Good morning, everyone. Thanks for joining us here at day three of the Leerink Partners Global Healthcare Conference. My name's Tom Smith. I'm one of the senior biotech analysts here at Leerink, and it's my pleasure to introduce our next presenting company, aTyr Pharma, and happy to be joined on stage here by CEO Sanjay Shukla. Sanjay, thanks so much for joining us, and I know you have a presentation here. Why don't you take it away?
Great. Thanks, Tom. Good morning, everyone. I'm Sanjay Shukla from aTyr Pharma, and we're gonna talk today about how we're translating tRNA synthetase biology into new therapies for inflammation and fibrosis. Here are some of our forward-looking statements. At aTyr Pharma, we are translating a new area of biology around our platform of tRNA synthetases, and these are enzymes that exist within all of our bodies. For many years, we knew them to do really one function, and that is to help conjugate a reaction between a specific amino acid and a tRNA. These were shepherds that brought this reaction, catalyzed it together. What we've discovered is these tRNA synthetases break apart into fragments, and those fragments do something very different. They have an interplay with the immune system, and that's where we see this as a potential new class of medicines.
Our focus is inflammation and fibrosis, where, we believe, there's an untapped potential to leverage some of this evolutionary intelligence within all of our bodies. This is a very, very differentiated approach which presents multiple, opportunities to address, different diseases. efzofitimod is our lead therapy that has just completed a phase III trial, and I'll go through some of those results, which is scheduled for a U.S. FDA Type C meeting upcoming here, in mid-April. In addition, we expect to complete enrollment in a phase II, EFZO-CONNECT trial focusing on scleroderma-related ILD. That will complete enrollment in the first half of this year, and we'll expect to have data, about six or seven months after that.
We just reported cash of just over $80 million as of year-end, so we're in really good shape here to complete some of this work, but also have this important FDA meeting that's upcoming. Here's our pipeline. I'm gonna talk more today about the results, but before that, I'll go through some of the background here. Efzofitimod dominates the top of the pipeline, but I'd also highlight 0101, which is a separate tRNA synthetase fragment that has done some really interesting things in modulating myofibroblasts, and we think this could be really useful in fibrosis. I'm anticipating that'll be in the clinic next year. A true anti-fibrotic, I describe it, as opposed to the fibrostatic drugs that have been available really for the last several decades.
Efzofitimod, let's get into that. Interstitial lung disease is really the target here for efzofitimod, and these are a group of diseases, chronic inflammatory diseases that cause lung fibrosis. While patients are dealing with interstitial lung disease and this inflammation, that inflammation creates a cascade of worsening lung function, fibrosis, and extremely poor quality of life. Many of these forms of fibrotic lung disease have survival rates that are worse than many common cancers. Right now, unfortunately, most of the therapies being used are either toxic, not disease modifying or both. Efzofitimod presents a really interesting novel mechanism of action that addresses this significant unmet need. We're advancing efzofitimod as what we believe is the standard of care for interstitial lung disease, and we are focusing on the inflammatory side of the fence.
ILDs can have a large swath of conditions that some present with an inflammatory phenotype, others can be quite fibrotic. Our focus is really to look at the inflammatory side of the fence first, looking at sarcoidosis and scleroderma-related ILDs. IPF is the most extreme form of interstitial lung disease, a very fibrotic form. This is an area where there are two drugs that generate multiple billions of dollars of revenue, but unfortunately, those drugs have toxicity and are not disease modifying. We view this as a very large market, up to $5 billion. Our goal is to first develop therapies on the inflammatory side and then potentially look to expand into fibrosis. Some key elements and highlights of efzofitimod. It targets the innate immunity at the site of inflammation.
It's designed to down-regulate many of those pro-inflammatory, and pro-fibrotic signals, primarily through its interaction with myeloid cells, macrophages, in particular. It's addressing a really complex immune biology, by working upstream through a receptor called Neuropilin-2. We find it to be very restorative of immune balance, but it doesn't tip you over into any overt signs of, immunosuppression. This is really important 'cause many immunomodulators, can be quite heavy-handed, with patients. Efzofitimod is a rather elegant immunomodulator that offers the benefits of tweaking and retuning the immune system without having, some of that toxicity. A little bit more into the details here, and we published this in a landmark, paper, made the cover of Science Translational Medicine. Very rare for a biotech, to have, gained that notoriety.
