Good afternoon, everyone. Welcome to aTyr Pharma's Key Opinion Leader call on current treatment options for pulmonary sarcoidosis. I'm Sanjay Shukla, Chief Executive Officer of aTyr, and today I'm in Cleveland, Ohio, with Dr. Daniel Culver, Chair, Department of Pulmonary Medicine and Director of Diffuse Bronchial Lung Disease at the Cleveland Clinic. Dr. Culver is a leading KOL in the area of pulmonary sarcoidosis, and we're here today to discuss a little bit about treatment options, etiology, potential needs for new treatments, and talk about steroid burden also in patients. I'll also be discussing aTyr's lead therapeutic candidate, ATYR1923, which is currently being evaluated in a phase I-B/II study for the treatment of pulmonary sarcoidosis. Enrollment in this trial has been completed, and data from this important study is expected in the third quarter of this year. We've invited Dr. Culver to provide a bit of a refresher on sarcoidosis to help get everyone up to speed on, as I said, what the current treatment landscape looks like, and to start thinking about what may be a potential meaningful outcome from the study with ATYR1923 as it reads out here shortly. I'll begin by providing a brief overview of aTyr, our biology, background on 1923. I'll also provide an overview on our study protocol. Dr. Culver will talk a bit more about sarcoidosis etiology, disease epidemiology, current treatments with a focus, as I mentioned, on the burden of steroids and the need for alternative options. Dr. Culver will provide some comments around his thoughts on how we may view potential outcomes from the phase I-B/II study. After the presentation, we'll open up the call to Q&A. We'll invite our analysts to come on and ask some questions. I want to remind everyone that this call is being recorded and will be available for replay on the aTyr website following the event. As a reminder, we will be making certain forward-looking statements, including statements regarding the future development and potential benefits of 1923. These statements are subject to various risks that are described in our filings made with the Securities and Exchange Commission, including our most recent annual report on Form 10-K and subsequent quarterly reports on Form 10-Q. Let's get started. At aTyr, our mission is to develop a new class of medicines based on a novel biology platform coming out of the work of Dr. Paul Schimmel at The Scripps Research Institute. Our job is to chart new pathways and develop new medicines from this new class of protein therapeutics coming out of the tRNA synthetase biology world. 1923 is an immunomodulator for severe inflammatory lung disease. As I mentioned, we're reading out here in Q3 our trial results for pulmonary sarcoidosis. Those will be upcoming in the next quarter. We also have a preclinical program testing Neuropilin antibodies. It's a program in which we have advanced one candidate called ATYR2810, which is a lead candidate targeting a subdomain of Neuropilin-2. This is currently in IND-enabling work, testing for very solid tumor models, and we expect to be in the clinic next year. Finally, we have a discovery platform that continues to identify new receptors and new biologic pathways related to tRNA synthetase biology, having found some functional effects recently with two additional targets on natural killer cells, which we announced earlier this year. Our financial position there as of the end of March was just over $50 million in cash. Next slide. This is our development pipeline. Again, to highlight here, 1923 is our most advanced opportunity. We are one of the furthest along in the ILD space for any company in biopharma. This is a program that has been partnered already with Kyorin Pharmaceutical, they have recently completed or are nearing completion a healthy volunteer trial. We're fortunate to have Kyorin Pharmaceutical as a partner to aTyr, where we have brought in already $10 million of milestone payments on a license deal that we announced a few years ago. Down at the bottom of our development pipeline, you see ATYR2810, currently in preclinical testing with solid tumors, and we have a number of discovery projects looking at cancer, inflammation, and fibrosis. Let's spend a minute on the biology in which the company was founded. tRNA synthetases may have novel functions extracellularly. These are enzymes that help us make proteins. They are basic building blocks in all of our bodies that help catalyze a reaction between an amino acid and a tRNA. What Dr. Schimmel and his colleagues discovered is for some reason, these enzymes break apart into fragments and splice variants, and there we are learning that they play a powerful role in controlling our immune physiology, implicated in a number of disease areas, inflammatory disorders, cancer, neurology. We're learning quite a bit. One of these fragments, a fragment of histidyl-tRNA synthetase, had some particularly novel immunomodulatory function around impacting immune cells in the lung. We followed that signal, and that's how we basically developed 1923. Next slide. 1923, one of the first experiments we looked at in animals was this gold standard bleomycin-induced lung fibrosis model. We presented this at American Thoracic Society back in 2018, and here you see healthy lungs of these rodents are injured with this toxic agent, bleomycin, which is known to cause quite a bit of interstitial and inflammatory damage. 1923 did a really nice job here of resolving that inflammation, restoring that normal architecture. This was presented to over two dozen leading pulmonologists back in 2018. Their view was 1923 could be a novel mechanism to treat inflammation. Next slide. Our mechanism of action, let's talk a little bit about that. Our drug binds to a receptor called Neuropilin-2. This is upregulated on immune cells during an inflammatory response. We have also observed Neuropilin expression and have shown this in a poster last year at ATS, that it's enriched in human sarcoidosis samples, looking at both lung and skin granulomas. From a safety perspective, we have really nice supportive evidence in a phase I study, and even in our current trial, looking at patients with two independent Data Safety Monitoring Board evaluations, thus far finding really nice tolerability. 