ProQR Therapeutics N.V. (PRQR) Earnings Call Transcript & Summary

Good day, and thank you for standing by. Welcome to the ProQR Therapeutics Analyst and Investor Event Webcast and Conference Call. [Operator Instructions] Please be advised that today's conference is being recorded. I would now like to hand the conference over to your first speaker today, Sarah Kiely. Please go ahead.

Thank you, and good day, everyone. We appreciate you joining our analyst and investor event today. I'm Sarah Kiely, Vice President of Investor Relations and Corporate Affairs of ProQR. Let's start by quickly reviewing today's agenda, which you'll find on Slide 2, along with our speakers. First, Daniel de Boer, our Founder and CEO, will provide a strategic overview of the business. Following that, Dr. Peter Beal, our Chief ADAR Scientist, will give an update on our Axiomer ADAR-mediated RNA editing platform in Science. Next, Gerard Platenburg, our Chief Scientific Officer, will present on AX-0810, our program targeting NTCP for cholestatic diseases. In this segment, we're pleased to include insights from KOL Gideon Hirschfield, Professor within the Division of Gastroenterology and Hepatology at the University of Toronto. We'll then shift our focus to AX-2402, our Rett syndrome program. This morning, we announced an expansion of our collaboration with the Rett Syndrome Research Trust, and we're thrilled to have Monica Coenraads, Founder and CEO of the RSRT, joining us to share her perspective. Following that, Gerard will return to discuss our AX-1412 program, which targets B4GALT1 for cardiovascular diseases, and then introduce our newest program, AX-2911 targeting PNPLA3 for NASH. We're looking forward to sharing these updates with you today. Following the presentations, Daniel will share a brief summary, and then our management team, including Daniel, Gerard as well as Rene Beukema, our Chief Corporate Development Officer, will conduct a Q&A session with covering analysts before we conclude the call. Today's event is being recorded, and we will have a replay available on the website following the event, along with our slides that you'll be able to access at that time. Before we get into the program, I ask that you note Slide 3, which includes our forward-looking statement. During the presentations today, we will make forward-looking statements. There are risks and uncertainties associated with an investment in ProQR, which are described in detail in our SEC filings. I will now turn the call over to Daniel de Boer. Daniel?

Thank you, Sarah, and good morning, everyone. We're excited to host our R&D investor and analyst event today and provide a broad update on our progress, both on platform science and the product pipeline. Before we start, I want to take a moment to welcome on board Professor Peter Beal as a team member in his new role as Chief ADAR Scientist at ProQR. Dr. Beal is a professor in the Department of Chemistry at UC Davis, leading a world-renowned research group that focuses on ADAR. And furthermore, Pete has served on our scientific advisory board for the last 6 years. Our long-standing collaboration with Pete has been instrumental in advancing the optimization of editing oligonucleotides, resulting in several discoveries that are foundational to our platform science today. Building on this fruitful collaboration, Pete is now joining the ProQR team as Chief ADAR Scientist, where he will play a pivotal role in overseeing Axiomer platform development and driving continued EON design optimization. We're excited to continue to work with Pete now in his expanded capacity as part of the ProQR team. Pete joins the company at a really exciting time. As we will share today, our R&D teams have made tremendous progress on the science, applying Axiomer to a wide variety of targets, scaling the application, and derisking the platform. In the next 2 years, we are expecting up to 4 clinical trials to read out clinical data, providing tremendous opportunity for value creation, further platform validation, and to make an impact to the lives of patients. Today, I am excited to lay out how our science positions us for his future vision and as a leader in this rapidly evolving field. Innovative RNA science is at the core of what we do and has been since our inception. In 2014, we invented our Axiomer ADAR-mediated RNA editing technology, and given the vast potential it holds today, it is our sole focus. Since the earliest days of our work on Axiomer, we have taken deliberate care to invest in a robust IP estate, which we believe provides ProQR with an important foundation for leadership and competitive advantage in the maturing RNA editing field. And ProQR continues to expand and defend its intellectual property portfolio. For example, in the last year, we have successfully defended several oppositions and subsequent appeals against our patents, further growing our conviction in the strength of this IP. Our patent protection is broad and multilayered, including foundational inventions on the use of ADAR-mediated RNA editing using and editing oligonucleotides and several patents on targets. Our foundational patent portfolio is also a critical driver of strategic interest. We are capturing the value of our Axiomer RNA editing platform through a dual strategy, advancing our own product portfolio and also selectively entering into high-impact strategic alliances. Our cornerstone partnership with Eli Lilly established in 2021 is making great progress. This year, we've started to receive milestone payments from Lilly, and as the projects in the partnership advance, we expect these milestone payments to continue and increase in size. As a token of their continued enthusiasm on the collaboration, Eli Lilly participated for their full pro rata in a risk financing. The partnership with Eli Lilly simplifies the strategic opportunities that are enabled by our Axiomer platform and positions us strongly to deliver innovative solutions to address unmet medical needs. As another example on the partnering front, today, we also announced that we will receive an additional USD 8.1 million from the Rett Syndrome Research Trust, or RSRT, to enable our development program in Rett syndrome. This funding comes on the back of a research collaboration with RSRT earlier this year, in which they had already funded us with approximately USD 1 million. This new funding will allow us to move a first program for Rett syndrome into the clinic. I want to thank the RSRT for their partnership, and we look forward to work together to hopefully make a meaningful impact to individuals and families living with Rett syndrome. We're pleased to have the Founder and CEO of RSRT, Monica Coenraads join us today on the call. With Rett syndrome as our newest addition, our pipeline with transformative potential is growing. ProQR currently has 4 wholly-owned development programs, 12 partner programs, and a few dozen in discovery stage, of which many are currently confidential. Today, we will shine a light on several of our development programs, including our lead program, AX-0810 targeting NTCP for cholestatic disease that will read out first clinical trial data in 2025. With the addition of the Rett project to our pipeline, we will now also move into CNS, a therapeutic area that we're excited about and have gained a lot of experience in through our collaboration with Lilly. Our CSO, Gerard Platenburg, will delve into this therapeutic area and the Rett program during today's presentation. Gerard will also talk about several other programs in our pipeline, including AX-1412 for cardiovascular disease and AX-2911 for NASH. And as our discovery engine continues to be very productive, we plan to add 2 new clinical programs to the pipeline each year. Financially, the company is in a robust position. Last reported, we had a cash position of EUR 89.4 million. And in October, we added USD 82.1 million in gross proceeds in financing, which positions us well to execute on this exciting platform opportunity, funding our operations into mid-2027, which includes up to 4 clinical trial readouts across 2025 and 2026. I will note as well that our run rate guidance does not include potential milestone payments from Lilly or income from any new business development activities. In summary, with our innovative Axiomer RNA editing platform, with a robust IP estate, a pipeline with transformative potential for diseases with high unmet needs, strategic collaborations and partnerships, an experienced team driving execution and financial strength, we are entering an exciting time of value inflection of our platform and pipeline. I will now hand over the call to Dr. Beal, our newest colleague, ProQR's Chief ADAR Scientist. Pete, go ahead.

