Hello, and welcome to Clinical Perspectives on Treating Idiopathic Pulmonary Fibrosis or IPF. I'm Brian Windsor, President and Chief Operating Officer of Aileron Therapeutics. I am so excited for the opportunity to tell you about LTI-03, a novel Cav-1 related peptide drug in development for IPF. During today's presentation, we will tell you more about the mechanism of action of LTI-03, as well as share preclinical data and information on our IPF clinical trials. I am joined by several recognized thought leaders in the field of IPF, including our own Chief Scientist, Dr. Cory Hogaboam, who will moderate today's panel discussion. Joining Dr. Hogaboam are Professors Fernando Martinez, Andreas Günther, and Tejas Kulkarni, each of whom has considerable experience in treatments and clinical trials for IPF. Firstly, however, I would like to tell you a little more about Aileron Therapeutics. In October of last year, Aileron acquired Lung Therapeutics, and as a result, Aileron shifted its focus to address significant unmet medical needs in orphan, pulmonary, and fibrosis indications. We have two clinical stage molecules in development for the treatment of lung conditions, with other preclinical candidates to potentially treat other fibrosis indications. The first of these is the subject of today's discussion. LTI-03 has a unique dual mechanism of action, which has shown the ability to both reduce pro-fibrotic signaling, as well as protect critical cells in the lung epithelium, which can potentially protect healthy lung tissue and restore lung function. We are also developing LTI-01, a proenzyme for loculated pleural effusions, a potentially fatal condition with no drug approved anywhere in the world. LTI-03 is currently in a phase I-B clinical trial in IPF patients, with top-line data expected by the end of the second quarter of this year. LTI-01 has completed phase I-B and phase II-A clinical trials and is phase II-B ready. Now, I'd like to introduce our Chief Scientist, Dr. Cory Hogaboam, as we turn our focus to LTI-03. Thanks, Brian, and it's my distinct pleasure today to present exciting preclinical data regarding LTI-03, which is a novel treatment for idiopathic pulmonary fibrosis or IPF. LTI-03 is a peptide region of the caveolin-1 protein indicated for IPF treatment. You'll be hearing later in this presentation from our KOL panel members, who will discuss current standard of care and treatment options in IPF patients, and they will reiterate how these options offer modest clinical benefit, have significant side effects, and are poorly tolerated. As a synopsis, Aileron has completed multiple preclinical studies supporting the dual mechanism of action of LTI-03 to inhibit multiple pro-fibrotic pathways, and equally importantly, protect lung epithelial cells. Aileron has successfully completed a phase I-A randomized, double-blind, placebo-controlled study in normal, healthy volunteers and is currently in a phase I-B randomized, double-blind, placebo-controlled study in IPF patients. Aileron has exciting novel data regarding the effects of LTI-03 on the expression of soluble receptor for advanced glycation end products, or soluble RAGE, which is a prognostic biomarker of IPF disease. LTI-03 preferentially increased soluble RAGE in ex vivo IPF tissue samples and in phase I-A treated volunteers. Importantly, soluble RAGE is primarily expressed by type I epithelial cells in the lung tissue. Now, caveolin-1 is downregulated in IPF, and I'm highlighting here key studies from the University of Pittsburgh, in which it was revealed that caveolin-1 is a critical regulator of lung fibrosis in IPF. In this study, they showed that both at the transcript level as well as at the protein level, that caveolin-1 protein is lost. This and several other published studies established that caveolin-1 is a key regulator of the fibrotic process. Now, caveolin-1 is a key structural component of caveolae, which form distinct structures in the plasma membrane of both non-immune as well as immune cells. Previous studies in several organ systems have shown that a low content of caveolin-1 leads to a higher propensity for hypertrophic scarring. Conversely, normal or high content of caveolin-1 is associated with a lower propensity of organ scarring. A high magnification view of caveolin-1, shown on the right side of this slide, highlights that this protein contains a key peptide domain called the caveolin-1 scaffolding domain, or CSD, and it's shown in this figure in purple. This CSD region is critically important for regulation of the activity of several intracellular signaling pathways that contribute to fibrosis. Aileron Therapeutics has advanced a novel therapeutic to mitigate the absence of this key regulatory component of caveolin-1, in essence, simulating caveolin-1 activity via a CSD peptide. Now, LTI-03 is a seven amino acid peptide that encompasses a portion of the caveolin-1 CSD. Another key innovation developed by the company pertains to the delivery of LTI-03 as a dry powder through an inhaler. Now, via its binding to caveolin binding domains that are found in multiple proteins, LTI-03 has been shown to attenuate multiple receptor tyrosine kinases and metabolic signaling pathways, specifically in fibroblasts derived from IPF patients. So this slide here highlights the effects of LTI-03 on the phosphorylation status of PDGF receptor beta and mTOR, shown on the left-hand side of the slide. And then on the right-hand side of the slide, we show that there are several other key pro-fibrotic factors that fall into these broad categories, including receptor tyrosine kinase and associated signaling molecules, metabolic signaling, cell invasion markers, and epigenetic regulators. So these and other data highlight that LTI-03 has broad inhibitory effects on multiple pro-fibrotic signaling pathways that are known to be active in IPF, lung fibroblasts, and myofibroblasts. Equally exciting to us and to the KOLs, as you'll hear later, is that there's growing evidence that LTI-03 also promotes normal epithelial cell survival and