Wave Life Sciences Ltd. (WVE) Earnings Call Transcript & Summary

Hello, and welcome to the Wave Life Sciences 2022 Analyst and Investor Webcast titled Towards the Clinic: Spotlight on RNA Editing for AATD. [Operator Instructions]. Please note that today's broadcast is being recorded and webcast. Following the prepared remarks, management will take questions via the phone line. [Operator Instructions] It is now my pleasure to turn today's program over to Kate Rausch.

Thank you, operator. Good morning, and thank you for joining us for this event. The slides that accompany today's presentation will be available on the Investors section of our website at www.wavelifesciences.com. Before we begin, I would like to remind you that management may be making forward-looking statements during today's presentation. These statements are subject to a number of risks and uncertainties that could cause our actual results to differ materially from those described in these forward-looking statements. The factors that could cause actual results to differ are discussed in our SEC filings, including our annual report on Form 10-K for the year ended December 31, 2021, and our quarterly report on Form 10-Q for the quarter ended June 30, 2022. We undertake no obligation to update or revise any forward-looking statement for any reason. In the room with me today are Dr. Paul Bolno, President and CEO of Wave Life Sciences, who will begin the presentation this morning with opening remarks and discussion of Alpha-1 antitrypsin deficiency or AATD. Dr. Paloma Giangrande, VP of Platform Discovery Sciences and Biology and WVE-006 program lead will present an overview and update on WVE-006 with RNA editing development candidate for AATD. Joining us by phone, we have Dr. D. Kyle Hogarth from the University of Chicago, who will share clinical perspectives on AATD. Our last presenter will be Dr. Chandra Vargeese, who is Chief Technology Officer and Head of Platform Discovery Sciences, who will give an update on future therapeutic applications of RNA editing AIMers. Following the presentations, all 4 speakers will be available for Q&A. I'd now like to turn the call over to Paul.

Thanks, Kate. Good morning. I'm excited to welcome you to our Spotlight on RNA Editing for AATD event. At Wave, we are building a leading genetic medicines company and developing oligonucleotide therapeutics to target the transcriptome and modulate gene expression with the ultimate goal of advancing life-changing treatments for patients diagnosed with genetically defined diseases. We have an innovative RNA-targeted therapeutics portfolio, made up of stereopure PN-modified oligonucleotide candidates developed from our PRISM platform. In the past few years, we have achieved significant milestones in validating our platform and approach. With our PN chemistry, we have consistently delivered improvements in tissue distribution, potency and duration of activity with our oligonucleotide in preclinical studies. Just last week, we announced positive updates on our SELECT-HD clinical trial of WVE-003 and shared a clinical data set supporting the translation of our preclinical data and showing a generally safe and well-tolerated profile with single doses. Our therapeutic guidance trends are designed to intervene at the RNA level and tailored to address the underlying genetic drivers of disease. The ability to access all these mechanisms with one platform enables us to develop the tools to optimally address disease biology. Whether it's silencing, splicing or RNA-based editing, one thing is consistent, we are leveraging free uptick in endogenous enzyme to avoid delivery vehicles such as viral particles and liposomes. This strategy expands the therapeutic areas we can address and provides us with an ideal balance of precision, durability, potency and safety as well as a line of sight to commercialization with established regulatory access and reimbursement pathways. Today, we will focus on the rapid progress we have made utilizing guide trends to harness ADAR enzymes to edit single basis in RNA to correct a genetic mutation and generate healthy wild-type protein. We'll also discuss later on how ADAR editing gives us the dexterity to modulate protein production by upregulating RNA expression. As a quick reminder, we developed our AIMers for ADI editing oligonucleotide in our discovery group, taking early structural insights into ADAR RNA substrate interaction to initiate work on this modality. The data we will share today on WVE-006 reflects the assessment of thousands of ADAR editing oligonucleotides, to glean insight into structure activity relationship and understand how cryo control and PN modification elicit robust ADAR editing activity. This SAR work was published in Nature Biotechnology earlier this year. Since then our highly efficient and specific editing results have continued to differentiate us from others in the field. Today, we remain at the forefront of this modality. Our AIMers are delivering potent and specific editing in vivo with potential for extended dosing intervals. AIMers are compatible with GalNAc conjugation for targeted liver delivery, but our designs also delivered to the CNS and other tissue types. We are very confident in our strong and broad IP position, which includes chemical and backbone modification, stereochemistry and novel nucleoside. The majority of today's presentation will focus on the swift progress we've made using AIMers to correct G-to-A driver mutations. As we look ahead, we are using AIMer tools to explore new and novel ways to alter disease biology and potentially reach patients suffering from an array of diseases, including neurologic disorders, recessive diseases and even such areas as renal cardiometabolic and immunology. I'll now pivot to the first therapeutic target we are addressing with RNA editing. SERPINA1 to treat alpha-1 antitrypsin deficiency. As you will hear today directly from an expert in the field, there is a high unmet need for effective therapies for patients living with this disease. AATD is caused by mutations in the SERPINA1 gene, which encodes the alpha-1 antitrypsin protein. A single mutation called the Z mutation is the most common cause of AATD. People with 2 copies of the Z allele are at high risk for disease with approximately 200,000 patients with the ZZ mutation in the U.S. and Europe. AATD represents one of the more common genetic diseases in these geographies. AATD may manifest with lung disease, including early onset emphysema and liver disease that in some patients may progress with cirrhosis and liver failure. Treatment options today are quite limited. The only treatment for AATD lung disease is plasma-derived augmentation therapy, which requires weekly IV infusions that pose a major lifetime burden for patients. There are no treatments for AATD liver disease, leaving many patients to ultimately require liver transplant. Dr. Hogarth will provide more perspective on the management and unmet need later on. We are actively building our relationships with the alpha-1 patient community to better understand their needs and perspectives of living with this disease. Through patient outreach, we have heard how they're most commonly burdened with pulmonary symptoms and often struggle with everyday activity. Patients also described the inconvenience of treatment options as well as the toll of living with liver disease. Feedback from the patient community and advocacy leaders is being incorporated into our clinical development plans. AATD patients encompass a broad spectrum of manifestation. Although the majority of patients experienced lung disease at diagnosis, liver disease may go underdiagnosed and often appears as patient age. Patients would greatly benefit from new treatment options, but most AATD therapies in development are focused on singular manifestations of the disease, such as next-generation augmentation therapies or RNAi. If approved, these treatments could also create the need for costly combination therapies for patients with both lung and liver disease. WVE-006 is one of the most advanced programs in development that address the root cause of AATD. We envision it could provide a holistic solution that would be applicable to those with lung disease, liver disease or both. From a market perspective, the opportunity is sizable today with over $1 billion in annual sales worldwide of plasma-derived augmentation therapy for AATD-related lung disease. These sales do not include significant contributions from multiple major ex-U.S. markets where augmentation therapy is not widely reimbursed. Market growth is projected in approximately 12% over the next few years driven by expanded treatment options, including AATD liver treatment and higher diagnosis rates. I'll now turn the call to Paloma Giangrande, who is the program lead for WVE-006 as well as Wave's VP, Platform Discovery Sciences and Biology. Paloma?