Thank you, Daniel, for that introduction, and I am happy to be here to present on the Axiomer platform. I'm also enthusiastic about my new role in the company and excited to work with the ProQR team to advance this exciting technology to develop a powerful new class of oligonucleotide therapeutics. So for those of you who aren't familiar with Axiomer RNA editing platform, I'm just going to talk a little bit about some of the things that we think are exciting about this approach and, we think, lead to the potential for a really powerful class of new drugs. This is a versatile technology. It can be applied to different RNA transcripts in different organisms, potentially targeting multiple different diseases, different indications. Not limited to mRNA, we can target other RNA species as well. We believe it's going to be a safe technology. There are no permanent changes being made in the DNA unlike other editing technologies. This targets RNA. It's transient. No specific modifications of DNA are made. It's highly specific, right? There are very few off-target effects that have been identified through this RNA editing technology. The effects can be long-lasting. The chemically modified oligonucleotides that are used can lead to a very durable effect, lasting weeks to months. Yet it is transient that we're not making any permanent changes. Importantly, there is no viral vector that's used for delivery. The effective molecule that we're using is an oligonucleotide, does not require a virus to deliver it so we don't have the capacity concerns or the immunogenicity that arises from the use of viral vectors. And also, we are using endogenous enzymes. So the enzymes that will elicit the effect, the editing effect are endogenous to humans, the endogenous ADAR enzymes. We're not delivering an editing enzyme that could lead to off-target effects. Now ProQR has actually been a leader in this field from the very beginning. ProQR invented the use of oligonucleotide-directed RNA editing using endogenous ADARs with our initial experiments in 2014. And I've been associated with the company in capacity as a collaborator and a consultant since 2017. And we've been continually working together to innovate in this space, making the molecules more efficient, safer, longer-lasting, et cetera. Importantly, in 2021, ProQR engaged in a partnership with Eli Lilly to advance this technology focused on targets of interest to them. And in 2022, that partnership expanded to additional targets. And in 2023, the team actually showed greater than 50% editing in the central nervous system and in the liver of nonhuman primate and, at that time, announced their therapeutic target pipeline. Now what is ADAR and what is RNA editing? I mean, this is a topic that's been a passion of mine for many years. My lab has been working on ADARs and RNA editing for over 25 years now. The name ADAR refers to adenosine deaminases that act on RNA so these are enzymes that can react with specific RNAs inside our bodies. And my lab has been very focused on understanding the mechanism of these enzymes, structures of these enzymes and how these enzymes actually work naturally. Now the natural substrate for the enzymes is a double-stranded RNA, right? So an RNA that will fold back on itself to form a duplex structure. And then within that double-stranded RNA, an adenosine is identified and deaminated. And so you see the structure of adenosine shown on this slide on the right-hand side with the amine the NH2 group highlighted. The reaction is a deamination, which generates the minor base in RNA inosine. Importantly, though, inosine functions in many ways as if it were a G, a guanosine. So this reaction takes an A and converts it into something functionally that's like a G. And so because of the genetic code, of course, that A to I change can change the meaning of specific codons. And that's the power of this approach. We can change the meaning of codons and then change amino acids that are going to be incorporated into proteins that are translated from the edited mRNA. Now as I said, the natural substrates for the ADARs are double-stranded RNAs that's shown on the left-hand side. So how are we going to use -- how are we going to redirect the ADAR activity to a site of interest to us? Well, we can make what's called an EON or an editing oligonucleotide that can form a duplex structure at the target site and direct the ADAR enzyme to deaminate within that newly formed duplex. And in so doing, we can direct that editing reaction to a site that's of interest to us that would be therapeutically beneficial. Now this could have multiple potential beneficial effects, and I'll just show you 1 specific example here, right? So we're -- we have a gene that leads to natural function, right? So I'm focusing on a gene called MeCP2, that is important for a healthy brain function. But when a mutation occurs in MeCP2, a G2MA, that creates a stop codon in the coding region for the MeCP2 gene, leading to a truncated protein and leading to a neurodevelopmental disease called Rett syndrome. Now if we can then develop an oligonucleotide that will bind to the MeCP2 transcript, recruit the ADAR enzyme to convert that A, that is there because of a genetic mutation, to inosine which will then function as a regenerating the tryptophan codon, converting that stop codon back to tryptophan codon and leading to a functional protein, okay? So this is the idea, that we can correct these genetic effects at the RNA level using the oligonucleotides. Now ProQR early on was developing EONs. They're first-generation EONs that had a recruitment portion as well as a targeting portion. So the EON itself formed a duplex region that recruited the ADAR enzymes by binding to double-stranded RNA, binding domains that are found in the ADAR protein. The second-generation EONs do not have that hairpin structure and entirely bind across the target transcript. And they have incorporated mutations, mismatches, wobbles and importantly, chemical modifications to the base, the sugar and the backbone that can increase the activity and improve stability of these molecules. Now the team has been continually innovating in this space, and we've been involved in much of this in our collaborations with ProQR team, optimizing the specific structure of the EONs. And this is using our understanding of how ADARs actually interact with their substrates. We can now go in and rationally change the structure of specific nucleotides in the EON to improve their properties. And so we've modified different nucleotides positions, for instance, the orphan-based position, the position that's adjacent to the editing site. And both of these types of modifications have improved efficacy in the ADAR reaction. In addition, we can modify the backbone of the EON in different ways, using, for instance, the phosphoramidate linkage or a methophospanate linkage. Both of these also improve activity of the EON. So we're innovating and we're improving the properties of these EONs through an understanding of how the actual ADAR enzymes can function. Now improvements occur, as I said, in the ADAR reaction but we also can modify the EONs to improve durability. And so these can be -- these are now very long-lived molecules. So you're seeing data on this slide showing a specific EON that's targeting the liver having a half-life of around 80 days, okay? And the metabolism that is occurring for these EONs are not occurring in the oligonucleotide themselves. These are GalNAc-modified EONs that are targeting the liver and the metabolism is coming primarily from the GalNAc moiety that's a part of the molecule. So these EONs have been optimized for -- to be highly efficient, direct high activity of the enzyme as well as being long lived. Now these EONs, as I indicated, there's -- we can make corrections that will cure genetic diseases, but because we can change the amino acids within proteins, you can imagine using this approach to modulate protein activity in other ways. For instance, we can disrupt multiple post-translational modifications by changing the amino acids at the target of the modification and also change protein-protein interactions by changing the amino acid that's critical for protein binding to another protein or a protein binding to other macro molecules like carbohydrates. So using an understanding of how ADARs work, we're advancing the ADAR technology and advancing the -- or improving the properties of these oligonucleotides. The approach is versatile. We can target many different genetic mutations and target multiple different types of diseases. And importantly, ProQR has been a leader in this field with the very first discovery of oligonucleotide-directed RNA editing in 2014. And because of our continual innovation, we have a dominant IP position in this space. And so what I'd like to do now is turn it over to Gerard Platenburg, who's going to talk about some more specific pipeline projects.

Thank you, Pete. We are very pleased to welcome you on board at ProQR and excited to continue what we have started with a collaboration at UC Davis. It is amazing to see all the progress we have made with the platform and the potential for therapeutic applications. I would like to now focus on our first pipeline program, AX-0810 targeting to address unmet medical needs in cholestatic disease. Cholestatic disease can present in many forms and symptoms, affecting the pediatric and adult population. And despite variability in clinical manifestations, cholestatic diseases share a common feature, excessive and toxic accumulation of bile acids in the liver and bile ducts, leading to cell damage and ultimately, liver failure. Indications within the cholestatic disease group with high unmet medical need are PSC affecting more than 8,000 adults in the U.S. and EU, and congenital biliary atresia affecting approximately 20,000 patients in the same regions. Both conditions have no approved therapies and ultimately require liver transplantation. Our program, 0810, is a unique therapeutic approach leading to a potentially disease-modifying therapy by targeting the NTCP channel in the liver which is responsible for the majority of in the liver through reuptake from the blood. And to give you more information about cholestatic disease and the unmet medical needs, I'm very pleased that we are joined today by Professor Hirschfield from Toronto Center of Liver Disease. Professor Hirschfield is a world-renowned expert in liver disease field, particularly in adult cholestatic disease. And his research focuses on advancing therapies for inflammatory liver disease to prevent the need for transplantation. Professor Hirschfield, I'm now handing it over to you.

