The Peter Attia Drive - #10 - Matt Kaeberlein, Ph.D.: rapamycin and dogs — man’s best friends? — living longer, healthier lives and turning back the clock on aging, and age-related diseases
Episode Date: August 20, 2018Matt is someone who is deeply interested in understanding the biology of aging. Why do we age? What happens to us as we age? What are the things we can do to slow the aging process? How can we delay o...r prevent the onset of age-related diseases? These are all questions that Matt thinks deeply about, and explores these questions with his research at the University of Washington. He is currently investigating many of these questions through the Dog Aging Project and the compound rapamycin—the only known pharmacological agent to extend lifespan all the way from yeast to mammals—across a billion years of evolution. We talk about cancer, heart disease, Alzheimer’s disease, healthspan, lifespan, and what we can do to provide longer, healthier lives for both people and dogs. We discuss: Matt’s early years and his a-ha moment on aging [4:00]; Studying dogs [6:30]; Dogs, rapamycin, and its effects on lifespan and healthspan [15:30]; An unexpected finding in presumably healthy dogs [36:00]; Rapamycin in cancer treatment [50:00]; Why isn’t there a rapamycin trial for Alzheimer’s disease (AD)? [1:01:30]; If Matt could do a definitive study on life extension in dogs, with resources not being a concern, what does that experiment look like? [1:16:00]; and More. Learn more at www.PeterAttiaMD.com Connect with Peter on Facebook | Twitter | Instagram.
Transcript
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Hey everyone, welcome to the Peter Atia Drive. I'm your host, Peter Atia.
The drive is a result of my hunger for optimizing performance, health, longevity, critical thinking,
along with a few other obsessions along the way. I've spent the last several years working
with some of the most successful top performing individuals in the world, and this podcast
is my attempt to synthesize what I've learned along the way
to help you live a higher quality, more fulfilling life.
If you enjoy this podcast, you can find more information on today's episode
and other topics at peteratia-md.com.
In this podcast, I'll be speaking with Matt Cabrillin
at the University of Washington.
I met Matt about a year and a half, maybe two years ago, through David Sabatini, who some
of you may be familiar with just based on all of his remarkable work around Emtoren-Rapamysen.
Matt's recognized globally for his research and the biology of aging.
He got his PhD from MIT in the lab of Lenny Garante, who's produced a number of notable folks in this field.
He went on to do his post-hoc at the University of Washington
and after completing his post-hoc, he has remained there
and continues to run a fantastic lab.
In this episode, we're going to talk about his experience
as the director of the Dog Aging project, which, as its name
suggests, focuses on the animal model of dogs for its research.
Now, of course, this is really interesting because, while fruit flies and yeast and mice
are interesting, dogs are obviously much closer to us. And, of course, these dogs, because
they're pets, generally, have something really unique to us that virtually no other research
animal has, which is they share our environment. And this puts them in a pretty unique spot
that even the Reese's Monkeys studied in the NIA
Wisconsin project didn't have going for them.
Now, if you haven't already done so,
I'd recommend listening to the podcast
that I did with David Sabatini
because that will get you some of the background
on MTOR and RAPA MICE.
And I think we get a little technical in this podcast,
but I suspect it's something that if you've listened
to that other one with 17,
you'll have the background to follow.
And we talk about a bunch of other things
that people seem to be interested in as well,
beyond RapaMice and an aging.
We also talk about NAD,
probably get into SirTu and it's a little bit.
The other thing I really enjoy about speaking with Matt,
and I had so many discussions with Matt,
over meals and stuff where I think to myself after,
man, I wish that was recorded because one, want to be able to hear it again and two
It's the kind of stuff that people are always asking me and I think Matt just has such an amazing way of thinking about this stuff
Matt's work is really remarkable because it's actually focusing on health span
It's easier in some ways to study health span because you can study it over a shorter period of time and in particular
When you look at the cardiomyopathy model,
meaning it's a type of heart failure that dogs experience,
and you look at how rapamycin can improve ejection fraction,
you can get these answers in a really quick period of time.
In fact, much quicker than I think Matt even expected.
And we talk, of course, about cancer, heart disease,
and Alzheimer's disease.
So if you're interested in rapamycin,
if you're interested in mTOR, if interested in longevity,
I think you're going to find this interview very interesting.
It was actually recorded initially in December of 2017 as part of the interview series I was
doing for my book, and we may at some point throw up the video as well.
You can find a lot more information in the show notes, of course, and without further delay.
Here's my conversation with the remarkable Matt Caperler. Matt, thank you so much for being here.
It's really fantastic to be able to talk with you in this format.
I've been a huge fan of your work for many years now.
Obviously, I know quite a bit about your background, but I think it'd be great for the listeners
to get a sense of what did you study in college, how'd you end up doing your
PhD, where'd you do it, and most of all, why'd it get you where you are?
Sure. So I got undergraduate degrees in biochemistry and mathematics at Western Washington University,
and then I went to graduate school at MIT, the biology department there, and my background
up to that point had been in biophysical chemistry.
So I really went to graduate school thinking I was going to work on structural biology
or x-ray crystallography or something like that. And I heard a seminar by Lenny Grantee
who I ended up doing my PhD thesis with during my first semester at MIT where he started
talking about how his lab had begun working on the genetics of aging and trying
to understand, you know, what are the factors that influence the rate of aging.
And this was in yeast.
That's what his lab worked on at that point.
And it was really almost like an aha moment where it just clicked with me that it was
really fascinating that you could use genetics and molecular biology and biochemistry to study
something as complicated and fundamental as the biology of aging.
And so I got fascinated by the topic, ended up going and talking to Lenny, and then subsequently
doing my thesis research with him.
So it was really that moment of hearing him talk, my first year in graduate school, that
got me interested in aging.
And that's what I've been fascinated by and passionate about since then.
And so then I went on and did a postdoc with Stan Fields at the University of Washington,
also working on aging, and then ultimately started my own lab.
So it's been almost two decades now that I've been working on this problem.
And if my memory serves me correctly, when you were in Lenny's lab, who's obviously
no stranger to probably people who are listening to this, you worked on Sertuan's, correct?
Yeah, so my thesis work was actually the work that first showed that if you activated or
overexpressed a Sertuan, in this case it was Sertuan, the founding member of the Sertuan's
in yeast, that you could extend lifespan in slow aging.
And obviously, we were very excited about that, especially when a postdoc who was in the lab
at that time, Heidi Tissinbaum, about a year later, showed that you could also over-express
the worm version of Certo and extend lifespan in Cialigans. And so that was really the first
example of a conserved genetic modifier of lifespan
across two widely evolutionarily divergent organisms.
Because it was a relatively similar version of CERT2.
Yeah.
So more different than the DAF stuff that we saw in C. elegans versus the IGF that we would
see in some of the higher mammals.
Right, so at that time, we knew that Deaf too could extend lifespan and see elegance.
I don't think we knew it was, let's know, similar mechanism.
That's right, yeah.
Now, I think one of the things that makes your work so interesting is that you work on dogs.
Right.
How did you end up doing that?
Yeah, so that's relatively new in my career.
It was about four years ago when Daniel Pramisl low move from the University of Georgia to the University of
Washington. And Daniel had started thinking about dogs as a
model to understand G how genetic and environmental factors
influence the aging process. And I'm a dog person I've always
had dogs. I have three dogs now that qualify. Yeah, right. And I
had never really made the connection
between dogs as companion animals and dogs
as a model for understanding aging
until I talked with Daniel about this.
And through those conversations, it occurred to me
that not only could we understand genetic
and environmental modifiers of aging,
but our pets could actually serve as a transformative
next step in testing some of these things that we know work in laboratory mammals like mice,
but have never yet been taken outside of the laboratory. And so it was really that sort of
connection in my mind about three years ago that propelled me to really move forward with the dog aging project.
One major goal of which is to actually do this, to take some of the interventions that we
know extend lifespan and slow aging in the laboratory and test whether they have that effect
in the real world.
In a larger mammal that's also very socially relevant, I think that that's an important
aspect of this.
People love their dogs.
If we can actually slow aging in people's pets,
that's going to have a huge impact
both on the quality of life for the pets and the owners,
but also the way that people think about the biology of aging.
They're gonna believe it a lot more.
They see that their dog is living longer
and aging more slowly than just reading an article
in the New York Times or wherever. Right, right. And it's, you know, I sort of, when I talk
about this, I generally talk about these four classes if you carry out
going from, you know, yeast to flies, worms and mammals. But usually when we
talk about mammals, we're talking about mice. And they have a couple of
problems at least, right? At one problem is they're generally, especially if they're in bread.
I mean, they're homozygous at all low size.
So you have to question their applicability to us in terms of their susceptibility to disease.
But then the second point which you alluded to, which I think the dogs might be the first
quote unquote laboratory study that gets out of this, is they don't live in our environment.
The mice, that is. Right. So the dog truly lives in the environment you and I live in, which at least in theory
should be the environment we care most about preventing aging in.
That's right. I think that environmental variation is hugely important. The genetics is also
important. And dogs are, so there's a couple things that are worth mentioning. Dogs have some of
that same genetic homogeneity if you look within individual purebred breeds. But we also have
many purebred breeds that are widely divergent, both genetically and morphologically. All you
have to do is look at a chihuahua on a great day and to see that divergence. We also have this really interesting and complex mixed breed population.
It's a combination of all these different genetic variants that each breed has.
We have the best of both worlds in the sense that if you want to do a study in a relatively
genetically restricted background, you can do it in a specific breed or set of breeds.
If you want to capture that genetic variation,
all you have to do is look in the mixed breed dogs.
But the environmental part of this, I think,
is probably the most important from a,
what are we going to learn from dogs that we can't learn from my perspective?