proliferation. Unlike most of the current anti-fibrotic agents under development, LTI-03 has shown both novel protective effects in lung epithelial cells in addition to its anti-fibrotic effects. As shown in this slide, we've seen that there are notable effects in precision-cut lung slices, in which LTI-03 promotes normal epithelial cell survival and proliferation. From these studies, it's apparent that LTI-03 is promoting the survival of type II cells, as evidenced by the expression of pro-SPC, indicated here by immunofluorescence and also by a Western blotting technique. LTI-03 also promotes the expression of ABCA3, which is a pro-SPC transporter. These studies have also directed Aileron towards the exploration of soluble RAGE, in studies in IPF patients. This soluble receptor is well known to the IPF clinical community since it's been shown that levels of soluble RAGE are decreased in IPF compared with control or other milder forms of ILD, as shown on the left side of the slide. Further decreases in IPF patients of this particular receptor have also been noted in patients with the progressive form of IPF, and by progression, they're referring to a greater than 10% decline in predicted forced vital capacity over the first year after diagnosis. Now, as a reminder, soluble RAGE is exclusively expressed by type I epithelial cells in the lung. When added to PCLS, LTI-03, both time and dose-dependently, increases the expression of soluble RAGE, as shown here. These data are exciting because they suggest that the increase in soluble RAGE might reflect overall epithelial cell survival, and this mediator can be readily measured in clinical samples from IPF patients, as I just showed you. The dose-dependent anti-fibrotic effects of LTI-03 are evident in the PCLS system as well, and as shown here, LTI-03 markedly attenuates the expression of several inflammatory and pro-fibrotic factors. Indeed, at the highest dose of LTI-03 tested in this PCLS system, LTI-03 exhibited a comparable scope of inhibition to that of nintedanib, a standard of care therapeutic in IPF. Now, with these exciting and novel preclinical findings, Aileron is now undertaking a phase I-B trial in IPF patients, and details of this two-cohort safety trial are summarized in this slide. Briefly, it will comprise two cohorts of patients who receive either placebo or LTI-03 via daily inhaled doses. Bronchoscopy is to be performed at screening and at day 14. Safety and tolerability are key endpoints, as are several novel biomarkers, which will be assessed in blood, BAL, and bronchial brushings. The scope of the biomarker analysis in this phase I-B trial is summarized here and involves validated biomarkers of epithelial cell damage, repair, fibrosis, inflammation, and thrombosis. In summary, LTI-03 restores key regulatory effects of caveolin-1, needed for both resolution of fibrosis and lung regeneration. Capitalizing on the interactions of several signaling proteins with the caveolin-1 scaffolding domain restores several critical physiologic effects in structural cells such as fibroblasts and myofibroblasts and in epithelial cells in the lung. Thus, LTI-03 both inhibits fibroblast activation and promotes the survival and function of alveolar epithelial cell types in IPF. Now, I'm happy to introduce Doctors Martinez, Kulkarni, and Günther, who are joining us for a panel discussion on LTI-03. I'll give them a few moments to introduce themselves and their work with LTI-03. We'll start with Dr. Martinez. Dr. Martinez? Hi. Fernando Martinez. I am the Chief of Pulmonary and Critical Care Medicine at Weill Cornell Medicine, NewYork-Presbyterian in New York City. I have been involved in the ILD space for 30 years, including with you, Cory Hogaboam. I have been involved in a whole series of translational clinical studies running clinical trials from phase I to phase III. Very good. Now, Dr. Kulkarni? Hello, everyone. I'm Tejaswini Kulkarni. I'm an associate professor and the director of the Interstitial Lung Disease Program at the University of Alabama at Birmingham. I have also been in the ILD space since graduating those past several years. My major clinical interests are in development of clinical trials and looking at imaging-based endpoints and biomarkers for idiopathic pulmonary fibrosis. ... Very good. And finally, Dr. Günther? Hello, everybody. My name is Andreas Günther. I'm MD, internal pulmonary and critical care physician, and running a specialized lung clinic in Giessen. I'm also heading the Center for Interstitial and Rare Lung Diseases in Giessen. I'm also quite active in the field of interstitial lung diseases, both on the translational as well as clinical research level. So I'm coordinating the European ILD Registry and Biobank. I'm also coordinating these activities at the German Center for Lung Research, and I've also been conducting clinical trials for more than 20 years now in the field of interstitial lung diseases. Thank you. Perfect. Thank you so much. So to begin our panel discussion, I'd like to delve first into the current landscape and challenges in idiopathic pulmonary fibrosis. And again, I'd like to start with you, Dr. Martinez, and I'm going to ask a few questions of you. Certainly would like your response, but if other participants on this KOL panel would like to provide their expertise as well, feel free to do so. So I'll begin with this first question, and that is: How has our understanding of IPF evolved over the years, and what gaps do you see at the current time? Well, yeah, Cory, you and I have been working on this for several decades, and I think that I've been in this field long enough to remember the days when all fibrotic lung disease was felt to be a result of an ongoing inflammatory pathology. And so many of our initial therapeutic approaches dating back 30 years were those that were sort of targeting that concept. Oh, this is all inflammatory. We need to be very aggressive with anti-inflammatory regimens. And I think a lot of that changed with one of our large clinical trials that we did as part of one of our NIH