Good day, everyone. My name is Kahe Alani, and I will be your conference operator today. At this time, I'd like to welcome you to the Chimera Therapeutics 4th Quarter 2025 results call. All lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question and answer session. If you'd like to ask a question during this time, and if you join via the webinar, Please use the raise hand icon, which can be found at the bottom of your webinar application. If you have joined by phone, please dial star 9 on your keypad to raise your hand. At this time, I would like to turn the call over to Justine Koenigsberg, Vice President, Investor Relations.

Good morning and welcome to Chimera Therapeutics' quarterly update conference call. Joining me today are Noah Meinolfi, our founder, president, chief executive officer. Jared Gallup, our Chief Medical Officer, and Bruce Jacobs, our Chief Financial Officer. Following our prepared remarks, we will open the call for questions from our publishing analysts. Please use the raise hand icon to indicate that you'd like to ask a question, and we ask that you limit your question to one in a brief follow-up so we can accommodate everyone. Before we begin, I would like to remind you that today's discussion will include forward-looking statements subject to risks and uncertainties described in our most recent Form 10-K filed with the SEC. Please note that any forward-looking statements speak only as of today's date. And with that, I will now turn the call over to Nello.

Thank you, Justine, and thank you, everybody, for joining us this morning. As is your year-end 2025 call, I wanted to spend a few minutes recapping what was an incredible year for Chimera. Those of you that know us well appreciate the fact that we're always forward-looking, highly focused on what's in front of us, and the bulk of the call would feature just that. But given how important our 2025 accomplishments were, I am hoping that a quick reflection on the year would provide some context for the foundation we have set for 2026 and beyond. Before we start, I would like to mention that this year we will celebrate our 10th year anniversary since Chimera's founding in May of 2016. Over the past decade, we have executed on our strategy and have built the capabilities, the platform, and the team to deliver on our goal to develop the next generation breakthrough immunology medicines. We've accomplished so much in our short history, but arguably 2025 was truly a breakout year. I'll start with the significant progress in our first and best-in-class STAT-60 grader We shared outstanding results from both our Phase I Healthy Volunteer Study and our Phase I-B study in AD patients. In the Healthy Volunteer Study, KT621 demonstrated robust STAT6 degradation with excellent safety and tolerability. That was followed by a highly encouraging impact on efficacy endpoints in Phase 1b that supports our view that KT621 has the potential to deliver robust efficacy in line with pathway biologics with the convenience of oral daily dosing. On the strengths of these two studies, we launched our first Phase 2b study in atopic dermatitis patients last fall and started the asthma phase 2B early this year. Jared will talk more about our KT 6-1 clinical development plans, but both studies are benefiting from the awareness of and appreciation for the data we have recently shared, as well as from clear enthusiasts from clinicians and patients around promising oral options. We were busy advancing the rest of our pipeline as well. In May, we unveiled our first-in-class RFI program, supported by a compelling preclinical profile and validating human genetics. Last year, we completed IND-enabling studies, and we're excited to announce this morning that after IND clearance from the FDA, we recently initiated dosing in the Phase I Healthy Volunteer Study with KT579. Finally, we're building on the success of our internal pipeline by advancing our existing collaborations with Sanofi around Iraq IV and by signing a new partnership last year with Gilead around our first-in-class CDK2 molecular glue program. Bruce will provide an update later in the call on the potential upcoming collaboration milestones which would be incremental to our financial position. Speaking of finances in 2025 we raised almost a billion dollars bringing our year-end cash balance to 1.6 billion. We believe that this amount of capital which extends our runway into 2029 will enable us to execute on our broad development plans that are designed to realize the full potential of our wholly owned programs while maintaining the productivity of our discovery engine which we expect will expand our innovative pipeline now with 2025 behind us we are focusing squarely on 2026 and beyond and the multiple milestones we plan to achieve for kt621 we expect to complete enrollment in the ad study this year and share data by mid 2027 the first patient was those in the asthma trial last month and we expect to share that data in late 2027 in the meanwhile we're planning to report scientific publication and presentation to continue to build awareness of this exciting program this is an important year for KT579 our lead IRF5 degrader we expect to complete the recently started phase one healthy volunteer study and share the data later this year and the next step will be to advance the program into a patient proof of concept study which we expect to be in lupus soon after that our partner Sanofi is expected to start healthy volunteer phase 1 trial with KT485 this year we also hope to be able to advance our CDK2 program in partnership with Gilead into further development finally our goal continues to be to announce at least one new program annually and we're targeting the second half of this year to share our new development candidate program we clearly I have a busy 2026 planned, which makes me particularly happy to announce the most recent addition to Chimera's leadership team. Neil Graham will join us as Chimera's Chief Development Officer. Neil is a seasoned life sciences executive with more than 30 years' experience in global drug development in both early and late-stage clinical trials across a wide therapeutic spectrum, including dermatology, allergy, rheumatology, virology, and pulmonology. Neil has led several groundbreaking programs, including the development of Dupilumab at Regeneron. Well, thrilled to have him join our team as we enter the next phase of our growth and look forward to his contributions as we continue our efforts to build a fully integrated commercial company. Now, before I turn the call over to Jared, I wanted to spend the remainder of my remarks speaking in more details of the unprecedented market opportunity of our STAT6 program. I can't overstate the opportunity we had to significantly increase the number of patients who are treated effectively. We hear overwhelmingly from both physicians and patients that current advanced therapies, including biologics, just aren't sufficient. There is a palpable excitement for the potential of a simple and convenient oral therapy for type 2 diseases that doesn't compromise on safety or efficacy. We have cited these numbers in the past. We believe there are about 140 million diagnosed type 2 patients in the US, five major EU countries and Japan. Of this total, about 50 million patients are estimated to be in the moderate to severe category. Yet, despite this significant need, only an estimated 2 million patients are treated with advanced systemic therapies, mostly biologics and overwhelmingly with dupiloma. So the question is, why are so many patients not treated with advanced systemic therapies? The gap is clearly not due to lack of need, but it reflects barriers built into the current treatment paradigm. There are many patients who rely on local therapies, most often topical or inhalers, depending on the diseases. However, most of these treatments do not address the underlying drivers of type 2 diseases and, as a result, do not deliver adequate treatment for many moderate to severe patients. There are existing oral systemic therapies in both asthma and AD, for example, but those can be limited by efficacy and certainly, for example, in the case of JAX, safety concerns, including box warning and the requirements from blood monitoring and initiation and or during treatment. Finally, injectable biologics have delivered important advances advances and now account for the majority of systemic therapy use, actually more than 75%. However, they're associated with significant treatment burden, injection site pain, needle fatigue, burdensome loading regimens, often four to five injections in the first month, cold stain storage requirements, and ultimately with high drop-off rates over time. So, when we ask why so many moderate to severe patients remain untreated with advanced therapies, the answers lie in the limitation in efficacy for some, safety concerns for others, and very real convenience and access hurdles built into the system. The consequence is that millions of patients who would benefit from more effective therapies remain untreated, cycling through suboptimal options and living with inadequately controlled disease. This is the unmet need, and this is the opportunity in front of us. Going from patients' numbers and unmet needs to market opportunities, the gap is even larger. As previously mentioned, about 2 million patients are currently receiving advanced systemic therapies for type 2 diseases. This segment represents an annual market value of about $20 billion, with dupilumab serving as the predominant drug. Although this is already a significant figure, the broader market opportunity is much larger, given that there's tens of millions of patients that are not reached by current approved drugs. In fact, I would characterize the current type 2 market as very early in its development. Historically, the introduction of new products and mechanisms has expanded immunology markets by enabling access to additional patient populations. In addition, an oral therapy that overcomes many limitations associated with existing treatments while maintaining safety and efficacy could, for the first time, provide a viable alternative for millions of patients across old age groups. It is reasonable to assume, in my opinion, that the current market for type 2 diseases is positioned for substantial expansion well beyond the current 20 billion. In fact, a comparable example can be found in the psoriasis market, which has experienced a five-fold growth over the past decade, mostly thanks to new drugs and oral therapies. I think this all comes well together when we consider the limitation of existing therapies and what KT-621 has to offer, a drug that has the potential to deliver biologics like efficacy and safety without requiring patients to compromise efficacy and safety for convenience, a drug that has the potential to change the way patients are treated around the world how will we do so in two important ways one expand the existing treatment patient but treated patient population which for us is the number one goal second provide an easy and convenient alternative to patients currently on injectable biologics many of whom based on our market analysis and under an industry survey data are eagerly waiting to switch to an oral therapy. So then, how might this paradigm shift look, and what will it mean for patients with type 2 diseases? Our goal, and the cornerstone of our development plan, is to position KT621 as the product of choice for this large underserved or inadequately deserved patient population. In many inflammatory diseases, advanced systemic treatments are typically reserved for patients we fail conventional therapies which in turn are typically biologics we believe having an effective safe oral medicine we can we can fundamentally change the treatment paradigm making it practical to intervene earlier in the disease course rather than waiting for significant progression or treatment failure if successful we believe kt621 is the potential to shift advanced therapy from being a last resort for a small subset of patients to a mainstream extreme options for millions and improve standard of care. I hope that context around the market opportunity makes it clear why we believe that KT621 has the potential to be one of the biggest programs in the biotechnology and pharma industry. With that context, let's turn the call over to Jared and discuss clinical progress with KT-621 and KT-579, our IRF5 degrader.