Thanks, Paul. As you heard from Paul today, AATD is an inherited genetic disorder that is most commonly caused by an ADAR amenable G-to-A point mutation in the SERPINA1 gene known as the Z allele. In the normal setting, when not mutated, the wild-type product of the SERPINA1 gene, alpha-1 antitrypsin is referred to as M-AAT. M-AAT is an acute-phase protein that is predominantly produced in hepatocytes during periods of stress or inflammation and then secreted in the circulation where its role is to protect the lung from neutrophil elastases. In contrast, in the disease setting, the G-to-A mutation corresponding to an E-to-K amino acid change of position 342 in the proteas leads to a mutant protein referred to as Z-AAT that is misfolded and prone to aggregation in hepatocyte. This results in the lack of functional AAT in circulation leading to progressive lung injury, liver injury or both and often culminating in end-stage pulmonary and liver disease. WVE-006 is designed to correct the G-to-A mutation in the SERPINA1 Z allele mRNA to address the therapeutic goals essential when developing a novel therapy for namely restoration of circulating wild-type M-AAT to protect the lung and reduction in the levels of Z-AAT protein in the liver to enable clearance of existing aggregates. By focusing on editing the endogenous mutant RNA, we would also expect to retain the innate physiological regulation of M-AAT. To establish a target editing threshold, we look to the heterozygous MZ genotype. These patients carry one copy of the healthy allele and one copy of the Z allele. And therefore, a mix of both Z-AAT and M-AAT protein. While homozygous ZZ patients have a high risk of both lung and liver disease, patients with MZ genotype have a much lower risk of disease pathology. Our hypothesis is that through approximately 50% RNA editing in homozygous or ZZ patients, one can shift the phenotype towards a heterozygous or MZ phenotype, significantly lowering risk of disease pathology. With our GalNAc conjugated stereopure AIMers, we anticipate replacing chronic weekly IV AAT augmentation therapy with a subcutaneously administered therapy that addresses all goals of treatment. This is superior to a silencing modality, which would only impact the liver. Importantly, we have confirmed robust editing with WVE-006 in 2 independent human preclinical model systems derived from AATD patients. On the left, we observe efficient editing of the mutant SERPINA1 transcript in primary human hepatocytes derived from an MZ doner. While on the right, we demonstrate robust editing in iPSC-derived human hepatocyte from a ZZ patient. Slide 21 shows the efficacy of WVE-006 in the NSG-PiZ mouse model, which is a well-established model in this space. WVE-006 was administered subcutaneously following an initial loading dose. At week 13, SERPINA1 mRNA editing was approximately 50%. And serum AAT protein restoration was 7-fold higher than PBS control, remaining above 11 micromolar throughout the dosing interval. To further investigate the dosing impact, we also dosed the same NSG-PiZ mice with WVE-006 without a loading dose. As you can see on Slide 21, a serum AAT protein restoration lagged behind that observed in the loading dose group for the first few weeks. But then was approximately equal with a nearly sevenfold increase over PBS control at the 13-week time point. Using mass spectrometry, we investigated the isoforms of the circulating AAT protein and confirmed that approximately 50% was indeed restored wild-type M-AAT as compared to no M-AAT protein in the PBS control group. These results are consistent with the RNA editing results. As you can see on Slide 23, we also observed that there was a significant increase in neutrophil elastase inhibition post editing in the WVE-006 treated group confirming the functionality of this restored wild-type M-AAT protein. Turning back to liver. I would like to start by reminding you that it is the continual production of mutant misfolded Z-AAT that prevents the liver cells from clearing the Z-AAT aggregate and globules that are formed over time culminating in liver disease. We enable -- to enable the cellular clearance processes to be effective, one must reduce the amount of Z-AAT being produced either by silencing or shutting off Z-AAT altogether or as with our approach by converting Z-AAT into healthy wild-type M-AAT. With mRNA editing -- with RNA editing in the mouse model, we expect to see changes in: one, the overall number of aggregates and globules; and two, in the size of the globules being produced. As we have shown previously, using one of our early lead preoptimization AATD AIMers, we restored functional AAT over the course of a multi-dose study. Shown on this slide, we performed histological analysis of liver biopsies at week 19, and see that treatment with the AATD AIMer result in: one, the reduction in the number as well as the size of Z-AAT aggregates or globules over time as assessed by PAS-D staining with reduction in the numbers shown on the far left and reduction in the size shown on the immediate right. Importantly, as shown on the far right, treatment with AIMers also resulted in reduction of lobular inflammation as measured by the number of inflammatory foci in lobules. Of note, both PAS-D globule burden and lobular inflammation are clinical features observed in AATD patients and are recapitulated in this mouse model. We have consistently found our AIMers are highly specific and do not lead to bystander edits on the target transcript. On Slide 26, you can see data we have discussed previously that evaluates the specificity of an AATD [indiscernible] AIMers using RNA peak. On the left, you can see total sequence coverage across the entire SERPINA1 transcript for the AIMer-treated sample. The percentage of unedited T and edited series are indicated for each group. Editing is only detected at the intended on-target sequence in the SERPINA1 transcript. Thus, the protein being produced using this approach is truly wild-type M-AAT protein. And this also confirms there is no editing of bystander residue, as has been seen with DNA targeting approaches. Furthermore, to assess off-target editing of the whole transcriptome, we applied a mutation-calling software to search edit sites. From this analysis, we observed nominal off-target editing across the transcriptome. Sites where potential off-target editing occurred had either low coverage in the analysis or it occurred at low percentage of less than 10% and were not dose-dependent, indicating that these are extremely rare events likely due to noise in the system. Thus, to summarize, in both analyses shown on the left and right, we find a high percentage of editing that is specific for the target site in the SERPINA1 transcript. In summary, the preclinical data for WVE-006 supports a potentially compelling therapeutic profile. We have demonstrated WVE-006-correct Z allele mRNA to restore wild-type M-AAT protein. With RNA editing levels supportive of potential conversion of a patient from ZZ to MZ mRNA expression. WVE-006 treatment would be potentially applicable across AATD patient subpopulation with a convenient subcutaneous administration and without risk of permanent editing. Planning for clinical development of WVE-006 is well underway. IND-enabling activities are ongoing. And today, I can share some additional detail on our planned clinical trial design. Our current plans include a Phase I/II placebo-controlled study to evaluate safety and tolerability, pharmacokinetics and changes in relevant biomarkers, including serum AAT. The study is expected to enroll healthy volunteers in single ascending dose cohorts followed by cohort expansion with Pi*ZZ patients to evaluate target engagement. The SAD portion of the study will inform the dose and dosing frequency of the multi-dose cohort. The MAD portion of the study will be used to determine an effective dosing regimen. We expect to submit PPAs for WVE-006 in 2023. I would now like to introduce our next speaker, Dr. Kyle Hogarth. Dr. Horgath is the Professor of Medicine in the section of Pulmonary and Critical Care Medicine at the University of Chicago. He is the Director of Bronchoscopy and is heavily involved in the field of advanced bronchoscopy and interventional pulmonary. He also runs the alpha-1 antitrypsin deficiency clinic Resource Center, one of the largest in the Midwest with over 250 patients and help rise at 2016 alpha-1 antitrypsin deficiently clinical practice guidelines. Dr. Hogarth is joining us here today to share his clinical expert perspectives on AATD and discuss the unmet need and the current treatment landscape for this disease. Without further ado, I'll turn the call to Dr. Hogarth.

