Good morning, ladies and gentlemen, and welcome to the Wave Life Sciences Third Quarter 2020 Earnings Call. At this time, all participants are in a listen-only mode. Later, we will conduct a question-and-answer session, and instructions will follow at that time. [Operator Instructions] As a reminder, this conference call is being recorded.

I would now like to turn the conference over to Graham Morrell, Investor Relations at Wave. Please go ahead..

Thank you, Operator. Good morning, and thank you for joining us today to discuss our recent business progress and review Wave's third quarter 2020 financial results. This morning, we issued a news release detailing these results which is available in the Investors section of our Web site, www.wavelifesciences.com.

The slide presentation that accompanies this webcast will also be available on our Web site following this call. Before we begin, I would like to remind you that discussions during this conference call will include forward-looking statements.

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 the press release issued today and in our SEC filings, including our Annual Report on Form 10-K for the year ended December 31, 2019, and our quarterly report on Form 10-Q for the quarter ended September 30, 2020.

We undertake no obligation to update or revise any forward-looking statements for any reason. I'd now like to turn the call over to Dr. Paul Bolno, President and CEO of Wave Life Sciences.

Paul?.

Thank you, Graham. Good morning to everyone on the call, and thank you for joining us today. I hope you and families are staying healthy and safe during these challenging times. We are excited to share the latest on our progress, new programs, and future plans.

I'll start us off this morning by providing an overview of recent achievements, a summary of the data that will be included in the readout for our PRECISION-HD clinical trial in the first quarter of 2021, a quick overview of our recently announced PN chemistry advancement, and then I'll talk about our first ADAR editing program.

Our Chief Medical Officer, and Head of Therapeutics Discovery and Development, Dr. Mike Panzara, will then discuss our three upcoming clinical trial submissions, including our newly announced clinical trial in Duchenne muscular dystrophy. Finally, Dave Gaiero, our Interim Chief Financial Officer, will discuss Wave's third quarter financial results. Dr.

Chandra Vargeese, our Chief Technology Officer, and Dr. Ken Rhodes, our Senior Vice President of Therapeutics Discovery will also be available during the Q&A portion of this call.

This past quarter, we continued to make significant progress with our clinical and preclinical pipeline, as well as advances in expanding the potential of our innovative PRISM platform. Despite the challenges of COVID-19 around the world, our research and clinical teams made tremendous strides.

As we look ahead to 2021, I believe we are ushering in a new and exciting phase for Wave. To start, we now anticipate having five clinical trials in 2021.

This includes our two ongoing Phase 1b/2a PRECISION-HD studies in Huntington's disease, for which we continue to expect data in the first quarter of 2021, as well as our new first-in-human studies of WVE-003, and WVE-004.

As a reminder, WVE-003 is our third allele-selective Huntington's disease candidate, and WVE-004 is our candidate for amyotrophic lateral sclerosis and frontotemporal dementia in patients with a hexanucleotide expansion in the C9orf72 gene.

The fifth clinical trial, which we are announcing today, will be for WVE-N531, our candidate for patients with Duchenne muscular dystrophy amenable to exon 53 skipping. Notably, the preclinical work need to submit the CTA was completed last year, and we expect to complete this trial with no change to our cash guidance.

Mike will share more about how we reached the decision to initiate this clinical trial, which is intended to assess dystrophin and initial safety, as well as help us understand the impact of PN chemistry on splicing in muscle. Of note, WVE-N531, WVE-003, and WVE-004 all incorporate our PN backbone chemistry advancement.

I'll talk more about this later. Thanks to the rapid advancements in our ADAR platform and PN chemistry we are also announcing today that our first ADAR editing program will be in alpha-1 antitrypsin deficiency or AATD.

This disease is ideally suited for an RNA editing approach, and we believe that our novel ADAR editing modality has the potential to address both the lung and liver manifestations of this disease. The program will also lead the way for future Wave ADAR editing programs.

We believe our approach has the potential to become best-in-class RNA editing system with applicability in many disease areas, including neurology. We are also continuing to grow our neurology pipeline through our CNS collaboration with Takeda, where we work collaboratively on up to six preclinical CNS targets.