Thanks, Nello. As you've heard, we're building significant momentum across our pipeline, driven by the strong scientific, clinical, and operational foundation that we've established. This morning, I'll discuss our ongoing KT-621 Phase IIB trials in atopic dermatitis and I'll then provide additional context on our clinical development strategy for KT579, our oral IRF-5 degrader. I'll begin with KT621, our oral STAT-6 degrader. In December, as many of you are aware, we released the broadened Phase 1b results, providing the first look at KT621's impact on patients with atopic dermatitis. The data demonstrated a dupilumab-like profile that strongly supports continued development of KT621 in both AD and asthma. Across all of the study's objectives, we exceeded expectations. We demonstrated strong fidelity of translation from healthy volunteers to patients with deep stat 6 degradation in blood and skin. We observed a significant reduction in type 2 biomarkers across blood and skin lesions, including TARC and EOTAXIN-3, and importantly, also in lungs, as measured using fractional exhaled nitric oxide, or phenol testing. The greatest impact on phenol was observed in AD patients with comorbid asthma who had the highest baseline phenol levels. We also achieved robust improvements across all key AD clinical endpoints, including EZ, curitus NRS, IgA, SCORAD, and patient-reported outcomes, or PROs, addressing disease severity and quality of life. For all of these endpoints, KT621 data were in line with or numerically exceeded published data for dupilumab at four weeks, further highlighting the exciting potential patient impact. In addition to these effects on AD, KT621 had a clinically meaningful impact on patient-reported outcomes measuring disease control in patients with comorbid asthma, as well as on symptoms and quality of life in patients with comorbid allergic rhinitis. And importantly, KT621 was well-tolerated with a favorable safety profile. I should also note that we recently completed the six to nine-month GLP toxicology studies in rat and non-human primate, and consistent with earlier KT621 tox studies, we did not observe any adverse findings of any type across all doses and concentrations tested we now have two parallel phase 2b dose ranging placebo controlled trials underway in ad and asthma supported by the positive biomarker and clinical endpoint results in both ad and comorbid asthma from broaden the broaden 2 trial in approximately 200 adult and adolescent patients with moderate to severe atopic dermatitis as a primary endpoint of percent change from baseline and easy at 16 weeks the study continues to progress as planned with completion of enrollment expected by the end of 2026 an announcement of top-line results by mid-2027 we will update you all on enrollment later in the year but we can say now that we are confident in achieving this timeline based on the strong interest from patients and clinicians in a safe and effective oral therapy, and given the high level of awareness of and appreciation for the KT-601 data we have generated. Moving on to asthma, just last month, we announced that we had dosed the first patient in our Phase 2B breadth trial in approximately 264 adult patients with moderate to severe eosinophilic asthma. The trial's primary endpoint is changed from baseline and pre-bronchidilator and VV1 at 12 weeks using pre-bronchodilator feb1 will allow effects across dose levels in a smaller faster study and will inform dose selection and probability of success for subsequent phase 3 trials data from this trial are expected in late 2027 taken together we expect to generate data in close to 500 patients next year from both KT621 Phase 2B studies, while also continuing to build our safety database with long-term treatment in AD patients rolling onto the 52-week open-label extension portion of Broaden 2. Importantly, these trials are designed to support parallel Phase 3 development beyond atopic dermatitis and asthma and other Type 2 dermatologic, respiratory, and gastrointestinal diseases as part of the overarching regulatory strategy for KT621. Turning now to our novel IRF-5 degrader program. We view IRF-5 as an exciting new opportunity to address complex autoimmune diseases. We continue to receive positive feedback from KOLs and investigators on the potential of KT579 to offer an effective oral treatment for diseases such as lupus, IBD, and RA. This past fall, we presented additional compelling KT579 data in lupus and RA preclinical models at the American College of Rheumatology meeting in Chicago. Chronic heterogeneous inflammatory conditions like lupus, RA, IBD, and others are driven by broad immune dysregulation across multiple inflammatory pathways, including type 1 interferons, pro-inflammatory cytokines, and B-cell-derived autoantibodies. While biologics have clinically validated each of these pathways individually, the current treatment paradigm has been constrained by the reliance on injectable therapies, optimized for narrow segments of disease biology, and therefore incapable of addressing the full complexity of the inflammation underlying the various disease manifestations. As a result, many patients experience incomplete responses or loss of efficacy over time. An oral medicine capable of modulating multiple disease-defining immune pathways simultaneously could enable more effective and durable disease control, and potentially expand access to treatment across broader patient populations. IRF5 is a genetically validated transcription factor that functions as a central amplifier of immune responses. In autoimmune diseases, where there is strong genetic association with IRF5, persistent IRF5-mediated immune activation drives skewed inflammatory signaling across type 1 interferon, pro-inflammatory cytokine, and autoantibody pathways. KT579 is designed to selectively degrade IRF5, enabling modulation of these interconnected inflammatory pathways through targeting of a single master regulator with the goal of rebalancing the immune system while avoiding the infectious adverse events caused by broad immunosuppression. We are encouraged by the strong genetic rationale, our compelling preclinical efficacy and safety data, and the potential to deliver a novel oral therapy across multiple serious autoimmune diseases with significant unmet medical need. With that said, we are now focused on advancing KT579 in our ongoing Phase I healthy volunteer trial and reporting the first in human data in the second half of 2026. In terms of the Phase I specifics, the study is designed to evaluate both single and multiple ascending doses of KT579 administered orally once daily compared with placebo. The primary aim of this SADMAT study is to demonstrate robust degradation of IRF-5 in blood, which we define as a reduction of approximately 90% or greater, at dose levels that are safe and well-tolerated. Because the IRF-5 pathway is not activated in healthy volunteers, we plan to use full-blood ex vivo stimulation assays to assess the functional impact of IRF-5 degradation on the induction of type I interferons, pro-inflammatory cytokines, and inflammatory pathway gene transcripts by TLR7, 8, and 9 agonists. It's our expectation that we should see a 50 to 80 percent reduction in these biomarkers across the three TLR pathways assessed if we're engaging IRF5 effectively, which would increase the probability of IRF5 degradation translating into clinical activity in subsequent patient studies with KT579. As we did with our STAT-6 program, we also expect to conduct a Phase I-B patient study and intend to share more details on the design and patient population later. We have said, however, that we would expect to focus the study on lupus patients, which we believe is the right patient population for our first proof-of-concept study, given the strong genetic association of IRF-5 with lupus and the robust activity of KT579 across multiple mouse models of lupus. I'll now turn the call over to Bruce for a review of the fourth quarter results. Bruce?