As you said, dogs really share our environment to a greater extent than any other animal,
maybe with the exception of cats.
And so they are drinking the same water.
In fact, may not even be drinking the same water.
Most people, maybe drinking worse water.
Yeah, right, are not gonna give their dog bottled water,
right, but they're breathing the same air.
If you smoke, they're experiencing that,
or someone in the house smokes,
they're experiencing that second hand smoke.
So they really do capture most of our environment.
The diet is about the only place where dogs don't quite have the same sort of nutritional
diversity that people do.
But with the exception of diet, the environment is pretty close.
And we have a pretty good idea of how we die.
Or that could actuarially map out how you and I are going to die based on our age and
a whole bunch of other factors.
Again, it's probably an oversimplification because of this species diversification,
but it's a general rule, how do dogs die?
Yeah, so I'll make one quick comment on that.
First of all, that I think you're right,
that we do know what diseases most often kill people.
And that's important information.
I'm not sure it's the most important information
because what people die from
does not always equate to what they die with,
especially today.
Most people are dying with
chronic diseases.
Multiple comorbidities, right?
So just because you may die from heart disease,
it doesn't mean that you didn't have kidney disease
or something moving towards kidney disease or diabetes.
So I think it's important to appreciate
that you can have multiple diseases
and only one of them is probably going to kill you.
Having said that, it is useful to think about
do dogs die from and with the same age-related diseases
that people do.
And the answer is, in general, the equivalency is pretty good.
So dogs get all of the same age related diseases
that people do.
They don't get them at the same frequency necessarily.
So one big difference is in dogs,
there's actually relatively little vascular disease,
which is a major killer in people.
So specifically, atherosclerosis,
whether it be peripherally or cardiovascularly,
doesn't seem to be as prevalent.
It does not seem to be as prevalent.
But there are breeds that die from heart disease and certain forms of heart disease.
Cancer is probably the most common cause of death in dogs, and big dogs tend to get more
cancers than small dogs, but across all dogs, cancer is probably the number one cause
of death.
Kidney disease is a major cause of death in dogs. Is the etiology of that kidney disease related to
blood pressure? Is it related to some other nephrodix syndrome that's otherwise
unidentified? I don't know the answer to that. Yeah, I don't, I don't have the
veterinary background to answer that. One of the things that's interesting in
dogs is that there's, it seems to be a little bit of a debate whether dogs
really get Alzheimer's
disease. They clearly get dementia, some dogs do, and they clearly show cognitive decline. It's not
completely clear whether they get what would be clinically diagnosed as Alzheimer's disease in people.
Apparently they do accumulate a beta in the brain, whether they get the plaque sentangles,
still seems to be a little bit up in the air air and there are people studying that. But at least at the level of cognitive dysfunction and dementia, it's clear that dogs experience
that with age as well.
So for the most part, they do develop the same age-related diseases.
The increase in risk for those diseases goes up essentially, exponentially, just like
in people.
But the relative prevalence of specific diseases is not always the same and can also be breed dependent.
So it is certainly the case that within purebred dogs, different breeds have different predispositions
to certain diseases, which is exactly what you'd expect based on the genetics.
So basically they're probably getting a little more cancer,
significantly more renal failure as a proximate cause of death as opposed to dying with
renal insufficiency, which to your point,, as opposed to dying with renal and sufficiency,
which to your point, I think a lot of humans do.
They're getting a lot of heart disease,
but it sounds like it's more cardiomyopathy
and or valvular disease, but not atherosclerotic
or ischemic disease.
And they unfortunately die of accidents just as humans do,
which would probably be in the top four
for humans and dogs I'm guessing.
Yeah, and actually that's an interesting point you're right.
What I haven't seen great data on is the age distribution
of death due to trauma.
I suspect it's going to be mostly younger dogs,
but I don't know for sure.
So that's actually an interesting question.
It is absolutely true.
The other thing that is worth noting about dogs
is it's actually the case that most pet dogs don't die
from an age-related disease, they
die from euthanasia, which is a difference between dogs and people.
That's a great point.
Well, let's turn the discussion now to what you do about this.
I've been a big fan of rapamycin and tour and that entire pathway for several years now.
It's become almost an obsession.
One can have an obsession that it's not pathologic.
And I think what attracted me to your work a couple of years ago, probably David Sabatini
pointed me in your direction. So maybe three years ago, it was actually after the manic
paper came out in 2014, right?
Which is sort of the first one. Really interesting look at the human data. I want to come back to that paper as it relates to immune function and stuff, but maybe
give us a sense of how you decided that the next logical step was to actually test the
God molecule as I looked at it all out of the wrap of my身 in this context.
Indogs, yeah.
Yeah.
So, again, this was all happening about three years ago when I first sort of made
the leap to thinking that we could test interventions in dogs.
And actually that's not, at least for me, was not an immediate, it wasn't immediately
obvious to me that we should.
So you really have to think, as soon as you start talking about bringing trial of a drug
out of the lab and into
the real world, whether it's the human clinic or the veterinary clinic, in the context
of aging, you really have to start to think about safety and side effects, right? Because
there is a very low tolerance for side effects when you're talking about treating a healthy
person or dog. That was the first thing that I had to really come to grips with is, could we do this
safely?
And especially normally, you were thinking, we're not going to take dogs that are already
sick.
That's right.
We were going to take healthy dogs.
That's right.
I mean, for me, as somebody who is fundamentally interested in the biology of aging, the intent
is to slow aging in people before they get sick, right, to keep them healthy longer
So in many ways it's it's the opposite of
Traditional medical approach biomedical research, right where normally
Historically we wait until people are sick and then we try to cure their disease. This is the reverse of that, right?
So that's right
So so because we are talking about intervening in a healthy
So because we are talking about intervening in a healthy person or a dog, the tolerance for side effects from a regulatory perspective, or even just public perception, is very low
when you're talking about a healthy person.
Now, the way I view that, first of all, I think that is we need as a society and within
the scientific community to have a discussion about this, because I
think that we need to recognize that a healthy, 70-year-old is not the same as a healthy 30-year-old,
right? And we know what's going to happen if we don't do anything about aging. So my
personal view is that there should be a tolerance for some level of risk if the outcome is going
to be 10%, 20%, 30%, more time spent in good health.
That's a discussion that we haven't had either at the regulatory level or at the society-wide level,
but I think we need to have.
So I digress a little bit, but I had to go through this.
No, I think that's one of the most important points you could make.
I sort of think a lot about this because my colleague and I were discussing this the other day, which was, you know, you take this oath at the end of medical school,
the hypocritical oath of your first thing you learn to say is first do no harm. And I
think the spirit of that is excellent, but I also think it's highly impractical in a world
where it forces you into binary thinking, which is we will only undertake interventions
that are guaranteed to have no harm. And otherwise, we will do nothing,
regardless of the outcome, which of course,
it's not practical.
We live in a probabilistic world
where the probability of harm is not zero or one,
but rather it's a continuum between zero and one.
And you really need to take a risk-adjusted approach.
That's right, two outcomes.
So I mean, I think that's an excellent one.
That's exactly right.
So I had to kind of go through that thought process
in my own head, though,
and especially thinking about
moving into pet dogs, where because of the way
that many people feel about their pet dogs,
you have to be as sure as you can
that you're not gonna hurt anybody's pet.
They like them more than their friends.
Yeah, absolutely, right?
Yeah, people love their dogs, right?
A lot of people feel similarly love their dogs. Right.
A lot of people feel similarly about their dogs as they do about their kids.
Right?
So you kind of think that's kind of the way I thought about it is, could we do this in
somebody's child?
And so with rapamycin, there is a perception out there that I don't share, but there's
a perception out there that rapamycin has lots of side effects based mostly on the human
clinical literature.
Which, to be clear, is generally in transplant patients. Transplant patients taking high doses and taking lots of side effects based mostly on the human clinical literature. Which to be clear is generally in transplant patients.
Transplant patients taking high doses and taking lots of other drugs.
Yeah.
So sick people taking a high dose of rap and mice and in combination with other medications,
right?
And it does have side effects.
There's no question about that.
But one of the things that's come out of my own research and other research in the field
is that the both the benefits and the side effects are strongly linked to dose.
So one question was, is there a dose of rapamysin that will have beneficial effects in the context of healthy aging without significant side effects?
That was an unknown. I think that we're getting to the point where we're pretty sure that that's the case.
At least you can get some of the benefits of rap and my son. We can talk more about
the data that support that. But at that point, it really wasn't clear.
And when you say the dose, do you think that the peak or the trough play a bigger role
in toxicity?
Yeah. So that's still an unknown, but I think the data that are out there suggest that the trough levels are most
strongly correlated with side effects.
Now what is most strongly related to lifespan or lifespan, there's no data, as far as I know.
And this is an area where I think there's a lot of work that could be done and should
be done exploring more broadly, even in laboratory animals in mice, the dose response
and dose timing space for where do you get the biggest effects on lifespan or specific
measures of health, where don't you get any effects?
Can you uncouple, say, the improvements in heart function from the improvements in immune
function by changing the dose or the timing?
That really has been very little done on that.
Now, maybe for the listener who's not familiar
with the pharmacokinetic discussion,
let's explain maybe trough and peak.
How do we think about those dose?
Yeah, so when you give a medication
to a rapid miceint pill,
when a person takes a rapid miceint pill,
there will be a rapid increase in the levels
of the drug and the blood.
And if they don't take another dose,
then the drug will start to get And if they don't take another dose,
then the drug will start to get cleared
and it will go down.
And so if you're taking a pill every day,
as soon as you take the pill, the blood levels go up
and then it starts to get cleared.
