All right, great. Good afternoon, everyone. Thanks for joining us here at the Leerink Partners Global Healthcare Conference. My name is Tom Smith. I'm one of the senior biotech analysts here at Leerink. It's my pleasure to welcome our next company to the stage, RAPT Therapeutics. Happy to be joined on stage here, CEO Brian Wong and CFO Rodney Young. Gentlemen, thanks for joining us. Thanks, Tom. Thanks, Tom. Cool. We're coming off of, I think, a really important pivot point for the company. In In 2024, I know in December, you licensed rights to a half-life extended IgE targeted antibody that we're calling RPT-904. You have some data that's currently being generated in China via your partner. We'll talk through, I guess, expectations for those data sets, as well as your plans for that program and broader development in North America, the States. Brian, why don't you go ahead and kick us off here with maybe some introductory remarks for those in the audience who may be less familiar with the story, and just tell us what you've been up to at RAPT. Sure, Tom. Thanks. Hi, everyone. RAPT Therapeutics is focused on the discovery, development, and commercialization of novel anti-inflammatory agents for a range of disorders. We recently licensed an asset called RPT-904, which is a half-life extended omalizumab biobetter. We're focused on food allergy and chronic spontaneous urticaria as our first forays into the clinic. In the meantime, our partner called Jemincare, which is a leading biopharmaceutical company in China with over $6 billion in revenue, is developing this in asthma as well as chronic spontaneous urticaria. They will have data readouts coming up in the second half of the year in those phase II trials. We became very excited about the food allergy space starting in the middle of the year when we started to see Roche's launch of Xolair. They had already 30,000 patients on Xolair for food allergy in the first two quarters. They recently reported a third quarter with over 40,000 patients. They are on track to have a billion-dollar run rate for a drug that is already 20 years old. That really told us that there is a huge unmet medical need in food allergy for an agent that addresses multiple food allergens simultaneously and is relatively convenient. Despite the attractiveness of 904, though, we think there are significant improvements to be made. That is why we were very excited about bringing in 904. That is maybe the highlight there. Yeah, no, that's great. Yeah, maybe if you could, I guess, double-click into 904 and some of the diligence you did around the asset and what attributes with this particular half-life extended IgE drew you to this opportunity. Yeah, so I think once we got comfortable with the market, and there's about 33 million patients in the United States, 17 million diagnosed, about 3.5 million patients go to the ER each year due to a food allergy-related incident. That, we think, is the baseline target population. We know we're going to be entering the market with the biosimilar on the market as well with Xolair. Even with that market size, even if you were to price against omalizumab biosimilar, we're still talking about a $40 billion market. We were comfortable with the market. We started to look at the technical attributes of the molecule that would be attractive to us. As you're probably aware, there have been attempts to develop better omalizumab antibodies. The most advanced one is called ligelizumab, which Novartis developed, which ultimately failed despite the fact that it was a higher affinity antibody. As we learned about the field, we realized that omalizumab was specifically tuned for some of these indications, particularly food allergy and asthma. As we looked at the field, this asset called RPT-904 really checked the boxes in terms of having the exact same epitope as omalizumab. There was very little sort of technical risk. It had the improvement of half-life extension that's using this YTE technology, which is well established, with some additional improvements in the variable domain to enhance drug-like properties. Very conservative approaches to the molecule to retain the epitope, but add that half-life extension, thereby increasing the convenience of the dosing schedule. Got it. Could you just describe, I guess, the process of actually diligencing the asset, I guess, how you got comfortable around the data that's been generated by partner Jemincare? They're in multiple phase II studies. You've already, you're reasonably well clinically advanced. Just talk about the process. Yeah, I think some of the obviously, we did very deep diligence into all the data they've generated. I think the key data that really helped us was their phase I healthy volunteer data. This was a pretty classical placebo-controlled double-blinded single ascending dose study where they studied five different dose strengths of 904. What was really important, though, is that they included an omalizumab comparator at the same dose strength as one of the 904 arms so they could really compare head to head. In that healthy volunteer study, they showed that 904 had half-life extension as predicted by the YTE mutation of 60 days after a single dose versus omalizumab's 26 days. It is over twofold extension in half-life. Also, very importantly, they saw better pharmacodynamics. They saw a deeper reduction in free IgE and also a more sustained reduction in