Thanks, Jared. As I walk through the fourth quarter results, please reference the tables found in today's press release, which was filed this morning. Collaboration revenue in the fourth quarter of 2025 of $2.9 million is attributable to our Gilead partnership. More broadly, with respect to Gilead, we received an upfront payment of $40 million upon signing the licensing and option agreement last year. Under this agreement, we're eligible for up to $750 million in total milestone payments, including $45 million payment payable if and when Gilead exercises its option on the CDK2 program at the declaration of a mutually agreed-upon development candidate. In addition, Sanofi is advancing KT485, our oral IRAC IV degrader, with plans to initiate phase one testing this year. We expect to share additional updates on this program in the coming months, including the receipt of a milestone upon dosing of the first healthy volunteer. As a reminder, under the structure of the Sanofi agreement, we have the potential to realize nearly $1 billion in total milestones. While these two potential near-term milestones are not reflected in our current cash guidance and are not expected to materially impact our runway, they remain important validation points and support the continued advancement of these partnered programs and the downstream value we can realize. We look forward to sharing further progress as these programs move forward. With respect to operating expenses, R&D for the quarter was $83.8 million. Of that, approximately $7.6 million represented non-cash stock-based compensation. The adjusted cash R&D spend of $76.2 million, which excludes that stock-based comp, reflects a 16% increase from the comparable amount in the third quarter of 2025. On the G&A side, our spending for the quarter was $16.9 million, of which $6.9 million was non-cash stock-based comp. The adjusted cash G&A spend of $10 million, again, excluding that stock-based comp reflects a 1% increase from the comparable amount in the third quarter of 2025. And finally, we are well capitalized to execute on our goals. As Nello mentioned previously, we ended in December with a cash balance of $1.6 billion, providing a runway into 2029. This allows us to complete both KT621 Phase 2B trials in AD and asthma and to fund a large part of the first phase three trial trial for KT621. The runway also will allow us to advance KT579 through initial POC testing and to progress our research pipeline as we scale and grow Chimera. With that, we'll pause while we regroup in our conference room and assemble the queue for your questions. Thank you.