Thanks so much for having me. I hope everybody can hear me okay. So as stated, and I guess, I'm here to provide, obviously, that clinical perspective. And with that, I'm going to give you a crash course more about alpha-1 in general. So first, I've listed every single conflict of interest, many of which have nothing to do with this discussion, though I do consult for obviously Wave and also InhibRx. In the past, I was under DSMB. And then I have worked with the plasma companies. So with that, let's go on to the history of alpha-1. So this is a disease discovered by accident. In 1962, a bunch of people were running gels, Dr. Carl-Bertil Laurell and his resident. And the resident noticed a bunch of people were missing the alpha-1 band when they did the protein electrophoresis. They also made note that 4 of these people were patients of his, and they were all young people of advanced emphysema. And so basically by accident, they discovered this thought process that missing alpha-1 would put you at risk for lung disease. And that normal protein, most of it is actually ultimately made in the liver. That's where, obviously, the next level of research went to figure out where it all was manufactured. And then a little bit is made in a lung. And as stated earlier, its main job is to function and to control neutrophil elastase. And of course, neutrophil elastase was discovered a few years after alpha-1. And it's always interesting -- if you find the history of medicine entertaining and interesting, prior to the discovery of neutrophil elastase, there really wasn't a good theory to explain lung disease, to explain lung breakdown. But the elastase -- anti-elastase hypothesis became pretty obvious when you saw an enzyme that in animal models could lead to massive destruction of the lung, almost literally melting it and that you had a protein whose job was to solely bind neutrophil elastase and essentially take it out of commission. And it's a very classic regulatory counter regulatory approach that occurs in multiple parts of the human body. And so every single alpha-1 talk always has a slide like this that you're going to -- because at its core, clinically, the disease is pretty straightforward, at least from a lung perspective. That you have way more alpha-1 than you need against whatever level of inflammatory burden. And that the patient represents the natural experiment of what would happen if I have an increase in the amount of elastase and whether that's smoke, secondhand smoke, infection, pollution, et cetera, but obviously not enough protection and the scale is tipped. And neutrophil elastase, as its name implies, the lung is principally made of elastin. And this is an immune-released enzyme whose job it is to actually destroy elastin. And if you think about it from a teleological perspective, it is meant to protect the remaining part of the lung from whatever infection would be going on sort of isolated, if you will. And so there's a rationale for this to occur. But the deficient patients, obviously, there's an unregulation and then now you add in generalized air quality in the world today, plus smoking, et cetera, this is where you see progression. Now as stated earlier, there are multiple other mutations, but the principal one that we're always interested in is the Z allele, this Glutamic acid to Lysine conversion. And this is one that is found in multiple present clinically, and this is the scenario where it is not released from the liver. And this is the bulk of the clinically based disease. The S allele is a milder efficiency associated with mild liver disease. And amongst all the other mutations, there's only one rare one in the south of France that's associated with liver disease as well. So Z is where it's at. Now after the discovery of alpha deficiency by accident by Dr. Eriksson, it's when it started to become obvious that there was more to the story here. And so this is what Dr. Sharp described the association between alpha-1 and liver disease and followed up by Sveger's work that demonstrated that 10% of all ZZs developed a neonatal cholestasis and that some of those actually progressed to cirrhosis in children. What was interesting is when you look now at indications for pediatric liver transplant, it's the second or third -- depends on the year, second or third most common reason for a child to need a liver transplant is essentially rapid failure of the liver after birth due to alpha-1. But what was also interesting that came out of the work and then follow-up was that 20% of ZZs developed a slow progressive portal fibrosis, which developed then ultimately cirrhosis in later adult life. We've been seeing more of this principally because the average life expectancy of an alpha-1 patient has increased by about 15 to 20 years over the last several decades. So the thought process -- it's clearly not proved, but the thought process is they're now living long enough as adult to clinically acquire the amount of liver disease than in the early '50s typically. Now obviously, there's wide variations in this and there's plenty of people developing liver disease earlier, et cetera. But the traditional thought process that had bid in alpha-1 was you either got lung or you got liver, you never got both, and the liver was a kid thing, and that's just definitively proving to not be true whatsoever. So moving on. This is obviously a schematic, but the idea -- and this was stated earlier, but it's really an important thing to understand why this accumulates in the liver and the process involved and some of the proposed ways to try to help this. So the synthesis, obviously, from the abnormal gene from the abnormal RNA into the endoplasmic reticulum after the protein is synthesized. And then the wild type, there's a protein sitting there in the endoplastic reticulum, most of it is secreted. There's always some amount of degradation. In the mutant Z form what ends up happening is you should think of alpha-1 like a mousetrap because that's exactly how it's shaped. And it has a hinged mechanism that essentially allows it to encounter neutrophil elastase to bind avidly. And once bound, lock on to neutrophil elastase and shut it down, shut down its active site. The Z mutation essentially makes this hinged mechanism of the mousetrap on a hair trigger and it takes very little for it to bind. And so it essentially polymerizes within the liver. And as you see here in the schematic, you get almost accumulated alpha-1 stuck inside the liver. Some is secreted. The Z patient has not zero alpha-1. Some of it is degraded, but most of it does accumulate. And in that work, that work on the etiology of the plasma deficiency was discovered due to be -- from this blockage as we just stated. And so as I always tell my alpha-1 patients, you make lots of alpha-1, it's just none of it is getting out of your liver and what's getting out of your liver doesn't work because the Z-protein has several other issues. So look -- on a biopsy, this is of a human, you get tons of accumulated alpha-1 inside the liver, which you'll see here. This is -- that's the polymerized alpha. And to put that into context, when we were looking earlier, what was presented on the mouse model, when they were talking about size of globules and number of globules as well as all the inflammatory response because this generates an inflammatory response. This -- being able to decrease this and keep this from happening, the number and size is extremely important. And the natural history is still being borne out. This is old data out of Sweden, but the ZZ patients that were found in a newborn screening study then followed up, you'll see the underlying liver problems that continue on. Some do revert to normal. There's a lot of work trying to tease out who's going to develop more liver disease or not. But then ultimately, these are the numbers that developed progressive liver disease as children. And then what's still not known is then the progression towards in adulthood. Talking to hepatology colleagues, one of the concerns they've all had is that, obviously, over a lifetime, there's multiple different potential insults to your liver. But if you're starting already with several insults to your liver because of accumulated alpha-1, then that mild amount of alcohol you drink plus that statin you're on, and you occasionally take [indiscernible] because your knees hurt, whatever, whatever. All of those are liver toxins. And in the background of a dysfunctional liver because of alpha-1 is how we think we're seeing more and more disease later in life. And so the need to fix the underlying problem, the need to undo the accumulation is really paramount. But I'm a pulmonologist by trade. So let's go back to why these folks get lung disease because it actually isn't just as simple as this uncontrolled proteolytic attack, though that is clearly the key. But one of the things that's really important, too, about trying to fix this underlying problem is that the Z mutation actually favors the spontaneous formation of alpha polymers within the lungs as well. And that these colocalize with neutrophil elastase. So in other words, that anti-inflammatory protein that your liver is secreting a little bit of still finds a way to polarize in your lung and then creates more inflammation, plus a Z-protein doesn't bind to Neutrophil elastase very well. So these people are in a bad position. There's a lot of research as to what else might be occurring with alpha-1, about many other properties that it has, other inflammatory markers, not just neutrophil elastase. One key one being tested is Caspase-3, which I'll jump into in a second. But it also has inflammatory effects on the vascular cells, which also have elastin in. And this is also why with the Pi*MZ, the loss of both the lung [indiscernible] then the underlying vasculature that's the backbone of gas exchange. So when you look at apoptosis, there's a lot of interesting work where pulmonary endothelial apoptosis ultimately result in emphysema. What this is, this came out of a workshop to discuss different ways that people could develop emphysema to get beyond just inflammation and then therefore, breakdown. But to look at emphysema instead as a disease of accelerated lung aging, that you might be 40, but your lungs are 80 is the thought process here. As it turns out that alpha-1 does get internalized into pulmonary endothelial cells, and it inhibits directly apoptosis. And as you know, apoptosis does that program cell death, that is your cell dying, that is you aging. And it's interesting, this uptake is blocked by cigarettes. So this would obviously be another barrier of where smoking ultimately, it's bad for many reasons, but also bad for its inhibition of alpha-1. But alpha-1's a direct inhibitor of Caspase-3. This is what helps to keep the cell's suicide gene, as it's sometimes called, from turning on. Now none of them has made its way into pure clinic, et cetera, et cetera, a lot of this is still on the theoretical side and some of this is older literature and research has moved on. But what it really highlights is that there's multiple things that alpha-1 does. And the lack of alpha-1 is the core problem here. So okay, we all get told that this is a rare disease, I remember being told in medical school. I got about 2 sentences of trading on alpha-1 in medical school, that there's a super rare thing, and it's young people dying of emphysema. [indiscernible] like next. It's actually one of the most prevalent genetic disorders within the United States estimated to be between 19 million to 25 million carriers, and that's carriers. Now that data comes from large screening studies where then you take the allelic frequency and plug it into Hardy-Weinberg or equilibrium equations and pop out at least prevalent thoughts as to how many alpha-1 patients. The data is old from de Serres. At that time, there was estimated to be about 100,000 ZZs in the U.S. alone, that number is probably thought to be an underestimate principally because larger studies screening in other countries have demonstrated slightly higher rates of alpha-1 that had been expected in particular out of Ireland. And obviously, there's a lot of Irish ancestry within the United States. And so the thought process here is that this number is been underrepresented. The problem is, and the sort of -- if this was a CME talk, the unmet need is that most of these remain undiagnosed, and there's a myriad of reasons for that. But if we want to get some kind of more granular numbers, when you look at that neonatal screening study in Sweden, this was just all live births, 1 in 1,500 came out ZZ. Now that's clearly not the most common disease on earth. But I don't know -- everybody's got different definitions of rare, but 1 in 1,500, I don't consider rare. And when you look at a biased population of blood donors because blood donors tend to skew towards healthier people, this was a study done out of St. Louis, 1 in 2,800 were ZZ. I think the really what highlights is, is that the folks that were doing this trial, this was Silverman and a couple of other folks. They then went, based on the number of people in the Greater St. Louis area, they said, okay, with this frequency, there should be x amount of alpha-1 patients. And then they contacted all the local pulmonologists and hepatologists and said, hey, how many alpha-1 patients do you take care of? And it ended up being less than 10%. And the issue is people don't test. And why don't they test? So part of the problem is that alpha-1, despite having a high prevalence compared to other diseases that people frequently see is that alpha-1 presents like COPD, presents like asthma, presents like emphysema, things that doctors see on a daily basis, regular basis, and it's sort of buried in the noise. Whereas, for example, sickle cell anemia there is nothing subtle about sickle cell. And if you look at all of these diseases, these are ones where you have a clinical suspicion and you order the testing. The problem with alpha-1 is that the disease is presenting like something you see all the time, and it doesn't have this sort of flag. But I think probably one of the best studies that really highlights the prevalence of this disease was -- it's an old paper by Lieberman, but it's still one of the best out there because basically, testing every single patient that came through the practice with emphysema and COPD. And 1.9% of the patients were ZZ and 8% were MZ. This is one of the first papers that really tried to undo the bias that came from the original work from Eriksson in Sweden where those 4 patients that were in his clinic, they were all young with advanced emphysema. And that sort of became the label for Alpha-1, and we definitely have to think broader. So moving into the concepts of alpha-1. There it is. Going back to the healthy person with tons of alpha-1 and not a lot of burden. This balancing act, what happens when I'm a carrier? So in a normal scenario, you make less alpha-1, but it's still way more than you need. And I'll get to this in 2 slides, but conceptually here, I'm well protected. It is the MZ who smokes or has other inflammatory disorders, but then the balancing act has shifted. And you'll see that from a very nice paper from Molloy. This was actually a subpart of a COPD gene trial. I remember -- you probably do, too. You remember high school biology. You're a carrier for a genetic disorder. It didn't matter, right? Carriers don't matter. That's what -- it's always been the drill and it's true because a carrier only matters when they have children with another carrier. Now the incidence of carriers in the United States is estimated between 1 in 15 to 1 in 30. So I challenge you to draw a family tree real quick and just run the odds here. But sure enough, when you look at MMs and MZs who don't smoke, their risk for lung disease is the same, aka, none. But you add in a smoking history and an MM, so one is well protected, you notice has a slightly more lung disease than an MM doesn't smoke. And of course, smoking is bad, duh. but look at the MZ, look at what happens when I'm in that partially protected state, that's how lung disease ultimately develops. But the core principle here of -- if I'm an MZ without obviously something happening inside my lungs, and I'm well protected is one of the strong clinical basis for the proposed approach that Wave is trying to accomplish here. Put another way, and I don't have to make you "normal," and in fact, the current standard of care for alpha-1, we don't make you normal. We make your levels into the MZ range. So let's go through other disease percents. So right up front, on the lung side, very nonspecific, dyspnea, decreased exercise and wheeze. There's the 3 biggest symptoms are so unbelievably nonspecific. But when you look at the labels, you'll notice that all different kinds of obstructed lung disorders are applied here. So you can mentally run the numbers in a number of asthmatic patients, the number of chronic bronchitic patients, the number of emphysema patients in overall COPD within the United States. And it's staggering. It's estimated to be about 14 million people with some level of obstructive lung disease in the U.S. Now some of them are still undiagnosed on the obstructive side, let alone obviously, on the alpha-1 side. It's no coincidence that the founder of the Alpha-1 Foundation, John Walsh, who obviously -- his life's mission was to try to essentially cure alpha-1. When he was making note of how little people are getting tested for alpha 1, he -- in his own words, he called it Operation Trojan Horse. He started the COPD Foundation to get more people interested in COPD, so they'd get more interested