Our PN backbone chemistry is helping us optimize profiles for these candidates, resulting in compelling nonhuman primate data that we will share today. On August 25, we held an investor analyst webcast, where we announced advancements to our PRISM platform, including our novel PN backbone chemistry.

This backbone modification has been shown to improve the pharmacologic properties among oligonucleotides across all three of our modalities, silencing, slicing, and RNA editing. Finally, we are well positioned financially to progress all of our planned and existing programs.

We are reiterating that our current cash runway takes us into the second quarter of 2023. Dosing in both the 32 milligram cohort in the PRECISION-HD Phase 1b/2a clinical trails continues, and we are on track to share data from all cohorts as well as initial data from the ongoing open-label extension study in the first quarter of 2021.

Specifically in the OLE, we will share data for patients who have received multiple doses for eight or 16 milligrams at the time of the data cut.

Results in these trials are expected to include safety and tolerability as well as biomarker data including mutant huntingtin knockdown, total Huntington knockdown, and the effect on neurofilament light-chain. We also continue to focus on the scientific challenge of measuring wild-type huntingtin protein, and have made good progress.

We believe that it's critical to understand the impact of potential treatments on wild-type huntingtin, and look forward to keeping you updated as we strive to complete this work in time for our data readout. As I mentioned, we announced, in August, that we expanded our repertoire of backbone linkages with PN chemistry.

This advancement has quickly become an important component of our PRISM platform as it provides another tool we can use to optimize the pharmacologic properties of our candidate. PN chemistry involves replacing a non-bridging Oxygen atom with a Nitrogen-containing moiety.

PN modifications are neutral, allowing them to break up the charge of the backbone while retaining specificity to the complimentary base pairings. Our preclinical experiments utilizing PN chemistry have demonstrated a general increase in potency, exposure, and durability when compared to identical sequences without the PN modification.

We are seeing the significant impact of PN chemistry on the amount of knockdown and durability across CNS tissues. As we have previously shown in mice, the PN containing molecule in this study showed meaningful persistent transcript knockdown of 80% to 90% throughout the central nervous system.

Importantly, we continue to see the effects of PN chemistry translate in our therapeutic programs. On this slide, you can see recent in vivo data for the most advanced therapeutic candidate in our CNS discovery collaboration with Takeda.

In this study for an undisclosed target, non-human primates received a single intrathecal injection 12 milligram dose. One month after administration, we observed that the candidate was widely distributed across the CNS, including the spinal cord, cerebral cortex, and hippocampus.

The single dose led to approximately 90% knock down to the target across CNS tissues. We view this new NHP data as a considerable advancement for our platform and the field in general. Further, these results have enormous implications for Wave as we look to deepen our pipeline, and add new wholly owned neurology programs in the future.

Our latest pipeline chart highlights the considerable impact PN chemistry is having on our portfolio as all of our current discovery and preclinical phase programs utilizes backbone modification. We're excited to start investigating the role of PN chemistry in the clinic through the plan clinical trials as WVE-003, WVE-004 and WVE-N531.

The advances we've made with Chiral control, PN chemistry modification and our PRISM platform have helped us to unlock our novel ADAR editing platform capability. Our approach to RNA editing employs short, fully chemically modified oligonucleotides, usually 30 nucleotides or less to recruit endogenous RNA editing enzymes called ADAR.

ADAR enzymes can be used to change an A to an I which the cells read as G in RNA.

Nearly half of known human pathogenic SNPs are G to A mutations, the capacity to leverage ADAR to correct these mutations opens the door to a number of therapeutic applications, including restoring or modifying protein function, and up regulating protein expression, which greatly expands the landscape of disease variants that we can potentially address.

Our technology has many advantages in the editing space and is at the forefront of RNA editing.

Our decision to pursue RNA instead of DNA editing was deliberate as RNA editing avoids irreversible off target genomic edits, and because we use endogenous ADAR enzymes, we avoid the risk that Introducing exogenous proteins may trigger immunogenicity and off target effects.