networks, where we actually tested the at that time standard of care combined immunosuppression IPF, and demonstrated that we had a ninefold higher risk of bad outcomes. It was very clear that focusing solely on an inflammatory component was biologically incorrect and harmful to patients. So that led to a lot of reconsideration of what the biological implications were. I'll let Andreas weigh in here. He understands this field much better than I do from a basic biology point of view. But it became clear that this was much more a dysfunction of the alveolar epithelial cell and how it tries to maintain the epithelial function and the pro-fibrotic state that, Cory, you've worked on for years as a biologist understanding fibroblast biology. So I think our understanding shifted, and that led to a shifting in the therapeutic approaches, and it's where we are now with two antifibrotics that have varying modes of action, but have been shown to ameliorate the lung function decline in patients with IPF. That's how we are in the IPF space right now, with two active, approved therapies globally, that clearly have efficacy. They've both been limited by the fact that both are difficult to tolerate. They have a modest effect, a real effect, but a modest effect, and are very expensive. So we certainly are in a situation now, compared to 10 years ago, which is very different. We have a much better understanding of how to diagnose, how to characterize patients, and we have two active antifibrotic therapies, but that's about it, Cory. So I think we need to move the field forward and provide our patients with a greater availability of effective therapeutic approaches and what is likely going to be the case, which is going to be combination therapies, and ideally, therapies targeted to particularly active biological mechanisms in an individual patient. That's what I would view as the goal of what many of us are trying to achieve now. Yeah, very good. I'm wondering, Andreas, if you have any thoughts here, particularly around the gaps as you see them in terms of our understanding of the pathogenesis of IPF. So I think I would like to orchestrate what Fernando has been stating, that our insight into the field of idiopathic pulmonary fibrosis and the mechanisms behind this disease have been greatly expanded over the last 20 years. I think it's nowadays pretty much accepted that the epithelial type II cell is one of the driving cells of this disease. At least our knowledge from the familial cases of IPF are very supportive of this concept that puts endoplasmic reticulum stress, defective autophagy, impaired mitochondrial ER interaction, and DNA damage at the forefront of those intra-epithelial events that drive type II cell apoptosis and cause an everlasting regenerative cycle of epithelial replacement and regeneration. And as a result of that driving mechanism, we can see a formation of a pro-fibrotic milieu, fibroblast expansion and deposition of collagen, and ultimately scarring. So I think we have been getting quite advanced in our understanding, but still there are, of course, very important lacks and open fields on the landscape where we are still missing important clues. For example, we still don't understand why we can see surrogates of similar levels of epithelial injury in sporadic IPF as compared to familial IPF... but we see mutations in familial IPF, which explain it, but we don't see corresponding mutations in sporadic cases. This is a kind of an interesting conundrum, and it's probably located in the interplay between senescence, aging, intraepithelial injury. And we are not yet at the position of very precisely defining what really drives sporadic IPF and epithelial injury in sporadic IPF. Also, for me, some still open questions remain with regard to the impact of the fibrotic structure and tissue per se. I mean, there is a lot of evidence showing that with advanced fibrosis, the fibrosis will trigger additional pro-fibrotic events through integrin-based activation of TGF-beta, probably also through overstretching the epithelium too, and causing additional damage. But to be truth, in a patient with IPF, we are yet not aware what the magnitude of this problem is. Are exacerbations driven by a progress in the initial triggering event, or are they a consequence of a response of the lung to the ongoing fibrotic derangement and loss of architecture? For example, these are two examples of where I think we still need to go on and... But we have made success. Yeah, we know better now than we did some 10 or 20 years ago. Yeah, that's very insightful. I'm just wondering if from your perspective, do you feel that the current standard of care treatments in IPF really address any of these unmet needs in the IPF space? You know, are they really tackling the mechanisms that you foresee as being important in driving progression and perhaps contributing to exacerbations? So we have been discussing already the clinical efficacy of the two standard of care drugs that are on the market, and if you break it down on individual patients, of course, the spectrum of scenarios is much different. It's not just 50% less progress, but it's in some patients, no response at all and dramatic progression. And in other patients, remarkable stability, even to some extent, visible reduction in fibrosis on the HRCT. And having in mind the mode of action of the drugs that we're talking about, at least for nintedanib, we can say a little better. It to my understanding, can only mean that there's a that multiple pathways lead to Rome with regard to fibrosis, and this is what we know. There is TGF-beta, there's PDGF, there's CTGF, a plethora of growth factors that are all acting in a similar manner on the fibroblasts and cause them force them to proliferate, to transform into a myofibroblast and to produce collagen. And obviously, we are yet not very good in trying to combine different treatment modalities with overlapping and perfectly fitting modes of action to completely block any pro-fibrotic signaling. So, we're lacking a combination therapy in a sense, which