in alpha-1. It's great. He's a great guy. But when you look at other things that weigh in, let's start with the smoking history. Most alpha patients do have a smoking history, 80%. But it's interesting is this old notion that they had to have had like no substantial smokes -- I'm sorry, they were like a barely smoker. And that's how they got advanced lung disease because of their alpha-1. And yet the average smoker that with alpha 1 as it was 23 pack a year. That's a pack a day for 23 years. Again, this notion that you can't have ever smoke and you're going to end with end-stage lung disease. This has been one of the things that those of us work in this field -- I spent a lot of time on doing to get people to think about this disease from -- often this is guideline based to test these folks. The average age of diagnosis too. This was a disease that supposedly is supposed to kill you before the age of 50. And apparently someone forgot to tell the 47% of people over the age of 50 that they were supposed to be dead. And so there's a wide clinical variation in how this disease presents and age and so forth. And when it's time to treat, when you find these folks, the standard stuff is what we do. What is unique for at least the disease historically has been the augmentation therapy. And augmentation therapy is the generic name for it because, obviously, there are in the U.S., there are 4 products available that alpha-1-associated lung disease, and it's used to increase the amount of alpha-1 that's circulating. And you have to have alpha-1 deficiency and evidence of airflow obstruction. And the idea, of course, is to try to fix things so people can stay alive. Conceptually, what this is, is I go from being my alpha deficient with my scale here, and then I get a little bit of someone else's alpha-1, and I tip the scale back. And so it's a kind of classic replacement idea of you don't make enough. We can purify it. I will give it back to you. The problem is, is that it's a once-a-week IV. And so the standard dosing that was developed, this is from the original NIH group. This is Mark [indiscernible] paper in the New and Journal in '87 that if you're a deficient patient with very low levels, we infuse you at 60 milligrams per kilogram. So it's a weight-based purified protein. That gets level sky high, super above normal. But the normal kinetics of protein breakdown by about a week later, you are down at that protective threshold that had been talked about earlier in 11 micromolar. So though that might not be in the so-called normal range, it is above a range that was determined through prior studies. If you're above 11 micromolar, your risk for lung disease is essentially nothing. And why is it every week, well attempts were made in every other week and every month and their numbers are all over the place, and they just didn't work. So what that ultimately meant before we had any other clinical data, this was just obviously like a PK study is if I'm a patient for the rest of my life, every week, you're going to put a needle into my vein and you're going to infuse someone else's protein, essentially someone else's plasma into me. And it's going to take -- given how fat I am because it's weight-based, anywhere from 20 minutes to an hour. You're going to typically come to my home. But if I am with Medicare, then I have to go to an infusion site every week. And that's what I have to do. And my life revolves around my infusions because I am deficient. And so right up front, you can immediately see the burden. But at the moment, this is all we have. Plus, if I have a liver disease, none of this works because remember, the liver disease comes from accumulated alpha-1. So the lack of alpha-1 protein is not why these folks are getting sick so replacing a liver patient doesn't do a thing for them. Now there are clinical trials that have highlighted this. I'm not going to dig through all of these. But all of them -- in the world of medical studies, they all do suffer from being the randomized, double-blind other than one very small trial done by Dirksen. And it was monthly infusion. So it was a really poor study. But all of the other ones that are either prospective but not randomized, et cetera, showed improvements and some decreases in mortality and slowed down the rate of lung loss, et cetera. So clearly conceptually indicating what needs to be done. But it is interesting that when you infuse these cells go backing up, the levels go up, but this is obviously the M protein partially, they still have their Z. So we are -- and by the end of the week, we have made you essentially an MZ patient. So one good study has occurred. And that is the RAPID study. This was a randomized double-blind placebo-controlled trial using CT densitometry as the endpoint to prove that alpha-1 infusion actually do help the lungs. And if we get your levels higher than where you start, can we keep things around? And all this was the annual rate of lung density lost at total lung capacity. And those who were getting treatment lost less lung per year than those getting the placebo albumin infusion. So that was -- one that was exciting. Conceptually what this looked like then -- and when you look at the number of months and the decline from baseline, if you kept going, you'll see obviously those getting infusion losses at a slower pace. What that ultimately means is that -- because what's interesting, they did a crossover design, they put people out to bid on the placebo infusion. They were then allowed an open label. And though these lines are not perfectly parallel, and the thought process is because of the degree of ongoing inflammation and destruction that occurred while they were on placebo, they did slow down their pace. What you, of course, will also notice is that lung density is a permanent loss. So finding these folks earlier and then being able to treat earlier is one of the key important problems with alpha-1. We've got to preserve what's left. And part of the -- I will say from those of us that work in this field, one of our excitements about kind of everything happening in this field is that new therapeutic and a new option, particularly on the liver, we know it's going to increase testing because the principal barrier is that most of these patients obviously sit in the primary care office until advanced disease kicks in. And if we have now a therapeutic that can help the liver, there's going to be then a -- Sorry. We're all on the phone calling and the other line just rang. I don't know if you guys were hearing that. But if there is a liver therapeutic, it would be easy. When I go to see my primary care doctor, and my liver function tests are a little abnormal and -- all right, you need to lose some weight. And make sure you cut down on any alcohol, blah, blah, blah. But they also immediately, of course, tested me for hepatitis B and C to ensure that I hadn't picked up a virus. But they definitely did not test me for alpha-1. Basically, it's just because I needed to lose weight. It was what I had abnormal. And I have, of course, tested for alpha-1, I don't have it. But all kidding aside, the -- when there is a therapeutic -- when there is an option to help people who might be doing liver abnormalities, those of us in lung side are super excited because we definitely feel we're going to find more disease at earlier stages, both lung and liver once we have a therapeutic and we shift the principle of when to look for this disease into the primary care study because they'll -- liver disease clinically presents essentially all the same. So they definitely take a shotgun-based approach. Now I think what's also interesting in one of the other exploratory biomarkers is desmosine. So desmosine is the breakdown product of elastin and in a normal scenario, We all have a little bit of desmosine because wear in tear you are breaking down lung, you are breaking down blood vessels. We all lose a little bit of lung function per year normally, ever one of us, no matter how healthy you are living. I've got bad news, all of us are going to die of emphysema at about 150 to 160 years of age, so plan accordingly. But those that are getting the augmentation products, you'll notice, is that in the study of -- have underlying lung disease, the risk -- amount of desmosine goes down versus those not getting the augmentation product. Putting that into the context of the RAPID study, those that will get a placebo continue to have desmosine levels go up and those that were getting the alpha-1 infusion continue to have desmosine levels go down as a marker that tied into the CT densitometry, which you then see here. It's a very noisy slide. But those getting placebo were losing more lung function and they were losing more lung function with higher desmosine levels. And then the blue with the folks losing less lung function and having lower desmosine levels. And so the beauty of this was a nice correlation between that you are -- getting the levels where you need, you get markers of improvement in -- the markers of loss -- less loss when you look at CT densitometry and markers of less inflammation. So that's our -- sadly, current state-of-the-art. You have this horrible disease. You worry about your liver constantly, and you get these infusions every week of someone else's blood. And so you can imagine, there's a -- everyone puts up with it because they don't have any other choice, but this is where the unmet need. So let's go through, at least from my perspective, the overview of the emerging treatment options. So on the lung-only side, essentially, there's the 4 plasma products. One of the things that's obviously got people interested is [indiscernible] with the recombinant alpha-1. The recombinant -- and they've obviously presented their data -- their Phase I data publicly. The recombinant conceptually, there's never been a real concern of viral transition. So it's not so much an issue that recombinant's going to protect patients from that, is that it's potentially longer-acting. And so that the infusions, at least from the initial data, would not be as frequent as weekly. And so there's -- if I'm a patient who has to get an IV and you tell me instead of every week, it's going to be every 2, 3, 4 weeks or whatever it ends up being. At its core, this is not a major shift in how we manage the disease, but it is a major shift from a patient's perspective and that my replacement product is now less frequent. The only thing I'm still waiting on, and again, I'm -- the DSMB was for the Phase I trial. And I have no access to information that wasn't publicly presented. What I am now waiting for, since I am -- no longer have any inside data and is -- the BAL evaluation of the alpha-1 that their product actually does make it directly into the lungs because the circulating levels are important. But it's also been important from the historical biochemical equivalent studies of all the plasma products that alpha-1 levels inside the lung, inside the -- on the airway side, are detectable. And there's only been 2 patients data presented publicly that I'm aware of. And so I just need to see that personally. Inhaled off one from Kamada is something that's been floating around for a while, quite a while. The concern I have personally is one has been the inability to consistently see the levels get high enough. But also, I'm trying to figure out where this is going to get placed because it's going to be a significant amount of time involved. And it's going to be a daily nebulization or inhalation. There's also a significant amount of cough. And I'm still concerned -- from the experience while we had inhaled insulin is the inability to get consistent deposition of the protein because of the airflow obstruction. One of the many reasons that inhaled insulin died was the inability to consistently guarantee how much insulin we're going to get into the body because of such variable amount of air flow, which is the core component of the disease in the alpha-1 patient. And then Mereo’s neutrophil elastase inhibitor conceptually is an interesting idea. I'm actually more excited about that from a perspective of, if they prove it out in alpha-1, I think it will be an add-on during -- exacerbations is my pure guess. And I base that on just how I view -- how people would manage off one, I've got no information per se. I actually would be more excited about neutrophil elastase inhibitors in the setting of the COPD exacerbation for all of my COPD patients. And I can view it in my mind for my cystic fibrosis patients, that my colleagues take care of because those folks have tons of neutrophil elastase. So I think it's an interesting concept. I don't know if it's going to be a big splash per se in alpha-1. Now on the pure liver side, [ silencing ] and inhibiting RNA, obviously, conceptually makes sense if this the protein accumulating in the liver, take it out, right? It's completely shut the gene down. So conceptually, it seems to make sense. The data that's been presented publicly so far from some of the companies is compelling from a liver perspective. I think if nothing else, it validates also the approach that Wave is taking. They're not doing silencing, but if you are ultimately modifying the amount of protein accumulating, there seems to be a liver signal. But my concern here, of course, is that we are going to plummet the amount of circulating alpha-1. Potentially, of course, have to drive up costs because if I'm going to have to change the dosing structure instead of the current 60 mg per kg, they'd have to go to 90 or 120 to cover for the fact that the levels are going to plummet. And that's concerning, just for nothing [indiscernible] that ultimately, we had a Medicare level, you pay by the milligram for alpha-1. So if I suddenly need more milligrams, there goes your cost. But still exciting if nothing else because we've had, obviously, nothing for the liver. So this brings up some opportunities. And then obviously, the -- what we'd all hope for is what I lovingly call the 2fer, can we take care of 2 problems at the same time. At its core, alpha-1 is a liver disease that then ultimately puts you at risk for lung disease, so if I can try to fix the underlying problem at the liver level. So the original study through Vertex with small molecules and another company, the only concern there is 814 -- sorry, 814 and 864, both studies were stopped. 814 because of safety; 864, not clear why. Gene therapy trials that are all preclinical, but stronghold that have taken with patients, they have several concerns on gene therapy trials. They are concerned about specificity and accuracy and worried about mutations. They are worried that prior gene therapy trials across multiple diseases have not ultimately worked. Prior gene therapy trials in the alpha-1 world have never led to levels that were even worth talking about. So obviously, that's where we are with Wave. And as stated earlier, and this will be kind of my last comment and then I'll past the ball. But the concept here of one RNA editing -- you saw the specificity of it, but even talking to patients, the idea that even if -- you pay a worst-case scenario and you say, "Okay, there's a colossal error and it adds a bunch of the wrong genes somehow," like Oops. What would be the negative effect? So the negative effect would be some abnormal proteins temporarily until your next injection. And that those -- you haven't modified the gene. There's nothing permanent here. And so conceptually, from a safety perspective, and clearly, we need to see safety data. But from a safety perspective, the concept rings true in a lot of patients. And then obviously, when going back to what we're trying to accomplish here. Well, if you get someone at levels that are above the protective threshold, you've already succeeded. And again, the preclinical data says that, that's what occurs, that we're able to edit enough that we get people essentially becoming an MZ. And as we already know from [ Molloy ], MZs don't matter. The beautiful thing about this, too, is that there's a subset when we think about the size and potential number of patients. So these are all the ZZs I'm talking about. But there are people who, for example, are FZ and SZ patients. Now why is this interesting? So the F mutation and the S mutation both, obviously, lead to some milder efficiencies. But it's that Z protein issue, not so much accumulation in the liver, but they are deficient. And if I could again fix the Z message and then make you essentially an MS for all intents and purposes, MSs have no increased risk for lung disease whatsoever. And then MF has very little increased risk for lung disease that some of the nuances of the F protein. So there's a lot of broader potential applicability here, obviously, clearly focusing on ZZs, but to make things extremely interesting. And then I think broadly speaking as well, the risk for liver disease, when we look at the huge MZ population, there's some thought that there might be a small percentage who do. And obviously, if we have an MZ who is manifesting with liver disease, being able to undo the liver accumulation from treatment here has a lot of potential. So there's a lot of different ways to think about this, at least, I do. But I think broadly on the assumption that we're going to have a viable solution for ZZs, and that's great, but I deal with a lot of other manifestations and a lot of other mutations mixed would the -- that are equally problematic and required at the moment, infusion therapy. And if I've got a better solution, then I'm obviously super excited. And with that -- that's the clinical background and I will be quiet and pass the ball back over to Paul.