that, which is tightly correlated with efficacy. Got it. OK. You have talked about your plans for kicking off a phase II B study in food allergy in the second half of this year, maybe some initial high-level thoughts on how you are thinking about approaching that study. I do want to get to, I guess, the data that is being generated in China. Is that data gating to you initiating the phase II B on your own? Their data, which is a phase II A in asthma and a larger efficacy study in CSU, is not gating for the start of our food allergy study. Part of it is that the diseases do bifurcate to some extent. For example, CSU is a relatively low IgE level disease, whereas food allergy tends to be higher level IgE disease. Drugs like Oma tend to be active across those diseases. Drugs like ligelizumab, which I just mentioned, do well in CSU, but they do not do so well in food allergy. We decided to not gate that. The food allergy study, we are lucky to have experience from Novartis and Roche. It is very much modeled off of the OutMatch phase III study, which was the basis of their approval. For those of you who are somewhat familiar with the food allergy space, there's a very classic endpoint called the double-blind placebo-controlled food challenge, where you enroll patients that are sensitive to certain foods at a certain level, call it 100 or 300 mg, depending on the allergen. After a dosing period, they're re-challenged. You look at how that threshold increases. For example, for peanut allergy, which is the most common, you look for patients who achieve a 600 mg threshold, which is sort of considered protection against accidental exposure. That's the trial design. We are planning to enroll initially adolescents and adults. As the trial proceeds, as we gather safety data, then to extend that to children, six and above. We're planning a Q8 week dosing arm and a Q12 week dosing arm versus placebo. If you'll recall, Xolair is dosed primarily every two weeks, some every four weeks as well. We think that that significant extension will be clinically meaningful. We do think that it'll take about 18 months from study start to top line data. We're planning to start the study at the end of the year, data readout first half of 2027. Got it. That makes sense. What's sort of the base expectation? You have the two different dosing intervals, Q8 and Q12. Maybe this can start to get into some of the market research that you've done. How much of a meaningful improvement do you think the Q12 would be over the Q8? Yeah, it's very interesting. Maybe Rodney can talk about some of the market research we've done to pressure test Q8 week versus Q12 week. Yeah, so Oma in food allergy is, Brian, it is Q2 week or four week, mostly Q2. Our first cut at research, we actually tested Q8 week with 904, same efficacy profile, same safety profile, but Q8 week. That profile was very well received by both prescribers and payers. When we subsequently tested Q12 week, obviously, it was even more well received. That gave us a lot of comfort that if we can get Q8 or Q12, we'd have a differentiating factor. Got it. OK. Yeah, could you just talk about, I guess, the dose selection rationale for what you're planning in the phase II B, obviously guided by the phase I experience and the data you've seen out of Jemincare? Yeah, so I think, again, we get to stand on the shoulder of giants. There has been a lot of data and information with Xolair over the last couple of decades. What Roche, Genentech, and Novartis have done is they have very sophisticated ways to model the doses based off of PK parameters and projected IgE levels. That is how they put together these dosing tables. We took the phase I healthy volunteer PK data, and we basically fed it into these well-established models with well-known thresholds for efficacy and modeled across every weight level and every IgE class. What we found is that we could cover all of the OMA-included patients with Q12 week dosing and many of the patients who are currently excluded from the omalizumab label because of too high IgE or too high weight with Q12 week dosing. There is a small fraction of patients that we think we might require Q8 week dosing. That is what our projections would highlight. The trial, which we think Q12 week should very much be able to cover the same level of pharmacodynamics as omalizumab across most of the dosing table, Q8 week is kind of a little bit of a backstop. It also allows us to explore patients with IgE levels over 1850 that are off the table or patients in the lower right corner of the table that are excluded from the Xolair label. What proportion of food allergy patients do you think falls into those buckets? It's roughly 25%-30% are sort of excluded from the dosing table. There's probably a smaller percentage, around 5%, that are above 1850, so a total of around 30%. OK. I want to come back because I know you did a significant amount of market research before making the in-licensing decision. Maybe if you could just talk through some of the payer and reimbursement survey work that you did and, I guess, conversations that you had around that. In a world of biosimilar competition, I guess, what is contemplated either in terms of number of biosimilar competitors or pricing power for OMA? How are you guys thinking about positioning 904? Great question. Yeah, great question. Yeah, we did do quite a bit of market research. I mean, I think