The mechanism here, as I said, is through macrophages. Inflammation in many of these conditions is triggered by a number of agents that can be coming from the environment, they can be a toxic inhalation, sometimes it can be an autoimmune disease like scleroderma, sometimes an unknown etiology, as in sarcoidosis. It causes sometimes a trigger, and that trigger then creates a cascade of macrophage-driven inflammation. Now, efzofitimod binds the macrophage by this receptor called Neuropilin-2, which is expressed on the surface of this immune cell. By binding, it retunes and nudges this macrophage into a less inflammatory phenotype, and there you see a number of markers that we've observed can be downregulated.
This turns a hot, red, inflamed lung into a more calm, blue lung there, as you see here in this cartoon. Quickly on pulmonary sarcoidosis. This is a rather large orphan disease. Some believe we're looking at 300,000, 400,000 patients in the U.S., but what we know is it's just about 200,000 patients. This is a chronic inflammatory lung disease. It's characterized by clumps of immune cells within our lungs called granulomas. It's those granulomas that provide a target, a nidus of inflammation. Most patients are presenting with sarcoidosis in the lungs, pulmonary. You see about 200,000 patients in the U.S., nearly as many in Europe. Diagnosis is done by looking at this granuloma, ensuring it is not TB.
A non-caseating granuloma is what the pathologists call it. Prognosis, you see most patients progress onto treatment. Most are using steroids, but I'm gonna come back to that because our data is changing practice patterns as we speak. Unfortunately, 20% of these patients are developing lung fibrosis. These patients are suffering from both the high disease burden, but also the treatment burden. We are changing because of our EFZO-FIT data, treatment practice as we speak. Limited alternatives, many off-label rheumatological drugs are used, but all of these drugs cause an eventual robbing of quality of life for these patients, a decline in their socioeconomic status, and 20% of these patients are becoming fibrotic.
The target population here, you see, a large swath of these patients are in that moderate to progressive range, half the patients. Again, this was before EFZO-FIT data. 75% of the patients were being treated with steroids or steroids plus a immunomodulator. That's really not acceptable at this point in time. Steroids are a legacy treatment, and we've proven some of that with our EFZO-FIT data. It's positioned here to be a frontline steroid-sparing agent. I think we've already done that, but it is reducing and eliminating the need for steroids. Here are some of the benchmarks. A number of drugs here in rare disease, other inflammatory diseases, and also those that slow lung function. We're right in the mix here with a number of these, well-known, approved therapies for other conditions.
Efzofitimod is now the lead candidate, and I think continues to be the lead candidate, potentially for sarcoidosis. Let's get into our top-line data that was presented in Amsterdam in September. As a reminder, this was a global phase III trial, about 90 centers, nine countries around the world, where we tested 5 milligrams per kilogram of efzofitimod compared to 3 milligrams per kilogram and placebo, where the goal was to enroll about 88 patients per arm. We enrolled 268 patients in U.S., Europe, Japan, and Brazil. This was a trial where we wanted to have stably managed sarc patients come in, anywhere between 7.5-25, and we were the first trial to basically try a very rigorous every two-week steroid taper protocol based on the patient's global assessment, the PGA, largely anchoring that.
The goal here was to really test the hypothesis that, look, can you get these patients off steroids? Can you do so more with efzofitimod? What experts told me based on 40 or 50 years experience is that the expectation here is the placebo would have a really tough time getting off steroids in this rigorous manner. Maybe you might see 10%-20% max of these patients be able to tolerate no steroids for a year. Let's see what we saw. Here's a study discontinuation. I think the take-home here is very low numbers from a discontinuation standpoint. We wanted to be in those more or less single-digit numbers, and there you see efzofitimod, also the high dose, no real signal there. That's good.
A large swath of these patients completing this study, so it allowed us to maintain our statistical power. Baseline characteristics, largely balanced. You know, there could be some numerical differences here, but the takeaways here are age, sex, race. It's what we expected. Sarcoidosis can disproportionately affect those in the Black population, especially Black women. These numbers having about 15, 20% is what we expected. In the U.S., you see this more like 30%, which is an outstanding number. There were some questions whether or not sarcoidosis is a type of study that could enroll in certain populations. I think we dispelled that. Really speaks to the need of therapy here. Duration of disease, you're looking at seven, eight, nine years. These are chronic patients.