1923 is also setting up rather well here from a safety perspective. When you look at efficacy, we've looked at it in animals. We see a significant downregulation of inflammatory and pro-fibrotic cytokines and chemokines. We have presented this multiple posters over the last several years at major medical conferences. We also have observed a reduction in inflammatory cytokines in a recent mechanistic trial we ran in COVID pneumonia patients. Next slide. This is just a slide of some of these models that we looked at. It really gave us the confidence to move into the clinic. What I can tell you here is in various animal lung injury models, no matter if we used a direct agent, indirect agent, experimental agents, we started to see a consistent downregulation of pro-inflammatory cytokines. This really de-risked this program. This was a poster presented at American Thoracic Society in Dallas. This is what compelled our partner, Kyorin, to join us on this journey. Next slide. Our basic mechanism of action. Disease triggers, sometimes organic, sometimes infectious, sometimes that's an autoimmune disease like RA or scleroderma. In some patients, you may have an aberrant immune response, and it's that aberrant immune response that can sometimes become chronic, lead to long-term inflammation, and eventually may kick off a cascade of fibrotic damage. 1923 dampens the immune response by interacting with these activated and inflamed immune cells by binding to Neuropilin, which we know is expressed on their cell surface, thereby creating less inflammation and leading to what we think is a much more stabilized lung. I'll talk for a minute on interstitial lung disease. Four major types, IPF, connective tissue disease-related ILD, chronic hypersensitivity pneumonitis, and pulmonary sarcoidosis. What they all share in common, even though they present differently, is a common immune pathology. Inflammation and fibrosis is a key component to all of these diseases, but progression of fibrosis is really the key driver of morbidity or mortality. We think our drug, by targeting that aberrant immune response driving fibrosis, really has the potential to improve outcomes for patients in all of these ILDs, but in particular, sarcoidosis is where we're starting. Market opportunity, just as a reminder, a large body of inflammatory lung disease needs new therapies. IPF has two drugs that are on the market, nintedanib and pirfenidone. These generate almost $3 billion in sales. Our view is there's a large market opportunity in these other three inflammatory forms of interstitial lung disease, equally potentially a $3 billion market opportunity. Let's talk for a minute about sarcoidosis. Dr. Culver is going to go into more details here, but it's an inflammatory disease. While we don't know the etiology, it's characterized by a formation of granulomas. About 200,000 patients in the U.S. have sarcoidosis, come down with sarcoidosis. A large number of these patients require some form of systemic therapy, but treatment options are limited. Most often, you see sarcoidosis present in the lungs, and the real concern here is, of course, the chronic progression to fibrosis. Lastly, I want to highlight our study real quick here. We have enrolled. Enrollment is complete. 37 patients will be read out here in Q3 2021. We took patients stably managed on anywhere between 10 to 25 milligrams of prednisone. We administered six IV doses of 1923, either 1 mg, 3 mg, or 5 mg in a randomized double-blind placebo-controlled trial. This trial had a unique component in that it incorporated a forced steroid taper. This is going to be one of the key endpoints we look at after proving that this drug has good safety and tolerability. The next slide goes into that study schema where you can see 12 patients were enrolled in each cohort. Eight received our drug, four received placebo. There you see in the first seven to eight weeks of the trial where there is a forced steroid taper. Our view is our drug will do a better job of maintaining that subclinical 5-milligram dose in these patients, whereas placebo patients will flare or exacerbate. This is how we're going to, in our mind, find the most clinically meaningful endpoint to determine activity for ATYR1923. With that, I'm going to turn it over to Dr. Culver as he can talk a little bit more about some of this. Thank you, Sanjay. Thank you for the opportunity to one second. Okay. That's hopefully better. Great. Thanks for the opportunity to talk about this. I'm always excited to talk about sarcoidosis because it's been an understudied and under-medicated disease in terms of the options that we have. Net slide, please. Some refreshers, s arcoidosis has been known for about 150 years, but there are still many things about it that we don't understand. People have focused for a long time on what triggers the disease. We think of this as an inflammatory disease. It can affect any organ in the body, and it's generally triggered by some spark or trigger that's depicted here. There's an emerging notion that the exact trigger may be more than one thing, and perhaps it doesn't matter so much what the trigger is. Maybe it matters what your risk factors are when you see a trigger. The genes, the epigenetic changes, host factors like obesity and modifier exposures. Photocopier toner is one that's been shown in a study in Michigan. That trigger happens, sarcoidosis develops, and then the same sorts of things, genes, epigenetic changes, host factors, and modifier exposures, lead to different pathways and different courses. A lot of work is happening around these green boxes to understand why patients get this and why things turn out the way they do. Next slide, please. The fundamental lesion in sarcoidosis is the granuloma that's depicted here on the right. This is a clump of cells, and I think you can hallucinate the blue cells with the brown center part are clumped together. It's like a rugby scrum, and they're trying to surround something that they've seen that they don't like. This is how we deal with TB, this is how we deal with foreign bodies, and this is how we deal with whatever triggers sarcoidosis. The immunology of this is complex, and in fact, many of the medications that we use are capable of hitting multiple targets, and so most of the successful medications will be able to do that. Around this granuloma as it gets going, some scar tissue can form, and in fact, that causes a lot of the problems. What we're actually seeing here in this picture is immunostaining for