Thank you. At this time, if you'd like to ask a question, please click on the raise hand button, which can be found on the black bar at the bottom of your screen. If you join by phone, please dial star 9 on your keypad to raise your hand. When it is your turn, you will receive a message on your screen inviting you to join as a panelist. Please accept and wait until you are promoted to panelist. Please unmute your audio, turn on your camera, and ask your question. As a reminder, we are allowing analysts one question and one related follow-up today. We will now pause a moment to assemble the queue. Your first question comes from the line of Mark from TD Cohen. Please unmute your line to ask your question.

Thanks for taking my question. And congrats on all the progress. AD, a high-level one for Nello, since your phase one data came out with the stat six, a handful of other early mid-stage programs in AD have also read out data. And there was some data even ahead of years. So over the past year, there's just a lot going on in AD. What's your kind of vision for what the treatment of AD looks like and how these therapies all fit together, you know, when you roll the clock forward a few years? And then maybe I can sneak a little bit in for Jared also, just for IRF5, can you just remind us what really can be learned in the healthy volunteer portion of that trial beyond target engagement and safety, or do we really, to learn more, have to wait for that lupus cohort to enroll?

Thanks, Mark. Great question. So, I'll start with the first one. So, just to remind you, as we shared today, hopefully even more clearly than before, the AD, I would say the type 2 diseases market is still very early. Again, there is, if you look at moderate to severe patients, there is about 40 to 50 million patients in the seven major market, and only about two have been those with advanced systemic therapy. So, clearly there is a need of more therapies. And as we, you know, we mentioned, and others have done so, we mentioned, you know, if you parallel AD to psoriasis, psoriasis market in the past 10 years has grown five-fold. Maybe AD is somewhere around where psoriasis was five, 10 years ago or so. So we expect this market to increase dramatically, and you can only do that by bringing new therapies to the market. So, first, I want to start by saying that this is obviously a non-zero-sum game, right? I think there is a need of new therapies, and new therapies would benefit patients first, but also actually companies that develop all the other therapies. I mean, for two simple reasons. We need, especially from our viewpoint, patients need convenient overall options that can increase the probability of patients with moderate to severe disease to access effective therapies. And so I think that that will transform how these diseases are treated. With our mechanism with STAT6, I think the main difference that I could point to without going company by company, which will take us half a day, is that we're targeting an infracellular target of the most validated pathway in TH2 inflammation, which is I4N13. So we're going after well-validated efficacy and safety. We're going after well-defined patient population. And so I think we have a level of de-risking that I would point to being, you know, I think superior to many other agents that are still, you know, interesting and exciting that are So I think, you know, we need more therapy. I think it's great that there are more drugs, and obviously we need to move into late stage development to really assess, for our drug and many others, what is the risk benefit that we can bring to patients. Jared, do you want to take the IRF-5?

Regarding IRF-5, as you mentioned, the primary clinical objective is safety, and then our primary translational objective is to show 90% or greater IRF-5 knockdown in blood. But, you know, and showing that knockdown is going to be important, we think, from a de-risking standpoint for the subsequent patient studies because of the strong genetic association between IRF5 and lupus and the strong preclinical activity in multiple lupus models that we've seen with that degree of IRF5 knockdown. Now, with that being said, yes, it's true that, you know, unlike STAT6, where we have circulating biomarkers like TARC and Eotaxin 3 that were useful for us to assess sort of that sort of translation in healthies with regard to IL-4, IL-13 pathway. Here for IRF-5, while we don't have those circulating biomarkers, as we mentioned, we have these ex vivo stimulation assays, which I think will provide very important functional information around IRF-5 degradation. These assays are looking at stimulation of toll-like receptor 789, which are the three toll-like receptors driving type one interferon, co-inflammatory cytokine, and B-cell auto-antibody production. And to be able to show an impact across those three pathways on the next Evo STEM, when we believe, you know, significantly at the risk, you know, our probability of success in subsequent patient studies, including the lupus studies.

Maybe just to add a quick thing on top of Jared, like if I think a bit more from my point of view, maybe higher, more simple level, which hopefully still scientifically sound, You know, we know that the strength of this program is the genetic association, right? There is very few programs in the history of drug development that have the strength and the depth of genetics that we have with IRF-5, and that's why it's one of the most interesting programs in immunology, I think, in the next five to ten years. So when you have genetic association, you try to figure out, okay, biologically, what does that mean? So we've shown pre-cleanically that actually IRF-5 activation leads to, as Jared said, activation of this pro-inflammatory cytokine, type 1 interferon, and B-cell activation, auto-antibody activation. So even in healthy volunteers, we can prove even ex vivo that we can block these three axes of inflammation. I think it's going to tell us that you combine that with the genetics that it should work into patients.

Next question comes from the line of Jeff Meacham with Citi. Jeff, you'll need to unmute to ask a question.

Can you hear me?

