All right. Thank you for joining us. My name is Leon Wang, the Healthcare Sector Specialist at Barclays, and it's my pleasure to introduce Brian Wong, CEO of RAPT Therapeutics, and Rodney Young, CFO of RAPT Therapeutics. Brian, Rodney, thank you for coming. Thanks, Leon. Perfect. Why don't we kick things off? I mean, back in 2024, RAPT was a different company from today. There has been a significant evolution of the company's story with the acquisition of RPT904. Can you give us some details of the deal that happened late last year? It may have been not on a few investors' radars. Anything that you can share about the asset that made you tune into it? Do you need to use that or... Hello? Yeah, I think it's just for you. Yeah. Okay. Before we start, we just want to remind everyone to review our safe harbor disclosures and our risk factor language in our SEC filings. Thanks, Leon. Maybe just for some context here. RAPT Therapeutics is focused on the discovery, development, and commercialization of high-value therapeutics for a range of inflammatory disorders. We're very excited to be talking about this asset called RPT904. We got very excited about the food allergy space last year, and we feel that RPT904, which is a long-acting anti-IgE, omalizumab biobetter, has an opportunity to transform the treatment of food allergy in a range of allergic disorders. We in-licensed this asset from a large biopharmaceutical company in China called Jemincare. RAPT owns all ex-China rights for development and commercialization. We are planning to develop this and start a phase 2b study in food allergy the second half of this year, with data expected 18 months later in the first half of 2027. Our partner, Jemincare, is planning to complete their phase 2 data sets in both asthma as well as in CSU the second half of this year. There is a lot of catalysts to be expected. I'll let Rodney talk a little bit about the market, and I'm sure you have additional questions, but that's sort of the genesis of RPT904. Yeah. Perfect. I guess with RPT904, can you talk about the development plans and any of the timelines or potential timelines going forward, as well as anything that you'd like to share about the market of food allergies? Yeah. I'll let Brian address the clinical development plans. I can't tell if I'm being heard or not. Okay. One thing that's really attractive about 904 are the market opportunities that we see in food allergy. Obviously, the omalizumab launch has indicated a big unmet need in that market. It's a huge market. Approximately 33 million Americans have some sort of food allergy. We see a really large opportunity there, potential market opportunity of about $40 billion. There's also a nice opportunity in CSU, which is a second indication that we'd be looking to pursue. There we see a potential $5 billion market opportunity. Right. In terms of development, I think we get to stand on the shoulder of giants. Roche and Novartis ran a phase 3 study in patients with food allergy called the OUTMATCH study. This was essentially an oral food challenge study where patients are brought in. Their food allergy is confirmed by laboratory testing as well as oral food challenge. If they reach a certain sensitivity threshold, then they're allowed in the study. After the treatment period with Xolair, there is a second food challenge to look at the change of sensitivity there. That is exactly how our phase 2b is going to be designed. Patients, and we're starting with adolescents and adults, but we do plan to include children in the study as we gather more safety information, will undergo an oral food challenge for inclusion. If they reach a certain sensitivity, they'll be enrolled on either a Q12 week dosing or Q8 week dosing of RPT904 or placebo. Twenty to twenty-four weeks later, they'll undergo a second oral food challenge. That's the basis of the design. Patients who do achieve a certain threshold based on the food that they're allergic to will be considered responders. Just as you may recall, in the Xolair, OUTMATCH study, roughly 60%-70% of patients actually were able to reach that threshold across multiple food challenges. That includes peanut, tree nuts, milk, and egg, as well as others. This is a multi-allergen trial. I think one of the exciting features of Xolair is that it doesn't just treat one allergen. It actually treats multiple allergens simultaneously. That's food allergy. Leon, you asked about other developments. We are very enthusiastic also about development in CSU or urticaria. Xolair is also the dominant player in patients who have failed to respond adequately to antihistamines. It has a 20-year safety record. The advantage here with 904 is that it really is based off of omalizumab, except it has half-life extension and additional properties. For urticaria, here we plan on the standard development, looking at endpoints