Yes, and what gets me even more, Harry, is that Biogen didn't miss a beat in advising patients to continue right along with their Avonex. Elan lost their shirts but Biogen, not so much.

???

If you shorten the half life of Tysabri, it stays in the body for less time, not more.

Azathioprine has an extremely short half-life itself, minutes, and its active derivatives have a half-life in the hours (1-3). I would be very surprised if it exerted any effect on the immune system months after discontinuation.

Thanks Pantos, I misstyped. I corrected my post.

BTW, Here is where I got the info.

http://www.yourlawyer.com/articles/read/10734

Pantos,

Yet Biogen tried to infer to this patient's family that, because of Azathioprine and other drugs the patient had used months earlier, this was the main reason he ended up with PML!!!

Harry

Hi Sally,

Thanks for the link. You gotta remember though that those are only allegations made relating to a lawsuit, none of those things have been proven. Also the guy who claims it's not safe works for competing MS drug co's.

I would really like to see the scientific research about whether Avonex with Tysabri increases the bioavailability of Tysabri or whether use of immunosupressants affect Tysabri's effects on the body. Could people who use Avonex use LESS Tysabri then to get the same effect but without going over to increasing the risks of developing infections?

I am surprised the FDA allowed it back on the market before knowing this. Avonex is not really even considered an "immunosuppressant" so much as immuno-modulating. But given that MSer's often ARE given immunosuppressants which would seemingly have more effect at suppressing the immune system in conjunction with Tysabri, and given that the Crohn's patient had been OFF Azathioprine for a while yet still developed PML, I would think that we really need the answer to the question of what the risks are of developing PML having EVER used an immunosuppressant or immuno-modulator.

Maybe the risks are still not huge given that we can assume that probably a fair # of people in the MS or Crohn's trials had used some kind of immunosuppressants at some point in their illness and only a very few developed PML. But how long does one need to wait to make sure that there is no contraindication occurring? What parameters put one at risk for PML? Is it even related to use of immune suppressants at all.

I really wish we could know exactly WHAT puts someone at risk for PML.

Hi Harry,

You slipped in there while I was writing my post.

Well given that both MS and Crohn's patients are often prescribed immune suppressants, I would not think it was in Biogen's best interests to try to attribute the cases of PML to prior or current use of immunosuppressants. It doesn't make much financial sense given that so many patients HAVE used immunosuppressants (or immune modulators if Biogen wants to assert it was concomitant use of Avonex that caused PML). They'd be better off saying it was just an unknown and extremely rare result than blaming the use of immunosuppressants or modulators.

But then again the strategy worked in pushing it through the FDA again.

When, in fact, you believe that the PML was caused by...what?

You would think that but that's indeed what the family was being told. It was interesting to note that shortly after PML showed up and Tysabri was pulled, Biogen's CEO James Mullen stated that in hundreds of thousands of patient years of Avonex use, there had never been a known case of PML. He was obviously protecting Avonex at the time.

The main problem that Biogen had then and still has now is that there are no real answers as to why these patients ended up getting PML. I'm sure that the company execs are holding their breath and really hoping that they don't hear the word "PML" for a very long time in conjunction with Tysabri use.

Harry

Hey Lauren, For the record, I was not rolling my eyes at you for your exuberance or the published data, but only at your rude assertion that I was grossly misinformed.

Sorry Sweety, come back and talk to us. I am truely interested in seeing you do well with Tysabri.

Hugs,