phospho-STAT1, which is really the dominant immune pathway that's seen in sarcoidosis. This form of signaling, which is through T cells activation, is something that I think has a crosstalk with Neuropilin receptor biology. In fact, many of the mediators that are important in this soup of inflammatory mediators in sarcoidosis are ones that are targeted by 1923. Next slide, please. On the left is a picture of a lung, and you can just see these balls that are in the lung. A lung should look lacy. It should look like a lace curtain where gas exchange can happen. You can see all these purple balls crowding into the lung. You can imagine if you had this, that your lung would be stiff and it wouldn't exchange gas very well. In fact, you might develop a good bit of shortness of breath, just like I'm sure this patient did. On the right is a PET scan, t his is showing inflammation in the body, and you can see similar to many other patients that this patient has sarcoidosis all over his body. He's a walking granuloma. Next slide, please. Epidemiologically, sarcoidosis occurs around the country. It's always been thought to be more common in the southeast, but really, in this kind of insurance database analysis from about five years ago now, the incidence and the prevalence are very similar in all the regions of the U.S. except for in the West. We can speculate about why that is. Maybe it's because of the more arid environment there. In any event, it's less common in the West. Similar to what we already knew, across all these regions, there's more sarcoidosis in African Americans than there is in Caucasians with, in fact, maybe even a little bit less risk in Asian and Hispanic population. Next slide, please. There is a slight female predilection. This is maintained across all racial groups in this particular analysis, females act a little bit different. There's a bimodal incidence, older females sometimes get sarcoidosis as well, whereas for men, it tends to be something that happens when you're less than 50 years of age. Next slide, please. Sarcoidosis does cause death, I think that that's a very important part of it, that's not the whole story. Here's an epidemiologic study from Sweden looking at the risk of death after diagnosis with sarcoidosis across the entire population. You can see that the risk of death is significantly increased with a hazard ratio of 1.6 for mortality. I think sarcoidosis has gotten a little bit of short shrift in the past because if you only focus on death, you lose a lot of the real issues that affect patients who are really getting this disease in the prime of life, when they're trying to raise their family, develop their careers, spend time with their kids, all those sorts of things we like to do in the prime of our life. Next slide, please. Here's another look at mortality. This is specific to the U.S. This is just in men, but there's a similar curve in women, and this is showing that despite the use of more and more medications and the recognition of sarcoidosis earlier and earlier, we're seeing increasing mortality in both Black and white patients. Next slide, please. As Sanjay said, not all sarcoidosis causes bothersome troubles. This is another reason why the disease has not gotten as much attention as it merits. In fact, if you take everybody with sarcoidosis, sometimes it's very difficult to know at the outset which patient is likely to have a real problem at the end. We think that about 50%-60% of all sarcoidosis patients will have bothersome disease, and about 30%-50% of those, which is an overlapping group, will have persistent disease. Of the total, 20%-30% of the total people with sarcoidosis will develop progressive disease. Of the total number of sarcoidosis patients, between 10% and 30% will develop some degree of fibrosis. You can have progressive, bothersome disease without any fibrosis, and I think that that's a key point here as well. At the end of the day, 5%-10% of people will have significant impairment, like they need oxygen or a lung transplant, or they die from their disease. Even more important than that, many of them will be affected before they get to that point, and they'll develop comorbidities because of their treatment. Next slide, please. One of the things that we've noted is that hospitalizations related to sarcoidosis appear to be rising over time. Again, this is probably because the epidemiology of sarcoidosis is changing, but we also think that some of it is because of more aggressive therapies, primarily with steroids. Next slide, please. Here's a study we did several years ago using a database from the Foundation for Sarcoidosis Research, and we just asked about risk factors for hospitalization. I'll just turn your attention here to the image on the right, which is the independent predictors using a random forest model for whether patients required hospitalization for sarcoidosis. Some of these things we can't change, age and cardiac involvement. The next two strongest drivers, the dots furthest to the right, are the need for medication and whether or not a new comorbidity developed after the development of sarcoidosis. Again, we think that many of these things may be relatable to the current therapies that we have for sarcoidosis. Next slide, please. Of course, fibrosis is another important target when we think about treating sarcoidosis. Here is a French series just looking at patients with fibrosis versus patients who don't have fibrosis, making the point that fibrosis is also an important driver of outcomes in these patients. The patients with stage 4 sarcoidosis, which is the fibrotic form, you can see do worse than the ones who do not. Next slide, please. As Sanjay mentioned, not everybody needs to be treated. There are certain organs that require treatment more often. The heart, the muscles, but you can see the lungs. Please go back. The lungs certainly do need to be treated quite a bit, and because the lungs are the most common organ involved, about 90% of people, that actually drives most of the treatment in the U.S. for sarcoidosis. Next slide, please. Another key aspect of the prognosis and therefore the drive for treatment is really the number of involved organs. This is an old study, but it's the only one that's been done on this question, and I think it's a really good one, showing that if you have more than three organs involved, four or more organs, there is a very high