In addition, our oligonucleotides are optimized using an expanding repertoire of chemical and stereo chemical modifications available through PRISM including PN chemistry.

Importantly, we employ a simplified delivery strategy that does not require AAV vectors or nanoparticles, which would allow us to leverage established oligonucleotide managed manufacturing processes. We saw many of these attributes represented in our proof-of-concept in vivo study in non-human primates, which you may recall from our research webcast.

The study showed up to 50% editing of beta-actin transcript two days both last dose was sustained editing at 45 days. We've also shown that our ADAR editing oligonucleotides are highly specific. In this morning's press release, we announced our first ADAR editing program, which will target SERPINA 1 for the treatment of alpha-1 antitrypsin deficiency.

Alpha-1 antitrypsin deficiency or AATD is a rare inherited genetic disorder that is commonly caused by a single G to A point mutation in mRNA coated by the Z OLE of the SERPINA 1 gene.

This mutation leads to misfolding and aggregation of alpha-1 antitrypsin protein or AAT hepatocytes, and a lack of functional protein in the lungs, where it would protect lung tissue from neutrophil elastase.

Patients with AATD typically exhibit progressive lung damage, liver damage, or both leading to frequent hospitalizations, and potentially terminal lung disease or liver disease.

While the few approved therapies modestly increased circulating levels of AAT in those with lung pathology, there are apparently no approved therapies to address the liver pathology. It is estimated there approximately 250,000 patients worldwide with the most severe form of AATD.

These patients are homozygous for the G to A point mutation on the Z OLE. Well, the AATD landscape is growing quickly, we continue to see opportunities to develop a best-in-class treatment approach, which would have three key attributes.

First, we would want to restore wild-type AAT protein and we believe an editing approach provides the opportunity to substantially improve upon the modest levels of AAT that are delivered through augmentation therapy, we would want to simultaneously address the aggregation of AAT in the liver.

By addressing both, we potentially remove the need for augmentation therapy and give patients the option for a single therapeutic regardless of lung or liver phenotype.

We would also want to develop a treatment that retains AAT's physiologic regulation, based on publicly available information and our understanding of the disease at editing approach appears to be the only one that could address all these attributes, and we believe RNA editing is preferable to DNA editing to avoid the potential for irreversible off-target edits to the genome.

Leveraging the work we already did with GalNAc conjugation and NHPs, we turned our attention to correlating the corrected transcript to wild-type protein.

Here we show that we've accomplished this in primary mouse hepatocyte z-cell model, we saw upwards of 60% correction of the Z transcript back to wild-type transcript, which prevented protein misfolding and allowed for better secretion from that parasites resulting in a three-fold increase in Protein Concentration.

The question we then asked ourselves is do we have the right in vivo modeling systems in place to develop best-in-class RNA editing candidates with our ADAR platform; one important learning for us with limitations of the humanized SERPINA 1 mouse model. This model contains mouse ADAR which behaves differently from human ADAR.

Our scientists therefore, develop a proprietary model, which contains both humanized SERPINA 1 and humanized ADAR. What's really exciting about this model is that we can now cross the humanized ADAR mouse with any specific disease mouse model thus providing a modeling system that can be used across our ADAR editing programs.

We're looking forward to optimizing this model further and generating data from our AATD program next year and applying the model system in neurology and other areas. At this time, I'd like to pass the call to our Chief Medical Officer and Head of Therapeutic Discovery and Development, Dr.

Mike Panzara to discuss our three upcoming clinical trial initiation..

Thanks, Paul. This quarter has been highlighted by tremendous progress.

We not only anticipate sharing data in the first quarter from PRECISION-HD1 and PRECISION-HD2 and their OLE as Paul already mentioned, but we're also preparing to file two CTAs before the end of the year, one for WVE-003, our third-allele selective candidate in Huntington's disease, and one for WVE-004, our variant selective financing candidate in ALS and FTD.

In addition, in the first quarter of next year, we're planning to submit a CTA for WVE N531, our candidates for DMD patients with mutations amenable to exon 53 skipping; more on that later in my presentation. I'll start with a few words on Huntington's disease.