such as the UAS7 score. The advantage here, though, is that our partner, Jemincare, is running a phase 2 study in 135 patients with CSU. They are exploring Q8 week dosing and Q12 week dosing versus Xolair's Q4 week dosing. That should read out before the end of the year. That will enable our development and design of our urticaria trial. The other exciting, I think, development here is that if that data are sufficiently positive, and we can talk about what that means, there's a possibility we could go directly to phase 3. That would greatly accelerate the time to approval. That's food allergy and urticaria. Those are currently our top two indications that we're planning development in currently. Gotcha. Yeah, I'd love to dig in more on urticaria later in the discussion. Going back to food allergy here, this is just one of those situations where while food allergy, it's kind of a nascent market, but the thing is because there's a precedent for Xolair out there, you kind of have these targets that what would be, what would be like your base case scenario. With that said, can you share some of your expectations of what we could potentially see? What would be like a base case scenario for you guys versus like a blue sky? Yeah. Right now, our base case target product profile is efficacy that's similar to omalizumab or Xolair with a similar safety profile. Instead of omalizumab's Q2 week or Q4 week dosing, which is fairly inconvenient, we're looking at Q8 or Q12 week dosing. Based off the phase 1 data that our partner, Jemincare, has generated, we predict that we could treat patients mainly with Q12 week dosing across the dosing table, with maybe only the highest IgE patients at the Q8 week dosing. That would be an upside to see Q12 week dosing. In addition to that, we believe we can also treat roughly the 30% of patients that are excluded from the Xolair label because their IgE is too high or their weight is off of the table. That would allow us to access patients that are now currently underserved. Gotcha. Let's say we are hitting the Q12 week dosing. How does that translate into commercial attractiveness or commercial competition in a market? Perhaps, Rodney, you can educate those people who are listening in terms of what the commercial competition currently is. Yeah. As Brian indicated, right now, Xolair is probably the best choice for those affected by food allergy. It can deal with multiple allergens. Relative to the alternatives, taking the shot is probably the easiest thing to do. However, they do have to take the shot every two weeks or every four weeks. When we did our market research into the target product profile of 904, when we talked to both prescribers as well as payers, there is really a high level of enthusiasm for a drug that could have a similar safety and efficacy profile, but less frequent dosing. The less frequent dosing would likely increase compliance, which obviously, if you keep your patients on the drug, you should get better outcomes. That was very encouraging from a prescriber and payer perspective. The prescribers believed a lot of their patients would prefer the less burdensome dosing regimen. Actually, when you talk to payers, they'd actually be willing to reimburse at a premium for 904 relative to omalizumab biosimilar pricing. Yeah. Maybe just add to that. Even with that attractive profile, there are roughly, as Rodney said earlier, 3.4 million patients in the United States who have required visits due to their food allergies over the past year. If you just take that small sample, and again, 3.4 million, even if you were to charge the same price as an omalizumab biosimilar, we're talking about a $40 billion market. The upside is the ability to price this at a premium, which the payers are willing to do due to this additional innovation. There is a lot of flexibility given the size of the market and the severity of the disease. Yeah. Indeed, it sounds like if a parent has a kid going to summer camp, you inject a kid once, and then like, all right, forget about having some food allergy issues in summer camp. That's a potential situation there. That's a great example. Summer camp, college where kids get pretty busy. They're not able to inject every two weeks or do an oral immunotherapy. Those are the types of patients that are immediately attracted to this profile. Has there been any type of, has there been kind of questions on the potential to achieve the Q12 week dose? Essentially, what gives you the confidence that you will be able to hit your target product profile? Yeah. I think it's a great question. The phase 1 data, this is a single ascending dose study that Jemincare ran, showing very clearly that the half-life of the drug compared directly head to head with Xolair was extended by over two and a half fold. It had a half-life of 60 days versus omalizumab in that study showing a 26-day