And then the next day you take the pill, it goes up
and then it starts to get cleared.
So if you were to take the pill every other day,
it would go down further before you get that spike again.
So the spike, the top of the spike is the peak level, the bottom before you take the next
dose is the trough.
And so the little bit of data that's available, and again, there's not much data for different
doses of rapamycin in people who are not also taking other drugs.
So the combination here is both dose and rapamycin is a monotherapy.
And so really the only study that I know of that looked at this
really at all actually didn't even use rapamycin.
They used a derivative of rapamycin called Rad001
or whatever alignments that's the man next to me.
We talked about.
So there's really no good data in people
on different doses of rapamycin as a monotherapy
in healthy people.
So we're kind of stuck looking at the data that we have.
So in, in Joan's study with Everalymus or Rad001, they gave the medication to healthy
elderly people and they tested three dose and delivery combinations.
So one of them was, I believe, 20 milligrams once a week.
One of them was five milligrams once a week,
and one of them was one milligram a day.
Right.
And this was looking in the context of immune function
as measured by a flu vaccine response.
So the outcomes were that I think at all three doses
they saw evidence for improved vaccine response,
which was consistent with prior data in mice
that immune function is improved by rapamycin.
Pause for a moment. That's still a bit counterintuitive to the lay person.
When I say the lay person, I mean like the lay person who still thinks about rapamycin.
Or actually lots of physicians. Sure. Because we think of this as an immune suppressant.
That's right. Yeah.
And yet, they took this drug in monotherapy
under a different dosing schedule
than a transplant patient would take it.
And we saw an improvement in their T cell function,
the same cells that we tend to knock out
in a transplant patient.
Yeah, so let's come back to that,
because that I think is, that's an important issue,
but it's complicated.
Just to come back to the trough levels and side effects,
so they saw evidence for
efficacy with every delivery method. Although they got I think the best efficacy at the five
weeks. Five wants a week. But they also had the lowest side effects. And the five side effects were
once a one's every day or the 20s once a week. I think it was at the 20s once a week but I can't
remember. Yeah. It was pretty comparable. So the first thing to say is none of the side effects were bad by clinical standards.
None of the people dropped out of the study because they were taking the drug, which is
I think a pretty good indication for how tolerable the drug is.
So even though they did detect some side effects, they really were not serious.
They weren't even serious enough that they were uncomfortable and people stopped taking
the drug. So I think that that's really the only evidence that we have that I know of
that it's really the trough levels that drive side effects.
So I kind of think that's probably true, but I'm not confident and I really think we need more data to know for sure.
It's certainly true in other classes of drugs.
And when you look at Gentamysin, for example, in the ototoxicity or nephrotoxicity, it's a
trough problem, not a peak problem. Right. Right.
So you have to make sure the patient's clear it before you re-dose it.
Right. So there are other reasons to believe that as well. Yeah.
So now coming back to this immune function. There's a wash out. There was. So
there's a couple things again there to consider. So the data suggesting that rapamycin can act
as an immunosuppressant again is almost exclusively based on,
well, I shouldn't say very high doses,
higher doses than were tested in the Novartis study,
in people who are also taking other drugs
that probably are true immunosuppressant.
Typically at least two, if not three other drugs.
That's right.
So it's really not clear to what extent
rapamycin as a monotherapy in healthy people
has immunosuppressive properties.
And the data in mice, I would say is mixed.
It really seems to be the case that
for some forms of immune challenge
at high doses,
rapamycin can enhance susceptibility to infection
for other forms of immune challenge
and enhances function.
But again, those studies are almost always done
at very high doses of the drug
that are even much higher than you would give to a person.
So it's an unknown.
Now, what seems to be the case,
both in mice and people,
is that short-term treatment with rapamysin,
and an old mouse or an old person,
followed by a two-week washout
where they stopped taking the drug,
when you then test immune function,
at least as measured by a vaccine response,
you get a better response.
So one model would be that the treatment with rapamycin is restoring
immune function in an aged animal, probably through enhanced stem cell
function, although I don't, I think that that hasn't really been demonstrated
clearly, and you might need that washout period if there is an immunosuppressive
effect, you might need that washout period to be able to see that rejuvenation into immune function.
Again, that's really speculative, though, because nobody's done...
In Jones paper, did they do...
I'm sure they didn't actually know that I think about it.
They didn't have enough people in the study.
It would have been very interesting to have seen the immune challenge without the washout
in the sunset.
No, I was just going to say nobody's done it and either mice or in people.
That actually would be a fairly easy experiment
to do in mice.
The problem is you would never get an NIH study section
to fund that experiment because we already kind of know
the answer that RAP and mice and works.
They wouldn't be viewed as an even though it's really
important from a translational perspective.
It wouldn't be viewed as innovative or important
enough for somebody to fund a grant to do it. So it's an unknown and I don't know how long it'll
be until we actually get the answer to that question. Now bringing it back to the dogs, one of the
challenges, of course, in leaping from mice to dogs is mortality becomes difficult to study.
You have an animal that lives a lot longer,
whereas mice, you can get a longevity answer
in months if you select them correctly.
And dogs, if you wanna study them for true,
hard outcome of death, it's gonna be one of those.
So you pick a proxy.
Well, you can.
Yeah, I'm saying, I'm saying like,
the shortest path would be,
let's look at organ function or something else. Right. So what we did, so we've done one study where it was a 10 week study of
Rapa Mison in middle-aged healthy companion dogs and we chose heart function as our short-term measure and that again was based on mouse data
Where two different actually three different labs now have shown
that if you take 20 to 24 month old mouse,
that's maybe the 40 year old.
Now, it's more like a 60 to 65 year old person
that if you just look at the heart of a 24 month old mouse
compared to, let's say, a six month old mouse,
you can see declines in heart function,
just like you can in people.
And the parameters that have been studied with the respect to rapamycin specifically are
mostly measures of left ventricular function.
So ejection fraction, fractional shortening, things like that.
And this is done by echocardiography, so it's relatively non-invasive.
So you can see a decline in function with age.
And what has been seen now in three independent studies is that six to 10 weeks of treatment with rapamycin
is enough to cause those measures of heart function
in the old mouse to go back about halfway
to what you would see in a young mouse.
So it doesn't bring you all the way back to a teenager,
but it gets you back to maybe a 35-year-old heart
if you're doing the sort of mouse to human equivalency.
And just to be clear, that was how many weeks?
So the studies have varied, it's between six and ten weeks.
All of them saw improvements, it's not clear whether you get bigger improvements by longer treatments.
So it's kind of in that range.
And did these animals also require a washout to see the benefit?
No, no washout.
So these are measures of heart function taken while the mice are still on the rapamysin.
And these animals were dose daily?
So yes, all three of those studies used the encapsulated rapamysin in the diet, so they were getting the drug daily.
And it was not, and this is where it gets a little bit complicated because I'd say 85% of the studies on aging or age-related functional measures in mice with rapamycin have been
done with an encapsulated form of rapamycin in the diet.
We call it e-rappa.
And so that's different from a pill, right?
Because mice are going to eat throughout the night.
So they're probably not experiencing exactly the same pharmacokinetics that you would experience
from a pill.
Or the other kinds of experiments that people have done in mice have been injections, where
you get, you know, this rapid peak in the drug and then a pretty steep drop off as the drug starts
to get cleared.
Nobody's ever done the 24 hour measures of rapid mice and blood level on the mice getting
erratic.
So I don't know how different it is, but it's probably different in the sense that it's
probably a more stable level of rapid mice and in the blood for a longer period of time.
I mean, I would expect that the e-rapper animals are going to have lower
peaks and higher troughs. I mean, that would be...
That would be the expectation, yes.
But I don't know that anybody's ever really carefully looked at that.
So, having said that, I think all three of the studies that looked at heart
function in mice used the e-rapper, And it was a pretty low dose of the,
the, how many milligrams per kilogram?
It's 14 parts per million in the food.
I don't remember off the top of my head
what that works out to in milligrams per kilogram.
I feel like it's in about the two range.
Wow, but, well, yeah, but again,
you have to, you have to keep in mind
that you can't translate the dosing across
species very well. Two milligrams per kilogram in a mouse is not going to be the same as two milligrams per kilogram in a person or it doesn't have.
Because the dogs in the human's eyes suspect are probably a lot closer than the...
You would think so, although I don't know that there's actually good evidence to support that.
So certainly in terms of body size, if you're talking about a bigger dog, they're closer.
In terms of metabolism of the drug though,
that I imagine could vary quite a bit.
It's hepatic pleases to species.
I don't know, that's a good question.
I thought it was pretty sure it's not real.
It's not from pee-formative species.
Yeah, it's seen as acyporphitis,
it's gonna be a new liver.
So how did you ultimately come up with both a dose
and a schedule of delivery for your first trial.
So this again goes back to this question that I was asking myself about, can we do this
safely?
And there's very little data in dogs on rapamysin at all, and just like in people, there's
almost none on rapamysin as a monotherapy in healthy animals.
So I started basically digging and talking
to as many veterinarians as I could
to find out what was known.
And I was very fortunate to actually be able to get in touch
with a veterinary group at the University of Tennessee
who was studying rapamycin in dogs
who had had hemangiosarcoma of the spleen.
And so they had done the pharmacokinetics
and had developed a dosing strategy
that they feel is extending life expectancy
in dogs who have had hemangiosarcoma of the spleen
and where they weren't seeing side effects.
And they had had some of their dogs on rapamycin
for more than a year.
So we were pretty confident,
or I was pretty confident after talking to them,
that if we took their dosing strategy,
that we're unlikely to see any significant side effects over a 10-week period.
And so I said that cardiac function was the functional endpoint that we were using.