Thank you, Gerard. My name is Gideon Hirschfield. I'm a hepatologist based in Toronto, Canada. I'm a clinician scientist who looks after patients with cholestatic liver disease, and I'm particularly involved in the development of new therapies for people living with cholestatic liver diseases, particularly using state-of-the-art technologies to really deliver unmet needs for our patients. These are my disclosures. So for us, as a hepatologist, cholestatic liver disease is very important. It really is an area of hepatology with great unmet need, and that unmet need spans pediatrics into adult care. And it has a key focus on the toxicity of bile acids. And with our understanding of these diseases, we've learned more about pediatric and genetic cholestatic liver diseases, adult liver diseases such as primary biliary cholangitis and primary sclerosing cholangitis. And where we have got to is a greater understanding of the relationship between the hepatocyte, the cholangiocyte, and very intricate bile acid transporters. We're also very acutely aware of where we have therapies and where we don't. So we have no therapies for biliary atresia or PSC, but we have developed successful therapies for PBC and for some pediatric rare liver diseases such as PFIC. These diseases not only impact quantity of life but also quality of life. And these diseases cannot also not only be associated with cirrhosis but also with hepatobiliary malignancy. This is just an image to show you the real impact for our patients living with cholestatic liver disease. This is a patient with intractable pruritus. This is what's happens when we cannot treat the cholestasis adequately. We see this in PBC and PSC in adults, and clearly, we recognize this also in pediatrics. And this is devastating for our patients. For me, as a clinician, we have a pathway, particularly in adulthood, of diagnosing patients efficiently and effectively. Similar pathways can be shown for pediatrics. This is important because it allows us to find the right patients and target treatments as well as also target patients for clinical trials. So from an adult perspective, when we see someone with cholestasis, we measure antimitochondrial antibodies. And if they're positive, we know that we're heading towards PBC. If they're negative, we look for AMA-negative PBC. And then if that's not the answer, we know that using MRI, biopsy and assessing for inflammatory bowel disease and genetic testing allows us to confidently diagnose the other cholestatic liver diseases that include PSC and adult versions of genetic cholestasis. It's also real for my patients. I see patients every day of the week. We see patients from across Ontario, and we see patients with very impactful disease. These are just the blood test of a young woman with cholestatic liver disease that is a PBC variant. This young woman has already got cirrhosis as evidenced by low platelet count and elevated liver stiffness and evaluation demonstrating portal hypertension. In her case, the immunology diagnosis is primary biliary cholangitis very efficiently. antibodies, antimitochondrial antibodies, anti-SP100. So here is a patient who needs better treatments. For primary cholangitis, we have an even bigger problem. We have to live with great uncertainty for this devastating disease, which to this date has no medical intervention licensed. And the only intervention that changes outcome is liver transplantation, so long as our patients don't develop cancer. You can see on the left the abnormal cholangiogram. You can see what the liver looks like when it's taken out at transplantation with this dense fibrosis around the bile ducts. And you can see why our patients have so much pain because at the bottom right, you can see cholangioscopy demonstrating a very inflamed bile duct. And the concern we have all the time at the top, cholangioscopy looking for cancer. So our patients live with uncertainty and are desperately seeking better treatments to improve the bile flow that we know is deleterious in this progressive fibrotic obstructive disease. So these diseases are a family of diseases. They go from childhood into adulthood. We have broad classifications of autoimmune and cholestatic liver disease. And from the cholestatic perspective, we have PBC is a small bile duct disease, primary cholangitis as a large bile duct disease and then the pediatric syndromes, including biliary atresia, which is also a medium to large bile duct disease. Behind the scenes, we know that there are genetic, epigenetic, exposome, and microbiome risk factors. And we also recognize that these are essentially common rare diseases. They are rare overall but not ultra-rare. Now to focus in on primary sclerosing cholangitis in the middle here, you can see why this is such a difficult disease to treat. Our patients are young. Our patients frequently have inflammatory bowel disease. Our patients have a focal fibrous obliterative cholangitis with secondary biliary fibrosis, infiltrates, which are inflammatory and symptoms and signs associated with these progressive strictures, ductopenia, obstruction, ducted reaction and end-stage biliary cirrhosis. We have no standard of care therapy. But we know that bile acids are very important, and we're therefore excited with the idea of molecular modulation of bile acid as a potential new therapy for patients with PSC. Hence, the excitement today around NTCP modulation and the concept that we'll come back to of reducing the amount of bile acid toxicity ongoing in the hepatocytes and demonstrating that a drug can increase bile acid in the blood as a mark of drug efficacy and drug engagement. So for PSC, we have many questions because there are many unknowns. But the 1 unknown that we all agree on is that we have to do better. We have to get better treatments. Our patients are willing to take part in clinical trials. Our patients across all ages want to have better symptoms. The disease is very highly biliary focused so it is a biliary disease where cholestasis and bile acids are key, okay? And to this date, we've had difficulty treatment treating the disease, but that may actually reflect that we haven't had the right tools with which to actually target at a molecular level all these relevant bile acid transporters that we know are absolutely key to bile acid homeostasis and normal function and then become key as pathophysiological themes over time. PSC is, as I said, rare but not ultra-rare. This is data we just published from Ontario. Our registry data has over 15 million people in this healthcare registry database. And we're able to show that if you have 100 people living with IBD, one of them will be living with PSC IBD. If you diagnose 50 people with IBD, one of them will be diagnosed with PSC IBD. Our patients have a higher socioeconomic class, suggesting that there are some environmental factors. And we can see the absolutely unacceptable morbidity and mortality for our patients as compared to patients with just inflammatory bowel disease and the very high rates of liver complications and malignancies. Now there's been a lot of work to try and understand the genetics of this disease. And whilst we've identified genetic risks, that hasn't really helped us therapeutically at this time. The genes that we've identified has really been phenocopy families. For example, this is a family of the CD100 mutation where they have a phenocopy of PSC. However, when from -- across GWAS studies and bigger cohort studies, we've not identified this as a risk factor. So we understand that immunology is important but the classical genetic work has not identified genetics to help us with the treatment. Bigger GWAS studies such as this one has highlighted some of the important features of PSC IBD, one of which is that it is different to inflammatory bowel disease. It has a different genetic architecture with a correlation of only around 50% genetically. And we've even been able to pick up things that we knew from our epidemiological studies that, for example, in PSC IBD, smoking is protective. And indeed, there are genetic risk factors that are associated with smoking behavior, and they turn out to also be associated with PSC IBD. But the answer has not been in the genes. If we go back sometime, we do recognize the importance of bile acids and bile acid toxicity. We recognize, therefore, the opportunity for new therapies to change this bile acid toxicity and to think about novel ways to do this, which we've not done before. So MDR2-deficient mice develop a clear cholangiopathy, a clear sclerosing cholangitis. This tells us that we have the opportunity to target toxic bile acids and to think about the site of toxicity, which is not just the cholangiocyte but also the hepatocyte. Furthermore, we understand that by manipulating bile acids, we will have an impact on immunoregulation as well. There is significant work. This is a couple of papers that have been published in Nature around how bile acid metabolites are controlling regulatory and Th17 cell differentiation and how human gut bacteria produce Th17-modulating bile acid metabolites. So again, we are confident that bile acids and bile acid pathways, bile acid transporters should be a prime consideration for new therapies, particularly with the opportunity to use molecular therapies and particularly where you can use molecular therapies and measure the impact of the drug. So for example, as this session is all about NTCP modulation, we can see the advantages of reducing hepatocyte bile acids, but we can also see the advantages of proof of concept of being able to measure targeting NTCP and measuring, for example, a twofold increase in bile acid in the blood as a marker that your drug is biologically active. Now bile acids are complicated but they're absolutely key. This is really the overall figure of bile acids in health. And I'm sure colleagues later on will go into much greater detail. But you can see this complex pathway between the liver and the bowel and intrahepatic recirculation and conjugation of bile acids. But importantly, the importance of these bile acid transporters, particularly NTCP, more so than OP1, in the transport of bile acids and in maintaining health. At a real molecular level, we're able then to think about the hepatocyte and the enterocyte. And this just highlights for you some of the bile acid biology that's going on there and the key role that a transporter such as NTCP is playing with effects then on CYP7A1 and then ultimately also on other bile transporters and what's happening in collaboration with the gut. It's really key to understand that a healthy hepatocyte should not have a high load of bile acids. And the unhealthy state in the cholestatic state, biliary atresia, primary sclerosing cholangitis, other cholestatic liver diseases, the opportunity exists to reduce toxicity by reducing the amount of bile acid in the hepatocyte and moving those bile acids into the blood and not into the biliary tree. Furthermore, it's important to recognize where we've had successes in treating related diseases such as primary biliary cholangitis have been with the FXR-FGF19 pathway between the enterocyte and the hepatocyte. And as you know with the pathways. And you can see, therefore, highlighted that in thinking about these pathways, we can also see the important roles of NTCP highlighted on the left with the FXR-FGF19, and again, the important roles of bile acid manipulation and transport by NTCP in the hepatocytes and how it also links into drugs that we've seen to be effective in primary biliary cholangitis that -- the PPAR agonists. Downstream, we therefore, predict that if we can improve this bile acid toxicity essentially by changing the pathways, we can have an impact also on the consequences of injury to the biliary epithelium, which leads to more activation of immune cells, which leads to damage to cholangiocytes, which leads to senescent cholangiocytes, which leads to more injury and which then also has a complex relationship with the gut in terms of immunoregulation. So this would be an opportunity to also impact downstream pathways, having focused very carefully on the hepatocyte and reducing bile acid toxicity in that setting. Now just to end, therefore, why from an adult position, I look after patients with PSC, the biliary atresia patients are looked after, obviously, by pediatrics. But this is a very difficult disease with a great unmet need. We developed this infogram just to help people understand what's happening with this disease. Patients have covert symptoms for pruritus. Patients clearly have cholangitis, as I told you, okay? That cholangitis leads to a secondary biliary cirrhosis. In association, more than 60% to 77% of patients have got colitis and that colitis and the cholangitis is associated with cancer risk. Our patients want cures, but we would accept control. And when we think of the different therapies that have been tried and where we've seen at least biochemical efficacy, it has remained in the bile acid therapy-based approaches. So this novel concept that you're going to learn more about today has a lot of potential to contribute to the hypothesis that we can control this very difficult disease better by having a better handle and compartmentalization of bile acids away from hepatocyte toxicity and shuttling the bile acids into a more nontoxic compartment. So with that, I'll thank you for listening to me today and listening to the unmet need of the patients that I look after, and I'll hand over to Gerard to continue this session for you.