chance that you will have significant functional impairment or require assistance with your activities of daily living. Again, we're going to treat the lungs, but we're looking at the whole patient. In fact, treatment decisions in sarcoidosis revolve around the entire patient. Next slide, please. Here are the options we have today. You can see in 1869, we used a lot of medications that maybe they're not even called medications nowadays. We certainly would like to avoid them. I suspect that in another 150 years, we're going to think that some of the things that we use today might be just as toxic as those ones listed over there on the left. The ones that we like to use most in our clinic are circled in red here. Only thing that's FDA approved for sarcoidosis is prednisone and repository corticotropin. Those are the two medications that are approved for it. Everything else here is used off-label. There are significant problems with all of these. Nobody's happy with the therapies that we have available right now. Next slide, please. Everybody writes in their chapters that steroids are the first line of therapy, and that's because we've used them for a long time. We've gotten into a habit, and yet everybody recognizes that these are particularly problematic for our patients. They cause plenty of side effects. These are severe abdominal striae from steroid use. When you talk to patients about what they dislike most about sarcoidosis, it's commonly the use of steroids. Next slide, please. We looked at patients that were seen here at the Cleveland Clinic several years ago. This is Nauman Khan. He just looked at 154 patients from the time of diagnosis and looked at patients who had been followed entirely with every single medical encounter within our system. What he found is that after developing sarcoidosis, on average, patients got two new metabolic complications, and you can see the frequency of them listed here. I could fill clinics with this. Obese patients who need a knee replacement and now have sleep apnea and uncontrolled diabetes and got their cataracts done because of the steroids they've been treated with for years. Next slide, please. Here's more analysis from this. This, again, is a Kaplan-Meier plot. The light gray line is patients who just started steroids, even if they stopped them early, and in fact, the average duration of this was six months. The black are patients who were not treated with steroids. This is controlled for confounding risk factors. You can see that those curves continue to separate even as you go out here to eight years. Again, suggesting that steroids change the metabolic milieu of patients with a hazard ratio of about 2.4. Age, preexisting disease, or other risk factors, but it's really the duration of steroids, it's the cumulative dose, and in fact, based on this analysis We've come to the conclusion at Cleveland Clinic that there is no safe maintenance dose of corticosteroids in patients with sarcoidosis. Next slide, please. Here are another form of analysis from a rheumatology database, just looking at the risk of side effects of steroids and toxicity of steroids based on quartiles of dosing. You can see that there's a dose response for things that you might consider not a big deal, like acne or skin bruising, but also for very important things like high blood pressure, weight gain, and risk of bone density and bone fractures. You can see the hazard ratios there, 2.2 and 1.8 for a couple of these. Again, we think that there's no real safe dose of steroids and that there's a dose-response effect to the risks of them. We're always looking for ways to get patients down or off of steroids. Next slide, please. One more form of analysis just to beat up on steroids a little bit more. This is an old analysis done by Marc Judson and Chris Cox at MUSC, looking at two ways of measuring quality of life. They adjusted these for baseline severity, whether you had lung disease, what your age was, what your race was, how bad your lungs were. If you look at St. George's Respiratory Questionnaire, which is the top one, or SF-36, which is the bottom one, there is a clinically significant and statistically significant difference with worse quality of life in patients treated with corticosteroids. Although these numbers are going opposite ways, that's because these two quality-of-life metrics actually measure quality of life in opposite directions. If you talk to patients, this is obvious. Patients will tell you, "I was feeling better till you started me on this medicine, doc." Next slide, please. Here's a schematic of this, o f course, death is important, but that's really not the only thing with the burden of sarcoidosis. There's damage to organs, which causes somatic burden. There's a psychosocial burden, and finally, an economic burden. This is related to both the disease and the treatment. Next slide, please. Here are data from the Foundation for Sarcoidosis Research, just looking at the respondent-reported rate of comorbidities that developed after the diagnosis of sarcoidosis, and some that are directly or very easily related to steroids are circled here in red. There are some other ones that probably are related to steroids but don't have quite a strong relationship. You can see that the prevalence of steroid-related side effects in these patients with sarcoidosis is very high. We have a tenable hypothesis. We have shown that steroids are associated with all of these things. In fact, a lot of the data on hospitalizations and on risk of things like cardiovascular mortality and sarcoidosis all line up and point to the same story, and that is that we're poisoning our patients. One of my patients called steroids the devil's drug. I think that's completely accurate. It's a two-edged sword for sure. Next slide, please. Here's a way of looking at this numerically. This is from two places, Poland and Spain. In Poland, they looked at the number of comorbidities their sarcoidosis patients had, and they just looked at the rate of death. You can see that as the number of comorbidities adds up to three or four or more, the patients die much more quickly. In Spain, they used something called the Charlson Comorbidity Index, either adjusted or unadjusted for baseline variables. You can see again that the survival was greatly impacted by the comorbidities that the patients developed. Next slide, please. Okay, that's the end of my