Most of these patients have pulmonary sarcoidosis, but a third of these patients have some extrapulmonary symptoms, sometimes the skin, sometimes the heart, sometimes the nervous system. These were patients that were sick by the KSQ lung, and they also, as you see, had about 10 milligrams average steroid dose coming into the trial. The primary endpoint, we were looking at steroid reduction. The expectation here was the drug would be able to perhaps get people 50, 60, maybe 70% in a best-case scenario off their steroids. We saw that with efzofitimod, almost 80% reductions. What was unexpected is the relative matching in placebo. We expected to see placebo decline maybe 3 milligrams, 4 milligrams. To see these curves overlap is disappointing, but we're learning quite a bit from this.
As I said, treatment practice is changing, as we speak. Now, efzofitimod had a fairly strong trend here in steroid withdrawal, but again, we just missed the p-value by a couple patients. Again, largely driven by this 40% in the placebo. Our modeling had, we assumed, as I said, the experts, maybe 20% max. We modeled to just. We thought to be safe, 35%. This was a number that I think everyone in the audience in Amsterdam among the pulmonologists really were surprised. What one pulmonologist told me is she went back to North Carolina from ERS and immediately started to take, about 40% of her patients off steroids, patients that sometimes had been managed for 10 years, in her clinic. This again is I think a transformative result for the field.
Unfortunately, we're not showing efficacy here for efzofitimod purely from the standpoint of statistical significance, but again, very strong trends. I'll point you to the Kaplan-Meier curve. There you can clearly see a very durable separation that's maintained when you go out to 180, 210, 240 days, 270 days. You're talking about a really, really long time where patients are seeing a durable response. Again, if you had told me that the drug would get people 70%, 75% off their steroids and more than 50% would be at zero, that would have been our best-case scenario for efzofitimod. It's really what happened with steroids in the placebo arm that we are now really unpacking.
When you look at quality of life, this is really where the drug activity starts to emerge, and breaks away from placebo. King's Sarcoidosis Questionnaire, the KSQ lung, is the primary quality of life instrument we looked at. This is an amalgam of cough and shortness of breath questions that experts use to determine severity and symptoms of disease. Here what you saw is a significant result when you look at the dark green dots and bars with the confidence intervals. This is plotting against a flat placebo line there. What you see is right after, say, about week eight, immediately you start to see patients feeling better, and that's maintained across every time point. We're not picking a certain time point where we see stat sig.
When you look at all across the study, it's a very durable, potent response where basically patients are feeling great. We heard this all along from experts that patients are feeling great, their lung symptoms improve immediately, and now we can see that's largely attributable to efzofitimod, in particular the high dose of efzofitimod. When you look at other pre-specified quality of life measures, looking outside the lung at the FAS, which is the fatigue assessment score, as well as the King's Sarcoidosis general health, which is more systemic aches and pains and some of the rheumatologic symptoms that some of these patients have, you see the same consistent finding.
That benefit observed for efzofitimod is consistent, it's durable, it shows clear drug activity that when you administer, especially our high dose of efzofitimod, patients' lung symptoms, they feel better, their overall health, their fatigue. One of the experts in Amsterdam pointed out this is the only therapy for sarcoidosis that's ever shown such a consistent quality of life benefit, over any available therapy that's currently being used. Steroids, methotrexate, infliximab, these are drugs that patients don't feel good. We are clearly showing that patients are seeing significant benefit, from efzofitimod over and over and over again with these quality of life measures.
When you dig in even a little bit deeper and look at composites, even higher bars here, where we had a number of these composites in our pre-specified analysis, looking at patients who are not only able to get off steroids but feel better. That's really what's important for these patients. Can you get me off steroids, and will I feel better? Will I feel substantially better? Again, you see efzofitimod here in the steroid-free and improved KSQ. This is folks that have more than eight points of improvement in their King's Sarcoidosis Questionnaire. You see a highly statistically significant result and a dose response also when you look at 3 milligrams and 5 milligrams. Looking on the right there, I'll point you to the bottom. Almost 2.5x .