both payers and prescribers really are looking for a better omalizumab. The less frequent dosing is presumed to enhance compliance. Better compliance should lead to better outcomes. That is really critical from both a payer and a prescriber perspective. They really much would welcome that. From a reimbursement point of view, when you talk to the payers, yes, we did assume we would have biosimilar competition by the time we get to market. The question was, what do you think the pricing would go to? Most of the payers kind of saw price erosion typically in the 30%-40% range. That is what we have assumed, 40% price erosion versus Oma branded. That is our assumption right now. Even then, when you talk to the payers about pricing, because of the increased compliance, the less burden on the patient, all that, they actually would be willing to pay a premium for that. The premium could range as high as 30% ish. We have done our work not assuming a premium. That is when Brian said, if you assume 3.5 million patients at $14,000 per, that is a huge $40 billion + market opportunity. Right, right. Still very much in its infancy, still a lot of very early days of awareness that there are even biologic treatments out there for food allergy and what is a life-threatening condition. OK. Yeah, that's right. There definitely are options available, like oral immunotherapy, desensitization approaches. I think what we're learning, though, is that those only treat, obviously, treat one allergen at a time. They're also quite burdensome as well. We think that an option, like a long-acting OMA, where you're basically dosing four times a year, could actually open up the market further and access patients who normally wouldn't want an injection. Yeah, that makes sense. OK. I want to talk about the Jemincare data that's coming. They have the phase II study in CSU. Maybe you could just help frame expectations. What are you expecting to see? I guess where we've gotten a number of questions. I think people are interested in the amount of visibility we'll have into that data set, how you guys are planning to communicate results, and what would constitute a good positive readout from Jemincare. Yeah, maybe I can start with the trials. You can talk about disclosure and that kind of thing. Good question. Jemincare is running two phase studies now. They're actually enrolling faster than expected. They moved up their timelines. A phase II A in asthma, which is really a smaller 60-patient PK/PD study to set their phase III dose for asthma, but a larger 135-patient study in patients who are refractory to antihistamines in chronic spontaneous urticaria. There, they are comparing a Q8 week, a Q12 week of 904 versus the approved omalizumab dose of 300 mg Q4 weeks. That will be very informative to see how that half-life extension carries through from an efficacy standpoint. That data also will be available in the second half of the year. It should be interesting not only to prove the hypothesis that half-life extension should translate into more durability, but it also could enable us to go directly to phase III in chronic spontaneous urticaria and enable rapid development and a faster path to approval. We are very excited about that data readout, although it is not gating for the food allergy study. In terms of disclosure. Yeah, so the important thing to remember is it's their trials, Jemincare's trials, and quote their data. Obviously, under the agreement, we have data sharing arrangements. We are talking to them about what their plans are and what our plans are with respect to disclosure. We just need to get coordinated with them. It is not yet been determined. We kind of know the timeline, right? We'll have the data by the end of the year. Understood. Yeah, help us think through, or at least explain how you view, I guess, the bar for success. We're testing less frequent dosing interval. Is there some margin of trade-off on efficacy and reduction of UAS scores or complete responses that you think patients or prescribers might be willing to accept? Have we done, I guess, market research around that particular aspect of the CSU opportunity? Yeah, we've started to do some research. Actually, it turns out that the less frequent dosing is such an attractive component to the target product profile that prescribers would be willing to actually allow lower efficacy than omalizumab. All that being said, given that this is an omalizumab epitope and the modeling is quite good, we're really kind of aiming for similar activity to omalizumab, but at less frequent dosing. Got it. That makes sense. You mentioned the potential to move forward in a fairly accelerated path directly into a phase III. Potentially. In the U.S.? Yeah, I guess, what would be involved there from a regulatory engagement standpoint? How much risk is there to, I guess, are there any analogs or precedents for China phase II exclusive data then translating to a pivotal phase III program in the U.S. in an allergic disease setting? Yeah, there are examples in different therapeutic areas of using Chinese data to go directly to phase III. I think it would require an end of phase II meeting to align with the FDA and the EMA on the trial design, patient population, and endpoints. Those are discussions we would have to have before we would kick off a trial. Got it. Yeah, I guess subsequent to data, what does that timeline look like? I guess in