slides, and I'll pass it back to Sanjay. Thanks. Thanks, Dan, for that really excellent overview. A lot of material in there that you covered. Before we open it up to Q&A, I just want to summarize what we discussed today about aTyr in 1923. As I mentioned, we're leveraging a proprietary new biology platform and have matured a candidate that has a novel MOA for inflammatory lung disease. We've demonstrated effects in multiple animal lung injury models. Thus far, safe and well-tolerated in phase I and phase II studies. Recently put out a proof of mechanism for biomarker data in a phase II study in COVID pneumonia patients. These phase I-B/IIa results will be expected here in Q3 2021. I'll now want to move a little bit more to invite questions from the analysts. I know we probably didn't cover everything that many of you have questions about. We would like to invite the analysts now to come on and ask Dr. Culver some questions. Let's get started with our first question, which will come from Zegbeh Jallah of Roth Capital Partners. Zegbeh, go right ahead. Thanks for taking my question. A really nice presentation here. I think my first question is just trying to understand what clinicians may want to see in terms of steroid reduction, because Dr. Culver noted that no amount of steroid for a long period of time is actually acceptable. What could be a nice, exciting signal from the data that we're expecting in the third quarter? Thanks for the question. The question is, what would clinicians like to see to be a signal that would get us enthusiastic about this? I think the first thing is that I'm really looking at this primarily as a safety study, and that's the first thing we're going for here. Of course, we want to see some difference between the placebo and the treated arm. What we know is that the placebo group probably will not relapse in great numbers in the first few weeks. I think that what you're likely to see as this goes out closer to the 24-week time point is that a proportion of those placebo patients are going to need escalations of those steroids. I think that's a little hard to predict right now, but I'd say over half of them at least, I think, will have some escalation of steroids. We hope that proportion is greater than the placebo group. We hope to see that the total amount of steroids given over the duration of the trial is less in the treated group. I think exact numbers are a little bit tricky to get into because the size of the study, the confidence intervals are going to be pretty wide. Thank you. Just another follow-up here regarding a potential phase III study. I was just wondering, what are some endpoints that you think are going to be important to clinicians or to get clinicians excited as well? Well, I think that sarcoidosis conventionally as used by capacity as an endpoint, but there's a growing sentiment that that's not the best endpoint. We're really looking at this as a chronic inflammatory disease that needs better long-term management. The sorts of endpoints that we're thinking about are things that would be more relevant in diseases like asthma or rheumatoid arthritis, that is steroid-sparing, quality of life. Of course, we want to see some evidence that we're impacting granuloma biology. Are you doing something with a biomarker? Are you doing something with imaging? Of course, those can't be the primary endpoints because those are not relevant to how the patient feels, functions, or survives. If you can show that you're doing something to granuloma biology and doing something that's directly relevant to how the patient feels, functions, or survives, then I think there will be real excitement. Thank you. I'll get back into the queue. Okay. Looks like we have a hand raised from Hartaj. Hartaj. Great. Thank you, Sanjay. Thanks, Ashlee and Dr. Culver. Had a couple of questions, and thank you for that presentation. One is, you mentioned you view this study as primarily a safety study. You present a lot of data in your slides showing the various side effects, both near term and long term, especially through the corticosteroid usage. Dr. Culver, would you like to see some differences in safety also, meaning that not just efficacy, but would you like to see changes in the side effect profile of the patients on the experimental arms versus the placebo arms? How would that look like if you expected that? Yeah, it's a great question. I don't think in a trial of this duration that you're likely to see differences that you can attribute to steroids, to a difference in the steroids between the treated group and the placebo group. It's just too short of a time. The side effects and consequences of steroids are sneaky, and they take a long time to come up. That's why they're underestimated, I think. When I said a safety thing, what we really want to see is that there's no downside to the therapeutic compound. If we see no downside to the therapeutic compound, to me, that's the main thing, and then the rest of it is trying to figure out what you're doing next. Yep. No, that helps a lot, actually. That was my follow-up question. You kind of guessed it, which is that, is 24 weeks going to be enough? If you see a sort of even with small patient numbers, how much longer would you like to see a follow-up on this kind of trial to start making you certain that the experimental arm is really performing? That's a great question. I think that it's a little speculative to talk about that. I think that the extent of the effect, the effect size, and how many of the endpoints, the secondary endpoints would be hit, would really influence my thinking. We know that that placebo arm, if we were to follow them out another 24 weeks, let's say, and get out to a year, that there would be an even higher number of people who will relapse or get worse. A longer trial would potentially unmask a bigger difference between placebo and an effective medication. I'm not convinced right now that you have to have a longer trial because I think a high proportion of the placebo patients who are going to relapse will do so in that first 24 weeks. I think we just have to look at the data and see what the message is. Yep. Just last question from me before hopping back into the queue, which is that based on the profile of ATYR1923 right now, assuming it hits some of the marks you're looking for in phase I, II, but what% of the patients that you treat with sarcoidosis could