Good morning, everyone. Thank you very much for joining us at the H.C. Wainwright Global Investment Conference. My name is Brandon Folkes, and I am one of the equity research analysts here at H.C. Wainwright. Next up, we have a fireside discussion with Enanta Pharmaceuticals, and joining me is Jay Luly, CEO, and Tara Kieffer, Chief Product Strategy Officer. Jay, Tara, thank you very much for joining us. Thank you. Jay, I like to just open these discussions with just turning it over to you. You have had a very good last 12 months, right, in terms of data readouts, but there is also a lot ahead in the next 12 months. Can you just walk us through the success you have had in the last 12 months, and then maybe some of the big events that we are going to see over the next 12 months? Sure. Before I begin, I want to remind you that I will be making some forward-looking statements. For a summary of the risks associated with these statements, please see our filings on sec.gov and on our website. The last 12 months, I think one of the things that the 12 months have given us is a real insight into how to treat high-risk RSV patients. So we had a data set that set the stage for what is now a registration study for zelicapavir, our lead RSV asset. The other is it has allowed us a chance to sort of spread our wings and grow beyond just virology in the I&I space. To that end, we've brought forward a KIT inhibitor into the clinic, a STAT6 development candidate, and a new program that's also going after mast cells as KIT is MRGPRX2, and setting the stage for the next 12 months of having data sets starting to read out in multiple of those. Fantastic. Yeah. I do want to start with zelicapavir, just given how novel that could be. Following your end of phase II interaction with the FDA, what did you learn that gave you the greater confidence in the registrational path here? Well, one thing, again, there are no approved RSV treatments. Prophylaxis, after 70 years, has started to come onto the scene, but treatments are still unavailable for patients. One of the things that we wanted to sort out is really trying to figure out what is the path to registration, since no one's ever done it before. To that end, we had an end-of-phase II meeting with the agency and really sat down to design what is the trial design, the path, registration endpoints, patient populations, et cetera. Where we landed was the good news is we didn't need to do two phase IIIs. FDA said as long as we had this supportive lead-in phase IIb study to the phase III, it could be a single phase III. That was good. We aligned on the HR3 patient population as being a good one to test. That was the patient population where we saw a signal in our prior high-risk adult study, where we saw that patients 75 and older or who had COPD or who had congestive heart failure, those three patient populations, if you will, and some had multiple of them, were in a position to give us a strong signal. We saw that. So we agreed on the patient population and also the endpoint, the time to complete resolution of symptoms. We also saw an effect on hospitalization, so that was good. We're looking at that as a key secondary endpoint. It was overall clarifying, and it gives us a clear look in terms of how to progress this. Fantastic. If we look at RESOLVE in particular, it differs a little bit from RSVHR in a few ways. Can you just walk us through clinical rationale between those changes and why you believe that that design maximizes the probability of repeating the very good data we saw? Well, when we went into the prior study, it was a little more of a broad survey in terms of different patient populations. In fact, we had people who were 65 and older in there. We also had the 65- 74 group in there. We had asthmatics in there in the prior study. What we did in the first study was we capped the numbers of asthmatics and people who were 65- 74 and otherwise healthy because we didn't want otherwise healthy, mild, 28-year-old asthmatics dragging down the signal that we might see in true high-risk patients. That was a teaching from the first study that we learned because we had it pre-specified to maximize or, I'm sorry, to cap at 20% those asthmatics in the 65 to 74-year-olds so that 80% would be that HR3, and that's exactly what we saw. That was one of the teachings that we carried into the new study. We're only looking at the HR3 population. Also the time to complete resolution. We found that that was the readout that gave the strong signal in that patient population. So we changed the primary endpoint of the study once we saw where the real signal was. Fantastic. You touched on doing a phase IIb. How should we think about that phase IIb portion of the study and its role in the greater development plan? Yeah. The phase IIB is really just to kind of confirm the elements now that we sort of focused on "the right high readout patient