is presently not feasible, probably largely because of the side effects of the two drugs that are on the market. So if we would have more anti-fibrotic agents with an overlapping but not identical portfolio of action, by combining them, we could probably much better control the part fibrosis. I do see a huge gap or a huge unmet medical need with regard to epithelial protective therapies. At the moment, we are addressing the downstream signal event of fibrosis, and that is good because many fibrotic diseases end up in this avenue, and if we could completely block it, that would already be a good step. But especially with regard to IPF and other forms of UIP being triggered by epithelial injury, of course, there's that would be a very great opportunity of more efficient therapies if we would be able to affect the type II cell, or let's say, alveolar epithelial biology, much better. And there are only very few approaches currently on the market that would probably be viewed under this umbrella or under this glass, pair of glasses. And, nevertheless, it makes me hope that once we identify drugs that affect type II cell biology and help type II cells to survive, the whole landscape may probably change. And even in a sense that we may probably reach reversible diseases. Yeah, very good. And how do you see LTI-03 fitting into that type of treatment landscape? It is one of the few examples where we can probably hope that we have a drug with a dual action on both fibroblasts as well as epithelial cells. Because, I mean, it's very well investigated, and I think it's without any doubt that in principle, LTI-03 exerts anti-fibrotic effects in experimental models, in cells of patients with IPF, even in 3D culture models such as precision-cut lung slices. And more recently, there's also some evidence that it may probably affect the cell biology. This is still something which is under further and continuous investigation, but at least based on the principles, I guess, and on a principled understanding of the role of caveolin peptides, it is conceivable that this particular product may have a dual role of epithelium protective role, as well as anti-fibrotic role. And that's the kind of thing we are looking for. Very good. Fernando, I'm wondering if you have any comments regarding how you view the impact of LTI-03 in the treatment landscape? No, I mean, I think Andreas has done a masterful job in providing some of those concepts, Cory. I mean, it, it's very clear that the current agents have a group effect, but there's tremendous heterogeneity between patients. And I think that sort of answers your question regarding where's the unmet medical need. I mean, it's clear that what we have right now is not a definitive approach. And so I think that the... What I find most interesting, Cory, is this effect on the epithelial cell. I think I agree with Andreas completely. We do not have any therapies that have made it very far that have attempted to address that key biological process that's likely driving most of this disease. And so I think that having an opportunity with what you're developing that provides sort of both approaches, you're targeting the fibroblasts, but also have that effect on the epithelial cell, I think is unique, and is one of the reasons that I'm really excited about what you guys are developing. I can see how this would be a perfect add-on to what we currently have, which is much more downstream in nature. And so I am totally supportive. You guys got to pursue this because it's, this is clearly an area that has not been appropriately therapeutically targeted, and it's likely biologically highly relevant. Yeah. So our next major topic of discussion addresses treatment approaches in IPF. We've already touched on this topic, but I'd like to develop it further with this panel, and I'd like to turn to Dr. Kulkarni now to provide some questions to her. And my first question really revolves around the pressing challenges that are involved in both the diagnosis and management of IPF. Dr. Kulkarni? Thanks, Cory. So you know, we've talked about the pathogenesis of IPF a little bit, but IPF is a disease of the aging population. Some of the early symptoms of IPF, such as shortness of breath and cough, can be nonspecific and can be attributed to much more common conditions like COPD or even some cardiac conditions in this older population. And these factors often lead to delay in diagnosis, and patients can be misdiagnosed for several years prior to being given a diagnosis of IPF. You know, Dr. Martinez has mentioned, you know, there have been a lot of advances in being able to differentiate IPF from the other types of fibrotic lung diseases, as well as from other conditions. But the diagnosis of IPF often relies on a combination of clinical evaluation, radiological findings, some laboratory tests, and in some cases, even invasive procedures like a surgical lung biopsy. So, you know, there's still some lack of awareness among healthcare professionals, and even the general public about IPF, and then add that with the limited access to resources such as a high-resolution CT scan, and all of these can contribute, you know, to delayed referrals to an ILD specialist for definitive diagnosis. This resulting in delayed diagnosis then leads to, you know, a delay in treatment or initiation of appropriate treatment. Now, early diagnosis is crucial, and we talked about, you know, starting therapy, but then that comes with its own set of challenges. I mean, from the biological standpoint, we talked about how it does not address all the specific pathways for IPF, but, you know, it does show, you know, the data do show that they can slow down disease progression, maybe even reduce the risk of acute exacerbations. But, you know, availability and access to these medications varies globally. There is this nihilistic approach or attitude from a lot of practitioners based on mainly given the modest response to these drugs as well as the side effects. And often practitioners are going for a wait-and-watch approach, and then it's