" who talks about his 42nd infusion. His opinion is very important to those who have tried all other drugs and are now down to just a couple of alternatives.