a best-case scenario, how quickly could we move this into a phase III pivotal in the Western regions? It's sort of hard to pinpoint now. Assuming that we have data second half of the year, we'd need to have the end of phase II meeting sometime next year. Obviously, we would try to kick it off as soon as we can after that. Yeah. OK. Maybe a similar question in terms of market research and dynamics. There's a lot of development work that's ongoing currently in CSU. There's a lot of excitement around KIT-targeted approaches. We could see approval of Dupixent, approval of remibrutinib. There's a pretty dynamic space at the moment. I guess, where do you see this half-life extended Oma fitting into a world of multiple branded competitors, also biosimilar Oma? Yeah, so we've done probably a little bit less research on CSU than we have for food allergy. I think where we start is Oma is still the first choice in the patients for whom antihistamines don't work. Our research suggests that, like in food allergy, payers and prescribers would welcome a long-acting version of OMA, like 904. Our presumption is we would be looking to maintain that sort of first line after antihistamine failure position. Oma is there. That's where we would look to be positioned. Yeah, I think there's obviously a lot of exciting mechanisms that you mentioned. There's the KITs, BTKs, and others. I think that there's different positioning, right? I think it'll sort of play out where the safety profile allows certain but certainly, the efficacy profile is very attractive, particularly, for example, as a c-KIT inhibitor. I see this very much sort of like you have the JAK inhibitors and the biologics in the atopic derm space. They're all going to have a place in the paradigm of therapy. I think what's going for us is the two decades of safety experience with omalizumab and how similar this drug is to Xolair with very conservative changes. That we're hoping to leverage to position the drug. That makes sense. Yeah, it's another market where patient numbers are substantial, still very much in the early stages of segmenting, right? We've essentially had Xolair as the only option post antihistamines for years. A market that's probably set for nice growth. Future growth, yeah. Let's talk a little bit about the asthma study and the asthma data and, I guess, how informative what are your expectations for that readout in China? How informative is that going to be to your plans and food allergy and/or other sort of pipeline expansion opportunities for 904? Yeah, the asthma study is a bit smaller. I think we have to probably keep our expectations a little bit lower. It is a 60-patient study, three dose strengths of RPT-904, 150, 300, and 450 mg dosed every eight weeks versus omalizumab's approved dosing table. Fifteen patients per arm, pretty small. It is really geared towards PK/PD. I think what we are looking for is the relative levels of target suppression versus omalizumab. How does that sort of adjust our modeling as we think about the dosing table for phase III for both CSU and food allergy? We are going to use the data as much as we can from that perspective, but probably reduce expectations just on the efficacy side just based on the small number of patients. Got it. That makes sense. Informative, but not critical. OK. Maybe you could just remind us, just blocking and tackling wise, as you think about starting your own phase II B study, manufacturing for the drug, I guess, CMC, all of those boxes being checked. Where is the manufacturing being done today? Is there a tech transfer aspect of this that has to happen? Great question. Yeah, we are working through or have started to get the tech transfer underway. I think both we and Jemincare are very motivated to get that done as quickly as we can. It's not going to happen in time for the start of our phase II B food allergy trials. The clinical trial material for that trial will come from Jemincare. That's already underway, the production of that. OK, awesome. Maybe just lastly on 904, I mean, there's, I think, a lot of places that you could look to take this. We're going to have, I think, very informative data sets across the indications we already spoke about. How are you thinking about other sort of pipeline and product potential here? What could be the cadence for moving this into other settings? Yeah, I can start. Obviously, when we did our research, food allergy was clearly the top in terms of high-end medical need and the need for new options. CSU was a close second. Certainly, having a broader label brings a halo to the whole product because many of these patients have coexisting comorbidities and indications as well. Allergic rhinitis is an IgE-driven disorder. There's a certain percentage of patients that are underserved with steroids, topical steroids. Chronic rhinosinusitis with and without nasal polyps is definitely IgE-driven as well. I think there are areas to kind of expand into as a lifecycle management perspective. Asthma, it's something that our partner, Jemincare, is quite interested in. It's a bit more saturated with options. We're a little bit more cautious about that, but certainly could be in the plans later down the road. Got it. That makes sense. OK, I want to switch gears a little bit and talk about the CCR4 antagonists. And you've guided to selecting a preclinical candidate during the first half of this year. Maybe you