I was supposed to have my 27th Tysabri infusion today. I happened to have an appointment with my neurologist the hour before my scheduled infusion. I had a few things on my list of things to talk about. Tysabri was the first - there has been a lot of activity in the last few months - an increased number of Tysabri patients who developed PML, and a study that showed that the longer one is on Tysabri, the more likely that one will develop PML. I had read that there was a test they could do to determine if you have the virus that causes PML, which would indicate whether continuing on Tysabri was the right thing for you.
I could see on his face as I talked that he was not thinking what I was. I was hoping I could do the test for the virus, and that would be that, and I'd continue along on my merry way with Tysabri.
He told me that the recalculated odds for PML for Tysabri users over 24 infusions are down to 1 in 600 - it started out as 1 in 1000 for everyone after the trials. The PML cases to date have occurred after 24 infusions. The odds have not changed, or have likely improved for those on their first 24 months of Ty. Because they are so uncomfortable with these odds, the three MS neurologists at my clinic (University of Colorado Hospital Rocky Mountain MS Clinic) have decided to take patients off Tysabri after infusion #24. They are going to the big gathering of MS neuro's in NY or London next week. They are supposed to coming up with a common protocol recommendation at those meetings.
He says he feels the risk of the Tysabri-withdrawal exacerbation is less worrisome than the risk of possible post-24-infusion PML with Tysabri. We talked for quite a while about it.