half-life. What's really great about this field is that there's been so much information on the clinical pharmacology and so many models that have been published that were used by Novartis and Roche to create these dosing tables that we essentially just plugged in this information. With the known thresholds of how much IgE you need to reduce by, we could, what we think, have a very high level of confidence in the dosing frequencies and intervals, as well as the dose strengths. We are planning on three different dose strengths of 150 mg, 300 mg, and 600 mg. If you use those projections, as I mentioned earlier, we can cover all of the OMA-included patients with Q12 week dosing and also treat many of the OMA-excluded patients on the dosing table with Q12 week dosing. There is a lot of confidence based on the modeling and the PK data that we've seen today. Looking ahead, there are other developments within food allergy. How are you thinking about competition, not necessarily today, but in the next five years or so? I think the one we clearly are focused on immediately are the biosimilars for Omalizumab, which I think the first one was approved very recently. We expect that to launch probably next year. Omalizumab is good, so we assume the biosimilars are going to be good. We will be differentiated, we believe, by the less frequent dosing regimen. There are other anti-IgEs in development. I think we're ahead from the point of view of stage of development. I don't know, Brian, if you want to. Yeah. Just to expand on that. Clearly, with Roche now having 40,000 patients on Xolair for food allergy with a run rate of $1 billion, there's quite a bit of interest now to develop the next generation anti-IgE. Probably the most advanced competition, there's a drug called LP003, which is also a half-life extended anti-IgE antibody. I think one thing that we were very aware of as you looked at the history of this drug of Xolair and the attempts to develop next generation anti-IgEs is that it very much is dependent on the epitope, the binding mode, and how the molecule is tuned. 904 uses the same epitope as omalizumab. There's very little sort of technical risk involved here. We think it's going to be tuned exactly like omalizumab, but have the extended half-life. Whereas other attempts or other competition, other approaches, many of them do not use the omalizumab epitope. We think there's additional risk there. Obviously, the clinical data will have to play out. We think this is the best in class, least risk, best-tuned antibody for a range of allergic diseases. Yeah. Perfect. We got about nine minutes left. In terms of, why don't we move on from food allergy? RPT904 wasn't an asset that you guys bought with the sole purpose of developing it in food allergy. Can you talk about the other plans in development for this asset? Yeah. That's a great question. As we touched on earlier, when we did our KOL checks and our payer checks, the second indication with the highest unmet medical need was CSU. This is an area that's really emerging because of not only recognition that this is a growing market, but that there are additional mechanisms that I think have brought considerable efficacy and excitement to the field as well. Xolair is the dominant first-line agent for patients who have an inadequate response to antihistamines. It has a 20-year safety record. We believe with 904's extended half-life profile and additional affinity that this could essentially displace omalizumab as the front-line agent for those roughly 400,000 patients that do not have an adequate response to antihistamines. As I mentioned earlier, we are waiting for data from Jemincare to drive our development plans. That data actually has accelerated in terms of enrollment and will be available before the end of the year. We're excited to see that data. You mentioned that depending on that data, it could potentially accelerate your development into phase 3. Kind of what should investors be looking for in that readout? Yeah. It's a great question. I think it's interesting. When we did the profile market research, given the higher convenience, higher compliance, a lot of the prescribers were willing to take a hit on the efficacy. That being said, again, given the similar binding mode, but the enhanced potency, we do not expect inferior efficacy. Similar efficacy to omalizumab, but now at Q8 week or Q12 week dosing is really the base case scenario for success. CSU definitely, you have other entrants coming into the space with Celldex, Jasper. I mean, those have gotten investors pretty excited. How do you think, how are you thinking about commercial dynamics with the newer agents in play? You guys are extended half-life Xolair. It sounds like your effort is to just completely displace Xolair in the front line. What type of challenges, I guess, do you anticipate in that