Almost 770,000 Canadians live with dementia today. That number is projected to rise to 937,000 by 2031. Alzheimer's disease is the most common cause of dementia, and currently there's no cure.

Could lecanemab, a drug recently okayed by Health Canada, make a real difference for patients and for our health care system? For more, I talked to neuroscientist Saskia Sivanathan, founder and CEO of the Brain Institute and affiliate professor in the Department of Family Medicine at McGill University.

Saskia, welcome to the program. How are you doing?

Good. Thanks for having me.

Well, we are talking about Lecanemab. What do we need to know about it?

Okay, so Lecanemab 101. So the brand name is Leqembi. And there's a lot of excitement around this new drug for a range of reasons. It's the first of its kind that really starts to get at the underlying pathology of Alzheimer's disease specifically.

So the way Lecanemab works is it binds to a certain protein that accumulates in the brains of people who have Alzheimer's disease, and that protein is called amyloid beta, okay.

So the way Lecanemab works is it goes in, binds to that protein and removes it from the brain. And what they see is that there's a slowing of the cognitive decline, which is one of the main symptoms of Alzheimer's disease. It slows it by several months to up to a year. So that's that's how Lecanemab works.

Is it are we using it as a pill? Is it an injection? How does it work in that way.

So it's not a pill okay. It is going to require IV infusion a couple of times a week. There's a there's a protocol for it. And so it means that you'd have to probably go into a specific clinical site if you're eligible for it to get it as well. You need to be monitored very carefully using MRI imaging.

So why is that?

Oh good reason. So first of all, in order to be eligible for Lecanemab, you have to have a clinical diagnosis of early stage Alzheimer's or mild cognitive impairment.

So I'll take a step back here. Zoom back a bit because dementia is the term that's being used more broadly, but that's really an umbrella term for over 100 different types of diseases, Alzheimer being the most common, but there are many others Parkinson's related, dementia, frontal, temporal, all of that. But this is only for Alzheimer's disease and early stage Alzheimer's.

And you have to have amyloid beta pathology in the brain. So that's why the imaging through the imaging, they can confirm if you have that pathology. And then they do need to monitor people who are on lecanemab, because there are side effects to it that require that kind of monitoring.

I want to make sure we're clear here, not a cure. Cannot reverse Alzheimer's disease.

Exactly. Absolutely is not a cure. Does not reverse Alzheimer's, but slows the progression. And it's the first class of drugs that is dealing with the underlying pathology of Alzheimer's, whereas all the other drugs that are currently on the market are more about the symptomatic management of Alzheimer's.

Is that why there is so much optimism, or is there.

More to it?

There's more to it. I think there's more to it. So I'll get into it a little bit. I think the first is it's been over ten years since there's been any drug on the market for Alzheimer or dementia broadly. So I mean, that alone is a big reason, right?

And there have been a lot of high profile clinical trials that failed with a lot of money that went into it for Alzheimer's. So again, to have this first class of drug, big deal. The second is, is this is the first class that has received market approval to again get at the underlying cause, which others didn't.

But the third for the controversy is the side effect. So it does have a side effect called Aria which is amyloid related imaging abnormalities.

Spell that for us.

Aria. Aria it's an acronym Love acronyms. And basically what it means is that some of the people who do receive Lecanemab have brain swelling and microbleeds. So this is the other reason why they need to be monitored very carefully through MRIs. But as we know, MRI infrastructure and access can be tough.

Okay, eligibility. Who gets this when it's on the market okay.

So market approval is very specific. It's for adults. And the reason I specify that is because there are childhood related dementias. This is for adults only. It's for mild cognitive impairment which is an earlier stage of dementia that can lead to Alzheimer's. But not everyone does develop it. And it's for early stage Alzheimer's only.