Our work and the work of others in this area over the past few years have emboldened us in our belief that allele selectivity is critically important as a foundational concept in the treatment of HD, and that preserving as much wild-type huntingtin as possible, while lowering mutant Huntington is essential for not only proper function of the central nervous system, but systemically.

In essence, this is balanced between these two proteins in a push-pull scenario, a tug of war of sorts between their opposing effects that over time leads to the invariable progression of disease, a process involving intense biological stress, where the beneficial effects of wild-type protein, maybe even more important, wild-type huntingtin carries out essential functions in both developing in adult brains, it protects neurons against various types of stress prevalent in cells with high metabolic activity, including excitotoxic, oxidative and protein misfolding stress.

Wild-type huntingtin also plays a key role in trafficking synaptic proteins, and synaptic vesicles. This trafficking function has been shown to affect synaptic plasticity, which is important for learning and memory, as well as for supplying the essential growth factor BDNF to striatal neurons to ensure their survival.

Additionally, wild-type huntingtin is critical for the formation and function of Cilia, which control the flow of CSF and help maintain homeostasis in the CNS.

Our approach to HD is guided by the recognition that in addition to a gain of function of the mutant huntingtin protein, patients with this disease have lost one copy of wild-type Huntington leaving them with a smaller protective reservoir than unaffected individuals.

We believe this scenario necessitates trying to preserve as much wild-type huntingtin as possible to give these individuals the best opportunity for beneficial outcomes. WVE-003 is our third allele-selective HD candidate and the first to incorporate PN chemistry.

It is designed to selectively target an undisclosed SNP that were turning SNP3 on the mutant HTT mRNA transcript, while leaving wild-type transcript and thus protein relatively intact. It's also the first of our HD compounds evaluated in an in vivo model system to better understand PK/PD relationships to guide initiation of human dosing.

This slide illustrates some of the in vitro and in vivo data supporting 003's movement into the clinic. On the left, we clearly see the in vitro selectivity of our candidates over a wide range of concentrations versus similar concentrations of a pan-silencing reference compound.

While we see a similar reduction in mutant huntingtin transcripts from both compounds, 003 leave the wild-type huntingtin RNA relatively intact. As I mentioned, we also examined the effect of our candidate in an in vivo model, the BACHD transgenic mouse.

We did this knowing that there were several limitations to the model, namely that it does not contain the wild-type HTT gene and it contains multiple copies of the mutant huntingtin gene, some of which do not have the SNP3 variant, therefore setting a higher bar for SNP3 selective mutant huntingtin knocked down.

Nonetheless, as shown on the right, we observed potent and durable knockdown of mutant huntingtin in the striatum of BACHD transgenic mice out to 12 weeks with a similar effect in the cortex although not shown in this slide.

These demonstrations of selectivity, potency and durability leave us enthusiastic about the prospects for 003 as we prepare to enter clinic. Further with the entry of this candidate into clinic, we are positioned to provide allele-selective therapeutic options for up to 80% of people with HD.

Now, moving on to WVE-004, our candidate targeting C9orf72 mutations for the treatment of amyotrophic lateral sclerosis and frontotemporal dementia, 004 is designed to address the GGGGCC hexanucleotide repeat expansions in the C9orf72 gene that lead to reduced expression of healthy protein, accumulation of repeat containing transcripts and the abnormal expression of neurotoxic dipeptide proteins, or DPRs.

C9orf72 hexanucleotide repeat expansions are the most common drive genetic driver of ALS and FTD, both familial and sporadic forms. Both diseases are devastating and represent areas of high unmet need. The preclinical data from our 004 program illustrate why we are excited about the potential of this variant selective compound.

In addition to in vitro data from iPSC lines that we've shared previously, the in vivo data from the C9-BAC transgenic mice, which express the human C9orf72 containing hexanucleotide repeat expansion, clearly tell the story.

After only two ICD doses on days zero and seven, 004 showed potent and durable knockdown of over 90% of the polyglycine proline or PolyGP DPR protein in the spinal cord and at least 80% in the cortex. This impressive effect persisted for at least six months, particularly exciting results as we consider dosing intervals in the clinical setting.