situation? Yeah. As Rodney pointed out, omalizumab biosimilars will be putting some pricing pressure on that front-line setting. Again, the profile of 904 is so differentiated that we think that payers will still be willing to pay a premium for this profile. I think it really remains to be seen. There's a lot of excitement now around KIT inhibitors, as you mentioned, BTK inhibitors as an oral option for CSU. What it'll really come down to is the risk-benefit, right? We've seen the c-KITs show very high levels of efficacy. They do come with some on-target liabilities as well. I think it'll really sort of play out how that will be positioned, whether that will be still behind the anti-IgEs or start to take front-line position. I think it remains to be seen. Same with the BTKs, the safety profiles that evolve, I think we'll see that positioning. I'll just say again, this is a very large market. As many, even larger than psoriasis, which has already absorbed many different mechanisms. I think there's room for many different mechanisms that allergists and dermatologists can use across their patients. When you're thinking about marketing, taking everything into consideration, right? You got food allergy, you got CSU. Oh, have you shared any details about other indications you are interested in pursuing? Yeah. It's a really good question. Xolair has been approved for asthma, in addition to chronic spontaneous urticaria and food allergy, also asthma, which was the initial indication, and chronic rhinosinusitis with nasal polyps. There's also been clinical data showing activity in allergic rhinitis as well. These are all very large markets. There's certainly a fraction of patients that don't respond to standard of care, which still represents millions of patients there. From our perspective, we think behind CSU that allergic rhinitis and chronic rhinosinusitis are particularly interesting for long-acting anti-IgE. There's certainly lots of patients who don't respond to topical steroids well or antihistamines. Asthma is also of interest. We know that we'll look at the Jemincare data in asthma as well during their development. We can make a decision of whether the profile would be exciting or not. It is a bit more crowded than some of the other disease indications. You own all the rights except for in China, right? Yeah. That's right. Yeah. China, Taiwan, Macau, Hong Kong. Okay. Got it. Okay. Can you remind me what your cash runway is and kind of where does that get you in terms of your development? Yeah. We just reported our year-end cash balance, and it was $231 million. We did pay the upfront fee to Jemincare in January. It is really, call it $195 million-ish. Our runway, we do project that to get us to the readout, our phase 2b food allergy readout in the first half of 2027, and then have a little bit of cushion beyond that. Great. For RAPT has been a company through this evolution. Maybe kind of an unfair question to ask would be, what has been your takeaway from originally when you set out IPO and what happened with 193? Essentially, what are the learnings here? How have you guys adapted or if you guys adapted to the current environment of clinical development as well as cash raises? Yeah. It's a really good question. Just for some context, we were in the process of developing a CCR4 antagonist, an oral, for a range of Th2 disorders. Due to a single safety event, we had to stop that program. I think there's certainly a lot of learnings and takeaways. We remain extremely excited, first of all, about the whole allergic space. We think there's a lot of opportunity there, which is one reason why we've decided to bring a molecule like 904 forward. We also continue to be very excited about CCR4 as a target and that there's still a need for a safe oral option for a range of these disorders, including as we were approaching atopic dermatitis, asthma, and others. We are planning to bring a second-generation molecule forward, different chemical entity, better potency, better selectivity. As we get closer to the clinic, we'll start to disclose more information from those trials that we ran. For competitive reasons, we're not disclosing that now. I think as drug developers, we continue to learn. This is always a very humbling and challenging experience. This was probably an event that no one really could have predicted because there was just no evidence of any sort of safety liabilities prior to that. I think just in terms of development, making sure you get the right patient populations, making sure that you're monitoring all the patient baseline characteristics and so forth, choosing the right sites, all of those have just come to the forefront and are front of mind. Okay. Perfect. It looks like we're right out of time. Thanks for stopping by. This was very helpful. Yeah. Thanks, Leon. Really appreciate it. Yeah. Thanks, Leon. Take care.