36 - IND-Enabling Studies Overview (S3E6)

All right, so today we're taking a deep dive
into this mountain of research you sent over
all about IND applications. That critical step
that takes a new drug from the lab to actual
patients. And I think it's really fascinating
how a company has to prove their drug is safe
and effective enough to even think about. human
trials. Yeah, it really is a high stakes process.
It is. You know, you are essentially building
a case to convince the FDA that your drug deserves
a chance to actually become a treatment. Right,
and that's what we're focusing on today, these
IND enabling... Studies the research that a company
needs to do before they can even consider giving
their drug to a human volunteer Yeah, it's like
laying the foundation You wouldn't build a skyscraper
without making sure that the base is totally
solid and the same principle applies here So
what are the key parts of this foundation? What
kind of studies are we talking about? Well, there
are three main pillars toxicology studies to
make sure the drug is safe for pharmacokinetics
or PK to understand how the drug moves through
the body and efficacy studies to show that it
actually works Okay, let's start with toxicology
I mean, that's got to be priority number one,
right? Oh, absolutely. Making sure the drug isn't
going to cause any harm. You got it. Toxicology
studies are all about assessing risk. Researchers
expose animals to different doses of the drug,
and they meticulously track any adverse effects,
everything from mild reactions to serious organ
damage. Oh, wow. So they're not just looking
to see if the drug is, you know, immediately
lethal or something. They're trying to find subtle
long -term effects as well. Exactly. They're
looking at the drug's impact on specific organs,
liver, kidneys, heart, you name it. They're also
studying how the drug behaves over time. Does
it accumulate in the body? Does it break down
into harmful products, it's an incredibly thorough
process. That is good to know. So all of this
is happening before the drug is anywhere near
a person. That's pretty reassuring. It is and
you know this very meticulous approach is driven
by strict regulatory guidelines that are set
by organizations like the FDA and the International
Council for Harmonization or ICH. Okay so there's
a whole rule book for how these toxicology studies
need to be conducted. There is these guidelines
ensure that the data is reliable and the studies
are ethically sound. For example, they might
say which animal species are most appropriate
for a certain study or how long those animals
need to be monitored after they've received the
drug. I see. So it sounds like they are trying
to eliminate as much variability as possible
and potential for error. It's like building a
scientific fortress around the data. That's a
great way to put it. And that same level of rigor
applies to the other two pillars, PK and efficacy.
OK. Well, let's talk about PK then. I think that's
the one that always seems a bit mysterious to
me, how a drug moves through the body. It's basically
a roadmap. PK studies track a drug's journey
from the moment it enters the body to its elimination,
absorption, distribution, metabolism, excretion,
ADME, as it's often called. ADME. OK, got it.
So they're looking at how the drug is absorbed
into the bloodstream, where it travels in the
body, how it's broken down. and how it's eventually
excreted, but why is that all so important? Well,
understanding a drug's PK is absolutely crucial
for figuring out the right dose and dosing schedule
for humans. You know, you need to make sure that
the drug reaches its target effectively, but
without causing any toxicity. So let's say you
have a drug that's rapidly metabolized by the
liver. You might need to give it more frequently
or in a higher dose to make sure there's enough
in the body to be effective. That makes sense.
So it's not just knowing how the drug moves.
It's using that information to really optimize
how it's used in people. It's like fine -tuning
a machine. Yeah, precisely. And PK studies can
also uncover some really interesting insights
about potential side effects. You know, for example,
a drug that can easily cross what's called the
blood -brain barrier might be more likely to
cause neurological side effects. Wow. So just
by studying how a drug moves through the body,
you can start to predict how it might behave
in humans, both the good and the bad. Exactly.
And that's just one piece of the puzzle. We still
need to look at efficacy. You know, does the
drug actually do what it's supposed to do? Right.
Because a drug could be safe. and have a perfect
journey through the body. But if it doesn't actually
work, what's the point? So how do researchers
even tackle that question in this preclinical
stage? Well, that's where efficacy studies come
in. And they are designed to provide evidence
that the drug is effective at treating the condition
it's meant for. And this is where things get
really interesting because researchers need to
create a model that actually mimics the human
disease that they're targeting. So if you're
developing a drug for, say, Alzheimer's disease,
you wouldn't just test it on any mouse. You'd
need a mouse that exhibits some of the same hallmarks
of Alzheimer's. Exactly. And that's just the
beginning. The study design itself has to be
incredibly rigorous. You know, you need to have
a large enough sample size appropriate controls
and clear endpoints that can be objectively measured.
It sounds like there's a lot of pressure to get
these efficacy studies, right? Because after
all they are the proof of concept, right? Right.
The data that shows that this drug might actually
work in humans. Absolutely. And that's where
those regulatory guidelines we talked about earlier
come back into play. You know, the FDA and ICH,
they have very specific requirements for how
these efficacy studies are conducted. And the
data that they generate has to be really, really
solid. OK. So let's say a company has completed
all three types of studies, toxicology, PK, and
efficacy. the data looks promising what happens
next. Then they compile all of their findings
into a huge dossier called an IND application,
and it's their formal request to the FDA to begin
human clinical trials. So it's more than just
presenting the data. They're essentially making
a case to the FDA, arguing that their drug is
worthy of moving on to becoming an actual treatment
for people. Exactly. They need to really demonstrate
that they have a deep understanding of the drug's
safety profile, its journey through the body,
and its potential effectiveness. And they have
to do it in a way that's clear, concise, and
scientifically rigorous. Remember, the FDA's
number one responsibility is to protect public
health. Right. So the FDA reviewers are kind
of like scientific detectives. They're scrutinizing
every single detail of the IND application. That's
a great way to think about it. They're looking
for any red flags, you know, any gaps in the
data and consistencies in the study, designs
any concerns about potential risks to those human
volunteers. So even if a company has followed
all the guidelines and you know the data looks
good on the surface, there's still a chance that
the FDA could say no. Absolutely. The IND review
process is so thorough and the FDA will not hesitate
to request more studies or clarification if they
have any concerns at all. Wow. It's really hitting
home how much goes into this process. We've only
been talking about the preclinical stage. I can
only imagine how much more complex it gets when
you start testing the drug in humans. Oh, yeah.