Thank you, Dr. Hogarth. In summary, WVE-006 has the potential to be a meaningful therapeutic option for thousands of patients living with AATD. We have a comprehensive preclinical data set supporting its therapeutic profile, and we are rapidly advancing IND-enabling studies and expect CTA submissions in 2023. Stepping back, today's update represents substantial progress since we initiated this program just a few years ago. This speaks to the potential to accelerate timelines to candidate with AIMer pipeline expansion and as we continue to iterate and incorporate our learnings from this platform. Achieving proof-of-concept with WVE-006 in the clinic is expected to unlock value for future editing applications in the liver and beyond. I'll now turn the call to Chandra, our Chief Technology Officer and Head of Platform Discovery Sciences, to review some future potential applications of AIMers, which are expected to fuel our pipeline growth. Chandra?

Thanks, Paul. As Paul and Paloma described, the substantial progress to date with WVE-006 program or AATD, demonstrates the potential of AIMer technology for precise correction of G2A driver mutation. If you think of AIMers as Swiss army knives, correction of driver mutations is just on one of many tools that we can leverage by harnessing AIMer enzymes to make specific RNA edits. AIMers can also modulate gains by disrupting protein working interactions or [ upregulating ] their expression as well as modifying protein function. We have focused our initial work on upregulation of gene expression, given the spectrum of disease targets that this approach could open up, many of which cannot be approached to modality such as balancing or small molecules. I'll now review the multiple book of concept data sets we have generated to inform how AIMer can active gene pathways by modulating protein-protein interactions and upregulating RNA expression by editing RMA-binding motives in proteins. I'll start with a review of KEAP1 NRF2 system, which we use to exemplify our ability to modulate protein/protein interactions using ADAR. This system shows the potential to edit a single site to activate a transcription factor and to upregulate downstream genes. Accessing such protein-protein interactions with small molecules have been notoriously difficult particularly when the interaction interface is shallow, large and hydrophobic and very deep within a protein [ port ]. Using RNA editing to change the amino acids within a protein interaction interface can overcome the limitation of small molecules such as core specificity and selectivity and provides a novel approach to modulate this class of targets. Again, if AIMers work as designed for this system, we would expect to see downstream activation of Nrf2 Gene Expression program, which improves genes such as NQO1. As shown on the right of the Slide 86, using GalNAc AIMer, we achieved efficient editing upwards of 80%, which results in dose-dependent upregulation of NQO1. We recently shared the first in vivo results using this system where we saw efficient editing with multiple GalNAc AIMers in the liver of mice, which resulted in downstream gene upregulation. If you fully disrupt the NRF to keep on protein interaction, we would expect upregulation of a key set of deals that are regulated by Nrf2, which we confirmed by RNAseq transcriptome analysis, as shown on the bottom right of Slide 87. Another potentially disruptive application of AIMers is to alter various mRNA properties by editing the sequence motifs recognized by RNA-binding proteins. RNA is highly regulated from transaction to translation, which creates an opportunity to make very specific changes, if we can apply the right tools. Specifically, by enhancing the stability of the mRNA, we can upregulate or balance RNA to increase downstream protein expression and treat haplo-insufficient diseases or diseases that require overexpression of a target gene. The ability to upregulate protein would benefit diseases such as those resulting from haplo insufficiency or loss of function. Our two-fold upregulation in RNA would clearly restore haplo-insufficient proteins to normal levels. With AIMers, we are able to achieve delivery to multiple tissues and cell touch. And they're also compatible with GalNac or other potential ligands. The dosing is titratable, and editing at the RNA level preserves the endogenous expression and regulation of RNA. Now we have demonstrated the ability to upregulate several different targets, including both metabolic or immune targets by editing automated motifs to regulate RNA half-life in vitro. We now focus on target A, an undisclosed liver target for a disease with high unmet need and potential for multiple large indications. Upregulating target A enables preservation of endogenous protein function, generating a serum protein as well as increasing levels of serum biomarkers that are indicative of pathway activation. The potential threshold for benefit is approximately threefold upregulation in mice. It is important to consider that in in-vitro, we observed significantly greater response in human hepatocytes as compared to mouse hepatocytes, suggesting results in mouse models may underpredict the biological impact of editing with AIMers for this target. On Slide 92, we successfully demonstrated in vivo translation of target An mRNA upgradation. We also show lean upgradation of mRNA and target A protein, above three-fold, the potential threshold for benefit. These results are encouraging proof-of-concept, and we continue to evaluate the specific target as well as others. While the specific upregulation example focuses on GalNAc-conjugated designs to access liver target, we also achieved substantial RNA editing with systemic delivery of unconjugated AIMers. We do not need to use complex delivery vehicles such as lipid nanoparticles or viral vectors. In in-vivo mouse study, we observed editing of EGP2 targets across multiple tissues, including kidney, adipose tissues and a range of liver cells, with a single subsidy dose of an unconjugated AIMer. We are actively evaluating disease targets across a way these tissue types to unlock the full potential of this target landscape which may include leveraging third-party collaborations. Now without [indiscernible] conjugates, AIMers can access tissues such as those in CNS, where we have observed RNA editing activity. Given the clinical data shared today supporting the translation of our LT and ALS/FTD silencing programs, we are increasingly interested in applying AIMers to CNS diseases. We shared this data for the first time last year where mice received a single 100-microgram dose of EGP2 to AIMer. And RNA editing was observed throughout the brain with robust editing persisting, at least, for 4 months post bill. These results underscore the broad tissue distribution and durability of AIMers, driven by advances in our PRISM platform. We are very excited about the future. AIMers have the potential for many different applications to treat diseases and correcting driver mutations is just the start. We can active gene pathways with a single edit, and we can dial up RNA production with our AIMer tools. With the liver, we are able to leverage the benefits of GalNAc. But in in-vivo data -- our in vivo supports the delivery to multiple tissues without any delivery vehicles, including CNS. I'll now turn the call back to Paul. Paul?

