I was aware that they were going to announce the numbers on the 13th . . . so they were fairly easy to come by.

I suspect there will be "revelations" for quite some time about what "might" unduly influence the PML risk (like mono vs. combined therapy, the prior use of certain types of immunosuppressants, etc.). There may even be some people that are given plasma (and perhaps IRIS) simply because they "suspected" PML . . . only to determine they didn't actually have PML in the end.

I think any of these factors continue to influence the risk factor "associated with" PML or Tysabri, at least at this point.

Recently I read that they are trying to figure out which other drugs might be increasing the risk for PML . . . but they don't feel they have enough data to firm up any conclusions. In the meantime, no matter what the currently unknown 'risky contributing factors' . . . confirmed (and/or treated for PML patients) should be counted, IMHO.

What would be ideal is if they can eventually determine the "X" factors, and eliminate PML (and IRIS) completely . . . then the "prior" ratio will be irrelevant to everyone!

Maybe they've changed their since their Q3 report, but a few months back they said that they do no longer intended to report EVERY single case as they occur:

"Jason Zhang - BMO Capital Markets
I have a question again on TYSABRI. You have so far reported PML cases when they appear and I have heard some, I don't know suggestions or rumor that you may decide not to do that because you consider this as a severe adverse event, not different than many other severe adverse events with other drugs. Could you comment on that?

James C. Mullen - President and Chief Executive Officer
Yes, this is Jim. I'll take that. We've reported on PML specifically, and particularly in these last two cases, because they did represent new information and important new information . . .

This product, we're evaluating how we do those communications, but fundamentally this is an adverse event that's in the label, its in the Black Box warning. Its sort of time I think to progress to looking at the overall safety and benefits of this product and updating in its entirety as appropriate. So, we are not necessarily going to report every single case as they occur, but only if it really provides substantial new information."

http://seekingalpha.com/article/1008...age=-1&qa=true

And on their first posting to the Biogen site, they reiterated that "The first such posting today includes only previously disclosed cases of PML":

http://www.sec.gov/Archives/edgar/da...3544bie8vk.htm

HOWEVER, I am NOT worried that they are holding back on any confirmed cases at this point . . .

My concern lies with the "suspected" cases of patients that were apparently just 'taken off' the med. As per my prior message, what we don't know is if they are just NOT able to confirm (or rule out) some cases . . . so those aren't counted, or ?

Anyway, yes we have a ratio to go forward with, and I hope to see that drop more and more as "experience" is tallied over time.

Cherie