Jonathan Zalevsky
Analyst · William Blair.
Sure. Andy, thanks for asking a human generic question, and that's super cool. So TNFR2 validation comes from a number of different sources. And before actually touching on human, let me touch on a few of the critical preclinical findings that I have made. So TNFR2 has both been overexpressed and it's been knocked out. And you see the kind of corollary phenotypes, like when it's gone, animals have a hard time maintaining T reg populations.
They also have a hard time amounting any kind of burst of T regs or T reg control, like in the setting of a model like PEG, for example. If you run EAE in TNFR2 knockout, the disease is extremely exacerbated, right? And it's much, much worse than it is. And whether you use [indiscernible] PLP, a similar kind of results.
Likewise, when you drive its expression, you could reduce the ability to even insult using various inflammatory agonists. Also studies that have made transmembrane TNF mice -- some of the studies that Jonathan Zedrick did in the early 2000s. Since that's the primary ligand, you really get TNFR2 in as the primary signal model. And again, you had very similar kinds of effects where those animals were driving R2 and they remain highly immunoregulatory.
Very hard to create an inflammatory model in that background. And then people, we see a kind of cluster of tips and other kind of polymorphism to go together. So first, like the most canonical sort of T regs like dysfunction is IPEX, right? And IPEX in humans is when you have a FoxP3 loss of function, very severe autoimmune skin type of disease.
And actually, TNFR2 [ sniff ] and things modified TNFR2 expression or signaling actually can resemble IPEX is not be as severe because obviously knocking out FoxP3 is much more severe than losing TNFR2. So I hope that answers your question. There are many, many streams of validation of TNFR2 and probably, I guess that one more is actually just sort of coming from the field that's using TNF and inhibition, right?
So we know that if you treat with a pan TNF inhibitor like Humira, REMICADE or Belimumab, pick your favorite what, right? They knock out transmembrane and soluble and you see that that's contraindicated in a number of indications. And it's a removal of that transmembrane that takes away the TNFR2 signal that kind of short circuits what you're trying to achieve therapeutically. So all of those roads kind of lead to Rome, and they've really led the field come to understand that the 2 receptors, R2 and R1 are they share very differentiating functions and that R2 is like the natural antagonist to R1 and it seems to turn off that inflammatory pathway that TNFR1 drives, it's highly tissue protective. So to create an agonist to capture that kind of biology could be we really, really therapeutically ideal and that's what we're trying to do.