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Originally Posted by lady_express_44
This discussion was about the announced 7th case of PML, and the recent death that occurred. It was not intended to center around how effective Tysabri is, or whether some might think it is a risk worth taking ... so that’s why you didn’t run into many comments regarding those points in this thread.
As far as efficacy, although Tysabri claims to be twice as effective in reducing relapses, there has never been a head-to-head trial against the CRABs. It is really impossible to know if it is "more" effective, as results from these trials may be very skewed by any number of factors:
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Statistically it would be impossible for confounding factors to have caused the difference in relapse rate. The Tysabri trials had almost 2000 patients which would eliminate any small sample bias. You also conveniently ignore the 6% of Tysabri patients who developed persistent antibodies to the drug effectively rendering the drug ineffective for them. These patients pulled down the reported effectiveness of the drug.
Quote:
Originally Posted by lady_express_44
While reducing relapses might be pleasurable, Tysabri proved to be only slightly more effective (in absolute terms) then the CRABs for short-term disease progression. There is no long-term efficacy measure of this drug for disease progression yet, so that is another “unknown” that people need to measure up against the risk, obviously.
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I would hardly use the word "pleasurable" to describe the need to avoid relapses but then again I'm not into inflicting pain on myself and I don't live in a parallel universe. Nothing about this disease is pleasurable.
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Originally Posted by lady_express_44
We knew/know the current “potential” outcome of PML, at least at this moment in history. We know that people may die from PML ... since two out of three in the original trials did. We also know that even IF they initially seem to survive the PML (as the recent US patient did), they may succumb in weeks, months, or die from IRIS (used to treat the PML). We don’t have autopsy confirmation on the recent death, but I'm “speculating” that Biogen spokesperson would not be “announcing” her death in the same breath as the fact that she got PML from Tysabri . . . if her death was unlikely to be related to the drug.
We also know/knew patients might live through PML. . . since the third trial patient in the trials did, as have 3 people since. We don’t know precisely “how” disabled that ANY eventually became from PML as much of the details are deemed “patient confidential”. In fact, it was only a few weeks ago that we got “news” that the Florida woman who got PML in Oct, was home and “recovering” under her doctor’s care. Next we know, she’s died.
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The 3 original PML cases in the trials and their outcomes can hardly be considered representative since these cases occurred in an environment where PML wasn't even being looked for and these cases were mistreated by applying even more immunnosuppression. In short, they didn't have a chance. In the commercial setting, Doctors are monitoring for PML and removing Tysabri from the bloodstream if detected. Significantly different situations to draw an apples to apples comparison.
Quote:
Originally Posted by lady_express_44
Currently the risk for PML is at about 1:1357, so we are not that far off. While there are many thousands of people on it now, the risk they estimated was 1:1000 for those who’ve been on it for 18+ months. Currently there are 9500 that have been on that long, or longer, and 7 cases of PML . . . so there estimation was pretty close ... SO FAR.
Cherie
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Be careful in quoting PML risk rates without all the correct numbers. We know that there have been 4 PML cases, 1 at 14 months, 1 at 14 months, 1 at 17 months and 1 at 26 months. The first 14 month and 17 month cases occurred prior to Sep 31, 2008 where there were 18,000 patients at 1 year, 9500 at 18 months, and 4000 at 2 years of treatment. The next case occurred on Oct 31st, so the number of patients had increased (probably by 1500 per month in each category). The next case occurred on Dec 15th so add another 3000 in each category (2 months of patient treatment). The denominator has definitely increased and I believe you are using the wrong numerator. Including the 3 PML trial cases with the commercial setting cases is apples and oranges as the commercial prescribing restrictions are obviously significantly different from the clinical trial use. The other confounding item is that only 1 PML case has been confirmed under the US TOUCH program with the other 3 PML cases occurring in Europe which doesn't have TOUCH restrictions while the number of Tysabri patients was higher in the US than in Europe. Does TOUCH offer further PML reduction?
Cherie, at the end of the day we're going to disagree on the relative benefits and risks of the drug that I have chosen probably because you've made a different treatment decision. I certainly respect people making different choices for their different circumstances and the last thing I would ever do is try to "sell" someone that my choice was correct or downplay some other choice as being incorrect. That's the line we all have to walk, being informative without our predisposed biases to the choices we have made.
Chris