Thank you very much, Professor Hirschfield, for this fascinating overview, highlighting the need for new and better treatment options for these devastating diseases. Again, reiterating diseases caused by excessive toxic accumulation of bile acid in the liver, increase in liver bile acids leads to cholestatis causing cell stress, cell death, inflammation, and ultimately progress to fibrosis. Without intervention, this cycle further damaging the liver and bile ducts. Interestingly, 95% of bile acids in the liver are reuptaken from the bloodstream through the channel, an approach leading to the modulation of NTCP bile acid uptake function as a very compelling profile as it has the potential to address different mechanisms involved in disease progression by stopping it at the root cause. By doing this, it can restore bile acid homeostasis by directly decreasing bile acid levels in the liver, preventing hepatocyte injury and to provide a further positive impact on the liver, high bile acid levels in plasma activates a signaling pathway through FGF19 to inhibit production of new bile acid, further reducing toxic bile acid load. This, in turn, then reduces inflammation and ultimately slows down progression to fibrosis. In order to interfere with the disease at the root cause, we turned to human genetics and found a human population with NTCP variants, which reduced bile acid uptake in the liver, keeping it in the bloodstream. We discovered this as a very compelling approach that could potentially lead to meaningful impact on the course of cholestatic diseases. This is strongly supported by literature. And as is shown over here, NTCP modulation has hepatoprotective effects in vivo in mice. Here, diseased mice were treated with NTCP inhibitor approved for hepatitis D, and this led to an increase in total bile acids around two- to threefold. This increase was associated with the reduction of intracellular bile acid accumulation in the liver, leading to a positive impact on liver enzymes. Furthermore, in the clinic, these findings were confirmed with an increase in plasma bile acid and associated with improvement in liver fibrosis score. We conclude that reducing liver bile acid toxic overload via NTCP modulation is a key driver for hepatoprotective effects. As said, human genetics validated this research to lower bile acid at the root cause. And using our technology, we can modify NTCP to recapitulate that effect. Our editing oligonucleotides are designed to introduce the Q68R NTCP. The Q68R NTCP variant disrupts key hydrogen bonds within the sodium-binding pocket of the NTCP channel. This structural change significantly reduces its ability to reuptake bile acids, and the molecular proof of this is shown on the right panel, where you can see that the bile acid reuptake in the cell is affected by the variant and not by wild-type. These findings form the foundation of our therapeutic strategy by effectively preventing bile acid accumulation in hepatocytes. Importantly, the Q68R variant does not affect overall NTCP RNA or protein levels, nor does it alter the channel's localization to the plasma membrane as demonstrated in this slide. This specificity ensures that our approach targets bile acid reuptake without interfering with other critical NTCP functions. Our preclinical studies with editing oligonucleotides established a clear dose-response relationship in inhibiting bile acid reuptake. Subsequently, we studied this in vivo. In this study, the objective was to show that there was a correlation between editing and changes in plasma bile acid levels. Nonhuman primates or NHPs were dosed with an early generation EON shown to be active in vitro. And what we find is a very nice correlation between editing level and plasma bile acid levels. Assessing now our early generation oligo in 2 different vivo models, [ humanized ] mice and NHP to better understand translatability of editing findings into biomarker effects. The results are consistent in both models and lead to expected level of NTCP modulation by achieving an increase in plasma total bile acid more than twofold, which is the target for clinical benefit as Dr. Hirschfield outlined for us. Plasma bile acid biomarkers helped to demonstrate the successful NTCP modulation, leads to a reduction in uptake of bile acids from the plasma to the liver. As previously mentioned by Dr. Hirschfield, bile acids are produced in the liver where they are conjugated and transported into the gall bladder for future release into the intestine. Conjugated bile acids are mainly being transported by the NTCP from the bloodstream back to the liver. Our preclinical in vivo data demonstrates that composition of plasma bile acid profile changed towards an increase of conjugated bile acids, further confirming that specificity of NTCP modulation achieved by editing. In an additional experiment, we artificially increased plasma bile acid load to further isolate the NTCP change in function following EON treatment. We administered TUDCA or tauroursodeoxycholic acid that is produced in very limited quantities in the liver and mainly taken up into the liver by NTCP. Quantifying and timing the clearance of TUDCA from the bloodstream serves as an additional biomarker for NTCP activity. And as you can see here, following treatment with Axiomer EON in NHP, a statistically significant decrease of bile acid elimination rate from the plasma was observed in the treated group versus the control. The data set presented in this previous slide constitutes a robust proof of concept on translational biomarkers, building conviction in this approach. After further optimization efforts, we have now identified a molecule, which has 5- to 6-fold higher editing potency and increased stability profile. As this molecule is materially better than any of the other molecules to date, we have decided to switch to this molecule for our clinical translation. This molecule we have selected as our development candidate for AX-0810, EON, and we will now take this forward into development. We have started CTA-enabling activities. The AX-0810 clinical candidate has passed the safety vitro screening for class toxicities and genotoxicity tests for chemical maker. We also have completed the dose range finding and bioanalytical method development. As mentioned earlier, AX-0810 clinical candidate is a GalNac conjugated molecule tox studies and clinical manufacturing are on track. We are currently in interactions with the regulatory authorities to the start of the trial. Our first in-human trial aims to confirm NTCP engagement, assessing changes in bile acid levels and profile in both plasma and urine. During the study, we will closely monitor safety, tolerability and pharmacokinetics of 0810, collecting important data to inform the next steps for clinical development. The trial features a combined single and multiple ascending dose design across 60 healthy volunteers in 4 cohorts. They will receive 5 weekly subcutaneous injections during a 4-week dosing phase, followed by a 12-week safety follow-up. The study will be placebo-controlled and includes standardized conditions for assessing biomarkers. Our objective for the trial is to measure a twofold increase in plasma bile acids and also shift in the bile acid profile as we observed in NHP, increasing the ratio of conjugated bile acid versus conjugated bile acids in plasma. The study is in preparation and on track. We expect to submit the CTA in Q2 and report top line data in Q4 of 2025. So in summary, modulating NTCP activity to reduce hepatic bile acid overload is a critical mechanism driving hepatoprotective effects. Our translational data in humanized mice and NHP have demonstrated consistent and promising results with meaningful impact on translational target engagement biomarkers, which we expect to be predictive for the clinic. With that, we have now selected our GalNAc conjugated clinical candidates for AX-0810 with an optimized potency and stability to enter the clinic with a planned CTA submission in Q2 2025 and top line data from the first-in-human trial expected in Q4 2025. Beyond these initial indications, NTCP and bile acids are involved in many diseases, providing significant potential for leveraging our NTCP program and expertise. PSC NBA are just the beginning of the story as NTCP modulation holds great promise to address unmet medical needs in other cholestatic indications, certain metabolic diseases, including obesity, and CNS conditions, to only cite a few. Hence, NTCP modulation holds great promise for the future development in multiple therapeutic areas. Moving on to our next program, AX-2402 targeting MeCP2 to restore protein functionality in Rett syndrome, a severe neurodevelopmental disorder. Before getting into the details on the program itself, I wanted to give you an update on EON potential for CNS conditions. We have presented over the past months at scientific conferences more details on our CNS data. And we think the brain and nervous system in general is a prime organ candidate for Axiomer RNA editing technology. Axiomer is especially meaningful to the CNS because RNA editing is highly prevalent in the brain, in different endogenous targets like ion channels. ADAR enzymes are highly expressed and active in the brain. And in addition, editing oligonucleotides have a favorable safety profile as a class in the brain and can be delivered in a proven way. In this slide, you can see that the ADAR enzyme is widely expressed throughout the brain, supporting the potential of editing in the brain. For the development of RNA editing in the CNS, we decided to develop a [ translational ] model. In this model, we can, by mixing specific neuronal cells, create 3-dimensional steroids. And depending on the specific conditions, we can recreate specific regions of the brain. This offers a very powerful, predictive platform model for studying RNA editing and accelerating drug discovery in brain. As an example, here we created neurospheroids, recapitulating human cortex. It expresses the appropriate neuronal and markers, making it an interesting model to develop EONs in multiple targets. For instance, in this model, we get excitingly high editing levels of the targeted messenger RNA up to 90%. So in summary, this is a very interesting model for the development and screening of drug candidates in the CNS. In vivo, EONs have a favorable profile in the CNS. Our preclinical studies have demonstrated extremely consistent RNA editing across multiple species. Across the species, we see high double-digit editing, translating from mice to nonhuman primates. These cross-species results reinforced the robustness and translatability of our RNA editing platform, positioning Axiomer as a highly versatile technology for CNS applications, and this bodes well for the translations into human. In summary, Axiomer has the potential to make a meaningful impact in CNS disorders with a broad applicability and durable effects validating its potential for CNS indications. Next, I would like to turn to our AX-2402 program targeting MeCP2 in the Rett syndrome. We are extremely proud and pleased to announce the expansion of our collaboration with the Rett Syndrome Research Trust or RSRT. Back in early January, we announced the beginning of our partnership in which RSRT awarded ProQR approximately $1 million as a research grant for initial phases of the project. We have since made a lot of progress from January and the collaboration with RSRT being extremely productive. Monica and the RSRT team decided to expand the partnership for an additional $8.1 million in co-financing of the AX-2402 development program. We are indeed very honored to partner with the RSRT and continue the search for medicines which would impact the course of devastating rare disorders. This cause is very close to our heart, and we are pleased today we have Monica Coenraads, Founder and Chief Executive Officer of RSRT to share more about her story and work at RSRT. Monica, I'm now handing it over to you.

