What would you do? Advice please


Okay, so this is a game of russian roulette only MSer’s can play. Here’s the history…

I’m on Tysabri. And it’s been great. The first year with MS was horrific - at least 4 disabling relapses, I was running out of symptoms I could have and life was just day after day in bed. Since Tysabri, I’ve had some flare ups and a couple of very small relapses, but nothing on the scale of that first year. So all in all, it’s kept the MS at bay for over 7 years. I have no doubt that without it, I would be quite severely disabled by now.

The other day, I was given a continuation form to sign when I went in for my infusion. Now, not knowing how much you know about Tysabri please don’t be insulted if you already know this - just skip on down. But it is associated with a risk of getting a rapidly progressing lethal brain swelling condition called PML. To get this, you must first have a particular virus - the JC virus. Most of the time, the JC virus is totally harmless to people. Approx. 50% of the UK live quite happily side by side with it in their systems. But sometimes, if you’re on Tysabri, it allows the virus to be a little more opportunistic and cause PML. If you’re -ve for JC or even if you have a very low titre (antibody load, say <0.1) and on Tys your risk of PML is very low - like 1/10000 or something, but it goes up with time (anything over 2 years, then increases year on year with data stopping at 6 years) and the higher your titre level is (anything > 0.9 I think).

So I was looking at this form, and I knew that when I moved from down south over 2 years ago I was JC +ve, but only just (like 0.01 or something ridiculous), but I hadn’t been told since. So I thought I should just double check before signing. I’m going to skip the part where it totally seems like they hadn’t even looked and go straight to the part where it’s now 4. Now skipping the part where they didn’t seem to realise the significancy of how long I’d been on Tys (over 7 years - data stops at 6), let’s go straight to where I’d fall on the chart of ‘risk of PML’, for the max. no. of years shown with a titre of ‘anything over 0.9’ which gives me a PML risk of 1 in 100.

Risk of dying from the condition - 1 in 30 if caught early (so by MRI, pre-symptom stage. Let’s not ask what happened with my last couple of MRI’s) and 1 in 3 if caught late (so post-symptomatic stage). And in either case, if you do live, you’ll be badly brain damaged. But I was unequivocally told in that first year that Tys was my only hope. So my question to you is - do you continue to take the medication?



N.B. I didn’t sign - said I needed to discuss with the Neuro first. We’ll see if they manage to pass that message on…

Hi Comet

I was in the same boat as you. Can’t remember what my JC level was, but it was rising. I’d been on it for at least 6 or 7 years, and my neuro put my risk of PML at 2-3%. I decided I’d had a good run, but it was time to come off it. I’m on Tecfidera now. It’s not as good, and side effects are more noticeable, but it’s easier to take.

Obviously, we’re all different. I guess you just have to weigh it up and see which option you feel most co’mfortable with.

Either that, or just toss a coin :slight_smile:


Thanks Dan

I would continue with the Tysabri.

Hello I’m jcv+ too and that’s why my neuro won’t even entertain the idea of putting me on tysabri. I was on tecfidera which was brilliant and after two new lesions, I’m going on mavenclad next. Would this be an option? A good new immune therapy with a much smaller jcv risk. It sort of resets your immune system. Katy


This is a bit “Catch 22” and you without 20/20 hindsight this is a very tough judgement. I would have to try and work out which of the potential bad outcomes scares me more and then weigh that against the benefits. I was only on Tysabri as part of a trial but the PML risk (as explained to me) increases the longer you are taking infusions. It is such a personal choice, but to answer your initial question “What would you do?” I would pick a number of 1 in XXX that I would be willing to risk and then keep reassessing. Sadly I do not know if there are finte maximum doses for this drug. I was on another powerful drug trial and that did have an absolute limit so the decision was easy. I think you need to have a detailed discussion with a competent experienced neurologist to try to get the most informed “guess / opinion”

Sorry if this is no help whatsoever, but I hope you get some good info and professional support to help with this high stakes conundrum.

Good luck which ever way you go. Keep us posted.


That sounds like good advice to me. Why take on the risk, when there are powerful (and, for you, safer) alternatives available?

Back when I started Tysabri, it was pretty much the only show in town in terms of powerful drugs for highly active MS. The JC test hadn’t been rolled out then, so I didn’t know whether I was JC+ or not when I started, and wouldn’t have cared if I was because I was in so much trouble.

But the world is different now, the PML risks are much better understood, and there are now effective alternatives to Tysabri for people with very active RRMS and who have tested positive for the JC virus, and hurrah for that.


I get the feeling that there is still a lot of uncertainty/confusion about the effect of these drugs and to some extent they are still at the experimental state.