So just had a couple. Thanks for the question, first of all. So on 621, the broadened to and breadth studies, you know, are probably mature next year. we're used to seeing you guys have you know phase one biomarker data and kind of maybe data a lot of data points along the way for these phase 2 B's is it going to be you know let's just wait until the full and final are you guys planning on having any kind of biomarker or interim analysis or anything like that for these two studies. And then for the IRF-5, you know, interesting program, you know, for sure. The indications you guys have talked about include some that are very much unmet need, lupus, Sjogren's in particular, and definitely not as crowded. I'm curious how that informs like your priorities when you think about, you know, kind of development for this program. Thank you.

Jeff. Thanks, Jeff. So, on the first one, obviously, we'd love to, you know, get data along the way and understand what's going on in the phase of these studies, but obviously, these are important studies that are placebo-controlled, and, you know, to protect the integrity of the study, we're going to wait until the end of the study to unblind and obviously share the data. For IRF5, yes, so I think I go back to the reasons to believe, and as I said, human genetics, lupus, Sjogren's, myositis, RA, IPD, those are, you know, areas that we believe this target is extremely relevant. And so we're letting that, combined with the preclinical data, guide us. So, the reason why we've talked often about some of those indications is because they match so well both the genetics, the preclinical data, the IMET-need, I mean, if you look at the ones you mentioned, lupus, Sjogren's, these are diseases that don't have effective therapies that are approved, or at least some that don't have, maybe I should say, at least oral effective therapies that are approved, which will serve a much broader population than what's being evaluated now in clinical development that I believe are really probably going to be positioned for really late-stage patients. I think another important axis of our development plan will be outside of, let's call it these interferon-related pathways or pathologies, which, you know, could be, again, IBD could potentially be a ray down the road. And, you know, I think we plan to share more data on IBD, which is increasingly becoming an area of focus for this program, at least pre-clinically, and we hope for it to be clinically as well in the not-so-distant future. Awesome. Thank you.

Your next question comes from Charles Ndaye with Stifel.

Sorry, how's on mute?

Congrats on the quarter.

You know, one question from our side, I guess, As you think about starting phase 2s for 6-to-1 outside of asthma or AD, what are sort of some of the gating factors?

Yeah, so as we've outlined in the past, I believe it's still on our corporate deck. There's a new one today on our website. Our strategy is to use the ongoing dose-ranging phase 2b study, the one in AD to support late development and all of the other dermid indication, the one in asthma to support late development, the other respiratory indications. So we actually do not plan to start any new phase two studies. The new studies that you see us starting will be, we believe, all registrational studies. Now obviously some of these still has to be vetted with the right authorities, but that's our current strategy and we believe this is a strategy that has been proven to be successful with other drugs in this pathway. So, it wouldn't be the first time that this is adopted. Thank you.

Thank you.

Your next question comes from Brad Canino. Please unmute to ask your question.

A question from me on the trigger to start the K261 Phase 3s. So, to initiate, how far into the Phase 2s do you need to reach and what needs to be collected from those studies? And will this be one study start or multiple at once? Thanks.

Yeah. So, you know, unlike what we may be getting everybody used to, that we start a study while the previous one was still ongoing, as we've done for the Healthy and Phase 1B. So, for starting a Phase 3 study, we need to complete Phase 2. We need to have an FDA meeting post Phase 2, and then we can start Phase 3. I assure you that we will do our best, as we always have, to do that as quickly as possible. But obviously, there are some things that we must do in order to move into phase three. With regards to how many, as you know, at least the paradigm that companies have adopted in the past 10 years for, let's say, etopic dermatitis registration has been three phase three studies. Two, there are two placebo-controlled, mostly placebo-controlled studies. studies, and then one on top of topical corticosteroid. So we, if that will continue to be the paradigm, which is something obviously we will explore given the recent news from FDA, but let's say that continues to be the paradigm, you should expect us to start all studies as much in parallel as possible.

The next question. Right, once, yeah, once we select. Okay, the next question comes from Polly Merle with Barclays. Hey, guys, congrats on all the progress.

In terms of 621, if you could talk about both the clinical and preclinical data that you've seen, where do you see the most potential room for efficacy improvements over to Pilamab? And can you talk about some of the respiratory preclinical model data and compare that to what's been seen preclinically in atopic dermatitis?

Yeah, thanks, Ellie. You often ask the tricky question. So we want to make sure, like, you know, we maintain kind of our credibility when we compare a drug that has been so successful in millions of patients with the drug that has been so far in, you know, about, you know, a couple of hundred patients for subject and up to 28 days. So I'm always very thoughtful about how we make comparisons. What I can say is that in our preclinical models, if you look at the asthma models that we both published, KD621 has performed always, at least as well, and in many cases better than the PILMAP. We don't know whether that is the result of the model or it's actually real biological differences or drug distribution differences, and that's why we're really excited that were in phase two studies so we can assess the full clinical activity of our drug in a large study with hundreds of patients. With regards to AD, the preclinical AD models are not very robust. We like to talk about the asthma model because it's a highly translatable model. The AD preclinical models, you have this local activation with a pathway activator that it's It's not really, in many cases, a type two discrete pathway activator. So we also show really robust activity. But to be honest, as a scientist myself, I don't like to talk about preclinical AD models. They're mostly useless. But if we look at the clinical data, obviously, you've seen the data from last December. We have shown really robust activity. I start from biomarkers. I look at, you know, what we've shown even with biomarkers that were either not shown to change much with the pilumab, like IL-31, or the ones that we showed comparable, not superior, eotaxin, even Xeno. And then we look at all the clinical endpoints that we measured, we'd be consistently at least as good as the injectable biologics. So again, it's hard for me to say it will be equal, it will slightly inferior, slightly better. But I think we delivered that ballpark scenario that we talked about for last year. And so for us to really know, you know, how it looks, we need to wait for the phase to And to be honest, the only other thing to keep in mind is you can never compare drugs unless you run a head-to-head study. But our goal, again, is to deliver an oral drug with biologics-like activity, with great safety and the convenience of being an oral pill that one can take once a day, stop and start whenever they want, I think that will transform the treatment paradigm for type 2 diseases well beyond whether the drug is exactly like dupilumab, slightly less or slightly better. I don't think that will matter if we can deliver the type of drug with the profile that we speak about.