Thank you, Gerard, and good morning to everyone. Thank you to the leadership team at ProQR for the opportunity to participate today. I'm Monica Coenraads, Founder and CEO of the Rett Syndrome Research Trust, and mother to Chelsea, a 28-year-old young woman who was diagnosed with Rett syndrome at the age of 2. Coming to grips with the fact that your child will be severely disabled is heart-wrenching. That was the first gut punch. The second came when I realized the cause of Rett was unknown, that very few scientists were working on the disorder and that there was zero industry interest. I decided to get involved and try to help. Fortunately, just as I was getting started, who would have thought that it had been discovered that mutations in a gene called MECP2 were responsible for Rett. In 2007, Adrian Bird published a paper that changed everything for me. Rett symptoms in mice disappeared when the MECP2 gene was turned back on, regardless of the age of the mouse. I started the Rett Syndrome Research Trust with the intention of focusing exclusively on genetic medicines. Today, we are pursuing a number of genetic medicine modalities, all of which are aimed at boosting levels of MECP2. We were early adopters of RNA editing, funding our first project in the lab of Gail Mandel 10 years ago. We are enthusiastic about RNA editing for several reasons. First, it provides a therapeutic that does not rely on viral delivery. This means less immune issues and easier and cheaper manufacturing, which should translate to better patient access. Not relying on viral delivery also means more options for patients since they can theoretically access a virally-delivered genetic medicine and an RNA editing therapeutic in much the same way as SMA patients can receive ZOLGENSMA and SPINRAZA. Levels of MECP2 are important. Too little causes Rett but too much leads to a very devastating disorder, MECP2 duplication syndrome. So another advantage of RNA editing is that correcting the mutation ensures the cells will make the appropriate amount of MECP2 in every cell type. Now my colleagues and everyone involved with the Rett Syndrome Research Trust are delighted to support ProQR's efforts to develop AX-2402. Our previous funding has generated encouraging data and we look to the future with optimism. I was asked today to speak to the unmet needs that exist in Rett syndrome. Rett is the poster child for unmet needs. If you've ever read a paper on the disorder, you will see a laundry list of symptoms: nonverbal, nonambulatory, seizures, scoliosis, breathing irregularities, loss of purposeful hand use, hand stereotypies and on and on and on. Now I would like to try to bring some of these symptoms to life for you. The loss of the ability to speak is the most tragic of all of the symptoms. Imagine going through life without ever saying a word, asking a question, telling someone how you feel. Not only is my daughter unable to speak but she can't use her hands so she can't type and she can't sign. She's truly trapped in her body. The worst part of not being able to communicate is that she can't tell me what hurts. So any time she's upset, crying or seems to be in pain, we start this arduous process of trying to figure out what is wrong. Doctor appointments, lab work, x-rays, ultrasounds, ER visits. Sometimes we find something, often we don't. The hallmark symptom of Rett is loss of purposeful hand use, which is replaced by stereotypical hand motions. Now let me show you what that looks like. Chelsea can't pull up a blanket if she's cold or take it off if she's hot. She can't scratch an itch. She can't bat away a mosquito or worse, a bee. Little kids with Rett usually have low muscle tone, but as they age, they develop high tone. Chelsea is really stiff. When I pick her up, it's like picking up a piece of wood. At night, she sleeps on her side and I have to pad the area between her ribcage and her elbow because if I don't, she holds her arms so tightly against her ribcage that she ends up bruising and it gets worse night after night. She also sleeps with the weight on her arm and her hand to stop the incessant hand stereotypies so that she can rest and eventually fall asleep. Irregular breathing patterns are common in Rett. Now here is an example of Chelsea's breath-holding from when she was younger. [Presentation]