Really, the goal of that 10-week study, though, was to confirm.
This is a phase one basically. Yeah, that we could do this,
that we could get people to participate, they would actually
give their dog the medication, and that we didn't see any significant side effects.
So I was pretty confident that based on their dosing and delivery protocol, we at least wouldn't
see any severe side effects in a 10 week.
At the NIH fund that study?
Well, not directly.
So we got a little bit of NIH money because we have one of these Nathan Shock Center's
of excellence in the biology of aging
and we had a small amount, it was on the order of a few tens
of thousands of dollars left over from the prior year
and so I asked Felipe Sierra,
who's the head of the division of aging biology at NIH,
if we could use that surplus specifically for this project
and he was kind enough to agree to that. But it wasn't, we didn't write a grant and get a grant. But you sort of bootstrap this thing. I would say, I would say, I would say, I would say, I would say, I would say, I would say,
I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, I would say, of Washington gave me some money that I could spend on whatever I wanted to. And I thought this was a good way to spend the money.
So what did that 10-week study show?
Right. So first of all, I'll go back to the dosing before I...
Oh, that's right, yeah, yeah.
So I talked to this group at the University of Tennessee.
And so their strategy was 0.1 milligrams per kilogram given three times a week.
Okay. Monday, Wednesday, Friday.
And that made sense to me
in light of the what we were just talking about from the manic paper where it
seems like if you give an extra day to let the trough levels get down it made
intuitive. Yeah, so I don't know that that's the case but but it made sense and
so that was the dosing strategy that we went with for our highest dose. And then we also tested a dose that was half of that.
So 0.05 milligrams per kilogram, again Monday, Wednesday, Friday.
So we enrolled dogs into this study.
This was a very small study all from it at a private veterinary specialty clinic in the Seattle area.
And so the dogs had to be at least 40 pounds and at least six years old and they could not have any pre-existing
conditions. So again, this is a study of healthy aging. We wanted healthy dogs coming into the study.
Six years old because at that weight range, we figured that that would be, you know, roughly the human equivalent of 55 years maybe.
you know, roughly the human equivalent of 55 years maybe, big dogs age faster than small dogs. So that's why we had the weight criteria.
So we wanted to have a population where we expected there would be the potential for some
age-related functional decline, but that we wouldn't get a high proportion of dogs.
Yeah, you don't have to be too close to the age of the close.
That's right. That we're really sick.
So one thing we found, though, that was unexpected was that about 20% of dogs in that age and weight range actually have asymptomatic
heart disease. That you will see if you give them an echocardiogram, but you won't detect
from a stethoscope exam. And that was in hindsight, it kind of makes sense, right?
Again, heart function is going to go down with age and where you decline, like,
what is the clinical threshold that we call disease is sort of a moving target sometimes,
right? If a vet with a stethoscope texts a heart murmur and then they give the dog
an echocardiogram and they see regurgitation, they'll call that heart disease. If they
don't hear a heart murmur, nobody is going to give their dog an echocardiogram, right?
It's expensive.
Yeah, and so I'm not a cardiologist, but I can't imagine the day
whatever come we're using a stethoscope,
I could detect, you know, a low EF, like to the tone of,
no, no, no, no, it's really the regurgitation
that they're hearing as a heart murmur.
And that was most of the dogs that we ended up having
to exclude, we had to exclude because they had a pre-existing
dog allergic agitation that came out from the echocardiogram. But this was actually a discussion
that we had to have with the cardiologist. You know, the cardiologist initially went into the study
with the feeling that if there's any regurgitation that's beyond trivial, that that's heart disease.
And so when we started to see dog after dog show up
with this level of regurgitation,
we had to have this discussion.
What's normal aging versus disease, right?
And so just because of the way that the protocol was written,
we ended up having to exclude about 20% of dogs
because they had underlying heart disease.
So we had 40 dogs come into the study for their first exam.
That was our target number. We ended up having 24 go all the come into the study for their first exam. That was our target
number. We ended up having 24 go all the way through the study. Most of those. Three groups,
three doses, plus a placebo. Yeah, and they ended up not being evenly distributed. And in part,
this was because, in part is because it was my first clinical trial that I'd ever done. And I didn't
didn't plan for the fact that we would have to exclude as many dogs as we did. So the way it ended up was we had eight placebo, 11 high dose and five...
Medium dose.
Yeah, right.
That went all the way through.
We only had one dog leave the study and that was because the owner just stopped giving
their dog the medication.
And we had one dog where the owner gave their dog the wrong amount of the medication,
which ironically enough...
Long and Pigeon Red Physician. Low. the owner gave their dog the wrong amount of the medication, which ironically enough long if he was in a position.
low. so the dog was randomized into the high rap and
mycine group and ended up getting one quarter of the expected dose.
so other than that, there was fantastic compliance.
all of the owners did what they were supposed to, came in for their exams.
so the main outcomes of this study were one, there was no evidence for increased side effects,
so the owners filled out weekly surveys that there was a long list of...
The dogs didn't fill them up.
Well, you never know.
There was a long list of did-your-dog experience any of these things, and then there were a
couple of just open-ended questions, you know, do you feel like you observed any positive
changes or negative changes in health?
Did the group in Tennessee see the apthosalcers in their dogs?
Because that seems to be I remember as a resident when we would give rapamysin to the
transplantation. I mean the biggest complaint by far was those apthosalcers. Yeah, and we didn't again in hindsight
We probably should have done a better job of looking
But we did not have any evidence
that that was happening.
The only thing that initially I thought that maybe we were detecting that was because
we had several owners, and this was while the study was still blinded, so I didn't know
which dogs were which at this point.
We had several owners report that their dog was drinking a lot more water,
and a couple of them actually came in for your analysis and stuff like that.
And so I thought maybe that could be like a dog's response.
If they have sores on the inside of their mouth and they're uncomfortable,
maybe that would be the sort of the canine equivalent of how they would respond to that.
As it turns out though, when we unblinded the study,
that reported observation of increased
water consumption was equally spread between the placebo and rapamycin groups.
So I don't know if that's happening in dogs.
That's something we'll look at in the next phase.
So again, for all of the side effects though, that we surveyed owners on no difference between
treated and untreated, the blood chemistry showed no significant changes with
rapamycin, which was actually a little bit surprising.
Did you do a glucose tolerance test?
We did not do any, we did not do a glucose tolerance test.
In part because we wanted to keep the, the number of assays that we were asking
the owners to subject their dogs to as small as possible, make it as non, non-invasive as possible for the animals.
We did get blood chemistry at, you know, before randomization at week three and at week 11, so within one
week of coming out of the study.
We saw improvements in heart function.
I will say it's a small cohort.
They were on the borderline of statistical significance.
Two of the three measures that we had as our primary endpoints, the three measures were
rejection fraction, fractional shortening, and EDA ratio.
And again, that was just coming directly from the mouse studies.
Two of those three were statistically significant.
One was p value of .06.
Yeah, but I mean, you must have been underpowered on absolutely anything.
Absolutely.
Yeah, no, I agree.
It's amazing you saw it significantly.
I agree.
Yeah.
So I think the way I view this is, it's about the most positive outcome that we could have
hoped for.
Clearly needs to be replicated, but at least the changes are going in the right direction.
And an interesting, couple of interesting things when you actually look at the heart data,
it very much looks like the dogs on-wrap mice and they got the biggest benefits were the ones
that started with the lowest function,
which is not surprising, but that also is encouraging,
because that's kind of what you'd expect, right?
The dogs that have undergone a greater age-related decline
are likely to be the ones that are going to get
the biggest benefit from a treatment that's actually
affecting that.
So that was really encouraging.
And then we actually had one doberman
pincher in the study. And this turned out to be interesting because doberman
pinchers as a breed are highly prone to dilated cardiomyopathy. Something like
60, 65 percent of doberman pinchers will develop dilated cardiomyopathy as they
get older. I wasn't really aware of this literature going into the study, but it turns out
that many doberman pincher owners will actually give their dogs echocardiograms or electrocardiograms
routinely as they're getting older to try to detect dilated cardiomyopathy as early as possible.
And the owner of this dog didn't tell us this before she came into the study,
had actually been aware of this and was giving her dog echocardiograms before coming into the study.
That dog had low cardiac function, but it was not yet to the point where it was clinically
diagnosed. But I think it's actually. As dilated cardiomyopathy. So our cardiologist in the study
also not knowing the dog's history of having prior echoes, did not flag the dog
as needing to be excluded.
So the dog was randomized, it just happened to be randomized into the higher rapimicin
dose group.
And its function was, that was one of the dogs where we saw the largest improvement in
function.
What is interesting about that is the owner then, after the study was over, continued to
get echocardiograms every three months and has shared that information with us.
And so it's really, it's an N of one,
but it's a really fascinating sort of case study
because you can see the dog's cardiac function declining.
Then the dog comes into the study,
gets rapid mice and it shoots up.
It's quite a dramatic increase.
And then within about-
What was the increase in EF? Do you remember?
I don't remember, I don't want to say the exact number,
which I don't remember.
It sounds like it was a big deal.
It was from the borderline of being a cult
dilated card in my op at least 10%.
10%, 10 absolute percent.
That's right.
It's enormous.
Well, it's back into the normal range.
And has that patient or that patient,
has that woman shared with you
what the resulting decline in EF has been since the trial.
So I've got the data out to about six months
and we're just now trying to reconnect with her
to see if she has additional data
that she'll share with us.
By about six months out, the ejection fraction
and fractional shortening were back right at the point
when the dog came into the study.
And at that point, her cardiologist diagnosed the dog
as a cult DCM.
So clearly going down the path to dilated cardiomy.