You're more than 2.5x more likely to be steroid-free and significantly improve with your lung symptoms when you're on efzofitimod 5 milligrams. That's what that box and whisker plot shows there at the bottom. Clearly that is statistically significant 'cause it doesn't overlap. This is something that many of the experts have pointed out. They continue to point out, many of them would like to see the drug approved immediately based on that signal 'cause this is exactly what they've been looking for, really over the last 50 years in a therapy for sarcoidosis. Forced vital capacity, this is an important functional measure. We wanted to be able to look at this. In an aggressive steroid taper trial, we would have expected FVC to decline.
It's well known in the literature that if you administer prednisone, patients get a boost in FVC. As you remove it, there's a slow decline. The key here was, do we see massive declines? We do not. We manage these patients really, really well. Experts have pointed out that, look, when you look at 5 milligrams, it is better than 3 milligrams, and placebo did about what we expected to see about a 2%-3% decline. Efzofitimod, it wasn't designed and powered to look at this because, again, we wanted to make sure we didn't worsen. But I also think there's some elements here where we start to see some separation as well, where there's just some nominal declines with FVC, when you look at this population. I'll also point out that this is a very homogeneous population.
Sarcoidosis patients can present with upper airway disease, lower airway disease, mixed, diffusion limited. There's a number of phenotypes we see in here. FVC is probably the most sensitive for our restrictive population, so stay tuned. This is some of the discussions we're having with the agency, that perhaps a restrictive population may benefit even more with efzofitimod. A little bit more on the safety. Well-tolerated here. We do not see a dose response here. We don't want to see that when you think about safety. I'll point out here a low number of SAEs, AEs leading to discontinuation. This is a disease where patients are quite sick. To see this over the course of a year, with almost single-digit numbers here for efzofitimod 5 milligrams is really positive.
We consider this a very safe and well-tolerated drug. When you look at anti-drug antibodies, since this is administered once a month through an IV infusion, something to pay attention to. We don't really see any treatment-boosted elements here. You can even see sometimes even before, even in the placebo, you see some ADAs develop. That tells you a little bit about some of the maybe inconsistency even with the assay there. Again, nothing really concerning at this step. Key takeaways here. We did not meet the primary endpoint. We think we have effectively sunsetted steroids as an endpoint at this point. We did something that was really highly unexpected by showing this amount of decline and those number of patients who can get off.
When this data, and it is being written in a medical manuscript, comes out, it's gonna serve as the basis of a change in the treatment guidelines. I would expect ATS and ERS guidelines are going to change because of the EFZO-FIT data. You are seeing the whole world now getting folks off steroids and even maybe sometimes, at a minimum, lowering them closer to the levels we saw in our trial. We are changing treatment practice.
Nonetheless, the improvement in quality of life and some of those consistent trends have us very intrigued, and this is why we're gonna be sitting down with the FDA to review the results, determine the path forward, and in the event that the FDA asks us to run another trial, we feel very confident at this point that we have a protocol that they'll really like. Experts have spent a lot of time with us over the last three or four months, and we feel as though we have a really excellent briefing book that we presented to the agency. I'll end here with just two minutes on the scleroderma trial, another very difficult disease to treat. Much more fibrotic, can also have really debilitating skin symptoms from the systemic sclerosis.
Again, an orphan disease where there's a large amount of morbidity and mortality. Patients become quite fibrotic. It's a more fibrotic disease than sarcoidosis, so we're testing the drug now in a different patient cohort. Again, here is a therapy that could be positioned as a second line. Most of these patients are on MMF for their systemic sclerosis. Once a disease impacts the lungs, patients can really become thirty percent of them become fibrotic rather quickly. It's a really bad manifestation of systemic sclerosis when you have ILD. Our trial looks at, again, a high dose, low dose. These are, we're testing here a fixed dose just to look at what 450 versus a weight-based might look like.
450, 270, this approximates 5 milligrams and 3 milligrams. It's a six-month trial. We're focusing on FVC here 'cause this is a very restrictive disease. I think the key thing here is we're also looking at skin symptoms within three months. We have reported an interim finding, which is rather quite exciting, that three out of four patients who have skin manifestations, diffuse skin disease, have already responded in three months to efzofitimod, based on some early interim unblinding. If that trend continues, I'll remind everyone no drug has ever improved skin symptoms for scleroderma. We're very excited to see this result, as I said, you know, towards the end of the year here with enrollment expected to finish here in the first half of 2026.