too late to get any benefit from starting these medications. And then the side effects. I mean, a lot of our patients are older, have several comorbidities, and you add on these potential side effects, and that can negatively impact the quality of life for these patients. In fact, I mean, if you look at some of the real-world data that has been published, which sort of reflects our experiences as a clinician, about 20%-30% of the patients try these medications but discontinue the drug permanently. And then another 25%-30% of patients who are even on the therapy are on lower doses because they're not able to tolerate the recommended full doses. So in spite of, like, what advances we've seen, and there is a high unmet clinical need for management of IPF. Very good. Yeah, I, I wonder if you might just expound a little bit more so on how you balance the benefits and risks of antifibrotic medications in your clinical practice. I can appreciate this must be a very challenging component to your, your practice. ... Absolutely, yeah. You know, we discussed earlier about how this disease course can be variable. I mean, right now, we don't have a specific biomarker which we can use clinically, at least, to tell us how our patient is going to respond or what the clinical course is. You know, some patients can have rapid progression, others may have more stable disease, whether on treatment or, off treatment. And really a shared decision-making approach, discussing the efficacy, the or the modest response that we see with these antifibrotic medications, but also discussing the potential side effects of these medications has been really crucial in clinical practice. And then, you know, with this shared decision-making, you know, decide whether you start one antifibrotic therapy with the versus the others, which often in practice is based on what side effects can I potentially tolerate, right? A lot of patients are making decisions based on that. And then this decision is followed by clinical monitoring at regular intervals. Usually, we see these patients every four to six months. You assess their symptoms, get physiological parameters, which are mainly pulmonary function tests, and then, if required, get a look at the radiological features to guide further management. And that allows us to understand how what the patient's response is to the medications or their tolerance to the medications, and assess for the need for dose reduction, if necessary. Very good. I know this is a topic that's a passion of yours, that being trial design in IPF, and you've been actively involved in the LTI-03 phase II-B trial. So I wonder if you might comment on, you know, how this trial compares with other trials that you've been involved in, you know, what your feeling is in terms of moving forward in clinical trials around novel antifibrotics like LTI-03. Yeah, absolutely. So, you know, we already talked about, touched a little bit about on the mechanism of action of LTI-03 and, potential unmet needs that it might address. I serve as the PI of one of the U.S. sites for this phase I trial, that is looking at assessing the safety, tolerability and pharmacokinetics of the drug. And as compared to other phase I studies, the inclusion and exclusion criteria, as well as the dosing strategy in terms of, cohorts looking at the lower dose and then escalating to the higher dose in the next cohort, as well as looking at the key safety endpoints, are fairly standard. What I think would be exciting from this study is the incorporation of bronchoscopies to obtain bronchoalveolar lavage, as well as airway brushings. I think this is an added strength to the study. It may provide key information on some of the biomarkers that could be associated with disease pathogenesis, as well as looking at the response to the study drug in this patient population. Very good. This has been excellent and highly informative. I really appreciate your input here. So I'd like to pivot finally to a topic of discussion that addresses research and innovation in IPF, and I'd like to begin with Dr. Günther's perspective on what are some key biomarkers in idiopathic pulmonary fibrosis. So, Dr. Günther, if you might weigh in with your perspective on biomarkers and their utility in IPF at present. Yeah, of course. Thanks. I would like to come back to that model of epithelial injury and consecutive lung fibrosis. I mean, if it comes down to assessing the extent of fibrosis, I think that some of the collagen peptides have been turning out as good surrogates of disease progression, and they have also been found to be prognostic and are currently used in some clinical studies. There is another very interesting candidate, which is soluble RAGE, which has been shown to be depressed in patients with IPF, but has also been shown to be correlated with the prognosis and the outcome of the patients. And I think that's a very interesting compound. And if we talk about epithelial injury and altered epithelial homeostasis, I think the surfactant proteins are quite interesting because they reflect the capability of the type II cells to properly synthesize and process surfactant. And if the cell is very busy with cell division and regenerative aspects, as we recently published in the Blue, as a part of this focus on regeneration, the cells lose a little bit of their competence to properly process surfactant. And as a result, you will see a lot of basolateral secretion of proforms of surfactant protein B and C, and also SP-D and SP-A. So that probably is a quite nice indicator of the extent of epithelial injury and regeneration. And these are all markers that can be drawn from the blood or from bronchoalveolar lavages. With regard to imaging biomarkers, I'm pretty sure that in the future we will also have CT-derived indices based on automatic assessment of patient lungs. And And if we will find a drug that is capable of reversing disease, my guess is that an imaging approach will be the decisive way to monitor that and to show that. As far as I know, however, visualization of the process of