Dr. Holly Fernandez Lynch

You're not gonna be able to get people to enroll in the study and you're not gonna be able to get your ethics approval if you don't have an appropriate standard of care.

But that's more, that turns out to be more complicated in practice.

There can be debates about what's the appropriate standard of care.

There's so much in that question that you just asked.

There's lots of different ways that you can meet that standard of effectiveness.

The best way is to show that this drug has a positive impact on how the patient feels, functions, or survives.

Those are things that we typically refer to as clinical endpoints.

You don't need a laboratory test.

You don't need a scan.

Right.

The patient will be able to tell I'm feeling better.

And over the course of looking at many patients, you would see a different outcome in their in their disease.

That is in contrast to what is referred to as surrogate endpoints.

Surrogate endpoints, they don't directly measure how the patient feels, functions, or survives.

Instead, they measure outcomes that are reasonably likely to predict the thing that we actually care about.

So I'll give you an example from the HIV context.

We know that if we can influence a patient's viral load or their CD4 counts, that is going to

have an impact on their disease course.

Those are called validated surrogates.

We know exactly how they relate to the outcomes of interest.