you see as being sort of patients you would treat in the initial group, let's say, if the drug was ever approved with that profile? Thank you. First of all, not everybody with sarcoidosis needs to be treated, and I don't think that's who you're asking about. If you have bothersome disease that's likely to need substantial treatment over a time period, then I think you have to see what the medication does. How it's tolerated, and the speed of effect before you decide that. If it's a wonderful medication that does everything really well, there's no reason why this couldn't be way up in the treatment algorithm, even before steroids. For example, in rheumatoid arthritis, we don't treat with steroids unless the joints flare up. We start off with methotrexate, for example. On the other hand, if it takes a while for the effect to build up and it's not quite as powerful, then maybe it's something a little bit later in the algorithm. I think it really depends on what the medication looks like. I think the notion that steroids have to be first-line has really been challenged right now, and I think as a field, we are casting about to try to find something that's a better first-line and a better second-line agent, frankly. The second-line agents have their own set of problems. They need to be monitored. They're effective maybe in about 60% or 65% of people, and they have some serious contraindications. Where it exactly goes in the algorithm, I think time will tell. Great. Thank you all. I'll jump back in the queue. Great. Let's move over. I see Joe's hand is raised. Joe, I'm going to turn it over to you. Great. Can you hear me okay? Awesome. Thanks for hosting the call, and I just wanted to maybe dive in a little deeper on a couple of the points that have been raised. First, I wanted to focus on the safety profile of 1923. Obviously, it's shown a good profile thus far, and I was just curious. Pardon me, sorry about that. Okay. I apologize for that. It's like an old recording that was still on there. From an immunomodulatory standpoint, the drug has obviously shown safety in the severe hospitalized COVID patients, and we appear it's going to be safe in this study as well. I'm just curious, would anything stand out as you look to the drug in other indications based on its immunomodulatory properties? Other indications. I guess I don't have a good biologic argument for why the safety profile would be different in other diseases that I think about than it would be in sarcoidosis. I treat a lot of interstitial lung diseases, and as Sanjay said, there's a mix of inflammation and fibrosis in many of those. I think something that can target both inflammation and fibrosis is prima facie very attractive because we like to dichotomize it into inflammation and fibrosis. In reality, these things quite often go together. For example, this is one of the reasons why a drug like mycophenolate is sometimes used for some of the rheumatic lung disease patients. Not a very effective drug for sarcoidosis, by the way. People make hand-waving arguments that pirfenidone has anti-inflammatory effects, and so maybe if there's inflammation, you should use pirfenidone instead of nintedanib. I don't know if there's any truth to that. That's not really been investigated, of course. I think that when I think about my diseases, I don't think about a differential safety profile between them, with regards to this. Of course, each of those diseases has its own set of issues and opportunities, but by and large, almost everything that's used in our space is off-label, hasn't really been carefully studied, and there's certainly a need in several of these diseases for better options. Got it. No, thank you for that. Then I'll ask for your forgiveness ahead of time for this question, but I'm going to pressure you with regards to some of the earlier discussion around steroid tapering and what would be meaningful. I guess as you look towards just sarcoidosis to start, and even potentially other ILDs, maybe just a broader answer in saying that would the broader physician community like to see a certain% of steroid reduction, or would you need to see complete removal to believe in a drug fully? Do you have any data to point to saying, even if you reduce your steroids by 25% or 50%, that you can impact those long-term, even survival curves that you were referring to earlier? The latter question about the data about how much you have to reduce the steroids to move those survival curves, I'm not aware of any yet. If you know something, please send it my way because I'd love to know what that cut point is. I think, in reality, just like everything in life, there's probably not a bright line where if you get below seven, then it's great, and if you only get to eight, then it's useless. This will be something where there's a gradient. I think that by and large, the expectation in the community, both in the academic community and in the general practitioner community, will not be that we have to get to zero. I don't think that's probably perceived as a realistic or a necessary goal. There has been a notion out there in the past that 10 mg is a safe dose. Over the last five to 10 years, that's been challenged. I think now people believe that there really is not a safe dose. Of course, many of these side effects are dose-dependent. I think if you can get below five, a lot of people would be quite happy. Whether that's truth or perception, you'll have to do your study to tell me the answer to that. Got it. Thank you very much for the adding color. Okay, let's move on to Prakhar. You've got some questions for Dr. Culver. Yep. Thanks, Sanjay and Dr. Culver, for taking my questions. My first question is, how important and realistic is it to show benefit on some of the functional endpoints, such as FVC, in a proof of concept trial at 24 weeks? Even if there is no FVC improvement, would that concern you at this stage of development? I have a few follow-ups. I think FVC is highly unlikely to be different between the two treatment arms. It would be an unbelievable result if there's a change in FVC in a positive direction for the treatment group. I think FVC in many ways is in there as a safety signal and as an exploratory signal. I have no expectation with this duration or with the sample size that we'll see a significant change in the FVC whatsoever. I don't expect that at all. Okay. My second question is, on