fibrosis, for example, by using some PET probes, have not proven that effective in patients with IPF. So it will probably just be the CT, the conventional CT and the longitudinal change in segmented CT slices that will tell us about disease progression or not in the future in response to treatment. Very good. Just wondering why we have seen so many therapeutic strategies fail in the clinic for IPF, and wondering what your view is then, in terms of a, perhaps a specific pathway targeting approach in IPF and its utility in a disease like IPF. So with regard to the first part of the question, I think there will probably be multiple reasons. So there may be some drugs that have been initially developed and dosed according to their safety profile because they are using systemic routes of administration. And of course, that always bears a little bit the risk of not reaching the optimum dose with regard to the target and the impact in the target, because you cannot dose it appropriately because of the side effects. And that's particularly true for systemically administered drugs. I mean, I'm coming from a department with a strong focus on inhalative therapies for lung diseases, and I have to say that I was really always somewhat astonished to see that so many drug programs always use the systemic application route, rather than trying to let patients with a lung disease inhale a drug of interest and see if you cannot dose it more appropriately with regard to the target, at the same time diminishing systemic side effects. That is of particular truth if we're talking about very central signaling pathways such as the TGF-beta pathway. So, where we have a very high dose response curve, or at least we are very close to overdosing it, as we probably understand from previous studies with systemic administration. So here, the beauty, of course, would be that you can probably apply much higher relative doses by giving it via inhalation as compared to systemic administration. And the argument that you don't reach the parts of the lung which are of interest is also kind of a bad argument, where in the same time we can see massive vascular remodeling in IPF lungs. And the question if a systemic drug would reach the site of interest through the perfusion is can similarly put up, and it's not answered, to be honest. Yeah. So I think one problem arises from the missing from the systemic administration of drugs that have side effects and that need to be dosed according to their side effects. Other drugs are very well focused, but may probably just target one pathway. And if we come back to the scenario I described before, especially with regard to fibrotic pathways and the plethora of different fibrotic pathways, just hitting one pathway may just not be enough. And since we see a lot of intra-individual changes with a predominance of single pathways, that also may explain why you see some positive results in a phase II, and then you fail to see anything in the phase III. Because by just chance, in the phase II, you had some patients that had a predominance of this particular pathway, and in the phase III, you have a more even distribution, and the drugs don't forward the same amount of efficacy. So these are two examples of why I think that in the past studies have failed, and promising candidates, despite they have well-described mode of actions, at the bench, in the cell assay, and also in early clinical trials, and ultimately failed. Yeah. And also some drugs may also have off-target effects that are truly not good for IPF subjects, yeah. Would you view an inhaled therapy like LTI-03 beginning to address some of the challenges that you just described? Yes, absolutely. As I said, I'm a great fan of inhalative administration. Even if you buy the note that there are ventilatory inhomogeneities in IPF lungs, I think that you can reach the distal lung quite nicely with an inhalative approach. Years back, we had been investigating the dose of unfractionated heparin to be administered to IPF lungs via inhalation, using a very special technology called the AKITA inhalation system, which would also control the inhalation maneuver and place the part of the aerosol administration into a certain part of the inhalative volume. And with this, we were able to gain very similar doses of heparin applied via aerosolization that would cause, in the beginning, increase in the plasma PTT. However, in patients with FVC values of 45%-90% predicted, suggesting that you can very efficiently apply a drug through inhalation, and still reach the distal lung in patients with either early, let's say, early or advanced disease. In this regard, I'm very enthusiastic that with LTI-03, we have now another drug compound that is tested under this kind of setting, and I'm looking very much forward for the first data of the interim analysis. Very good. Thank you. So in the few minutes we have remaining, I'd like to tackle one last question, and I'm going to open this up to the panel. And this really pertains to how we can enhance patient participation in clinical trials for IPF. Perhaps we can start with you, Dr. Kulkarni? Yeah. So one of the, you know, IPF trials have historically been, you know, the phase II trials or 6-month trials, and then the phase III, typically, looking at 52-week trials. And we have to think about how can we make this easier for the patient? I think that's the first thing when I think about enhancing patient participation in clinical trials. Like, typical, trial designs require patients to come to clinic or the, the site every four or six weeks. And one of the considerations, especially practicing in an area where I get referrals for patients traveling 4-6 hours to come see us at the ILD center, trying to develop or trying to develop an aspect of decentralization to clinical trials is something definitely that, we should start thinking about as a field. There are some trials that are currently utilizing this approach, and trying to apply that for trials with IPF, I think, would enhance patient participation. But in addition to that, I