Given that 004 was designed to be very unselective, we were further encouraged by these results from the same study demonstrating preservation of healthy C9orf72 protein at the same six month time point, confirming selectivity of the compound.

We look forward to evaluating this candidate's combination of variant-selective targeting, potency and sustained activity in the clinic next year. One important aspect of our clinical program is the inclusion of the patients diagnosed with ALS, FTD or both in our proof-of-concept clinical study.

The primary objective will be to assess safety and tolerability of single and multiple doses of 004, but as in our preclinical in vivo studies, we will measure the PolyGP biomarker and human CSF to assess target engagement. We also intend to look at neurofilament light chain, as well as other biomarkers.

As noted previously, we plan to file a CTA this quarter and expect to provide an update on the trial design early next year. Finally, I will discuss our announcement that we plan to advance WVE-N531 to the clinic next year. N531 targets exon 53 in boys with DMD, who have mutations amenable to exon 53 skipping.

Like 003 and 004, this candidate was designed with PN chemistry. Stepping back you may recall that we were fully prepared to file CTA for this candidate at the end of last year.

At that time, our preclinical data package, which included in vitro data demonstrating a dose dependent increase in dystrophin production of up to 71% in DMD patient derived myoblasts supported rapidly advancing the candidate.

However, as you also know, we had suspended development of N531 and other DMD programs following the discontinuation of our Suvodirsen program. Since then our assessment of muscle biopsies from the program indicated that the drug did not engage target, most likely due to poor intracellular access in dystrophic model and mock muscle.

Based on the preclinical data for our PN containing compounds, including 531, there is a possibility that we may overcome this challenge and a clinical study is the best way to rapidly assess the impact of this chemistry on tissue distribution and splicing in dystrophic muscle.

One key piece that supported preclinical data is from an ongoing study in a mouse model for DMD with a devastating phenotype. This study was done in a double knockout or DKO mouse model, which has a mutation in exon 23 leading to a lack of dystrophin as well a mutation leading to a lack of utrophin.

We compared the effects of a PS/PO containing molecule dosed at a 150 milligrams per kilogram weekly to a PN containing compound dosed at 75 milligram per kilogram every other week, as well as the control. Other than the placement of the 3 PN backbone linkages, these molecules have the same sequence in chemistry.

Despite administering 50% less drug, 50% less frequently, the mice receiving the PN containing molecule shown in light green have all reached at least 36 weeks of age. They are thriving and the study remains ongoing indicating that PN chemistry is having a compelling effect.

Based upon a greater understanding of the Suvodirsen study outcome, preclinical evidence supporting an improved muscle distribution and skipping efficiency with PN chemistry and an extensive obligation to the DMD community we are now ready to initiate a clinical trial.

We are planning an open-label trial with up to 15 boys with DMD, who eventually received N531 every other week. The trial will be powered to detect a change in dystrophin production, measure drug concentration in muscle and to assess initial safety. We plan to conduct the trial in Europe.

If successful, there was a potential to apply PN chemistry to other exons as well as the opportunity to advance other compounds for neuromuscular disease. We look forward to submitting the CTA in the first quarter of next year, continuing our mission to help patients in desperate need of new therapies.

I'll now turn the call over to Dave Gaiero, the interim CFO, to bring you through our financial results.

Dave?.

Thanks, Mike. Wave ended the third quarter of 2020 with approximately $216.4 million in cash and cash equivalents compared to $147.2 million as of December 31, 2019.

During the third quarter of 2020, we substantially extended our cash runway by raising $93.7 million in net proceeds from our September 2020 public offering and $48 million in net proceeds from our at-the-market equity program and receiving $16.8 million in refundable tax credits. Now I would like to review our income statement for the quarter.

For the third quarter of 2020, Wave reported a net loss of $33.1 million compared to $50.7 million for the same period in 2019. Research and development expenses were $28.3 million in the third quarter of 2020 compared to $44.6 million for the same period in the prior year.

