Trial results/Tysabri (Antegren) - confused

A board to discuss the newly-released drug Tysabri, (formerly known as Antegren) as a treatment for Multiple Sclerosis

Trial results/Tysabri (Antegren) - confused

Postby Hsan » Sun Nov 28, 2004 12:49 pm

From what I have read there were 2 trials, the AFFIRM and the SENTINEL.
One with the medication alone and the other was the medication with Avonex. Which of these trials showed the 66% reduction? My daughter's neuro wants her to stay on the Betaseron and start on the infusions. He thinks I might have problems with my insurance covering both medications. With the price of those meds there is no way that I could afford to pay out of pocket for either one. What is everyone else thinking of doing regarding this matter? Are you staying on your current medication along with the Tysabri or just switching to the Tysabri?

My daughter has been on the Betaseron a couple of years and has had several relapses but overall is doing well. I want to make sure we make the correct decision if we have to pick one medication over the other.

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Postby MeadowStream » Sun Nov 28, 2004 1:29 pm


Tysabri showed 66% fewer relapses than placebo in the Affirm trial and showed 55% fewer relapses in combination with beta interferon than beta interferon alone (Sentinel trial).

The label is available on and labels for other drugs are availabe on their respective websites or at FDA.

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Postby carolsue » Tue Nov 30, 2004 5:34 am

So if I do the simple math--and someone please correct me if I'm wrong or have missed something (who am I kidding, of COURSE you will :lol:) --and start out with, say 10 relapses in a given time period on placebo (10's just an easy number to work with). The AFFIRM trial suggests Tysabri alone would bring the relapse rate down to 3. Now what about the Sentinel trial? Well, previous trials suggest that Avonex alone would bring the relapse rate down to 7 relapses (33% reduction). So reduce those 7 relapses by 55% when you combine Avonex with Tysabri and you get 3.

Important caveats are that trial data were for different groups which could have different starting levels of disease progression/activity, the trial data are relatively short term, etc. But it's certainly not obvious (to me, anyway) on first blush that combination therapy would be the route to take if you believe these data and are interested solely in relapse rate...

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Postby HarryZ » Wed Dec 01, 2004 5:44 pm


So far Biogen's claim has centered on lesion load and reduction in relapses. That's the data from the trials so far (Phase III has only one year data)

Lesion load reduction has no correlation to disease progression and symptoms but many MS docs feel that fewer lesions are better. It's just that nobody can tell you what "better" means in this situation because of the lack of correlation.

Reduction in relapses can also be difficult to assess because like you said, we don't know the status of each patient when they entered the trial. Since RRMS patients have naturally occurring relapses and remissions, it's kind of hard to pinpoint the overall situation after the trials have had such a short duration.

EDSS scores, which have a better measurement of the clinical aspects of the patient, haven't been provided as yet because Biogen states they won't be available until the end of the two year Phase III trials.

Add this all up and in my opinion, you have the FDA approving a drug that hasn't quite proven itself when you compare it to the trials done for other drugs. Perhaps the data obtained in the following 6 months or so will be as good as Biogen has stated the current data shows. Until then, I am very cautious about this new treatment for MS.

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Postby Observer » Wed Dec 01, 2004 6:46 pm

See my last post at 12:35 pm on Thu, Dec 02 on the thread ... 5&start=60

for some comments on MRIs and relapse rates and how they affect EDSS. Interesting stuff.

Here is a summary:

1. Correlation between MRIs and disease progression, (there is one for RRMS), and
2. Relapse rate and EDSS scores (relapses generally increase EDSS scores).

This from the Biogen IDEC 30 Nov 04 R&D day, which can be listened to at this link: ... tID=924982

I don't know how long this link will be 'live' and its 4 hours! When/if a transcript is posted, I'll post a link.

The slides from this presentation can be viewed at
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Postby Observer » Wed Dec 01, 2004 7:05 pm

but I might add that the comments from Biogen IDEC seem not to correspond to the label. The label says the exact relationship between MRIs and EDSS is ?

The exact relationship between MRI findings and the clinical status of patients is unknown. Changes in lesion area often do not correlate with changes in disability progression. The prognostic significance of the MRI findings in these studies has not been evaluated.

so I'm confused.

The BIIB comment on relapse rate vs EDSS does look interesting, however.

Gosh, we need the EDSS to put this whole thing to rest!
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Tysabri alone?

Postby batpere » Sat Dec 04, 2004 5:03 am

carolsue wrote:it's certainly not obvious (to me, anyway) on first blush that combination therapy would be the route to take if you believe these data and are interested solely in relapse rate...


I attended a seminar by one of the clinics that participated in the trials and it was said that it wasn't clear that there was any additional benefit from using tysabri plus one of the interferons, and that there will be upcoming studies done to check that. That plus the high prices, it's doubtful that any of the insurance companies will pay for both. Biodec was there and said that currently Tysabri is on a pre-approval basis only with all the insurance companies but that they are working to get it added to the approved list.
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