Imagine trying to feed a child who is breathing like that. Now Chelsea started having seizures at 5 years old, and they've never been under control. She's had seizures everywhere, at school, at the grocery store, in church, in the car going 70 miles an hour on the highway. We have oxygen at home and in the car because her oxygen saturations usually tank after a seizure. If we're going for a walk or going to be in a mall or somewhere where the car might not be close by, we bring the oxygen with us. Now I'm going to spare you from watching a video of one of her seizures, but I will describe one particular seizure that stands out, Thanksgiving Day 2020. She had, had a very normal day. Now everyone had left and I was feeding her a little taste of ice cream. She had a seizure. And at first, the seizure was no different than hundreds she's had before. I grabbed the pulse ox. I put on her oxygen mask, and I watched as her stats started to go down, 80s, 70s, 60s, 50s. They just never stopped plummeting. She hit a saturation of 9. She was lifeless, turning blue. I started blowing air in her mouth and managed to get her O2 levels to the low teens, mid-20s. Of course, we called an ambulance. In the blink of an eye on that day, Chelsea went from this to this, hanging on to life by a thread. Now I could go on and on about symptoms because there are so many of them, and I've just scratched the surface. The symptoms are horrific for people with Rett, but of course, the entire family is impacted. Most people assume that parents who have an adult child with a disability have had years to accept it, come to terms with it, move on. And to some degree, that's true. The raw kicked-in-your-gut, can't-catch-your-breath emotions that I felt when Chelsea received her diagnosis have certainly subsided, but the pain never really goes away. You cannot move on from having a child who can't experience the most basic of life's pleasures, eating by mouth instead of a feeding tube, having a best friend, riding a bike on your own, singing along to a favorite song, blowing out the candles on your birthday cake. On behalf of Rett families in the U.S., in the Netherlands, and around the world, we are excited about the work taking place at ProQR and we wish you God speed. Back to you, Gerard.

Thank you so much, Monica. For me -- for me, this is really the important reminder of why this work we do is so essential. As Monica explained, Rett syndrome is a devastating condition caused by variance in the MECP2 team. Approximately 350,000 patients have Rett syndrome worldwide and [ nonsense ] variants, which have the most severe phenotypes are projected to affect 20,000 individuals in U.S. and EU. As this disease is a neurodevelopmental disorder, symptoms caused by the MECP2 deficiency in Rett could be reversed if normal protein levels could be restored. Axiomer RNA editing represents an elegant approach to address multiple nonsense variance by restoring physiological levels of MECP2 and to create a wild-type-like protein even the regulatory systems of the cells in place to regulate MECP2 expression. MECP2 is the gene that goes CPG binding protein 2 and is known as a master epigenetic regulator via chromatin. It plays a critical role in gene expression, neuronal maturation and brain function. Premature termination codons in MECP2 lead to a loss of function and account for 35% of premature termination codon in Rett syndrome cases. Importantly, Dr. Bird's team led breakthrough research in 2007, leading to the discovery of reversibility of Rett syndrome symptoms following re-expression of normal levels of MECP2. This is what you can see on the graph depicted on the right. MECP2 mutant treated mice displayed close to wild-type phenotype on the disease severity score assessment. The regulation of MECP2 expression in neurons is critical for normal brain function. A deficit in MECP2 leads to Rett syndrome. Conversely, overexpression of MECP2 can result in MECP2 duplication syndrome, a condition linked to toxicity and significant health challenges. Notably, even a modest 1.5-fold increase in MECP2 levels can lead to adverse outcomes. This is why Axiomer is an elegant approach as it focuses on restoring physiological MECP2 levels, targeting the root cause of the conditions while avoiding the risks associated with overexpression. The Axiomer platform uses the endogenous ADAR system to correct specific mutations at the RNA level. The AX-2402 EONs are designed to correct the converting it into a functional wild-type like R2 variant. This has been shown in the MECP2 270W mouse model. This transgenic mouse model, as demonstrated that correcting the mutation to R270W restores MECP2 functionality to wild-type function, and this observation has been transformative. Mice with the R270W MECP2 variant are indistinguishable from healthy wild-type counterparts. Our current lead editing oligonucleotide demonstrates an impressive 80% editing efficiency in patient-derived cells carrying the R270X mutation. Premature termination codons usually lead to nonsense-mediated DK reducing target messenger RNA levels. Editing with Axiomer EONs lead to an increase of MECP2 RNA to normal levels due to inhibition of NMD and restoring protein expression. This dual action the PTC and stabilizing the messenger RNA ensures that the corrected RNA is not only functional but also abundant, maximizing therapeutic impact. Such advancements highlight the robustness of our approach and its potential to set a new standard in treating RNA-related diseases. As we look ahead for clinical applications, we are working on the design of a Phase I/II trial for patients with R270X mutation. This trial will evaluate both single-dose and repeated dose regimens, aiming to assess safety, tolerability and pharmacokinetics as primary objectives with secondary objectives focused on target engagement and biomarker analysis. The study is designed to include up to 80 participants with top line data expected in 2026. Supported by the $8.1 million in funding from the RSRT, this trial represents a significant milestone in bringing this innovative therapy to patients. Through our Axiomer technology, we are at the forefront of addressing the challenges both for Rett syndrome caused by MECP2 variants. With that, we are now in the process of optimizing our lead EON with the objective to select the clinical candidate for AX-2402 in 2025 with top line data from the trial expected in 2026. Now I would like to turn to our 1412 program for cardiovascular conditions. Cardiovascular conditions, or CVDs, remain the leading cause for mortality worldwide, claiming nearly 18 million deaths each year and despite therapies on the market, a high unmet medical need remains. The AX-1412 program is designed to address these gaps by introducing a protective genetic variant in B4GALT1 gene. This variant has been shown to reduce cardiovascular risk by 36% in human genetics, and it has the potential to become a stand-alone therapy or a complementary addition to existing treatments to further reducing the risk of CVDs. The B4GALT1 gene plays a pivotal role in cardiovascular health, specifically, asparagine-352 serine variants that we have identified as a protective vector, significantly reducing the risk of coronary artery disease. This rare variant, often referred to as the old [ Amish ] order variant due to its prevalence in this population, achieves its protective effect to dual pathways, reducing both farbinitian levels and LDL cholesterol. These pathways are independent of the mechanisms targeted by PCSK9 inhibitors, offering a unique therapeutic advantage. Glycosylation is a fundamental biological process, particularly in metabolism. As part of this, B4GALT1 is an enzyme responsible for galactocosylation of proteins. The process of galactosylation and glycosylation ensures the proper folding and structural stability of lipoproteins, which are essential for lipoprotein assembly and secretion, but also regulates key receptors like the LDL receptor, facilitating efficient clearance of lipoproteins from the bloodstream. Moreover, it supports the activity of enzymes such as CETP, which are critical for lipid transfer and remodeling. The variant that was identified through human genetics research reduces cardiovascular risk through 2 independent mechanisms. It lowers fibrinogen, a key clotting factor, and LDL cholesterol, a major contributor to plaque formation in arteries. These effects operate via distinct pathways, reinforcing the variant's robust protective effect against coronary artery disease. By introducing this variant through RNA editing, AX-1412 has the potential to replicate these benefits, providing a novel therapeutic avenue. EON-mediated editing depicted in the left panel leads to the reduction of B4GALT1 enzymatic activity as depicted in the central panel, which is mimicking the effect as reported in a human genetic population, as you can see on the right. Studying cardiovascular therapeutics often requires animal models that closely mimic human lipid metabolism. The E3L CETP mouse model is the industry standard as it expresses cholesterol transferase protein or CETP, a protein absent in most rodent models but crucial for liver transfer between lipoproteins. These mice exhibit liver changes similar to those in human diseases and allow us to rigorously evaluate the impact of B4GALT1 editing on cholesterol metabolism in cardiovascular risk factors, providing critical insight for our AX-1412 program. After those in mines with our LNP-formulated EON, we investigated changes in key CETP protein expression and function. We observed that as expected, our protein expression levels remain the same but that indeed, the enzymatic activity of the protein is reduced by 34% by the RNA edit as it's observed in the panel on the right due to reduced galactosylation of the CETP protein. We tested an LNP-formulated EON in these mice and observed substantial reductions in total cholesterol, LDL cholesterol, fibrinogen and levels with very significant improvements ranging from 39% to 72%. These changes were evident as early as day 19, validating our approach and highlighting the potential to address critical cardiovascular risk factors. The impact of AX-1412 on lipid protein profiles is both profound and specific. Treatment with EON editing significantly reduces levels of ELDL and LDL cholesterol, the lipoproteins most associated with plaque formation and cardiovascular risk. Importantly, HDL cholesterol, often called good cholesterol due to its protective role, remains unaffected. This specificity ensures that AX-1412 targets harmful lipoproteins while preserving beneficial ones. These tremendous results were produced with LNP-delivered EONs. However, we have not observed effects to the same extent with GalNAc-delivered molecules. As we believe that for cardiovascular diseases, the target product profile requires advantages of GalNAc delivery, we will conduct further work to optimize EONs to establish similar results on this target with GalNac delivery. In summary, AX-1412 leverages EON-mediated RNA editing to replicate the protective effect of the and B4GALT1 by impacting cholesterol and fibrinogen. This innovative approach reduces glycosylation, aligning with observed human genetics and demonstrates meaningful improvements in biomarkers in an industry-leading disease model. These results are a great proof of concept for B4GALT1, and as I mentioned in my previous slide, we want to achieve these LNP-delivered results with the delivered molecule as we think LNP-delivered EONs do not have a viable TPP in cardiovascular disease. As we are optimizing this molecule, we plan to come back with a data update, mid-2025. With these proof-of-concept results, we are very excited about the potential of this target for future development into a product through in-house development or with a strategic partner down the line. We will now dive into our AX-2911 program, which focuses on targeting PNPLA3 to address unmet medical needs in NASH or metabolic dysfunction-associated steatohepatitis. This program represents a groundbreaking approach to treating a severe and widespread liver disease that currently has limited therapeutic options. Liver diseases such as NASH are highly prevalent and increasing rapidly across the globe. These conditions represent as a fair health crisis due to their progressive nature, leading to complications like cirrhosis and hepatocellular carcinoma. Unfortunately, therapeutic options are still limited. PNPLA3, or patatin-like phospholipase domain-containing 3 is a gene strongly implicated in development of NASH. The I148M variant, which is present in 20% to 60% of affected individuals, alters the function of PNPLA3, increasing susceptibility to disease. Our Axiomer RNA editing technology offers a targeted approach to correcting this mutation, replacing methionine with failing a position 148. This correction has the potential to restore wild-type-like PNPLA3 function. For PNPLA3, the I148M mutation is a key driver of this function as it introduces a nonconservative amino acid substitution that changes the structure of the protein. The structural change reduces substrate access to the act, impairing its lipid processing function. Using RNA editing, we cannot directly restore the wild-type isoleucine 148. However, by editing methionine at this position to failing, our technology effectively restores the protein function as exhibits similar properties and behavior to wild-type isoleucine. This approach highlights the potential of Axiomer to create proteins with a wild-type like activity, addressing the root cause of the disease. This slide represents data demonstrating the functional consequences of different PNPLA3 expressed variants in lipid metabolism in cells. The wild-type 148I variant supports normal lipid processing, resulting in smaller lipid droplets. In contrast, the pathogenic 148M variant significantly increases lipid droplet size, reflecting its role in disrupting metabolism. The cells expressing the PNPLA3 148V variant show lipid droplet sizes comparable to the wild type as you can see on the slide. This proof of concept underscores the therapeutic potential of RNA editing to restore normal lipid metabolism in patients with a 148M mutation. For the next steps, we developed very efficient EONs to edit 148M variant. Our current lead editing oligonucleotides achieved over 50% editing efficiencies for the PNPLA3 gene. Further, in the homozygous 148M cell model, Axiomer editing resulted in a significant decrease in lipid droplet size, proving the effective correction of the mutation. In summary, the AX-2911 program is a promising approach for addressing the unmet needs of NASH patients. Our focus is now on final optimization of the AX-2911 to select a clinical candidate by 2025. Following this, we plan to initiate development activities with subcutaneous GalNAc-delivered doses expected every 3 to 6 months. Our goal is to begin clinical trials in 2026, marking a significant step forward in the fight against NASH. We look forward to sharing more updates as this exciting program advances. This concludes my prepared remarks on the exciting progress we made on our platform and pipeline. I will now hand the call over to Daniel for closing summaries. Daniel?