think another area is increasing awareness, not, you know, telling patients more about clinical trials, how they work, and why, what is the need for these clinical trials, as well as talking to the healthcare providers. I think one of the barriers is, you know, the patients have a very good relationship with their primary care providers, who are not aware of the clinical trials or even the unmet need in IPF at this stage. So, you know, who may not advise the patient to participate in trials. And so, like, trying to encourage or increase awareness about clinical trials and providing this information and engaging patients in the clinical trial design, I think would be helpful to enhance patient participation. Very good. Dr. Martinez? It's an interesting area, and it's obviously a crucial area, Cory. There was a recent FDA meeting that many of us were involved in that just went online, and the Blue Journal will be online. It'll be published in the Blue Journal in the next few weeks. That was really very, very instructive, because there was very active participation from the FDA. They're co-authors in this statement with regards to endpoints and study design for IPF. And there was a lot of discussion regarding numerous factors. Some of the factors, Andreas, that you'd mentioned in terms of the format for study designs, inhalational versus systemic administration, as you know, is a very controversial topic, and having success, Cory, will be crucial in being able to advocate the cause. My other life has been COPD, so I've been in this inhalational space for 30 years as well, and there are clear, interesting challenges and hurdles from the regulators, from inhalational administration. And similarly, there was a lot of discussion regarding what would be the appropriate endpoints that would be most likely to fit at least the FDA construct of function feel survives. I mean, that's really the principal guiding force, particularly for surrogate markers, and not hard clinical endpoints. And there was also a lot of discussion regarding what would be the optimal format to enhance participation and particularly, Cory, enhance participation of individuals that are traditionally underrepresented in clinical trials. So some of the underrepresented minorities in the U.S., it's a huge issue for us in trying to ensure that those studies have access. I think that the FDA, I'm speaking now from the FDA because they were part of this construct of this meeting that took place several months ago, is open to examining innovative formats for study designs to maximize participation and maximize generalizability. So to just some of the components that you mentioned regarding a simpler clinical trial with more sort of local collection of information, whatever the optimal terminology is, I think that they're open to. I think, Cory, to some extent, the pandemic influenced this. There were multiple clinical trials in IPF and COPD. I was running clinical trials in both spaces during the pandemic, which, as you know, dramatically altered the structure of how to conduct clinical trials in that setting. Some of that has remained even as the pandemic has waned. So some of the ideas that you can remotely collect information that would have the appropriate rigor to be considered important for registrational trials. I think that the FDA is open to that kind of an approach. I suspect that as we proceed over the course of the next five years, study designs, even really very rigid registrational studies, will adapt to this, and will accept some of these components to enhance the structure of the clinical trial, thereby making it easier to engage patients, their caregivers, and their providers in conducting studies in a rare disorder, which is now a competitive space with multiple agents trying to recruit the same patients. Yeah. And Dr. Gunther? Yeah, I would like to echo Tejas's comment. I think that, I mean, traveling in Europe and in Germany is not such a big issue as compared to the U.S., obviously. But it is still an issue. I mean, if you have so many visits at a site, some patients may probably feel reluctant to take this burden and to travel, especially since we are talking, as has been mentioned before, about people at a more advanced age of their life. So I personally like the idea of trying to integrate self-measurements into trial concepts. Although I have to admit that I guess at the moment, we are still looking for the best algorithm that has some checks and balances, some control of the blow, for example, and give feedback to the patient. So kind of a self-educative system that the patient can be using upfront the trial for some time in order to be completely familiar with the system. But I, I think there is a great opportunity in it. In the European IPF and ILD registry, we have now fully established an algorithm, including an exercise test at home, employing a one-minute sit-stand test alongside with saturation measurement and also with a spirometer test. So and we will see if that turns out to be robust or more robust as compared to the [UIOD] study from Toby Maher, where some patients had a VC of 28 liters, in retrospecting. So there are things to be done, but I guess that the modern PI technologies, the modern information technologies, including video conferencing, virtual visits of patients, may help them to make the decision to participate because they know, "Okay, I will get a tracker. I will take the track, but I will stay mostly at home, and I will be monitored from a site through these kind of measures." And I think that's promising, and I look forward to changes in landscape based on these developments. Cory, I suspect by the time you get into late phase II and phase III, some of this will be more operationalized for you and the group. Right. Right. Well, this has been tremendously informative. Many thanks to, to our KOL panel. They're all actively involved in the LTI-03 program at Aileron Therapeutics. We really appreciate your input, and we'll now transition to an open question-and-answer session with participants on