Great. Thanks so much.

Your next question comes from Annalie. Hi.

This is Anna on for Gripa. One quick question on 621, I was just wondering if you could give us kind of an overview on how you're thinking about compliance or seeing it in the Phase 2B trials right now and how the durability of 621 kind of ties into that. Thank you so much.

Cool. So, that's a great question. So, when you, when you, when you combine to mean patient taking the drug, that's what Or, yeah. So, you know, I think that's obviously, it's a very important point because, you know, when you're on a clinical trial on injectable biologics, you can actually ensure 100 percent that here, and that's right, because patients often, in most cases, actually go on site to receive the injection. When you, the beauty of oral drugs is actually you give patients freedom, right? That's the beauty of oral drugs, and that obviously plays a role into clinical studies. So, we have measures that probably go even beyond what has been done generally to make sure that we understand a patient's adherence well. So we are confident that the adherence of patients would be the one that will allow us to have a great integrity of our study. I will also add that the beauty about protein degraders, unlike small molecule inhibitors, If you miss a small molecule inhibitor dose, you actually lose all your activity. If you miss one dose of KD6 to one, this is not an advertisement to not take the dose every day. But I will say if you miss a dose of KD6 to one, if you miss one dose, you will not lose any of that with the relation. So we have that additional layer of let's call it protection against any challenges that might come with, you know, humans forgetting one dose during a study or during normal life.

Thank you so much.

The next question comes from Judith Frommer with Mvork & Stanley.

Hey guys, thanks for taking the question. Congrats on the progress. Just on IRF5, I think we're clear on how you think about STAT6 degradation versus inhibition, you know, kind of same question for IRF5. I think we'll get a little bit of preclinical data from an inhibitor next month, and then just on the targeted nature of your degrader, any risk of kind of pan-IRF inhibition? I think, you know, IRF-8 has been a question in degrading IRF-5 previously.

Yeah, maybe I'll start and then I'll pass it to Jared to speak. Even maybe it's an opportunity to talk about how we think about the safety of IRF-5, and Maybe I'll talk more about the chemistry of it, given that I'm technically still a chemist. So the beauty about this target and the challenges with this target is that it's extremely hard to find a molecule that binds to IRF5 only without binding to all the other IRFs. You mentioned a few. I think there is 11 or 12, but sometimes I lose count, but there's more than 10 IRFs. So, we need to bind only to IRF5, and there are different, I like to call them splicing variants, people call them differently, but there are different IRF5 splicing variants that all need to be targeted. So, you need to be consistent across the IRF5 family, but do not bind to any other IRF. So, we've been able to do that. Our selectivity is pristine because we've been able to find this molecule that is actually not functioning. So it does not inhibit anything, it only binds to IRF-5, all the IRF-5s, 5 invariants, but not other IRFs, and this allows us to give the utmost selectivity, so we're not worried about any of those things. But Jared, do you want to speak about why we think 5-only is potentially really interesting?

Yeah, I think IRF-5, because it is one of multiple different IRFs, there is a certain redundancy there when it comes to the role of IRFs in innate immunity. So even getting rid of IRF-5 really does not impact overall innate or adaptive immunity. It's also true that IRF-5, its expression is very restricted, you know, essentially to certain immune cell subtypes like B cells and dendritic cells and monocytes and macrophages. So it's not ubiquitously expressed, which is another reason why one can knock it down and do so safely. And its activation is also very context specific. So, here, again, in the context of pathologic inflammation, that's where you're going to see activation, but you're going to see activation in restricted cell types. And that's the reason why you can really degrade on IRF5 strongly and chronically and not get broad immunosuppression and not have infectious adverse events. And in fact, if you look at knockouts for IRF5, you don't see any susceptibility to infections or any phenotype. And in our preclinical animal tox studies, including our four-week GLP tox studies in non-human primates as well as in rats, you know, we don't see any adverse events, adverse findings, and we don't see any susceptibility to infection. So for all those reasons, we believe that this is the same target for us to degrade deeply and chronically.

Thank you.

Your next question comes from Joe Kansansara with Mizuho.

Great. Thanks for taking my questions. Hopefully you guys can hear me okay. Maybe 1579 and something kind of maybe related to something you just said, Jared. But I was looking at another healthy volunteer study for another anti-inflammatory drug, and they actually utilized a skin immune challenge model where they injected volunteers with actually a TLR agonist and then looked at cytokines. Wondering if you guys are aware of that model, whether you consider this, and if you did consider why you didn't decide to use it. And then I guess related, what informs the 50% to 80% target reductions in biomarkers? Is that all preclinical, or is there some genetic basis for that target reduction?

So maybe I'll take the first one, and Jared takes the second one. So yes, we're obviously well aware of there are many type of skin challenge models, sometimes even systemic models, systemic challenge models, people have done FPS, email FPS, local FPS. So there are many models that one could run pre-clinically for healthy volunteer studies. We philosophically feel like the right context to ask these pathway questions are in patients. And what you do by activating the skin is you artificially activate a pathway and then you look at downstream regulation. You can do that just the same way by taking the blood and ex vivo activating the pathway. So yes, you could do those things. We just don't believe that the complexity of it, the risk is any more or less what we would do with an ex vivo blood stimulation. If you have questions about, does your drug reach particular tissues, and especially with small molecule inhibitors where you actually cannot measure target engagement, that is a way to do it. But we can measure target engagement directly, so we don't need a surrogate downstream biomarker to make sure our drug gets to the tissue. So that's at least our view. Jared, do you want to speak to the…

Yeah. I mean, we know in terms of the amount of knockdown that we think we need or the amount of functional inhibition that we would need for those pathways. One has to keep in mind that here we're talking about not just one pathway that's controlled by IRF-5, but multiple pathways. Here we're looking at three different TLR pathways, for example, 7, 8, and 9. And so we're talking about one pathway and all your activity is dependent on one pathway. You might have a threshold that could be 80%, 90% or more to really have clinical impact. Here we know that if you're impacting multiple different pathways in parallel at the same time, you don't need necessarily 90 plus percent inhibition, you know, 50 to 80 percent inhibition from our preclinical data across multiple different pathways can have a synergy that can give you significant activity in preclinical models. So that's the reason why we say that that's sort of a range, which is really just a range if you're seeing it across multiple different TLR pathways with these X-Divo STEM models would be very encouraging and we would expect to translate into activity in subsequent patient studies and diseases like lupus.