Thank you, Gerard, for walking us through the exciting progress made in our platform and pipeline. We look forward to an exciting translational phase ahead with many clinical readouts beginning in the year ahead of us. Beyond that, we have been diligently working on expanding our discovery pipeline and continue to build out our portfolio of product candidates. As reflected in our pipeline, we have added programs in other rare and common indications across liver and CNS. In particular, we see significant opportunity in expanding within Rett through other mutations that also cause the disease. And beyond this pipeline, there are many other programs that we are currently not publicly disclosing yet, all to work towards our objective to broadly apply our proprietary Axiomer platform to make an impact to the lives of patients. In the years ahead, we plan to add 2 new clinical programs to our development pipeline each year in addition to our work with strategic partners. In the near term, this gives us a rich catalyst calendar with many important validating and value-creating milestones. For our lead program, AX-0810, we will start clinical trials in 2025 and report top line data on that first human trial, including target engagement as measured by biomarkers before the end of the year. With the addition of the AX-2402 Rett program to our pipeline, enabled by the additional $8.1 million funding from the Rett Syndrome Research Trust, we plan to advance this program into CTA-enabling activities over the course of '25. And this will then lead to a clinical trial in patients that's expected to read out top line data in 2026. For our cardiovascular program, AX-1412 targeting B4GALT1, we have presented important proof-of-concept data today in an industry-standard disease model. As we plan to further optimize this molecule for GalNac delivery, we expect to provide an update on these efforts in mid-2025. And for our newest addition to the pipeline, AX-2911 targeting genetically defined NASH, we plan to select a clinical candidate in 2025 for a trial to read out in 2026. On the partnering side, we have the opportunity to earn milestones in the Lilly partnership that total up to USD 3.75 billion and an opt-in payment for the potential expansion of the partnership of up to $50 million. And beyond our existing partnership, we have ample opportunity to enter into one or more additional strategic collaborations. So in summary, we will have initial clinical data on our lead program, AX-0810 for cholestatic disease within the next 12 months, and we expect up to 4 clinical trial readouts across the next 2 years. We see tremendous opportunity beyond that as is substantiated by some of the pipeline that we have shared today. Going forward, we expect to add 2 clinical programs per year through our development pipeline. With our leading IP position, our strategic partnerships, and our robust cash position, ProQR is well positioned to execute on this exciting opportunity. I will now hand over the call to the operator, and we will begin the analyst Q&A session.

[Operator Instructions] And your first question comes from the line of Steve Seedhouse from Raymond James.

This is Nick on for Steve. So for AX-0810, is the 2x increase in serum bile acids that you cited the target threshold at the optimum dose? Or do you think you'll be able to achieve much higher levels than tied at the high dose?

Nick, thank you for the question. This is Daniel. I'll let Gerard address the question for you.

Thank you for your question. I think on your question on can we go higher, I think it's possible to go higher as we've shown in the presentation. However, we feel that based on the clinical studies and the effect, we feel that twofold increase should be sufficing to get the clinical result as we've seen in the animal models as well in the demonstration of vulifrotide in the clinical trial.