Now that is very important as well, because it's often difficult to get the diagnosis. Yes, and we can get into that a bit later. But the other piece to remember is, is that you have to have amyloid pathology in the brain, hence the imaging. And the third is, is that people who have a gene called the Apoe and specifically the Apoe e4, it's a variant of that gene, puts you at a higher risk of developing Alzheimer's. So they are ineligible for the drug if they have both of the variants.

Very interesting. Okay.

Yeah.

I want to talk. You know, there's a lot of optimism, a lot of excitement around this. But there is also you mentioned the side effects, but there's also a cost associated. Do we know what the cost is?

It was approved in the US, in countries like Japan, etc. So the the important piece about that though, is that you have more real world data because they've been approved and accessible in those markets. You now know how that drug is doing in those communities and you have more longitudinal data. So that's important for how some of the decision making might be made price-wise.

In the US, it's priced at about 27,000 USD annually only for the drug. Okay. It's not including the cost potentially of IV infusions and MRIs. Now, they do have a private system. Ours is a public system. So there's a lot of those pieces to think through as well.

Well, let's talk about it. Yeah. Will it be publicly funded.

We don't know because that is a decision up to each province around how much they're willing to fund whether private insurers will cover it or not. But this price piece has come up a bit, right? I mean, if it's 27,000 USD, you know, what will that mean for Canadian dollars? But I often do think about other large conditions like cancer, stroke. Right. And you know, for some of those those drugs, it's comparable if not more for those treatment options.

So I think when you're thinking about a disease like Alzheimer's disease, you're talking about a disease that has had really no other really good treatment options. You're living for on average eight years with the disease. And the progression means that it's language loss. It's cognitive loss, functional loss, until eventually this person can no longer take care of themselves. Right. They need 24 over seven care. It's a it's a devastating disease in many ways.

Well, if it's not publicly funded, how do people who do need it, as you mentioned, how deadly it is, how will they get it?

It will likely be private insurance if they have private insurance at that point and if private insurers will cover it. So there's a lot of pieces to consider with the drug on that front.

All right. There are over three quarters of a million Canadians currently living with dementia. How do we ensure that when this drug does hit the market, Canada is accessible, has, you know, they have the ability to get it when they need it?

Yeah. Well, I mean, it is very tight eligibility. So what that likely means is only a small percentage of people will even be eligible for the drug, likely under 10%. But the other piece to this is being diagnosed in a timely way. So we touched on that briefly. Right. On average, it's taking about two years to get a diagnosis of dementia. That's a long time. And that means that that window might close.

And in order to really support that kind of accessibility, we need coordination and better clinical pathways. And you need more treatment options. This is just a first class of drugs. There's a whole pipeline that hopefully will be coming through. But we also know there are other treatment options that need to be available for dementia. And we just don't have that in our health system at all. There's really no coordination. You're kind of left on your own once you get the diagnosis to figure out what to do next.

All right. Well, let's talk about that. Aside from Lecanemab, what are some other new treatments that are out there or that are in that pipeline that are giving you some hope?

So there are kind of three things. There's the drug treatment options. There's a whole pipeline, things that are targeting a different type of protein called tau that's also in the brain thinking about neuroinflammation. So different types of markers that are getting again at that underlying pathology of Alzheimer's and then broader dementia. So there's I think a lot of hope because a lot of those will read out, those clinical trials will read out over the next couple of years.

The second are blood based biomarkers. So these are much closer to getting to the market. And what they do is it means it's a blood test to be able to see if someone has Alzheimer's or other forms of dementia.

Again, that's important because right now it's just a cognitive test, mainly for being able to diagnose someone, which is really difficult. Especially someone speaks a different language. Cultural nuances that don't get considered in a cognitive assessment.

But the other piece is, are rehabilitation therapy, which we now know is really important and supports slowing the functional decline and then multimodal lifestyle options. So exercise, diet and cognitive therapy, which in combination can also slow cognitive decline. And we don't offer any of those right now to people living with dementia.

Saskia, we're going to leave it there. Thank you so much.

My pleasure. Thanks for having me.