population," the endpoint with the large signal. It is basically a recapitulation in a certain way to make sure we can confirm that and also to look at the effect size to make sure we do not need to tweak a sizing element in the phase III component, either up a little bit or down a little bit, depending upon the signal. I think that is basically it. It should be hopefully pretty streamlined. Fantastic. Moving to LOTUS, just sort of the pediatric side of things. What are the most important things you are trying to establish there in that study? How should investors think about the potential development path if that study is successful? Yeah. In LOTUS, and this is a pediatric study we are conducting it in Thailand right now. They have a season that comes on a little bit earlier than in other parts of, for example, North America or Europe. We are looking at about 150 young children age 28 days up to three years. What this is going to allow us, recall we did a ped study before this, and the one before this was a first in ped study. Anytime you are going in and dosing babies as young as 28 days, you better get your dose right, you better get your PK right. Better make sure you have got really good safety going into that, and you confirm safety in the study. We did all of that in our first study, and we demonstrated virology, and that was how we sort of made sure we were on the boards in terms of the right dose. We did a careful dose escalation. We found the right dose. We demonstrated really the largest viral load drops that had ever been seen in a pediatric patient population. At the tail end of the first study, we got our tool in to measure symptoms. Unlike the adults, which are patient reported outcomes, the babies cannot report. You are relying on caregivers and other observers. We built this tool that could be used for a registration study down the line called RESOLVE-P, and it was carefully planned. We spent a few years actually developing this, getting input from caregivers, physicians, regulators at FDA and Europe. We had a tool company helping us. We built this tool called RESOLVE-P. In the first study, we only had it, I think, for the last 15 patients. We were doing those two things in parallel. This time, we now have the tool RESOLVE-P, so our plan is to use that tool, gather all the symptom information because the agency won't give you an approval just on viral load drops. You really need to have something else. For us and where other, for example, flu drugs have been approved, it's been with symptom reduction. So that's what we're doing. The plan would be to use that to help again validate RESOLVE-P as a tool. Of course, we'll be getting viral load information and safety and PK and all of that. Then that study, if positive, should be a prequel to a registration study. Fantastic. I do want to just hop to the commercial side. If we think of pediatrics and we think of adults, can you just walk us through what's complementary in terms of having a broader RSV franchise with those two indications or patient populations in the label. What do you have to treat very differently when commercializing a drug in those two different populations? Yeah. It'll be the same drug. Actually guidance from the agency is focusing on high-risk patients, so either high-risk pediatrics or high-risk adults. I think we've carved out those two patient populations and defined them pretty well. We've got supportive studies in each, and the market research that we've done strongly supports each probably leaning a little bit heavier to adult. But in the aggregate adult and peds sort of representing plus or minus a couple billion dollar market opportunity. So obviously we'll have different dosing schemes in terms of milligrams per kilogram in the little folks and sort of standard pills in the adult population. But apart from that, it should be a seamless branded solution for high-risk patients in general. There are other high-risk categories that we haven't yet explored, but we could do that down the line in terms of label expansion. Fantastic. Talking about things you can do down the line, I'd be remiss not to ask about the positioning of EDP-323 going forward. How are you thinking about that drug? Yeah. It's a really interesting molecule. It's our L-protein inhibitor. It's another replication inhibitor, and right now our capital is largely focused on zelicapavir and these next studies. But it has a very strong profile, potentially as a combination agent or a next-gen profile down the road. There's some really intriguing aspects that deserve to be studied in subsequent studies in terms of especially the speed with which it attacks the virus. But I would put that into the down-the-line category right now. Fantastic. I do want to move to immunology, because we have a big readout coming up soon on EDP-978. When we do see the data set, what do you think we should focus on as