msladyinca wrote:3 patients out of 3,000 in the trials contracted PML.
Correct...but according to statistics, it is wrong to state that the probability of getting PML from using Tysabri is 1:1000. I made that assumption on the Brain Talk MS Forum and a person who was a statistician (or knew a lot about statistics) told me that was wrong when it came to statistics. He went on to say that probability depended on several variables of which were not known so the number here could be higher or even lower.
2 of the PML patients received Tysabri in combination with Avonex. Eliminate them from the risk ratio as Tysabri can only be prescribed as a monotherapy.
Shortly after Tysabri was pulled, James Mullen, the CEO of Biogen stated that Avonex had several hundred thousands patient use years behind it with no known cases of PML. So was it the combo or Tysabri all by itself. Nobody today knows the answer to that question.
1 of the PML patients received Tysabri as a monotherapy, however...note: he was a Crohn's patient with a severely compromised immune system which included a past medical history of use with very strong immune suppressant medications for his CD such as azathioprine (Imuran).
Biogen would like you to think that but this Crohn's patient had stopped using Infliximab 20 months before using Tysabri and stopped using Azathioprine 8 months before. Although he was in an earlier Tysabri clinical trial, he was on the placebo. The JCV virus appeared in his blood during the monotherapy Tysabri use between Feb - June 2003.
Thus, the unjust 1:1000 risk ratio for PML when using Tysabri, and the risk factor is probably much lower than the 1:1000 due to: "Tysabri is indicated for use as a monotherapy, meaning it should not be used in combination with other immune system modifying drugs, and is for patients who have not responded adequately to, or cannot tolerate, other treatments for MS. "
Which begs the question...why was Biogen combining Tysabri with another immune system altering drug such as Avonex when they didn't even have safety data figured out for the Phase III trials of the drug by itself. One financial analyst stated it was to keep the market share of Avonex up....something that big pharma is always concerned about.
I just wish that Biogen had stuck to their original plan...Tysabri by itself, Phase III trials for two full years...analyze the data, determine the safety, get the FDA approval and THEN release the drug to the public. They gambled, took the fast route, it blew up in their face and now MS patients such as yourself are having to fight needlessly to use a drug that you desperately want to try. It simply isn't right!
Harry