Equillium, Inc. Common Stock Stifel 2026 Virtual Immunology and Inflammation Forum

Well, thanks for everybody to join. Thanks, Alex, for hosting this, and Steve, of course, for throwing the event on. Just very quickly, Equillium is a company that was founded back in 2017, went public in 2018, and it's historically really focused on novel mechanisms of actions which can really bring benefit to patients, in areas of high unmet medical need, be that rare or common diseases. Our latest two programs, the EQ504, which is an oral aryl hydrocarbon receptor that's being formulated for colonic delivery. But then we also are working on a lung formulation, an inhaled formulation for a variety of fibrotic or inflammatory lung diseases.

We also have EQ302, which is an oral peptide that inhibits both IL-15 and 21, which we'll be developing for celiac disease, but of course, there are a number of other potential indications where IL-15 and/or IL-21 could be really important. As we stand here today, we're well-capitalized for those programs in terms of the development, namely a phase I study for EQ504 that's initiating here within Q4, and we'll have data within six months of that. Then we'll be working on lung formulations and IND-enabling for a potential lung program, as well as IND-enabling and scale-up manufacturing activities for EQ302. So a lot of activities ongoing. We're really, really excited about those programs, in terms of the value they can bring to patients. So with that, Alex, I'll open it back up for you to questions.

Yeah, sure. Equillium's historically been a company focused on mucosal immunology of the gut, the lung, et cetera, the skin. We had partnered itolizumab during the phase III that read out early last year. We had noted that if that was the successful story, we would have capital, but no pipeline, and if it was unsuccessful, we would have very little capital and no pipeline. So we set about looking for mechanisms that could be really valuable in a variety of different indications, ones which had good validation, but we could solve for delivery, pharmaceutics, et cetera. We'd become particularly interested in the AhR pathway. We'd looked at a number of different molecules across those derived from botanicals, those that are entirely de novo designed. We had settled on EQ504, which is derived from ITE. ITE was the first naturally occurring AhR modulator.

It was synthesized in situ in the guts and lungs of humans. It was discovered out of Madison, Wisconsin in 2002. A company then looked at using the natural product as a drug. Later, that was acquired by Desheng Capital. Arogen was the company, and they conducted a really comprehensive medicinal chemistry campaign that really improved the properties, improved the potency, selectivity, and drug-like properties, of ITE and its analogs, and that's where EQ504 comes from. Really, that molecule was developed to really solve for a lot of the challenges you have with AhR modulators. The first one is they're incredibly insoluble by nature.

Yeah. Alkyl heterocyclic compounds. If you're going to deliver something to the colon, it needs to have a degree of solubility in an environment that really doesn't have much aqueous or fluid.

The next one is selectivity. Again, aryl hydrocarbon receptor modulators are flat, typically planar. Our molecule has a chiral center, and it's very selective for AhR. Then lastly, things like PK, metabolites, et cetera, have all been tuned. So we like to think that we've taken what is nature's scaffold, a bio-inspired competitive advantage, and derived from that a very, very attractive drug, to be used as a molecule for oral delivery as well as potential inhaled delivery.

Yeah. The aryl hydrocarbon receptor resides in our barrier tissues predominantly.

Yeah. Also expressed in the liver.

Its role in the barrier tissues is to take chemical signals and turn them into biological functions. We tend to think about those in two main buckets. The first one is xenometabolism. As we are bombarded with all of these compounds each day, particularly things like aryl hydrocarbons, which can be promiscuous molecules, that is absorbed by our tissues. It activates the aryl hydrocarbon receptor, and that causes metabolism of the molecule. But that typically happens predominantly these xenobiotic mechanisms for exogenous molecules, things like drugs or toxins. But there are a second class of ligands. These are these endogenous or exogenous dietary derived, and they trigger the second bucket of activities, and that is things like modulating the barrier function and immune homeostasis. The reason we were attracted to ITE is it is the naturally occurring molecule.

It triggers mostly the barrier function and immunology. When we think about this in the drug development perspective, not all of these modulators have the same chemical signature, and that is really important. There is a concept in agonism called biased agonism. You see it with PPARs, glucocorticoids, selective estrogen receptors. One of the key elements when we were looking for an aryl hydrocarbon receptor modulator was does it have strong activity in modulating both the immune system and barrier function? Because not all do. There are hundreds, potentially thousands of AhR modulators, but they all have distinctly different signatures. That is something that we spend a lot of time really honing in on, and plays an important role as we think about indication selection.