Got it, okay. And then what drove the decision to do a weekly subcu regimen? Do you plan to evaluate extended dosing intervals in later-stage studies? And does this imply you'll only be looking at a GalNAc-conjugated formulation or do you plan to look at an LNP formulation as well?

So the decision to go with subcu injections will go less frequent in the end. We are aiming for a very low frequency in dosing regimen.

Yes. So Nick, typically, what you see is a loading phase with GalNac oligonucleotides, where you drive the levels in the tissue of the therapeutic levels. And then switching over to maintenance dose, that is obviously way less frequent.

Got you, okay. And then just one last question. Regarding more so Rett, can you confirm that your editing oligonucleotides are optimized for more of an ADAR2-enriched environment like the brain? And how much of an impact do you think this will have on potency and dosing for Rett and for other CNS candidates? That will be it.

That's an excellent question. I think that the molecules that we developed are actively -- are active with both ADARs actually, and they work very well with ADAR2. So -- and yes, it will read through to other targets in the CNS as we are developing those as well.

Yes. Maybe to add to that, Nick, as Gerard and also Pete outlined in our presentation during the call today, we see really efficient editing with these editing oligonucleotides in CNS. We've done a lot of work there about in-house as well as in the partnership that we have with Eli Lilly. And therefore, we know a lot about how this partnership -- sorry, how this -- how the editing in CNS functions. And what we see there is a profile that looks really favorable. We see high editing efficiency, durable editing effect. We see a really, really favorable safety profile so far. So across the board, we really like what we see with EONs and CNS.

Your next question comes from the line of Jon Wolleben from Citizen JMP.

I'm not sure if Dr. Hirschfield is still on the line, but I was wondering if you had some comments here as well. But how do you think about the potential opportunity in cholestatic disease and how you prioritize the therapeutic indications? And then if Dr. Hirschfield is on the line, thinking about the best application for targeting NTCP.

Jon, this is Daniel. Thank you for the question. So Dr. Hirschfield is not on the line. So when we look at the cholestatic landscape, we see that especially the more severe cholestatic diseases, PSC and BA currently have no approved therapeutics available to them. And as we concluded, and I think as we shared during the call, we think NTCP modulation as we are doing with AX-0810 is specifically suited for those more severe forms of cholestatic disease as they -- essentially with AX810, we can stop the bile acid uptake into the liver, which is the target organ of interest, and this allows us to directly treat the disease at the root cause. So our objective for this treatment is to develop this for PSC and BA and then potentially also for other cholestatic diseases after that.

Okay. That's helpful. And then the PNPLA3 target, interesting, I like that opportunity for you guys. Can you discuss a little bit any learnings you have from the more advanced RNAi approaches? And then if you could kind of walk us through again the advantages, disadvantages for ADAR editing versus the RNAi approaches, specifically for PNPLA3?

Yes. Happy to address that, Jon. So with siRNA, there have been some results observed, especially in the homozygous population, where there was a meaningful increase in liver health, a reduction of fat of 40%. The variant that is introduced in these patients carry essentially is a toxic gain of function mutation. So notably with the siRNA approach, there was no effect measured in the heterozygous population. And because with editing instead of siRNA, we restore a normal wild-type profile on both alleles, we think that, that could also help the heterozygous population. So we think indeed it's a really exciting opportunity. And with this novel therapeutic strategy for PNPLA3, we think we can potentially expand beyond the homozygous population.

And one more, if I may. You had a compound labeled 0601 for obesity and type 2 diabetes on your pipeline chart. Wondering if you could give any update on that program.

No, all the updates we had to provide we did on the call today. All our other discovery programs that we did not touch upon remain confidential at this stage.

All right. We'll stay waiting, but thanks for all the updates today, Daniel. Appreciate it.

[Operator Instructions] And your next question comes from the line of Jennifer Kim from Cantor Fitzgerald.

I appreciate the update on the selected candidate for 0810. Can you outline your confidence in the translatability of the higher potency in the PHH model and perhaps NHPs and humans? And do we expect more preclinical data for the selected candidate ahead of the CTR Phase I? And then my second question is, I know you said you're exploring -- you will explore a maintenance dose. Can you touch on, I guess, what your thinking is around that? I know you said 3 to 6 months from I'm wondering if it's similar for this asset. And then the last question on 0810. Any thoughts on what you would expect in that initial clinical data in the fourth quarter next year, given I think those will likely be at the beginning lower doses?

Jen, thank you for your question. So first, on the translatability, we see generally that the translatability from the primary human hepatocytes, that's what PHH stands for, to the in-vivo situation is really strong. The correlation, because these are similar cells, that -- where we delivered a molecule with GalNAc, which targets specifically the hepatocytes, we see similar delivery and that leads to similar editing levels. Now what that will mean exactly for this particular molecule once we put in remains to be seen. There's more work to be done there. But the initial experiments that we've done in vivo look really encouraging. And to your second question, yes, we will be generating more data with that on doing further experiments with our clinical candidates ahead of and also in parallel to our clinical and development activities. You asked about the dose frequency. This is, first and foremost, a safety, tolerability, PK study. We obviously have a specific interest in the target engagement as mentioned by the biomarker. That's our strategic objective for the trial. But through study safety and PK, well, you typically dose more frequent. Ultimately, we think these oligonucleotides all have similar stability, and we could be looking at similar dosing frequencies roughly once every 3 months with GalNAc delivery across the board. So that's no difference for program to program within the delivered programs. And then to your question, what we can expect in the clinical data, in the data, we will study active doses where we do anticipate that the NTCP modulation that we achieve does affect the bile acid levels, so the twofold bile acid targets that Dr. Hirschfield alluded to on the call would be the target, and anything over that would be clinically meaningful. We'll also be looking at other measures of bile acid. So we'll be looking at bile acid levels in urine because as soon as they increase in the serum, they do get excreted through the kidney. So you will be able to measure an increased level of bile acid in urine as well. And we'll also be looking at bile acid profile. So as Gerard presented during the call, we can measure difference forms of bile acids, conjugated, unconjugated, and different types of conjugation. And the profile there needs to change in favor of less unconjugated bile acids and more conjugated bile acids. So all of those things we'll be looking at, and that will be part of the data we're looking at this time next year.

[Operator Instructions] And your next question comes from the line of Sushila Hernandez from Van Lanschot Kempen.

This is Sushila for Suzanne. First question on your Rett program. What makes you go for the MECP2 R270X versus the other targets that are now listed on your pipeline for Rett? And also any thoughts if you can share on what to expect from the readout in that?

Sushila, thank you for the question. So look, Rett is super high unmet medical need. There are several mutations that are targetable with Axiomer. I think we listed some in our presentation today. Together, that accounts for the majority of the patients with the severe form of Rett. We chose the 270X one because for this particular variant, there's really good models available that can help us in the translation, so mouse models, models, which helps us to translate this into the clinic. When we go into the clinic, we'll be looking at the number of exploratory endpoints. So we'll be looking at biomarkers but also at functional outcomes. And in collaboration with RSRT, we'll be looking at some of the new objective measures that we can potentially use in the trial.

Yes. Maybe one addition to that is that for the R270X, there is also a transgenic model that actually recapsulates the corrected version, the R270W, and that actually shows distinguish of both features to the wild-type animals. So we have a really good proof of concept that our editing would yield the traits that will be very much indistinguishable to wild-type situation as well.

[Operator Instructions] There are currently no further questions at this time. I will hand the call back for any final remarks.

Thank you, operator. I want to thank everyone for joining our R&D Day today, where we shared important updates on the progress in our pipeline. We wish everyone a wonderful day. Thank you.

Thank you. This concludes today's conference call. Thank you for participating. You may now disconnect. Speakers, please stand by.