steroid tapering, are there specific guidelines that you or other institutions follow? Is there a lot of variability on these protocols between different institutions? Related to that, what are the key symptoms that will ultimately lead to steroid dose escalation? Thank you. Yeah. There are some suggestions for how to taper steroids, but I don't think there's any one community-accepted way to do it. If you go around the different sarcoidosis centers, there's a different variety or a different flavor in every single center. In fact, even in my center, I think we all do it a little bit differently. Part of it is a feel thing. Frankly, I think there's a conversation with the patient about how to do it as well. I don't think that there's an ironclad specific guideline for how to do it. I'm sorry, I think the second part of your question was about symptoms from the steroids? Just trying to get a sense of what will drive the dose escalation on steroids. What are the key symptoms that you see in a patient that will ultimately drive that decision? As the patient deescalates their steroids for pulmonary sarcoidosis, shortness of breath and cough are the two most common ones that we'll see. Of course, we like to try to couple that with data like radiographs or pulmonary function testing. Shortness of breath, cough, sometimes wheezing, sometimes some systemic symptoms. In general, when we're faced with non-specific symptoms that aren't related to the lungs, like I'm tired or I'm achy, we try to look around for other data to really show that this is a worsening of lung disease before we reescalate the steroids. In fact, in this trial, Sanjay can give us some nuance on it, because I'm sure I won't remember the details perfectly, we are capturing cough, we are capturing shortness of breath. If the patient goes down or escalates, we're going to measure all those things. They're being measured. Thank you. Okay, it looks like Zegbeh Jallah may be raising your hand. Actually, you know what? Let's go to Yale, if, Yale, you have any questions before we go back into the queue. Sure, appreciate that. Thanks for offering this KOL course. My first question to Dr. Culver is that you mentioned that you could use this potentially as a first line in some selected cases or patients. Could you elaborate a little bit more in terms of what type of patient and what circumstances you consider the drug could be used as a first line if it get approved? Yeah, thanks for the question. I don't know for sure if this would become first line. Again, it depends on the performance characteristics of the medication. It depends on the tolerability, the ease of use, the accessibility, and the efficacy. I think there are three kinds of patients that I have in my mind broadly. There are patients who have relatively modest disease that's not organ-threatening, but it's bothersome to quality of life and perhaps self-resolving. Those are patients that I'm thinking about a short-term management, and I don't worry so much about the long-term toxicity of medications. On the other end of the spectrum, there are patients who have prognostic signs that tell me there's going to be problems down the road, and they're going to need long-term aggressive treatment. For those patients, I think many of us now use several medications right up front. We want to control the disease, and we want to maintain control. Finally, in the middle, there are patients who have progressive disease, bothersome disease, usually persistent disease, that need a strategy. I can identify many of those people really earlier on in their disease. When those people show up, the conversation usually is around, are we going to try to take a strategy that will be maintained over a period of time, or are we going to just put steroids on board because I can get an effect within several weeks? Quite often, patients will say, "No, just give me the long-term strategy. I don't need this to go away in three weeks." I think, again, this will depend on the operating characteristics of the medication and all the other factors I said. I think an effective and tolerable medication that is accessible would be embraced for some people upfront. Okay, great. That's very helpful. One more question here is that given the target for the 1923 is known as NRP2, obviously, there's more data to need to be confirmed this, but could this drug potentially be considered to be disease-modifying instead of just relieve the symptoms? I think that this will be more than symptomatic relief. When we think about organs that are under threat, lung is deteriorating, gas exchange is impaired, airways are becoming closed off, fibrosis is setting in, and we can either stop that or reverse that, I would characterize that as disease-modifying. I'd say that's much more than symptomatic. I would draw a distinction between disease-modifying and cure. Cure means you give the medicine and the disease goes away forever. Whether or not that's the case, who knows? Certainly, all the therapies we have right now are disease-modifying insofar as they can make granulomas get erased. Whether or not they cure the disease is controversial. Okay, great. I really appreciate the answers. Okay, it looks like we have another question from Zegbeh Jallah. Thanks again for taking another of my questions. I think this one is also for Dr. Culver. Just following up again on benchmarking in terms of what you think might be an acceptable time to response. I thought it was interesting that you also mentioned what you guys do with methotrexate for other indications. I was just wondering what would be attractive in terms of a time to response. The second one here is for Sanjay. Sanjay, can you just comment a little bit on the patient population? Because I thought this was an interesting part of the study design in terms of selecting patients that aren't very fibrotic and are more likely to respond based on the mechanism of action of the drug. Can you also comment a little bit on the tapering guidelines? I think that's important for kind of appreciating, again, the study design and how it's likely to lead to more consistent results because of those guidelines. The time to response, I don't think there's one number I can give you, frankly. I would like five minutes. If we can have five minutes, I think everybody would be happy with that, and five years would be too long. Not to be flip about it. With