Thanks, Chandra, and thank you to all the speakers for excellent presentations today. As you heard from Paloma, the preclinical data generated with WVE-006 supports a compelling therapeutic profile with highly efficient editing and restoration of AAT protein. We've seen exciting clinical translation with initial data from our silencing programs this year, and we're excited to bring our first GalNAc conjugated oligonucleotide to the clinic next year. As Dr. Hogarth described, there is significant unmet need among patients living with AATD, in particular, for therapies able to address all manifestations of the disease. Looking ahead, we are actively evaluating new applications of AIMer such as for the upregulation and gene expression to fuel the growth of our AIMer portfolio. And with that, I'll turn the call over for questions.

[Operator Instructions] Our first question or comment comes from the line of Joon Lee from Truist.

So what was the human equivalent dose in the humanized mouse model needed to achieve a 50% CR AAT? And how close is that the -- is that dose to the planned dose in your Phase I/II single ascending dose study? And was the human ADAR in the humanized mouse model expressed under the endogenous locus? So basically knock out, knock in? Or was expressed as a trans team under its own promoter? Just trying to understand how translatable that data is or will be -- to be in the human? And is MAAT an approvable biomarker for AATD or will you need to demonstrate efficacy in the clinical endpoint? And if so, what would that be?

Thank you, Joon. And that's a lot of questions packed in there. So we're going to do our best to kind of unpack them. And along the way, we'll check in with you to make sure we didn't miss one. But I think I'll work from back to front, in terms of clinic to preclinical. And I think -- your question on MAAT is an interesting one. We are watching as others, and I think Dr. Hogarth was referring to Inhibrx on the protein side. I think we're going to learn a lot about the regulatory pathway as it relates to protein replacement. I think it is interesting that unlike other aspects of programs, we're not a recombinant protein. So we are a natural endogenous protein. So we also have to look at this in the context of restoration of a natural protein and whether or not those thresholds from other plasma-derived product supply. But as I said, we're going to learn a lot about that. I think that's also only the pulmonary side. So as we are building this program and thinking forward, about various reimbursement strategies. Obviously, the other component is looking at the liver. So we do plan to build into our clinical studies, the valuation of the liver as well. And we'll watch some of the RNAi programs as they advance as well as defining some of those endpoints, too. And then we'll continue to look at outcome, measurement. Subsequently, obviously, to continue to support the growth of the product. But I think first and foremost, in the clinic, is a determination one of editing; and 2 impact on biomarkers. So I think that's the critical piece. Going back to your other question about thinking about translation of dose specifically. We will be guided for dosing based on the subsequent experiments we're running. So I'll let the team refer to kind of how we think about the doses that we're using in the current preclinical studies. I think there's a lot of experience of translating GalNAc-conjugated oligonucleotides from mice to larger species to humans. So we do rest on the translation and delivery of GalNAc conjugation. But ultimately, we'll give more guidance as we think about the dose selection in the clinic as we make that transition. I'll turn to the team. Chandra -- or maybe Paloma, to talk and refer to your question specifically about the models. Paloma?