investors to determine whether this program has been meaningfully de-risked at this stage of development? Yeah. I'll let Tara Kieffer talk about immunology. Sure. EDP-978 is our oral KIT inhibitor, and we're looking at that for mast cell-related diseases. The mechanism when you inhibit KIT drives mast cells towards apoptosis, so it could be very useful in any disease that's driven by mast cells. The nice thing about these diseases and this mechanism is that you can get an early read on at least target engagement in healthy volunteers through a PD biomarker called serum tryptase. So our phase I study is in healthy volunteers. It's a traditional SAD/MAD study. The MAD portion's 14 days. So we'll get safety and tolerability, PK, and then serum tryptase, which will give us an idea of activity. So we'd be looking to see dose-dependent reductions in tryptase, up to about 80%. Obviously looking to see that profile on a whole to move that then as a next step into patients. Okay. If we assume that the data is positive, what does the next phase of development look like? How are you thinking about designing a trial there? Mm-hmm. Right. The next step would likely be a proof of concept in patients. We're thinking in urticaria, either CIndU or CSU are fairly well-established in the field. You can get a pretty quick readout with clear endpoints there. But as I mentioned, any mast cell-related disease is something that we'd be interested in studying down the road for the development path. Okay, fantastic. You talked about studying additional mast cell diseases. You've been very deliberate in terms of taking an approach of how you've built your pipeline. Can you just walk us through that rationale and how deliberate that approach has been in terms of the targets you've chosen? Yeah. The immunology portfolio has focused on Type two immune diseases, and we've got three mechanisms now, as Jay Luly mentioned earlier. The KIT inhibitor, which is EDP-978. We have an oral STAT6 inhibitor, and then an inhibitor against MRGPRX2. These are all targeting Type two immune diseases. We like that we have multiple unique agents, some of which could be thought of in combination to treat specific diseases. It just gives us multiple shots on goal in terms of being able to treat these diseases. Fantastic. I do want to ask on EDP-3903, what early characteristics do you think would establish a competitive profile for that product before we move into later efficacy data? From a preclinical perspective, or Yeah. Just that we're going to see over the next while. Yeah. Do you want to put a timeframe? Yeah. Yes. We generated a nice preclinical package with that molecule. We've shown that we can completely inhibit phosphorylated STAT6 in a mouse, and that is at the Cmin time point at 24 hours. That's really important data to show that with an inhibitor you can fully suppress phosphorylated STAT6. We've also run disease models. We have a couple in asthma as well as atopic dermatitis. We've run DUPIXENT in those models alongside our molecule and have shown that we can see equivalent efficacy in terms of both biomarkers, phosphorylated STAT6 reduction, and histology. I think that is a nice package that we'll be moving forward with and excited to ultimately see clinical data with this compound. Fantastic. I do want to just touch on the balance sheet, because you've got a very compelling opportunity ahead in zelicapavir. If 978 reads out in 4Q, it's obviously a tremendous opportunity ahead as well, along with the rest of the pipeline. Very near term, you could have an inflection there. How do you think about if we do get very compelling 978 data in terms of capital allocation between the pipeline programs? Yeah. No, it's always a balance. I think what we do every day is we're staring at all the various opportunities we have and figure out what squares we're going to put capital on and which squares we don't or which squares we'll defer putting capital on for another day. We ended the last quarter with a little over $200 million and continue to get royalty stream from our hepatitis C product with AbbVie. In balance, it's a good capital allocation to get us to multiple next data catalyst, a couple in RSV, and a few also in the clinical stage of immunology. Somewhere along there, I think there'll be opportunities to figure out how to propel things forward in a more robust way than we are right now even, and that could be through partnership or through other means. We'll Should we still think about the RSV commercial side of the business or opportunity being a partnering opportunity, or is that something we should think of all avenues? Yeah. No, I don't think we will not take that on ourself, given that patient population and to really maximize that asset on a global basis, you really do need the breadth of a large commercial partner. Fantastic. Jay, Tara. Great. Thank you very much. Thanks. Thank you.