Claire asks Anna what she thinks of treating MS with chemotherapy?
Right, the next question. What do you think of treating MS with chemotherapy?
Yes. So we’ve been doing that. It depends on what you call chemotherapy, because I don’t know if you remember mitoxantrone?
No, I don’t.
So that was, we used that maybe ten years ago and it is a drug that people use for chemotherapy. It was never licensed for use in MS, but until we had better things, sometimes we ended up using it because we felt we had to do something. And that was very much chemotherapy. That’s really gone out, I don’t really know anyone using that as a standard therapy now, because we’ve got licensed therapies which are as good, if not better, and safer. But that’s many years old. And the other one that’s come up recently, which is chemotherapy, which is licensed for MS treatment is alemtuzumab or campath. So that’s fairly recently licensed, was developed for a leukaemia and then people in Cambridge used it in trials with MS patients and it looked really quite good, though it does have some side effects. And so that is definitely what you would class as chemotherapy. Now, if we’re classing chemotherapy or things that people would for cancers, then we’ve got that one and it’s licensed and we use it. And if we’re linking this one to the stem cell transplants, then it’s actually the same drug that people use for some of the stem cell transplant trials. So in stem cell transplants, what you need to do is either take out your stem cells, put them in a bag for a while, then get rid of all of your immune system, or at least most of it, and then give you your stem cells back, or people in the past tended to get somebody else’s stem cells back. But the chemotherapy bit is getting rid of your immune system.
No, I think it was the chemotherapy combined with the stem cell transplant.
Absolutely. But the chemotherapy drugs that some people are using for getting rid of all that immune system, actually one of them was alemtuzumab which we’ve now got licensed for MS, which is why the first trial was a little odd because some people were saying, well maybe it wasn’t the stem cells, maybe it was the alemtuzumab because you know that the alemtuzumab works on its own, so it’s a bit difficult to know. So I suppose it’s the same idea, is what you’re trying to do with drugs in MS is sort out your immune system. Now, you don’t want to wipe them out if you’re not going to replace them with something else, but you want to at least suppress them. Whereas in stem cell transplants what you want to do is wipe them out, or at least wipe them out a lot, maybe not completely, but at least hit them hard and then you can give back stem cells to regrow your immune system. So the idea is the same, it’s just amount really, if you’re not going to give something back to replace your immune system you can’t knock them out completely, you’ve just got to sort of suppress them. Whereas in stem cell transplants you want to knock them out quite a lot so that then you can rebuild an immune system from the ones that you give back. So in a way it’s the same idea, it’s just extent. So we are using chemotherapy, drugs for cancer, on their own, but you can also use them to a greater extent and then replace your immune system with either your stem cells or somebody else’s and it seems to be safer to give your own stem cells back, because then you don’t have problems with them not matching. You know, it’s like having a kidney transplant, ideally you’d want one from your identical twin so that you would totally match, but you can’t get that totally so you have to take the nearest match, but that’s always more risky if you take it from somebody else. And it’s the same idea in MS, if you get your own back it’s less risky than having somebody else’s. The problem of course is, is that it was your immune system that went wrong in the first place, so if you get your own back, is that going to be ideal. It’s safer, but is it going to last forever. And that’s the key at the moment. I think there’s no doubt that the chemotherapy plus stem cell transplant works in relapsing remitting disease, as was shown in the Panorama programme by several trials that have come out. It works in relapsing remitting disease where you need to suppress the immune system, what we don’t know is how long it’s going to last. If it lasts for 40 years then that would be really good.
If it lasts for four years, then you have to say is it worth that risk, bearing in mind we’ve got other drugs now that work really quite well. You have to take them every day, but it’s not quite… you’ve got to do a balancing act. And to be fair, the people doing the trials are very open about that, they say it clearly works but the question is, long term, how long for. And if it did work for 40 years then this would really become something that maybe would be worth having, or even ten years. But you wouldn’t probably want to go through it twice, because it’s really nasty as a treatment, with a mortality rate. And with young people who might do very well, it’s difficult to know whether that’s worth it or not. Which comes back to the future of MS side of things, if we can predict who’s going to do well and who’s going to do poorly, then the people who do well, you don’t want to give them risky treatment, but we do want to perhaps where your risk-benefit for the people who do poorly is higher. We’ve got to be able to predict that at the beginning to say to some people, don’t worry too much, we’ll give you this, which is a milder drug with less risk, because you’re going to do better and you’re going to do worse, therefore we’re going to have to hit you hard with drugs like cancer drugs or like stem cell transplants because we need to know that the risk of you getting disabled is greater. So it’s quite difficult to work that out at the moment, but at least people are trying to work out who’s going to do well, who’s going to do poorly, and then we do now have a lot of options. So it’s just trying to work out who would benefit most from which option. It’s not easy. It’s not easy for patients either, because you have to then say, okay, am I prepared to take a risk of two per cent death, having my stem cell treatment, when I’m 20 with a family. It’s really difficult. We have to work out risk-benefits and we’re not used to, that’s a financial job isn’t it? It’s like who buys shares, who deals on the stock market, who’s a risk taker, who isn’t. And so it’s not just how well people are, it’s what they’re prepared to take in terms of risk. It’s complicated, but at least we have these options now. It’s better. It’s better but it’s not easy for either patients or doctors trying to work out what the best route is.
MS Reporter: <strongClaire
MS Expert: Dr Anna Williams works in research and is an Honorary Consultant Neurologist, at the Centre for Regenerative Medicine at Edinburgh University, she researches why remyelination fails in MS and what can be done to improve its efficiency.