could just talk about some of the properties that you expect from this next-gen compound and how you're looking to improve upon. You have zelnecirnon as well as tivumecirnon. What are you looking for in that next-gen compound? Yeah, just so as a reminder for folks, we were both in a phase IIB study in atopic dermatitis as well as a phase IIA in asthma. Due to a single event of serious liver injury with no other evidence of liver injury, both clinically and preclinically, we had to stop those trials and terminate the program. From our perspective, the number one thing to do is to bring forward, so first of all, the data still continues to support CCR4 as a compelling target. We plan to bring a second-generation molecule forward. Obviously, the first change is it has to be chemically distinct significantly from zelnecirnon. Also, there are ways where we can improve the potency and selectivity even further. We will continue to do that as well with the next-generation molecule. As we get closer to the clinic with the molecule, we do plan to disclose data from the zelnecirnon trials. Hope to do that. OK. Yeah, and I guess not to run that, but the way that you talk about the mechanism and still genuine excitement behind the mechanism suggests that you were seeing signs of activity in that kind of early truncated study. I guess with the nomination of the next compound, is it reasonable to expect, yeah, we would potentially see some of that data? And then could we also expect to see some preclinical data from the next candidate, the next gen? Yeah, certainly. I think from a competitive perspective, we want to wait till we're closer to the clinic before we disclose more data from the trials. Certainly, I could foresee us disclosing some of the preclinical data. We haven't planned that far ahead. That would be sort of a natural course to do that as well. Were there any learnings that we had from the zelnecirnon program that would influence, I guess, the initial direction that you might take a next-gen oral CCR4? Are we still thinking atopic derm or asthma or some different direction within type two? Yeah, all we really want to say now is that we still think that an oral CCR4 antagonist could be attractive for a range of Th2-driven disorders. OK. We'll stay tuned on that front. You also have tivumecirnon where you generated a nice amount of data. Maybe if you could just provide sort of high-level overview of the data you've generated there. You've kind of, at this point, I said you're looking for partnership opportunities with that compound. Maybe just walk us through rationale, data, and then where we stand on the partnership front. Yeah, so again, tivumecirnon is another CCR4 antagonist that, because in cancer, T regulatory T cells express high levels of CCR4 and it's required for the entry into the tumor and are highly immunosuppressive. CCR4 is able to actually prevent Treg entry into the tumor and actually inhibit their ability to directly interact with effector cells. It is a very sort of Treg-driven hypothesis. What's very compelling is that we've been able to generate monotherapy activity, including complete responses, particularly in high Treg tumors, but also high levels of combination activity, particularly in lung cancer as well as gastric cancer. In the lung cancer, what's particularly exciting is that we saw very high response rates that would exceed pembrolizumab alone, particularly in the PD-L1 population, where we saw a four-fold increase in responses relative to pembrolizumab historical data. In the gastric cancer population, particularly in virally-driven cancers, we saw over a 60% response rate. This is a very active molecule. We are looking for a partner to extend the development of this and move forward. Anything else to add? Yeah, and we're talking to folks. It's just really difficult to predict timing of those kinds of transactions. Understood. Is there still data that's being collected, generated, and collected from the oncology setting? This is a program, if I remember correctly, that's partnered with Hanmi. Yeah. Yeah, and so are they taking this? The gastric data set was the Hanmi data set. Are they actively advancing this into either a next phase or a different tumor type? Yeah, they're looking to advance the program based off of our data. I would say that. Yeah, part of their interest is they want to go into China. They're looking to find the right partner for China as well for them to go into China. The right combination partner. Yeah, the right combination partner. Right, that makes sense with the gastric data. OK, and just last question. There was a financing around the in-licensing event. Maybe if you could just talk about cash on hand and what data readouts are funded using existing resources. Yeah, so our year-end cash balance was $231 million. We did pay the $35 million upfront fee in January. You really should subtract that off. With the remainder, roughly $195 million, we believe we are funded into the second half of 2027. Again, our food allergy, phase IIB food allergy trial, we expect the readout in the first half of 2027. We sized the raise to get to that readout and have a little bit of a cushion. Got it. That makes sense. All right, guys. Thank you for the updates and the insights. A lot of data coming in 2025. We'll stay tuned. Thank you to the RAPT team, Brian and Rodney. Thank you. Thank you. Thank you, Tom. Thanks, Tom.