this call. We're now moving into our live question-and-answer phase of this call, and I'm going to begin with the question directed to Dr. Martinez, and that is, "Aside from forced vital capacity decline, what are other surrogate endpoints do you believe are informative regarding clinical benefit in an IPF trial?" Dr. Martinez? Cory, I think Dr. Martinez may have had to drop. Okay. I apologize for that. I'd like to direct that question then to Dr. Kulkarni. Yeah, thank you for that question. That's actually a very, you know, difficult question that we've been, as a field, trying to address for a long period of time. The forced vital capacity or changes in forced vital capacity over time has been the most established primary endpoint for all the clinical trials for IPF. When IPF trials initially started in the early 2000s, mortality was considered as well. But considering the challenges to trial design, ultimately, FVC was thought to be the best surrogate marker. But the concern with that is FVC is an objective value. It doesn't really tell us how the patient feels or functions, right? And that's what what Dr. Martinez alluded to earlier with this entire meeting with the FDA, to try to understand how we can actually capture what the patient feels and functions. You know, in clinical practice, often, you know, for me, the patient comes to clinic, I say, "Well, your FVC looks stable." But the patient is like, "Well, I don't feel good." Right? How do we capture that? And so there's been a lot of discussions about utilizing patient-related outcome questionnaires and how we capture this information. Apart from that, there has been a lot of advances in utilization of imaging biomarkers and... but whether that's, you know, prime time is not quite validated yet. Eventually, we would have to think about biomarkers, which are very specific to the drug that is being investigated, so that we can get an early readout and try to reduce the time duration of the clinical trials, as well as, you know, the patient sample size that is required for these clinical trials. But for right now, forced vital capacity is still the standard accepted primary endpoint. Very good. Dr. Gutberlet, any comments? Yes. I would say IPF is a very complex disease, and it deserves a thorough assessment. I think we will certainly not be able to nail it down to just one pivotal parameter. If you look at fibrosis development in the lung, the final readout may be different if, as compared if you look for epithelial injury and epithelial homeostasis and epithelial function. And also, the view on the patient may be different if you would like to look at pulmonary hypertension that eventually can develop in some patients with IPF. So I think there's not an easy answer to that obvious easy question. My guess is that also in the future, we will have several readouts that tell us about different facets of this complex disease, with a key endpoint being chosen on the basis of the putative action or mode of action of the drug we are looking at. Very good. Thank you. Cory, I have an audience question here for you. It says, "We are interested in the predictive value of p-SMAD biomarkers for LTI-03. It seems it was the most important early-stage preclinical biomarker for another drug program. Do you think p-SMAD may have the same value for LTI-03? Thanks, Ryan. Yes. My short answer would be yes, that there is value in looking at the phosphorylation status of SMAD2/3 in any kind of trial, and particularly with LTI-03. What we've noted in the preclinical studies that we've undertaken is that LTI-03 modulates the phosphorylation status of SMAD2/3 in a number of different cell types, including basaloid cells, fibroblasts, and myofibroblasts. Now, we have to bear in mind that this particular transcription factor is more or less selective for the effects of TGF-beta on the cell type that we're looking at. Quite frankly, we've seen that LTI-03 modulates the phosphorylation status of several different transcription factors and signaling molecules within certainly epithelial cells and fibroblasts. So we're planning to monitor what's happening to the phosphorylation status of SMAD2/3, but we're also looking at protein kinase B or AKT and the phosphorylation status of that particular modulator or mediator in the context of peripheral blood mononuclear cells. So, we're excited by the fact that LTI-03 is modulating a variety of different pathways, and we're able to monitor that through the phosphorylation status of the transcription factors and signaling molecules that are modulated in our activity. So I'll just end our question and answer panel with a return to a question regarding some of the other measurements we might consider in a clinical trial, and it relates to health-related quality of life and how these questionnaires can be informative with respect to the impact of a therapeutic being tested. You mentioned this briefly, Dr. Kulkarni, but I'm just wondering if you could expand a little bit more on your thoughts in this area? Yeah. So when we think about the patient-related outcome questionnaires that have been utilized in trials for IPF, a lot of these were previously validated for COPD. And we've applied that and does not necessarily have to, you know, capture all the data that, you know, is different for a patient with IPF compared to a patient with COPD. More recently, there are other questionnaires that have been validated. One of them is Living with IPF questionnaire, which actually was specifically created for patients with IPF, and hopefully, as we design for the clinical trials, we'll be able to employ more of these questionnaires that are more specific to a to an IPF patient and not just generic to a patient with chronic lung disease. Very good. Thank you. Cory, any other thoughts? Any last thoughts? At this point, no. Thank you for attending our KOL event this afternoon. I'd like to thank Dr. Hogaboam, as well as our panel of distinguished speakers, Dr. Günther, Dr. Martinez, and Dr. Kulkarni. We hope this time has been both enjoyable and informative.