Great. Super helpful on both points.

The next question is from David Archula. Sorry, excuse me, Derek Archula with Wells Fargo.

Good morning. Thank you for the question. And this is Hal, I'm calling you for Derek. So I guess our question is about the potential oral autoantibody delivery program. Just kind of the timing and what data, what events maybe we can hear more from this asset.

Sorry, I didn't quite get the question. Say that again.

The internal potentially oral autoantibody.

Oh, so do you mean the next oral immunology program that we were going to disclose? So as we said, I believe it's in the press release and in our remarks earlier, we plan to disclose at least a novel program, most likely an immunology program this year and likely will be the second half of the year.

Thank you.

The next question comes from Brian Chang with JPMorgan.

Hey guys, thanks for taking our question this morning. Just on IRF5, as you mentioned, 50 to 80% reduction across the TRR 789 pathways. You know, just thinking about IRF5 regulates many of the levers in the pathways. Are there any specific downstream cytokines that you can point to today that will be be the most impacted, most reliable, and perhaps the easiest to monitor from an ex vivo stimulation test setting to best assess the PD of the drug?

Yeah, that's a great question.

Joe, do you want to take it? Yeah, through the other stimulation of these pathways, there are key cytokines that we can look at. So, for example, type 1 interferon, psychointerferon beta, we can look at, you know, interferon beta protein production, you know, any of these ex vivo stem assays. We can also look at, you know, gene transcripts, you know, that are part of the type 1 interferon pathway. So, looking beyond just the interferon itself, you can look at various genes that are part of the type 1 interferon pathways. We can also look for pro-inflammatory cytokines like IL-12 and tumor necrosis factor and even IL-6, which are stimulated by, you know, macrophages and dendritic cells. So, these are a number of different pro-inflammatory cytokines that are coming off of these dealer pathways that can all be measured, either the protein level or the gene transcript level, that will be the very helpful biomarkers for us. Thank you.

Thank you.

The next question is from Brian Aperhams with RBC. Brian, please unmute to ask your question. Hi, guys. Can you hear me?

Yep. Hi. Thanks so much for taking our questions. This is Kevin on for Brian. Maybe just on On IRF-5, how are you guys thinking about degradation in, I know you mentioned whole blood, but just in PBMCs and maybe potentially skin as well? I think that's something you're looking at in the mat portion. And I know you talked about IRF-5 not being as activated in healthy volunteers. So just maybe curious what our expectations should be there for degradation in those tissues. And just kind of how much do we really know about sort of IRF-5 expression in healthy volunteers and how that impacts your expectations for the study.

Yeah, I mean, in blood, we know that we can measure IRF-5 well, and in fact, when we say blood, we obviously then practically need PBMCs because we isolate PBMCs, we measure it using mass spec. The expression of IRF-5 in healthy volunteers in the skin is extremely low. And so, for that reason, we believe it's going to be, it would be really hard to measure IRF-5 ineptic volunteers. This is something that, as we go into patients, and especially if we go into, you know, with continuous manifestation or even CLE, eventually, that's maybe a context where we could look at IRF-5 expression. I think ineptic, the expectation is to be extremely low, lowest than any other program that we've looked at, even pre-clinically.

Thank you.

So hard to measure.

Yeah.

Now I will be moving to only one question due to time. Your next question comes from Sudan at Stevens.

Good morning, everyone. I wanted to ask my question around 621's opportunity in asthma. You know, looking at the current FDA approved treatment options for AD, not all of them have really panned out that well in asthma as maybe people have expected. You know, statics degradation is a new approach. So curious to hear what theoretical and preclinical data you may have that gives you some conviction here that it also has an opportunity in asthma. Thanks.

Yeah, I think I4N13, and just I remind everybody that there's only one drug that blocks I4N13, which is trupilumab. And so that is shown to have really, really robust activity in eosinophilic asthma and actually eosinophilic COPD, chronic rhinositis with nasal polyps, so it's well established to really have huge impact on patients with type 2 inflammation in respiratory tract. So stat 6 biology, again, we've shown it extensively pre-clinically and also in the early clinical development that we can mimic the same I4N13 blockade, and again, I refer you to the asthma studies that we published, preclinical study that was published, showing that the robust activity we see both on biomarkers and efficacy endpoint, the phenoreduction that we've seen in patients is actually even more robust than biologics in asthma patients. So we have all the ingredients to have reasons to believe that this drug actually is going to, has the potential to be extremely effective in asthma. Thanks.

Next question is from Jeet Mukherjee with BTIG.

Great, thanks for taking the question. As we just look ahead to the evolving competitive landscape in atopic dermatitis, and specifically on the next-gen oral agents that might be coming around the corner, just your thoughts on ITK as a target and some of the recent data we've seen there and how that might compare and contrast to STAT6.