It definitely gets more complex. But the preclinical
stage is so critical. It's the foundation that
the entire drug development process is built
on. So we've got these three pillars. Toxicology,
PK, and efficacy, all meticulously designed and
conducted according to all these strict regulatory
guidelines. But it's not just about checking
boxes, right? You mentioned this overarching
idea of data integration earlier. The FDA doesn't
just want to see three separate reports. They
want to see how the data from all three studies
fit together. You know, how does the drug's safety
profile align with its PK properties? Does the
proposed dose and dosing schedule make sense
given the drug's behavior in the body and its
observed effectiveness in the animal models?
It's like putting together a puzzle. Each study
provides a piece, and only when you put all the
pieces together can you see the complete picture.
Exactly, and that whole picture, you know, that
integrated understanding of the drug is what
allows the FDA to make a well -informed decision
about whether or not to allow the drug to move
on to human trials. I'm realizing that there's
so much more to drug development than just, you
know, discovering a new molecule. Yeah. It's
this incredible journey of scientific rigor,
regulatory oversight, and ultimately, you know,
the hope of bringing a new treatment to people
who really need it. It really is. And while the
preclinical stage may seem like just the first
step, it's arguably one of the most critical.
It's the stage where those researchers lay the
foundation for a drug success and where they
try to answer that most important question. is
this drug safe and effective enough to actually
test in humans? What I find so fascinating is
that we've been talking about this from a very
scientific, you know, data -driven perspective,
but there's this human element to it too, isn't
there? Absolutely. Behind every single IND application,
there's a team of incredibly dedicated researchers
who are driven by the desire to make a difference
in people's lives, and behind every potential
new treatment, there are patients waiting and
hoping for a breakthrough. Okay, so we've covered
those three key study types. the regulatory landscape
and the importance of data integration. What
else should we be considering as we try to really
wrap our heads around this whole IND application
process? Well, one thing that is often overlooked
is the huge amount of collaboration that's involved.
Collaboration in what way? Well, you've got toxicologists,
pharmacologists, efficacy experts, statisticians,
regulatory specialists, all of these different
disciplines coming together to contribute their
expertise. It's like an orchestra with each section
playing its part to create a harmonious whole.
And the conductor in this case is? The project
leader. They're the one who's responsible for
coordinating all the moving parts, making sure
that the studies are conducted according to the
plan, and that all of the data is meticulously
analyzed and integrated. So it's not just about
scientific brilliance. It's also about project
management, communication, and teamwork. Exactly.
And that's something that people don't always
fully appreciate. It really takes a village to
bring a new drug to market. And the preclinical
stage is where that village comes together. This
has been incredibly eye -opening. We've gone
from thinking about these individual studies
to seeing the IND application process as this
intricate web of scientific disciplines and regulatory
guidelines and collaborative effort. It's amazing
to see how much work goes into building a case
for a new drug before it even reaches a human
volunteer. It really is remarkable. And remember,
we've really only just scratched the surface
here. There's a whole world of fascinating details
within each of these study types. And we could
easily spend hours unpacking them all. Well,
I am definitely intrigued what stands out to
you as particularly fascinating within this world
of preclinical research, perhaps something that
our listener would find particularly interesting.
One of the things that I always find so fascinating
is how researchers actually figure out the right
dose for a new drug. It's a lot more complicated
than just picking a number at random. Yeah, how
do they determine what goes into it? Well, you
start with those toxicology studies. They give
us the drug's safety margin, that range of doses
that are likely to be safe for people. But, you
know, it's not just about avoiding toxic effects.
You also have to think about the drug's PK properties.
How fast is it absorbed? How long does it hang
around in the body? How is it metabolized? Oh,
right. So the PK data helps refine the dosing
schedule, like how often someone would need to
take the drug to keep enough of it in their system.
You got it, but it doesn't stop there. You also
need to consider... efficacy, what dose is needed
to actually have the desired effect, and that's
where the animal studies are so important. I
see it's all coming together now. You're essentially
taking information from all three study types,
toxicology, PK, and efficacy, and using that
to come up with a dosing strategy that works
the best and minimizes risk. That's it, precisely.
It's a complex puzzle, but it's a puzzle that
researchers are getting better and better at
solving. And, you know, that's really good news
for patients because it means that new drugs
are more likely to be both safe and effective
when they finally do make it to market. OK, so
we've covered a lot of ground here. We've talked
about the three pillars of preclinical research,
toxicology, PK, and efficacy. And we've seen
how these studies are shaped by strip regulatory
guidelines and this spirit of collaboration.
We also touched on data integration, putting
all those pieces of the puzzle together to get
a complete picture of the drug. It's clear that
the IND application process is a complex and
really challenging thing, but it's also super
exciting. It's the gateway to bringing new treatments
to people who are waiting and hoping for relief.
It really is. And remember, this is just a small
glimpse into the world of drug development. There's
a whole universe of information out there. And
I would really encourage you to keep exploring.
Oh, I definitely will. And to our listener, I
hope this deep dive has piqued your curiosity,
too. The journey of a new drug from the lab to
the pharmacy is a long and winding one. but it's
filled with scientific breakthroughs and collaborative
spirit and ultimately the promise of improving
human health. Well said. Keep asking those questions,
keep learning, and don't ever underestimate the
power of scientific discovery. Until next time,
stay curious.