So the million dollar question in a study like that,
or in a case like that is,
if you had to guess what would be the ideal way
to take care of that dog to delay the onset
of cardiomyopathy as long as possible.
Would it be, just keep this dog on that dose
three times a week in perpetuity?
Would it be, give the dog a 10 week holiday,
10 on 10 off, 10 on 10 off?
Right, so it's clearly 10 on every six months
is just a seesaw back to this one.
If everything is working the way that we think it is.
Yeah, my guess is that the default there would be to keep the dog on the drug unless you start
to see side effects.
So continue to monitor by ECHO's every three months and unless you see side effects or unless
you see something else that makes you worried that rap miceen is having a negative effect,
just keep the dog on the drug.
But it's an unknown as to whether we would eventually see side effects at that dose, because
as I said, the only data that I know of is that University of Tennessee group, where they
did have some dogs that survived more than a year and continued to take the drug.
Those dogs, as I said, had had hemangio-circum of the spleen, they had surgeries, they were
very sick coming into that study.
And so I don't know, even if there were mild side effects, that you would really be
able to tease that apart from everything else that's going on with those dogs.
There are other larger mammal studies that are going on, correct?
With rapamycis, specifically.
So there are research studies in the context of aging in Marmosets, the very small and very
early, but those are being done at the University of San Antonio, the Bar Shop Institute.
Then there are a variety of cancer studies in dogs with rapamysin.
There is a large study of rapamysin for osteosarcoma in dogs, and then there are a few smaller clinical trials.
But I don't know of any other large animal studies in the context of aging.
Antiaging, yeah.
Yeah.
Now, I want to obviously come back to the anti-aging in the dogs, but on the cancer topic,
there are some data that are actually suggesting that the increase in autophagy that one might
see with rapamycin, which one would expect to see, at least with mTORC1 inhibition, might
be paradoxically not ideal in the active setting of cancer.
Right.
So I guess my first question is, are you swayed by those data and if so, what would be the teleologic explanation?
Yeah, so I'll say I'm not swayed much. I think that those kind of data are important to be aware of.
I think one of the real challenges in the autophagy field is that not everybody-
So I think we can't measure it.
That was the only one of them.
Yeah, beside the fact that we don't measure it. That was the only one of them. Yeah. Beside the fact that we don't really know how to measure it, I think as a community,
we really don't know what we mean when we say that autophagy is increased or decreased.
Different people use different markers or measures for autophagy.
So my view is that one of the things that can happen, not just for cancers, but for lots of different pathologies,
is one of the ways that cells try to deal with many different forms of stress,
in particular protein misfolding, but also other forms of stress, is to turn up autophagy.
So I think that autophagy, some markers of autophagy going up,
can be a response to a pathological condition.
Also what often happens is that response of turning up autophagy does not lead to productive
autophagy, so you actually get an accumulation of autophagosomes because they don't ever
make it all the way through the process.
So depending on how you're measuring autophagy, what you really might be detecting is a block
at the late stages of autophagy.
And what you're seeing is you're measuring a backlog.
So it's not necessarily the case that more autophagy is bad in that context.
It's the failure to actually bring it to completion.
And again, I don't have a lot of data to support this.
My intuition is that at least for some diseases,
one of the things that RAPA Myson does,
and I don't really understand the molecular biology here,
it seems to alleviate that block.
So you actually get productive autophagy working again.
And again, I don't know exactly how that works,
but that's what it seems to me as happening.
And so we have seen some evidence for this
in mitochondrial disease in the brain, where
if we look in the brain, we can see these sort of massive auto-faggisomes that are trying
to digest mitochondria that can't do it while the disease is progressing.
Somehow rapamycin fixes that.
So I think you have to be cautious in interpreting an increase in autophagic markers in a disease as necessarily meaning that increased
autophagy is causing or contributing to that disease. And it could be the case that depending
on how you activate autophagy, it could be detrimental or it could be beneficial.
And so there's really two different questions. The first would be if you take a patient with cancer and you inhibit MTOR, is it not
helpful because the tumor has already evolved so much to be outside of MTOR's purview
or is it, it's actually harmful and that's of course separate from the option that could
be helpful. Right. So, my understanding of the clinical and the literature in humans is that for most cancers,
once it's reached the point of diagnosis that rapamycin is disappointing in its effectiveness.
It's not particularly effective. That's not true for all cancers, but for most cancers,
it has not been as effective as
you might expect, given that we know that activation of mTOR is common when you get high proliferation.
And the turning down mTOR should stop that.
Turn off a proliferative cell.
So I think you're probably right that at least part of the story is that one of the steps
in the progression to cancer is evolving to ignore
the break of turning it down, MTOR.
So, rapamycin may not be effective there.
I think it's a complicated system, though,
because the effects of rapamycin on the immune system
could have beneficial effects in terms of cancer
or detrimental effects.
So, we know that immune surveillance
is probably the most important
anti-cancer mechanism. We're certainly one of the most important anti-cancer mechanisms.
And we know that immune function goes down with age. That's probably one of the reasons why most
cancers are age-related. So if you can boost age-related immune function with rapamycin,
enhance immune surveillance, that's going to have a potent anti-cancer mechanism. And again, this is my guess.
My guess is that's why we see in the studies in mice that cancers are pushed back during
aging by rapamycin.
On the other hand, if the dose of rapamycin is high enough that you're actually inhibiting
immune function, that could be...
That could promote...
It could amplify us. That could amplify.
There's not a lot of data yet.
We did one study in my lab where we gave mice,
I think it's the highest dose
that's ever been given in the context of an aging study.
This was a daily injection of eight milligrams per kilogram.
So as we call it the party dose.
Yeah, right.
Right.
This was a study where we only gave the mice,
Rapa Mison, for three months.
This was from 20 to 23 months, and then we stopped the treatment.
And what was interesting there was we got completely different effects in male mice versus
female mice.
The male mice lived 60% longer after the end of treatment.
They had better muscle function, they got less cancer.
The female mice had no difference in lifespan.
The mice that got rapamysin or didn't get rapamysin.
But they died with, I wanna say from,
but it's hard to say for sure what a mouse dies from.
They died with very different types of cancers.
So the female mice that had gotten this high dose
of rapamysin for three months
all had aggressive hematopoietic cancers.
Whereas about, I think it was about 30 or 40% of the vehicle treated mice. all had aggressive hematopoietic cancers,
whereas about, I think it was about 30 or 40%
of the vehicle treated mice.
So in black six, that's not an uncommon cancer to get.
But none of the rapamysin treated mice
had non-homatopoietic cancers, whereas like 60%
of the mice that didn't get rapamysin.
Now the 2009 study that kicked all this off
actually showed a greater survival benefit
in the female mice, didn't it?
That's right.
So I think, and again, this is a guess because I don't actually have the data to back
it up.
My guess is that because we pushed the dose so high, we might have actually taken it too
far in the female.
So one school of thought is that female mice, at least, we don't know if this is true
in any other organism.
Female mice are more sensitive to rapamysin, and that could either be that we don't know if this is true in any other organism. Female mice are more sensitive to rapamycin.
And that could either be that they don't clear the drug as quickly or that for whatever
reason in female mice, the same amount of rapamycin has a greater emtory inhibitory effect.
But that's one school of that.
And I kind of think that's right.
So at lower doses of the drug, you see a bigger lifespan benefit in females than in males.
Did you repeat that experiment, like, for makes per gig or something different?
We haven't.
We should.
So we did do...
We just need an infinite pool of money to do all of these, like, just answer all these questions.
And you figure out the most important questions.
Yeah, and I think the dose response is really important.
We did do a lower dose for three months as well.
And there we saw increases in lifespan in both males and females,
roughly the same magnitude.
So that dose was nine times higher than what the ITP tested.
Wow.
So one of the things that's interesting though is as you go higher in dose,
so three times higher than what they originally tested,
the females still live a little bit longer,
but the difference between males and females,
the gap has closed quite a bit.
I think that females, for whatever reason, at a given concentration of rapamycin are just
more affected by that amount of the drug.
I think what we did in our high-dose study is we just pushed it a little too far.
We pushed it to the point where rapamycin did something, probably to the immune system, that allowed these immune cancers to escape surveillance
or become hyperproliferative.
And again, I'm not a cancer biologist,
I'm not an immunologist, so I don't have a good feel
for what the mechanism is.
I can tell you what the observation is,
and that's that all of those animals
had aggressive hematopotic cancers
when they got this three months of
rabbi.
Just out of curiosity, more B cell or T cell, do you recall?
I don't recall.
It's in the paper.
We could look it up.
Because there's an opportunity here to do the reverse, right?
I mean, there's an opportunity to take right now we're seeing just an unbelievable amount
of activity and adoptive cell therapy.
And or even when you just talk about like checkpoint inhibitors and things like that,
like it makes you wonder, are there ways to make these things better?
Maybe the checkpoints are wrong example
because you might get more autoimmunity,
but certainly when you talk about adoptive cell therapy,
anything that could boost either, you know,
CD8 function or inhibit the regs or something,
there might be ways, like it almost makes you wonder
if using RAPA mice in a different manner
in combination
with immune-based therapies might make more sense.
Yeah, I know, I think there's a lot
that could be done there for sure.
Part of the reason why we haven't explored this
in more detail, one reason is again,
as I said, I'm not a cancer biologist,
so it's not the thing I'm most interested in.
I think it's really interesting biology,
but it's not the thing I'm most interested in.
But I also feel like, because the dose that we gave
was so high that, again, thinking translationally
about rapamycin as a drug in the context of aging,
my feeling is that what we've uncovered here
is not going to be relevant at the doses
that we would think about giving to you the dog.
Yeah, yeah, yeah.