steroids, typically, we can get a good response in the lungs within four weeks. With a drug like infliximab, we usually think the response is about as good as it's going to get in two to three months. With a drug like methotrexate, we look at more like six months. If the drug is a home run in efficacy, I'm willing to give it longer. On the other hand, if it's not such a home run, we want to see something a little bit more quickly as a patient. Remember that in this, we're not really trying to show that the FVC gets better. We're trying to show that we can successfully get patients down on their steroids. In fact, in the foreseeable future, if people are still being treated with steroids and you can add a drug that then allows you to taper in a rational way, I think that's something that if it happens over several months and it works fine, I think people would embrace that. Zegbeh, the question is directed to me. When we started this trial, we brought in experts like Dr. Culver to our original advisory panel. One of the things we did want to hone in on were those patients who had bothersome disease that was persistent, disease that had certainly advanced to the point where they needed day-to-day steroid therapy. You're right in that we didn't necessarily want those more fibrotic patients because we think the mechanism of our drug works better when there's more of an inflammatory target. It's part of the reason why we prioritize sarcoidosis, perhaps, as the first ILD that we went into as proof of concept. I do think we looked at the biology, but we also looked at the biology of our drug and also the need for a therapy in this cohort of patients. Dr. Culver will probably agree that we will also need better therapies for those patients who have more fibrotic damage. I know there are some experts who use some of the more anti-fibrotics over there. I don't know how successful those drugs are outside of IPF, but I know they are in the treatment mix. For our study, we really think we brought in a patient population that was sensitive to our therapy, and also a patient population where there was a great amount of need. To your second point, the need also exists to have a better therapy than steroids, which is why we incorporated a steroid taper. I think we were one of the first studies looking at interstitial lung disease with a pretty robust steroid taper. We talked to the experts around would we want to taper in about one month, two months, three months. Obviously, we were aiming for a six-month study. We settled in on about seven weeks there. We wanted folks by their week eight visit to be down to that 5 mg dose. We did create a stepwise taper protocol. Depending on whether you came in at 10 or 15 or 20 or 25, the seven to eight weeks was viewed to be a palatable amount of time from the opinion of the experts. This will be an important thing for us to observe in our current trial. How successful were we with that taper protocol? To Dan's point of view, if we are to do a trial perhaps longer in the future, is this a component that we want to keep at about seven or eight weeks? Did we learn anything about the ability for patients to taper? It also allows our drug to get on board. We'll learn how quickly our drug may start to demonstrate efficacy. These are things that we're going to be looking at closely as we map out next steps. Thanks, Sanjay. Speaking of next steps, I was just wondering if you guys had an internal benchmark for what you're looking for from this study to decide on whether or not you're going to go after some additional ILDs and what might the next one be. I think overall, and this echoes some of what Dr. Culver's saying here, is we want to first establish the drug is safe, and that is the primary endpoint. I think that is no small feat in an area where the current therapies have been described sometimes as poisonous, toxic, devil's drug, things of that nature. We need to first have a safe therapy. We think we can accomplish that primary endpoint in the trial. Secondly, as we are also trying to demonstrate some clinically meaningful sign of activity, I think by removing steroids and at least keeping people's quality of life at or near where they were on that toxic therapy, I think that would be another really nice checkbox there. To see more response in our treatment group versus placebo is also something that I would like to see here, and I think Dr. Culver would agree with that. Lastly, I think if there were any of our secondary, the additional endpoints we're looking at, for example, inflammatory biomarkers, if we saw directionality in some of those markers also go down, we saw those inflammatory markers trundle down as we are also getting people off steroids. To me, when you add those two findings together, a decrease in your steroid burden and an improvement on your inflammatory markers, I think if those two things start to move in the same direction, my guess is Dr. Culver will be very happy with those findings. Yeah, I agree. I think that, of course, the total steroids and the different ways you can look at steroid reduction are important in and of themselves. If you talk to patients, they're the most important thing. Also by tapering the steroids like this, you're unmasking active disease in the placebo group that ideally will not be unmasked in the treatment group. The need to re-escalate or the worsening of the symptoms, I think is a really important thing to watch for here. I don't know if you heard any of that. Okay. Well, I just wanted to say thanks for all the great questions today. Very helpful refresher on sarcoidosis. Good discussion as we now head into the readouts for our trial in the third quarter. I really want to thank Dr. Culver for hosting us here today at the Cleveland Clinic. His experience and knowledge related to sarcoidosis is really quite unmatched here, especially, I know he's going to be modest saying that, but really appreciate him lending his thoughts on the burden of sarcoidosis steroid treatment, highlighting a real need for a new treatment option of this debilitating disease. If there's something we didn't cover today, anyone from our audience has additional questions, we'll be happy to get them to Dr. Culver in the future. Feel free to send them to us. We at aTyr want to thank everyone who joined today. Thank you for your interest, your support. We will be in touch. Be well. Thanks, everyone.