Yeah, it's a great question. As I said earlier, I think more mechanisms are great for patients first. I think, obviously, these are very different mechanisms. STAT6 is an I4 and 13 drug, as I said, the most validated pathway in the space, both in terms of safety and efficacy. We have shown pre-clinically that we can mimic biologics, both in terms of efficacy. And I would actually argue that in safety, We just shared today that we completed chronic talks, so six to nine month talks in rodents and non-human primates, again, without any adverse event. You know, other targets, you know, ITK is a target that we've looked extensively at Primera. We decided not to work on it because the human genetics show that because of the challenges with clearing ETB, I think all patients end up developing some form of lymphoma. So, this is a reason why we decided not to work on that target. That doesn't mean that it could not be a great target. It's just something that we don't believe fulfill the risk-benefit profile of Chimer and how our target selection strategy has been evolved over the years. But again, I think more mechanisms, especially with complementary pathways, whether it's ITK or others, I think are going to be great for patients are expanding this market that we need to do so that more patients get access to more therapies.

Thanks for taking the question.

Thank you.

Next question is from Faisal Khashiv with Jeffrey.

Hey guys, thanks for taking the question. Wanted to ask, as you guys get the sites up and running in the Phase II B studies, do you expect to provide any kind of color or context around how enrollment is going in those studies?

No, I think, you know, I think what we, obviously, if we feel we're, you know, we're not on track, obviously we will share, but as long as we remain on track with the expectation, we don't plan to be providing, you know, ongoing updates on enrollment. I don't think it's necessary. But obviously, again, if we deviate from expectation, we will make sure to do so.

Sounds good. Thank you.

Next question is from Buren Amman with Piper Sandler.

Yeah, hi, guys. Thanks for taking my questions, and congrats on the quarter and all the progress. For the face-to-be AD trial, what measures are you taking in the trial to mitigate against placebo response? For example, will you be requiring photographic evidence of AD at baseline, you know, to provide evidence of moderate to severe disease on screening? So I guess that's, you know, first question. Second question on 579, I know you're enrolling healthy volunteers, however, there are healthy volunteers that may have positive anti-nuclear antibodies, but do not have autoimmune disease. Would you potentially screen for these types of healthy volunteers, you know, and you know, that may potentially provide read through into your phase 1B lupus trial? Thanks.

Great question. And I'll take the second one quickly. Jared, do you mind taking the first one? Yeah, so great idea. Sometimes simple is better than complicated. So we're going to actually enroll healthy volunteers that are healthy more quickly through it, selected those and go into patients. That doesn't mean your idea is not a good one, it's just not what we're planning to Jared, do you want to take the first one?

Yeah, I think for the Phase 2B, I mean, your question about, you know, avoiding, you know, high placebo raises is an important one. And while I can't get into all the details at a high level, I can tell you that we're We're paying a lot of attention to this, both with regards to our eligibility criteria, how we're providing oversight, you know, with every patient that comes on and is screened in terms of looking to make sure that patients are truly meeting eligibility criteria, not just in terms of actually having AD, but also having moderate to severe disease. And we've carefully, you know, trained the investigators and selected investigators who are board-certified dermatologists to make sure that they're fully capable of doing all of the clinical endpoint measurements across the study and that they're doing it consistently from, you know, baseline all the way through to the end of the study. And we also have global, you know, site selection. So we're not just in the U.S., we're also ex-U.S. And, in fact, the majority of our sites are ex-U.S., whether that be in Europe or in Asia or in Australia. And I think that's also important because access to drugs like dupilumab, you know, are diminished, you know, ex-U.S. And so those are patients who are more apt to come in, maybe more on the severe end of the spectrum of disease. And that can also be very helpful in helping to mitigate the placebo effect, which you tend to see in milder patients compared to more severe patients. So I think all of those steps are being taken and we're really very actively staying on top of all of that to try to mitigate, you know, a high placebo rate.

I mean, we're doing, I'm sorry, we're way out of time, but we're doing lots of things, probably more things that anybody has done before to ensure that we do that. Obviously, we can't guarantee the lowest placebo rate, but we're trying our best.

Perfect.

Excellent.

Thanks, Duran. Your final question comes from Parath Desai with B. Reilly.

Hello. I'm on from Mayank. Thank you for taking our question. On asthma trial, if you could kindly confirm the dose levels are the same as broadened 2, and how might you be enriching for phenol in your target patient population? And is there a chance your 12-week FEV1 endpoint data could come around the same time as your 16-week broadened phase 2 study? And also would be helpful to learn competitive trial enrollment dynamics in atopic dermatitis versus asthma? Thank you.

Yeah. Thank you. These are four questions in one, but let's see if you guys have to have me remembering. So, the first one, those levels, yeah, they're the same across AD and asthma. So the inclusion criteria for the asthma studies, high EOS, more than 300, high FNO, more than 25. So that's how we're going to select that patient population. In terms of timing, we said that we expect the phase to be a AD study data by middle of next year, while the asthma data by the end of next year. So I guess that answers the questions. Things that always change one way or the other. And as I said earlier, if that changed materially, we will share. And then competitive dynamics, all I can say that we have seen a ton of enthusiasm for our study in both, actually, I would say AD and asthma. And that's for two main reasons, actually, I would say three reasons. One, sites, and hopefully also patients, appreciate the really, really interesting and innovative science of our program. They appreciate that this, while this is a novel target, is within a well-established biology and clinical experimentation, it's an oral drug and has some compelling early data. When you put all of that together, we have seen a ton of enthusiasm. So, we really hope that this enthusiasm will translate into good enrollment and that's what we're seeing so far, but, you know, we're still a long way to the finish line.

Thank you.

Thank you.

There are no more questions at this time. Yes, there are no more questions at this time. I'd now like to turn the call over to Nelan Meinolfi for closing remarks.

So, first, let me apologize. This call has taken the longest that we've ever done. I'm not really sure why, but I want to thank everybody for attending the call. All great questions, so I don't blame our analysts, and you know where to find us. We're very excited about where we are. This is a pivotal time for the company, and so we're excited to engage beyond the call if there are questions, and enjoy the rest of the day.