So that's why I haven't really spent a lot of my time
trying to figure out what's going
on there.
But I think, certainly in the context of cancer immune therapies, I think we do need to
think a little bit more about how effective those kinds of therapies are going to be in
the elderly and maybe something like rapamysin could help, could actually enhance the ability
of those therapies.
I mean, this question you posed when David,
Sabatini, Tim Ferriss and Napcentle,
and I were in East Ireland a year ago, over a year ago,
this might have been our favorite meal time discussion,
which is what best explains the increase in cancer incidents
with age, being in other words,
when the primary driver be the reduction in immune surveillance
or the length of time to accumulate mutations
or the frequency of mutations?
Like, I mean, it's not an obvious answer.
And I don't think it has to be just one.
No, exactly.
I think all those things are working together.
Yeah, yeah.
I certainly, over the last few years,
have come to think that the decline in immune function
is, it's certainly more important than I had initially thought.
That's my...
I mean, I secretly want that to be the biggest driver
because I think we have a better chance to control that
than some of the other ones.
And I think it probably is, that would be my guess.
And I also think it kind of makes sense
that if you have an immune system that's functioning
the way it's supposed to,
you can actually deal with the mutation accumulation because your immune system has's functioning the way it's supposed to, you can actually deal with
the mutation accumulation because your immune system has been declared those before they
become problems.
So now let's go back to the anti-aging thesis, right, which is we're going to take healthy
dogs, eventually healthy people.
We want to reduce the rate of decline, is probably the best way to think about it, right?
So we have a deterioration in organ function.
One of the things that's been surprising to me, again,
over the last few years, is the different ways
that rapamycin not only seems to delay the decline,
but it seems to make things better.
There clearly seems to be, in at least some organs, a rejuvenating function.
And I suspect that's mostly stem cell mediated, but again, the mechanisms haven't been worked
out yet.
So we've already talked about immune function.
You can take an old immune system and make it work more like a young immune system.
We've talked about cardiac function.
You can take an old heart, you make it work more like a young heart.
There's some evidence from David's lab that intestinal stem cells can be rejuvenated by rapamycin. We've recently published that
alveolar bone levels, so in the mouth, the bone around the teeth, can be rejuvenated back to
a more youthful level by short-term treatment with rapamycin. So there are now multiple different
places in the body, at least in mice, where you actually see
functional improvements back to a more youthful state.
And so I don't think rapamycin's gonna do that
for everything, but at least for tissues and organs
where stem cell senescence plays a big role,
I suspect that rapamycin can have not just an effect
on delaying declines, but actually bring things
partially back towards a more youthful functional state.
What's the best available evidence for that centrally in the CNS?
It's a good question.
So there are studies on cognitive function in mice showing that you can improve cognitive
function in aged animals.
I believe at least one of those
started the treatment late in life
and saw improvements in cognitive function.
And then in all of the major Alzheimer's disease
mouse models, the literature's a little bit mixed.
There's at least evidence that you can wait
until the pathology of the disease is set in.
You see the A-beta accumulated.
You see the functional deficits in terms of cognitive function.
You can start the treatment and you can improve things.
And on post-mortem, are you seeing an actual reduction?
Again, yeah, you are.
So, I mean, we haven't done this.
This is the work of several other labs in the AD area.
Yes. So again, the data is a little bit mixed.
So there are a couple of papers out there where they see that you can get really robust
benefits if you start rapid mice and treatment early, but they didn't see benefits in the
AD models when you started late.
And then there are studies that did see declines in aggregation, increased autophagy, and functional
improvements.
Even when you start staggering, if you could take an animal
and ultimately of course a human
who's already accumulating AB and Tau.
Yeah.
And even just halting that is a big deal.
There's one drug in the disease approved.
Now you're going right into my biggest pet peeve right now,
which is why there hasn't been or isn't a current
rapamycin trial for Alzheimer's disease.
But I think you're right. And again, three years ago, if somebody had asked me,
will rapamysin, is it likely to have any benefit
in somebody who's been diagnosed with AD?
I would have probably said no.
I come around to thinking that there's at least
a reasonable chance that it cannot just halt progression,
but it could actually make-
Well, especially if you, you know,
one of our colleagues is a neurologist here
named Richard Isaacson, and he runs
the largest Alzheimer's prevention clinic
in the country at Cornell.
You know, Richard's thesis, which I think makes a ton of sense,
is, again, I think other people share this view,
is you want to catch people while they just have
the first signs of myocognitive impairment.
Sure, absolutely.
And your ability to actually impact them is enormous.
And so the question is, why aren't those people being considered for clinical trials,
when we already know that these other agents aren't really doing anything?
Right, yeah, I agree.
I think that if I was going to design a clinical trial for Alzheimer's disease or dementia
with rapamycin that I thought had the best chance of success, that would be the target population.
Those trials are harder to do in some ways because they're longer, right?
And not everybody moves from MCI to full-blown AD at the same rate.
And we don't have, at least my understanding is, we still really don't have great predictive biomarkers
of how fast that's going to happen in an individual.
But that would be the study that would have the best chance of working.
Having said that, I still think there's a decent chance in somebody who's already gotten
to the point where they will be diagnosed as having Alzheimer's disease, serious functional
deficits.
There's a chance that Rappamysin could make things better.
Now, I get the practical reasons for why people don't want to try a risky clinical trial.
It's expensive.
If you fail, you know, your, then your drug gets a bad reputation, all of that.
So, I understand why people are hesitant to do that trial.
I think there's actually a pretty good chance of it.
Especially if you can combine it.
I mean, I think, you know, Richard often talks about and others do as well, that one of our
failures in Alzheimer's
is we consider it a single disease.
I agree.
It's as naive as saying, John has cancer.
Oh, well, gosh, that's the end of his life.
Well, don't you want to know what kind of cancer is?
Right.
Or maybe what mutation.
So similarly, but broadly speaking, and this is a gross oversimplification, if you consider
the metabolic version of Alzheimer's disease, the vascular version of Alzheimer's
disease, and then the sort of toxin clearance impaired version of the disease, to me, I'm
generally most optimistic about the metabolic one.
So the variant of this disease that seems to be mostly due to a failure of energy metabolism
in the brain, that also strikes me as the one that's most amenable to sort of systemic therapies
as well. If you improve insulin sensitivity, if you improve glucose disposal, if you reduce
hypercordicillemia, you can actually through nutrition, exercise, sleep, a number of other
things start to modulate that. That strikes me as the one where you want to at least take
your first shot at adding rapa.
I think you're probably right. Although, again, with rapid miceen, because we know that it is effective at, for example,
turning up autophagy, it might also be better.
It might work in the harder ones, so that's a harder one.
I agree.
I tend to agree with you.
I think that's a good point.
I also want to add that I actually think the biggest problem with the way that the scientific
community has thought about Alzheimer's disease, aside from considering
it to be one disease, is not really recognizing that it's a disease of aging. I really think
that one of the reasons why the preclinical research has been disappointing at developing
therapies for Alzheimer's disease is because very rarely have people approach that from the perspective
that this is a disease of aging.
And so something that can affect the mouse models of Alzheimer's disease when we create
this disease in young mice may not work the same way in an aged person or an aged animal.
And that's one of the things that also makes me optimistic about rapamycin is we already know
that it hits the hallmarks of aging.
And it also seems to be effective
in these Alzheimer's disease models.
So that makes me think that it's acting
at a sort of a more fundamental level
to target the molecular causes of this disease.
Well, especially look, I mean, if you can regenerate
a cardiac myosite from its stem cell,
it's not an impossible thought that you could regenerate neurologic stem cells.
Absolutely. And this is, again, an area where...
Which, which, I mean, 20 years ago, we would have said that's impossible, metaphysically impossible.
Right. Going back to the dogs for a moment, I, again, I'm not familiar with dog literature.
What is the fasting literature look like in dogs?
There's not a lot that I'm aware of either.
And I think that kind of makes sense.
So, you know, first of all,
you have to differentiate the literature
in laboratory colonies from companion dogs.
There's probably not much in companion dogs.
I don't know of true fasting experiments in like Beacon.
So we can use like the fasted versions
as proxies for what we would hope to see on the rapa dogs.
Which is the way they sort of did it in mice, right?
They sort of said, well, you know,
we know that if you colorically restrict this mouse,
this strain of mouse under this degree
of coloric restriction can expect
as much of a longevity boost.
And oh, low and behold,
rapa mice is probably even better than that.
Right, although from a metabolic perspective,
I think it's still unclear even in mice,
whether Rapa Mice and Chloric restriction
are working through the same mechanism.
And this is actually another area
where there haven't been a lot of good experiments done.
So there's a portion of the field
that argues strongly that the caloric restriction and
rapamycin are completely different.
Which to my mind is absurd.
I mean, we know that one of the main things that caloric restriction does is it inhibits
emtore.
And we know that rapamycin inhibits emtore.
So they're not fundamentally different.
So I think they are overlapping but distinct.
Not everything that caloric restriction does is going to be mimicked by Rapa Mison and vice versa. Having said that, when you look at the gene expression
profile or the metabolic profile, they don't look all that similar, at least at the low
doses of Rapa Mison. And so I think it's a little bit unclear. You're right, lifespan,
they both extend lifespan. Rapa Mison might actually extend lifespan across a broader
genetic background
than caloric restriction.
But when you get beyond that,
I think it's still an unknown,
whether there are, say, are there metabolic signatures
that are common to both
that might therefore be more likely to be causal.
I think we don't know the answer.
So what you're really getting at
is probably the next thought I had subconsciously,
which is could we use caloricly restricted animals
to develop a metabolic signature
as the gold standard for how we would then titrate
rapamycin, both in dose and frequency?