Just to wrap up here, efzofitimod, talked a lot about it. Large market opportunity. The key is gonna be this FDA meeting upcoming here, mid-April. We expect to come out of that with a clear signal around, is this program viable with sarcoidosis? We feel as though it is. What would be the next steps? Preparing ourselves that we could potentially be asked to run another trial. Feel really good about some of the learnings from the previous trial. I would anticipate we would focus a lot more on quality of life and perhaps also looking at function, pulmonary function in the next trial. This is a trial that has changed treatment practice around the world, so patients now are being actively managed out of their steroid regimens because of efzofitimod. We'll also highlight that we have a burgeoning pipeline looking at other inflammation and fibrosis and really feel like we're in a strong financial position at the moment as well. I'll stop there and take any questions from you, Tom.
That's great. Thank you, Sanjay, for the presentation. Maybe just coming back to the Type C meeting, may you just walk us through sort of your base case, I guess, going into that meeting. Do you think there may be a path forward on the basis of some of the secondary analyses, some of which look frankly quite striking, and you alluded to a lot of the KOL feedback around things like steroid-free plus quality of life improvement, or is the base case here you expect you would have to run another study?
I think, the way we look at it, we wanna be prepared in this discussion to do more than just say, "Hey, is the program viable or not?" I think it is. I think we clearly have demonstrated in many of our pre-specified analyses that the drug has activity. The drug is certainly helping patients wean off steroids, but also feel quite better while preserving their lung function. You know, I think there's always that chance that you have to look at that and say, "Well, could things go sideways?" We feel very confident that the program is just gonna have a green light. The question then becomes, what does that green light look like? Is this something that immediately you can file off of our data package? I find that will be very challenging.
I think you have to own it and say you didn't hit the primary endpoint. This is a primary endpoint that again, I think now will never be used again because we effectively blew it out, and you see what happened with placebo. There aren't gonna be that many patients now managed on steroids. Nonetheless, methotrexate alone is not gonna do the trick for these patients. Efzofitimod, based on the experts, they feel as though it can play a role, maybe not a frontline role, but it could be used in maybe more of a severe population. That's where we wanna be prepared with a base case of here's another protocol, let's get some feedback on it and treat this discussion more than just a typical Type C, really get a protocol assessment, if you will, at the same time.
That makes sense. Maybe just the way you're thinking about communicating results, Type C meeting in April, possible we could get feedback coming out of that meeting. Do we need to wait for the meeting minutes? Like how are you thinking about communicating to the street?
I think given the current climate, if you will.
Environment
Environment at the FDA, probably best for us to have a meeting and then wait for some official correspondence. I think that's smarter. I think most biotech companies are doing this. You typically would get a response, you know, about four weeks later. You know, things are not typical right now with the agency, but we're planning to then communicate to the street once we have some definitive. I'd like to see things written down. Then if we are in fact asked to run another trial, we'd be able to communicate exactly what that trial looks like, the size of the trial, the power of the trial. I mean, these are all things that we've already prepared. The key thing is what would the endpoints be?
This time around, moving forward, you know, I think of this as a very late phase, second phase three. Let's also lock down. When you look at quality of life, that could serve as a primary endpoint. When you look at pulmonary function test, okay, if that's the direction we wanna go, I feel good about that too, but then let's also hone in on which patients are we talking about. Obstructive patients, you have to look at FEV1. Restrictive patients, you have to look at FVC. Diffusion limited, you have to look at DLCO. So we have the largest natural history database in sarcoidosis ever, so there's a lot of jump points from our data that we can go and look at. I haven't presented anything today post-hoc, so that's another thing that we're gonna discuss with the agency.
Yep, that makes sense. Maybe just elaborate because you ran this large pivotal study, some other operational learnings in terms of recruiting the patients. You obviously have the scale and the relationships with the clinicians. Maybe just talk about how that would help you in a subsequent phase III.
Well, I think we've already demonstrated we can enroll, activate sites, move forward. I would say there's a good 15 or 20 in the U.S. right now that wanna get started on the next trial. They want access to the therapy immediately and maybe understanding you have to run another trial. The efficiencies there are set. We're the only company to ever have run a phase III trial, so we know what we're doing. The execution, when you think about a well-controlled, adequate single trial, we've already demonstrated we can do that. Big pharma has never done this aTyr has. I feel very confident in our abilities to operationalize once again.
Yep, that makes sense to me. All right, Sanjay. Well, unfortunately, we're up against time, but, important feedback coming and...