Yes. Yes, that's correct, Paul. And we do see just to reiterate that the doses are within the ranges of other GalNAc-congregated drugs currently in humans. And that has also carried over from the animal model. There are differences in the animal models. Our model in for [indiscernible] human ADAR model, slight differences with the conventional mouse model that's used by our competitors and is a common model that's used in the field, the NHG model. But we're seeing comparable levels of RNA editing in both models that then translate to very comparable fold increases in the corrected wild-type MAAT protein. And again, just to go over what Paul already has mentioned, we do that human equivalent doses from these mouse models into the clinic will be determined from our GLP study.

I think to Paloma's point, I mean, we're using low doses of drug with GalNac. So as you'd expect, with our dose ranges would be within ranges that are seen with other RNAi therapeutics. It is important, and I think to Paloma's point, and we should reemphasize, while today, we continue to present the data off of the standard PIZZ model to kind of replicate. Remember earlier, we did show a human model. And I think a big driver for that was for us to be correlating the rationalization of thinking about human ADAR, mouse ADAR and how to translate that and feel very confident as we look at both models that we see substantial, not just percent editing, but really translation to fold increase in protein as we shared today, fold increase of protein that suggests now that we're in the MZ range rate. So I think again, all of that data, coupled with our preclinical IND-enabling experiments as we think about GLP planning and being able to look at those exposures in larger species, we'll ultimately plan the dose for the human study. But so far, based on these models and translation, again, we wouldn't expect this to be dosed differently than other GalNAc-conjugated oligonucleotides in the liver. [indiscernible]

That's really helpful. Yes, those are really helpful. And then one last question. Is there a dose at which -- is there a dose limiting aspect to ADAR-mediated RNA editing? In other words, are there endogenous targets that ADAR needs to be editing endogenously that you wouldn't want to disrupt and deliver?

Great question. And it's one of the things we had done early on -- and I believe -- but we actually -- I remember sharing with data, may be it was almost a year ago, and I know it was in some of the papers that we show. We showed that we don't deplete ADAR. So it's a great question because it was one of the experiments we ran early on just to validate the platform capability itself. And we show that you don't disrupt ADAR from doing its job. We show that we could edit multiple ADAR construct. So you're utilizing this catalytic enzyme and it's still able to exert its normal function of cells. So there's no disruption of ADAR activity. Going back to your question on kind of thinking about those, and this is kind of, I call it the higher-level PRISM follow-up is. We have gotten a lot more refined, as you'll recall from discussions across multiple programs now. I'm thinking about predictive modeling of dose with PN chemistry from preclinical models to humans. So I think our confidence in those translations and what we see with our existing programs with low single doses exerting target engagement, I think, gives us increased confidence, particularly in a setting where we're using GalNAC conjugation. So again, we're excited to advance this program to the clinic.

Our next question or comment comes from the line of Lisa Walter from RBC Capital Markets.

This is Lisa on for Luca. First, I have a question for Dr. Hogarth if he's on the line still. I was just wondering, Dr. Hogarth, what would be the ideal age to begin treating patients in order to prevent loss of lung function? And for the Wave team, I was just wondering about ADAR expression levels in humans. I was just wondering if there's been any studies done that have explored maybe the variation in enzyme expression levels across different patient populations? Maybe differences between men and women or adults and pediatrics, where people have different ethnic backgrounds? And then maybe as well, have you ever looked at the [ DNA ] expression levels that are in A1AT patients versus a healthy normal patient?

I'm on the line. Paul, do you want me to answer the clinical? [indiscernible]

Yes, sorry, I was going to say -- you are here. So great.

Okay. Yes, Yes. So it's a good question. Unfortunately, short answer is no one really knows. But what I guess I would say is because we don't have, at the moment, obviously, any form of universal testing. Though, as a side note, those home genetic products like [indiscernible] and things like that actually test for the Z mutation. And so in the -- apparently demographic for who purchases that product skews towards younger. And so we are finding patients with Z protein or Z mutations who, arguably, at least, as far as anyone knows, doesn't have clinical manifestations of disease yet. And I've seen several of these people in my clinic. They're in their [ 50s ] and they got it as a Christmas present and they found out they were alpha-1. And so when to begin? Historically, the guidelines have said we're not going to do so-called prophylactic therapy because if there's no clinical manifestations of lung disease, alpha-1 is viewed as, obviously, a huge risk for lung disease, but not a guarantee of lung disease. And so it's been active following. The hope is that with more data that points towards biomarkers, we'd be able to measure, for example, desmosine levels and try to flag someone long before they start to lose lung function because the counter has been is that the patient comes to see me complaining of pulmonary symptoms and the time on average, when someone says hey, I'm having trouble breathing. I'm going to go see the doctor, the data supports that their lung function is usually between 50% and 60% predictive. So they've already lost a good amount of lung function, so that, obviously, wouldn't need to be put on therapy. But there's a long lag time, and that's where we hope to change things. I think because of the hope I guess stated earlier, where we have something that has potential liver implications here that we'd find liver abnormalities sooner because of just general blood testing that your in-service does. That we would find then, obviously, lung disease earlier. Because whenever a liver patient is sent to my clinic, the first thing we do, obviously, is evaluate their lungs even if haven't any pulmonary symptoms. And sure enough, not infrequently, we find people in lung function at 80% of predicted. And 80% is obviously more than enough to get around for the average person, but is clear lung disease and is only going to progress. And so we do think we're going to shift earlier once we start finding these people in earlier stages, and that's where, I mean indirectly 23 [indiscernible] is helping. And then obviously, when the liver therapeutic becomes available, we're going to shift even more.

Thank you Dr. Hogarth. And just to answer the other question, so to make sure we get it right. In terms of variations on ADAR, we think about could there be difference between men and women, disease state, healthy state. ADAR seems to be highly conserved. So from what we can tell and through some of the experience out there, there is not a difference of expression between men women or in health and disease. So it's a highly conservative.

Our next question or comment comes from the line of Paul Matteis from Stifel.

This is Katie on for Paul. I had a quick follow-up to the previous question. Do we know anything about if ADAR levels vary across tissues? Are these similar as well? And also, I was wondering if you could kind of talk about your long-term ADAR strategy? And is there any potential color you could provide on your potential CNS programs?

Awesome. I'll let -- maybe, Paloma, do you want to talk about ADAR expression? I mean, obviously, there's different ADAR substrates, so that might be your question. We're targeting up the more ubiquitously spread.

Yes, absolutely, Paul. So yes, so we're targeting ADAR1, and that is an enzyme that's ubiquitously expressed. So there are high levels in liver and hepatocytes as well as other tissues.

And that was intentional, obviously, as we think about some of the data Chandra shared today, to be able to think about. Maybe that's your follow-up question of being able to think broadly. So I think to the strategy, step 1 with ADAR has been we're bringing an entirely new biology forward. And I think that's a really exciting opportunity and time for Wave for us to think about translating the chemistry innovations that we've seen translate around target engagement, around important areas in the CNS to a new area of biology, base editing. And as Chandra shared, thinking broadly beyond their capability, not just in looking at monogenic fixes, but thinking about RNA upregulation and RNA binding proteins, and really thinking differently about biology. So I think we're really opening up that space. When we brought a new area of biology for a couple of chemistry, we believe for the right reasons. And I think -- and the appropriate indication that alpha-1 antitrypsin and hepatic is the best first place to go. One, we can leverage GalNac can really open up hepatocytes. And I say liver, but when we talk about GalNac, we start to remember we're talking about hepatocytes in that context. But really be able to meaningfully show in the clinic against a really important disease that we can edit and correct protein function. And that data is really helpful as we think about treating a broader range of hepatocyte-driven diseases, and we shared some of that data on upregulation today. And then to be thinking more broadly. And I'd say more broadly being both the liver where we've shown [ haplo ] and GalNAc, we get good editing data and liver, kidney, lung, CNS. And so it really does let us step back and think about a strategy around ADAR where, how do we tackle important and meaningful areas of diseases, where rather than taking away a toxic protein. And that's also an important mechanism of treating diseases, really thinking about the broad landscape of loss of function diseases in areas and haplo insufficiencies where we want to do correction. And so I think that's where we see a huge opportunity for the ADAR platform more broadly. That's why we think alpha-1 antitrypsin is a great first step. And as we shared today, other examples of opportunities that we have for correction. So I think we will be seeing and you will be seeing a lot more on the editing and correcting side of what we're delivering at Wave and not to discount the progress that we've made in silencing and slicing. So we are excited as data continues to emerge clinically on our silencing programs and upcoming data in slicing. So I think it's really important that we see our capability translates to this new area of biology.