I don't know of any evidence to support that.
That would be a stretch.
Yeah, I mean, it might be possible,
but there just isn't much good data out there at this point.
I do feel like if we want to put the resources
into trying to identify predictive signatures,
which I absolutely think we should do,
I think the Metabolum is probably the place to go,
and the Serum Metabolum makes a lot of sense.
So that would be where I would look,
and nobody's really done it well.
Part of the problem is the data that's out there
for RAPA-MIS is, again, all at that very
low dose that the ITP tested originally.
We know that suboptimal for lifespan.
It's quite likely that the effects that the lowest dose of RAPAMICEN are having on metabolism
are going to be relatively modest compared to higher doses.
So the changes might be there, but they might be so subtle that you're not going to detect
them in a sort of high-throughput screening approach.
So I think there's a lot we don't know, but that would be where I would put my effort in trying to identify
serum, metabolomic signature of rapamycin that we could then correlate with the effects on
function in a variety of different tissues as well as life.
Yeah, because I mean I think as wonderful as it would be
to just wave magic ones and have biopsies of tissue,
it's just not going to be,
I mean, we're not gonna take cardiac biopsies.
Yeah, right.
So if you're looking for predictive signatures,
you can do those experiments initially in mice,
but you really have to think about,
is this something that's reasonable to do in a person,
or a dog?
Now, have you looked at the gut biome and the dog at all?
A little bit.
So we did a study in mice.
This was that study I referred to previously, where
we treated them for three months with either the high-high dose
or the high, but not high-dose.
And we did look at the fecal microbiome,
and we saw quite dramatic changes there,
some of which are interesting.
And so that's an area that we would love to pursue.
I've tried to get a grant to do that,
and so far haven't been successful through NIH.
But it hasn't been done in dogs yet.
Has not been done in dogs.
So we have a little bit of preliminary data
from our phase one study,
and we're seeing changes on the microbiome there as well.
So far the data that we've got in dogs
is not the sort of comprehensive
metagenomic approach or we sequence everything that's there. And it's more of a standard
veterinary approach where they have sort of broad classifications of different types of
microbes. And there are definitely changes with rapamycin. It looks, it's very early,
but it looks as though at least in dogs that have a bad microbiome, a dysbiosis in their microbiome,
which can be defined clinically from this test.
There were two dogs that we've looked at
that started out with a bad microbiome.
They were in the rapamysin group.
They were better by the end of the study.
Obviously don't know if that's meaningful or not.
So there are changes in the dogs,
but it's really too early for us to know
whether they look like the mice and or whether that is going to either be predictive or potentially play a role in
some of the effects of rapamycin.
It is definitely the case, though, in both dogs and mice, and I'm sure this will be true
in people as well, that rapamycin has a large effect on the composition of the gut microbiome.
I suspect that will also be true for other compartments in the body, like the gut microbiome, I suspect that will also be true for other compartments
in the body, like the oral microbiome, maybe even the skin microbiome.
Nobody's looked yet.
So, there's a lot to be done there.
I also don't necessarily think that's going to be unique to rapamycin.
I think that lots of drugs that we take.
Yeah, food will change then.
And absolutely diet.
And it's not clear if that's the effect or the cause of it.
Yeah.
So, one of the reasons why I think that there's reason to think that at least some of the changes in the microbiome could be causal for some of the effects of rapamycin
is that one of the things we saw in our mouse study was a pretty profound increase in
bacterium called segmented filamentous bacteria or SFB in the rapamycin treated mice.
It turns out if you look in the literature, there are links between SFB and diabetes and obesity
and also between SFB and T-helper cell maturation.
So it could be the case that changes that rapamycin
is having on this specific bacterium,
as well as other bacteria,
are then having effects both on potentially nutrient utilization and
uptake, but also direct effects on say immune function. I mean the intestine is
an important immune compartment. The bacteria are physically right there. These
SFB actually form filaments directly associated with the intestinal cells.
So it certainly could be the case that there are signals being sent back and forth
that RAPA-MICEN is modifying
through modification of the composition of the microbiome
and that that's affecting immune function,
adiposity, all sorts of different possibilities.
So like I said, that's something
we're really interested in testing.
There's like an infinite number of things I wanna know.
Yeah, there's this company out there
that's looking at Duodinal ablation
to ameliorate diabetes.
And the data are actually really interesting.
So interesting, in fact, that when I first saw them,
I thought this has got to be nonsense.
What's not clear is the durability and the economics
of it, just from a scientific standpoint,
they're doing these ablations of the Duodinal Mucosa
and they're seeing like immediate step function changes
in insulin sensitivity, arguing in fact that this may be the mechanism by which the Ruinwai gastric bypass
is emulating type 2 diabetes. It's basically taking this dysfunctional duodenum out of the loop
and just saying, we're going to Junum to Junum, or you know, stomach to Junum to Junum basically.
It's really interesting. So this is another area that I've gotten interested in, and we haven't really dove into
it yet much.
But I think there's clearly a literature growing in all of the model organisms that with aging
there is a decline in intestinal barrier function, and that at least in flies, that seems to
be causal for death.
So in other words, it's strongly correlated,
and there are ways, every way that extends lifespan
also seems to improve this intestinal barrier dysfunction.
And I've been thinking, and we have, again,
a little bit of data suggesting that
RAPA-MISIN might actually have an effect
on this age-related decline in intestinal barrier function.
And why would a loss of intestinal barrier function be important?
Well, one thing that happens, we know this happens,
is that you tend to see an increased level of microbial proteins
and DNA in the circulatory system with age.
That causes an inflammatory response that
may contribute to the systemic increase in inflammation
that we see during aging.
So the loss of intestinal barrier function may actually drive, to some extent, the
inflammation, the increase in inflammation with aging, or at least contribute to.
And so anything that you can do that is going to improve that will potentially have an effect on systemic inflammation.
And that again could be another way that Rapa rapamycin is sort of impacting the entire body
in addition to the effects of rapamycin when it gets to a cell and inhibits emtory in
that cell.
And whether that's through changes in the microbiome, you know, or changes in intestinal
stem cell, like Xavitini has shown right, there's lots of possible ways that it could
be working.
But I do believe that this decline in intestinal barrier function with age probably is contributing
to this sort of increase in systemic inflammation that we see during aging.
And it's very clear that that happens in people and in non-human primates as well during
aging.
Now, talking about people again, I don't hold out much hope that there's going to be an anti-aging trial in humans
using rapamycin or a rapologue.
Watching how much difficulty it is to even try to get that study done with metformin,
which is about the most inert, you might as well just do it with drinking water.
We're going to randomize you to self-serversus flat water here.
The real question is for the people who want to be on the tip of the spear, you're not
going to have gold plated stamped RCT.
You're going to have to triangulate from everything else.
Many roads point to your work and more importantly, what your follow-up work will look like.
So again, I realize that to try to secure funding to do this from NIH is slightly more
complicated than trying to get bipartisan support on healthcare.
But if we took the economics out of the equation, if there was a 10 to 20 million dollar pool
that the National Institutes of Aging said, you know, Dr. Kiberlin, we want to, we want the definitive work on
how to extend the life of dogs, knowing that that's probably the best thing we're going
to get towards humans.
What do those experiments look like?
Right.
So, the study that we want to do is a five-year study with rapamycin.
And certainly, this is scalable, right?
So, what we have designed is a study with
Rapa mice and there are other interventions coming down the pipeline that I think have
the potential to be as effective as Rapa mice. So this doesn't necessarily, as long as you
can do it safely in pet dogs, you can test any intervention. And one of the things that
I am now convinced is owners are enthusiastic about participating
in these kinds of studies.
We've had more than 6,000 people sign up through our website with no advertising at all
to participate in the rapid-mice and-
And human clinical trials, which I'm more familiar with recruiting cost is an enormous
cost.
Yeah, it doesn't cost anything.
Yeah, you get free recruiting.
Right, right.
So having said that, the study we would like to do is a five-year study in dogs starting
treatment at middle age so again the dogs would come in you know at least six years old we might
push that up to seven or eight years old and they'd probably there would probably be a weight
limiter like I talked about before because again big dogs age faster so let's just say 40 pounds
six years old at least six years old so there will be dogs anywhere from six to 10 or 11.
Bring in 450, 500 dogs, or enough dogs to get 450 all the way through the study and look
at not just lifespan, but lifespan is actually a really important metric here, right?
Lifespan is certainly still the gold standard in the aging field.
If we want to convince the scientific community that this is affecting aging, it darn well better
increase lifespan. It's also important to owners for obvious reasons. And I think because as we
talked about, euthanasia is really what most dogs die from because the dog gets sick enough that the
owner and the veterinarian decide that it's time to put the dog down. I think lifespan is actually a really good metric
of health span in dogs.
Because most of the time that's not an easy decision, right?
Owners are not going to put their dog down usually,
especially owners who want to participate in a study like this,
unless that dog is really sick.
So I actually think lifespan is really maybe more important in dogs
as an outcome measure than it is in mice. So lifespan is one of the key endpoints that
we want to look at. And then we want to look as broadly as we can at functional
measures of aging that we know are important in dogs. And so this goes way back to
what we were talking about before, what do dogs get sick with as they get older.
So heart function we will definitely look at,
in part because that's what our preliminary data.
Yeah, you showed that with a handful of dogs.
We have good evidence that we can detect
and expect to detect improvements in cardiac function.
Activity, so one of the nice things about dogs is,
you can put a GPS tracker on their collar
and get very quantitative measures of activity.
As the sensor technology improves,
it might be feasible to use a microchip
instead of a GPS tracker on the collar
to also get some physiological measures.
Or just draw a fit that on their wrist, yeah.
Yeah, right.
Well, I mean, that's really what the tracker
on the collar is, right?
But it would be nice to get some physiological measures
in sort of continuous real time, if we can.
So far, the sensor technology isn't quite there,
at least that's my understanding.
But well, at least get activity,
and that'll give us a measure both of things like arthritis
or dogs that have arthritis are going to be less active
and also muscle function and also how well are they feeling?
Again, a dog is more likely to be active if it feels well.
Now, obviously that's confounded a little bit
by whether the owner takes the dog for a walk,
but I still think total activity
is an important thing.
And is this a three group study in your mind?
So the study that we're designing now
is three groups, it doesn't have to be,
but the three groups are a placebo group,
short term group, so six month or a year long treatment,
and then the continuous treatment group.
The reason for doing that, again,
comes back to the mouse data in part,
because we, as I mentioned,
we've published that a short-term treatment in mice
is enough to give you large benefits on lifespan,
and at least some measures of health.
And also because, again, as we're thinking
about ultimately bringing this to people,
it's easier to envision transient
or in a mixed treatment than it is a continuous for the rest of your life.
So it would be single dosing.
That's the way we have the study design now.
I can see a rationale for doing three months on, three months off or some variation on that.
We felt that the simplest thing to do first.
So it's always a balance between getting as much information as you can from a study like
this and doing things that are going to be where the complexity isn't so great that it
is.
Yeah, your power analysis could give you a study.
So the design that we're working with now is one year on and then the rest of the time
off.
So we'll get.
So I have one group that's five years on, one group that's one on four off,
and then placebo, blinded across the board.
It's all gonna be a randomized double blind trial, right?
In addition to lifespan and heart function and activity,
we'll track cancer incidents.
Probably kidney function.
Kidney function, get routine blood chemistry on the dogs,
probably every six months,
we'll ask the owners to bring their dogs in, Kidney function. Kidney function. Kidney function. Kidney function. Kidney function.
Kidney function.
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Kidney function.
Kidney function.
Kidney function.
Kidney function.
Kidney function.
Kidney function.
Kidney function.
Kidney function.
Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidney function. Kidneyrition. So it would run about 5 million.
That's about the budget for that study.
Some of that depends on what we can ultimately
get the rapamycin for.
Because right now, it's the street values about.
The lowest we've been able to find is about $7.00
a milligram.
Now, it may be possible if we have a large study
that we can identify a supplier that would kind of
deal for less.
And the drugs are actually a pretty large amount of the budget.
The veterinary costs are the other large expenditure.
Again, the nice thing about companion dogs, it's unlike a study in mice in the lab,
is they live with their owners.
We don't pay cage costs and things like that.
The other major costs are going to be for the analysis. The analysis, and also we need people to be able to communicate with the owners.
Retention will be important.
I don't think it's going to be as hard as it is for some clinical trials, just based
on our experience.
Even though it was a short-term trial, the owners that came into the short-term trial,
they were extremely...
This will be easier than communicating with patients in a trial.
I think so. Yeah, and there's actually, I mean, it's kind of funny, but there's actually data that dog owners are more likely to give their dog a
prescription medication than they are to take their own prescription medication. I would not doubt that for a second.
So, yeah, so the owners that come into this study are highly motivated, and some of them are
extremely disappointed after the study ends when they find
out their dog was in the placebo group. But there is a communication component to this where
we have to keep the owners engaged, maintain communication, we'll be sending out regular
surveys, but it needs to go beyond the surveys.
That would, these all have to be dogs that live in the Northwest. They'd have to be able
to come in to...
In fact, they almost certainly would not be. So the way that we're planning the study now is that we will partner with five to seven
veterinary schools around the United States.
Oh, that's great.
And that actually, there's lots of reasons why that makes sense.
Well, diversity alone is right.
But veterinary cardiologists, there's not a huge population of veterinary cardiologists
out there.
So if we were to try and do a study like this in the Seattle area, I don't think that we have the enough veterinary cardiologists to actually do just a cardiology part of the
study. So fortunately, you know, veterinarians are very enthusiastic about participating in projects
like this and we have collaborators lined up at the vet schools around the country. So it
will probably be five or seven sites. Obviously all of those sites have to have veterinary cardiology. But almost any major veterinary school is going
to have that. And we prefer to work with veterinary schools that are in a suburban or urban area.
Some veterinary schools like like our school in the state of Washington is all the way on
the other side of the state from Seattle. It's kind of out in the middle of nowhere. So that makes it harder to get owners to actually bring their dogs there.
Yeah.
So our lead veterinarian is at Texas A&M Veterinary College.
And so she would be the head clinical person on the study.
And that would probably be the site that the other veterinary sites coordinate with.
Yeah.
Well, Matt, I could sit here and have a discussion for another two hours.
It's fun stuff to talk about it.
It is.
And I really appreciate your time in your insights.
And I think the work you're doing is certainly what I would
consider to be among the bodies of work that
are at that tip of the spear, because I guess I don't have
a lot of hope we're going to get the answer to this question
directly.
I think it's going to be an indirect triangulation of data.
And I think to be able to do this in companion dogs
that live in our environment is gonna be a really important thing.
So let's see if we can get that study done.
Yeah, I also wanna, I mean, I think it's also important
to at least note the impact of a study like this
would have on public perception, right?
I mean, I think in the absence of any data, and then the little bit of data we got from
the Phase I study, the amount of media attention that we've got.
Yeah, I've heard you on NDR talking about this with Terry Gross.
Right.
It has been huge.
And so I tend to agree with you that it's going to be challenging to generate enthusiasm
for a double blind placebo-controlled clinical trial of
rapamycin for healthy aging and people.
Challenging is probably not even a strong enough word.
But I think we should at least not underestimate the potential impact if we're successful at
accomplishing this in people's pets, that that will have on public perception, as well
as perception among the broader scientific
community. I do feel like the field of aging research still has a bit of a reputation problem
among the broader scientific community. Part of that is historical. Part of that is because there
are some fringe elements that get a lot of attention, but that aren't scientifically credible.
I think that actually being able to show in dogs,
living in the human environment that we can modify aging,
will have an impact not just on the public,
in terms of I'm sure we'll get lots of media attention,
but also among scientists who might actually say,
okay, aging research has arrived.
I think that's happening already.
I think the tame trial has actually been mostly
a positive in that sense, or the proposed tame trial,
I should say.
But I think we still have some more to do.
With the listener is,
the targeting agent with metformin.
Yeah, which is, I mean, I support that study.
I think that it's probably the right first study
in this area, because as you've already said,
metformin, we know that it's very safe, at least as far as a drug you might consider for a study like this area because as you've already said, metformin, we know that it's very safe,
at least as far as a drug you might consider for a study like this. It's very safe.
There's very good human data suggesting that diabetics taking metformin not only have
less diabetes, but they have fewer other age-related diseases. So I think the human data is
pretty compelling. The downside to metformin, and I think one of the reasons why it has been a struggle to
get that study funded is that I think there's a perception that we already know about metformin.
It's not going to be completely surprising given the literature that's out there if it
does have relatively small effects on other age-related diseases.
And then I also think it probably isn't going to have that large of an effect.
I could be wrong, I hope I'm wrong. But again, my view of the literature that's out there
is that Medformin probably has modest effects,
but they're not gonna be 20% increase in lifespan
and rejuvenation of heart function and immune function.
So I agree.
So I think that that's probably the downside to that study.
But again, because we're also battling this perception of resistance to the potential for
side effects when you're talking about treating healthy elderly people, that's probably the
right way to design this first study.
The other thing about the tame trial though is it's not being done in healthy elderly people,
right?
The people that they're enrolling have to have at least one age-related disease,
and it can't be diabetes.
So even that is really not the gold standard study
that we'd all like to see, whether it's metformin
or rapamysin or something else.
We've got some work to do to get
to where we can actually do that study.
And maybe the path forward is, as you said,
individuals who are willing to kind of come together
and do these sort of self-experiments,
if you can do it in a rigorous way where you're actually measuring the things.
There needs to be a model system that allows it so that if you and I and Bob and Rick and
John do it, we're, you know.
The downside to that kind of a model is that it's still going to be hard to convince,
just the scientific community, the way that it is.
No, of course.
It's much harder to convince you that it's real.
Having said that, if the effects are robust and you see it over and over and over in
multiple people, we'll get there eventually.
So that may be the path that we end up taking.
You know, I'm not betting on that path.
I'm betting on the path that you're describing
as being the shortest distance between these two points.
And I hope that as we start to do more of these studies
in dogs and also the preclinical stuff in mice,
as we start to find functional measures
that are improved over a relatively short time frame,
that people will start to do some of these
clinical trials that are feasible in people.
I mean, you could, I mean, no vardices already done it, right?
You can do a clinical trial where you treat healthy elderly people for six weeks, eight
weeks, ten weeks, and look at a functional outcome.
And so if it's the case that RAPA MISIN rejuvenates a immune function and rejuvenates cardiac
function and delays or restores alveolar bone levels in the mouth, right?
Those are clinical endpoints that are impactful and could be studied in a short clinical trial.
So we may get a few of those that will kind of build this body of evidence that rapamycin
is having a similar effect in people.
Again, the hard part is there's not a lot of money in rapamycin, so I don't know who's
going to fund those trials.
That's the challenge.
That's right.
So we need to identify.
So either it's going to be rapamycin derivatives that are under patent, like Novartis has developed
and now Restor Bio is further developing, or it's going to be alternative funding sources,
whether that's foundations or wealthy individuals,
who recognize the potential impact of this work
and are willing to fund a clinical trial
and actually start to look at some of this.
Matt, thanks again.
It's the super interesting and best of luck
when you continue to work.
Thank you.
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