Our next question or comment comes from the line of Salim Syed from Mizuho Group.

Great. First, I just wanted to say thanks to Mike Panzara, I know he's not on the call, but I know he's leaving the company. So if he's listening. Thanks for all the help, Mike, and welcome to Anne-Marie. Paul, I had a couple of questions on the off-target editing that you guys spoke to. I know you guys kind of described it as perhaps noise and it's less than 10% of the edits that you're seeing. But just curious if you could just elaborate a little bit more on potential AEs that could come from that, that you're thinking about or looking at or scanning for? And how you're exactly ruling out that we may not see those AEs with higher doses or multi-dose? And then the second question is just on the time lines for the CTA submissions in 2023. We're pretty close to 2023. So I was just curious, what are the gating factors there, in terms of the IND-enabling studies and so forth that can help us think about when in 2023 we should [indiscernible] submissions.

So a couple of things. On the first, obviously, thank you for the first comment. I think we appreciate everything Mike has done [indiscernible] a very strong, capable development organization. And in particular, next to me, is Anne-Marie -- say hi. So at least, we can we'll spend more time getting to know Anne-Marie, who are excited, not -- is important anyway. She's been a critical part of Wave. So continuing to step into her new role. So I'd let her just to say hi.

Hi. Hello.

You'll be hearing a lot more from Anne-Marie. As it translates to your specific question around editing, I'll let Paloma talk a little bit more about that and happy to add additional color to that.

Yes, absolutely. So we don't believe those off-target events that we've observed will carry over. Those events have not been -- they're not dose-dependent. So increasing the dose does not seem to lead to changes in those events. So we really do see that, that's a just -- background noise in the system in the assay that we're using to determine the off targets. We've also performed really robust and in-depth analysis, both on the -- with regard to the by-standard of targets as well as the whole transcript dome. And again, none of those off-target events that we've seen with both systems are dose-dependent.

I think it speaks to the specificity. I mean one of the things that we've seen -- an interesting example is even looking at the targeting. So we've seen, with single drug high degree of specificity, and it's exciting to see this continue to translate over to ADAR. I think as we think about dosing and I think some of your other questions related to whether or not we can predict events. I think one of the advantages of GalNAc-conjugated AIMers approach, too, is the dosing range are different. These are going to be dosed like other GalNAc-conjugated RNAi. So we're talking about a hepatocyte targeting strategy, too. So I think overall, we think it's a great first way to bring a new modality into the clinic in a way that we can measure, define and develop program that are going to be important and meaningful. And as it relates to specifics around the CTA submission time line. I think at this point, it's fair to say 2023. And obviously, earnings will continue to provide updates to guidance.

Our next question comment comes from the line of Mani Foroohar from SVB Securities.

Lili Nsongo for Mani on the line. So my question was related to testing. So you mentioned, I think, during the presentation that the current rate of testing is around 10%. Realistically, what percent of the improvement can we expect, especially in potentially nonsymptomatic younger ZZ or MZ patients? And related to that, in the multiple ascending dose portion of the study, what type of enrollment rates you expect? And are there any specific phenotype that you'd be seeking out?

All right. A lot to unpack. I'll start at the end and work forward. So I think your last question about thinking about rates of enrollment, I think the starting point for us is the CTA submission '23. Obviously, as you've heard from Dr. Hogarth, and we can let him talk about, obviously, clinical trials. I think given that this -- while these are rare depending on how one defines it, these are consequential diseases of lung [indiscernible]. So we don't anticipate enrollment being a challenge, particularly bringing in an entirely new medicine forward. And we've got great examples of other therapeutics in this space that have enrolled studies quickly and demonstrated that. I do think it played into a role as we think about the healthy human volunteer dose escalation into that expansion cohort because we do think actually on the front end of the study, that's going to enable us to much more rapidly enroll and establish the dose to then move into that ZZ population at the expansion cohort, and then subsequently and, obviously, move into the MAD. So I think we put a lot of thought into the trial design that we have -- as we have into all of our trial design to be able to expeditiously get to dose in a signal. So that we can continue to bring important medicines forward. So I mean, that's what I have related to that. And the other question at the beginning. I got the 10%, but I'm trying to -- maybe if you could repeat the first question because it was...

Sure. It was just basically, realistically how much improvement can we expect in testing especially in potentially younger ZZ or MZ that are symptomatic?

So this is testing rates in -- for diagnosis? So I think -- and I'll let Dr. Hogarth refer a little bit to this diagnosis. I think one important point that he mentioned, which we should underestimate, too, is the impact of consumer genetic testing and the fact that with 23andMe, this is now part of the 23andMe panel. So it's interesting as we see more and more genetic testing that's not disease-defined but more population-defined. We're seeing those rates go up. But Dr. Hogarth, I don't know if you have any responses to the kind of the testing rate.

Yes. No. So testing rates have been increasing on several different fronts. One, the consumer genetic level as discussed. But then the second component has been, obviously, the plasma industry is very interested in finding patients to go on their products. Obviously, until [ editing ] changes, the business model is still the same. And so one of the companies underwrites a free test and so there's an ability to do the genetic test that the patient just has to swab their cheek in clinic. And that entire test is paid for by the [indiscernible] company. And then the other companies, reps spend a lot of time, actually, most of the time, not -- were talking about product, we're talking about testing. So there is an active engagement at the sort of promotional level from a test effective. I think, again, what we're looking forward to is with any new therapeutics having it enter the discussion more, but especially if there's something that has an effect on the liver because that's going to dramatically shift things in the workup component to it because it will bring it more front and center, and give opportunities to talk to those primary care factors and so forth, and find these does at earlier stages. Now in regards to trial enrollment and trial designs, I think one of the advantages that Alpha-1 trials have over multiple other trials is that this is a well-organized patient community that is actively involved in a lot of different clinical research. So the Alpha Net is a patient support organization with several thousand patients. They are a well-mobilized group. Clinical trials in Alpha-1 pitfall rather quickly. I think advantage here is that the discussion has always been historically of, "Hey, placebo trials or you take an Alpha-1 patient," and you're not going to give them some kind of an infusion product. That's going to make people nervous. But of course, the core concept here is we are going to give you a "infusion" except in this case, it's our own. And so you're not going to be getting pure Z. Now if you're in the placebo arm, so be it. But the nature of these initial trials are going to be obviously low. And believe it or not, the RAPID study, which was a 2-year placebo-controlled trial, though there was a lot of recruitment outside of the U.S., there was a significant amount of recruitment within the U.S. And it's because it's that motivated other patient community. The various trials that have been requiring to liver biopsies, including one that are not a therapeutic but a natural history liver biopsy study has had no trouble recruiting. It's a really amazing patient population.

We have a follow-up question from Mr. Joon Lee from Truist.

Just wanted to follow up on the presentation by Chandra about modulating protein-protein interaction through RNA editing. What's the relative size compared to, say, a PROTAC? And how do you view the differentiation versus PROTAC's -- based on the programmability, by availability or something else? And what appreciating concrete examples you can offer and possibly a time to lead candidate disclosure?

Chandra, do you want to?

Yes, sure. So the protein-protein interactions, what we presented today is a first point, it is actually a proof-of-concept that we provided. And the editing is what we are looking at. So we haven't compared with the PROTAC. So this is -- what we are trying to say is a small molecule, it's going to be nonspecific. And here, we can do it at the mRNA level, not at the protein level. So editing is going to give us a good opportunity to modulate these kind of protein-protein interactions. So it's not a direct comparison.

Yes. I was going to say -- if you were trying to say by modulating on the transcript and instead of impacting just the protein itself, I mean, that lets us think about tissue accessibility, durability and specificity. So a number of the features that -- obviously, we've been the program from the beginning and actually starting at where it begins, again, the transcript. So I think more to come. We need to generate data. We need that to continue to see how it evolves for comparisons. But I think as we've seen before, intervening at the transcript level instead of at the protein level directly is an advantage.

Thank you. This concludes the Q&A portion of today's webcast. I will now turn the call back to Dr. Paul Bolno, President and CEO of Wave Life Sciences, for closing remarks.

Thank you. Thank you, everyone, for joining the webcast, and thank you to the team at Wave for everyone's hard work and dedication in bringing these transformative therapies to patients. Have a great day, and we appreciate your time.