The decrease in research and development expenses in the third quarter was primarily due to external expenses related to suvodirsen due to our December 2019 decision to discontinue to program, as well as decreased headcount and other external expenses driven by our February 2020 cost reduction plan, partially offset by increased external expenses related to our clinical and preclinical activities related to our HD programs and our C9orf72 program for ALS and FTD.

General and administrative expenses were $9.6 million in the third quarter of 2020, compared to $12.5 million in the same period in 2019. The decrease in general and administrative expenses in the third quarter of 2020 was primarily due to the February 2020 cost reduction plan, which included workforce reduction.

We expect that our existing cash and cash equivalents, together with expected and committed cash from our existing collaboration will enable us to fund our operating and capital expenditure requirements into the second quarter of 2023.

As a reminder, we did not include potential milestones and other uncommitted payments related to our Takeda collaboration in our cash runway. I will now turn the call back over to Paul for closing remarks.

Paul?.

Thanks, Dave. I hope you all are sharing in our excitement for what we expect to be a catalyst-rich year ahead, driven mostly by the five clinical trials that we expect will be ongoing in 2021. To recap, this quarter, we expect to submit the CTAs for WVE-003 and WVE-004. In the first quarter of 2021, we plan to submit a third CTA for WVE-N531.

Also in the first quarter, we expect to report data from all cohorts of the PRECISION-HD studies as well as initial OLE data. Finally, we plan to share updates on our AATD program, including data in the humanized model, and I expect we'll have other ADAR editing updates to share as we continue to build this novel platform capability.

We are well-capitalized to advance our pipeline of potentially transformational programs, and realize the value of our platform. And with that, we'll open up the call for questions.

Operator?.

[Operator Instructions] Your first question is from the line of Joon Lee with Truist Securities..

Hi, guys, and thanks for the questions and the updates. I have a couple of questions.

For your ADAR program, for the antitrypsin program, number one, what percent editing would you need to have a therapeutic effect and could you explain in what way your approach is better or different than the knockdown approach being taken by Alnylam and Dicerna? And for the DMD program, can you remind us again how your PN chemistry is able to overcome the tissue access from the patients of your prior chemistry, of backbone chemistry? Thank you..

Thank you, Joon, and we'll divide this into two parts; I'll bring Chandra in a second.

As it relates to ADAR, we're excited about the differentiation, as we laid out, for brining an editing approach or a correction approach forward over silencing, and while there's been a lot of excitement around silencing, and we don't discount that on knocking down or the mutated protein within the liver.

I think when we think of and approached the alpha-1 antitrypsin deficiency we really approached it from the area of correction. So that is, how do we fix this point mutation such that we restore the physiologic balance of the protein, enabling it to treat both the pulmonary as well as the hepatic complications of the liver and lung.

So this is a key driver for us to drive down the correction arm. As we talk about the heterozygosity of these patients, we do know that if a patient is heterozygous, so a 50% correction or restoration, it doesn't manifest the disease.

So we think about where the correction needs to be with the physiologic protein between that up to 50%, but you don't -- by no means [anything to] [ph] 100% correction in terms of restoring normal physiology.

Chandra, is there anything you want to add to the ADAR question?.

No, I think that you pretty much covered..

Hey, Paul, just from that….

Yes..

Just to finish up the ADAR question, assuming both the knockdown approach works as they expect will be, and then your approach works surely as you expect by editing, how would you envision these two approaches manifesting clinically differently? How would it be different clinically?.

Yes, I mean as we know now there's -- the initial therapies that are out in terms of the protein replacement to treat pulmonary complications.

So there is this augmentation therapy that's there, and so there is a desire to kind of think about the interchangeability of protein replacement or of protein augmentation therapies as well as now liver correction with silencing.

I think we stand to be able to work in both, therefore really correcting and restoring the normal protein, so the wild-type protein to restore physiologic balance, letting the body use the proteins as they need for both the lung and the liver.

So they would really -- potentially wouldn't require the necessity of silencing or protein replacement therapy..

Yes, and the DMD….

Yes, and as it relates to DMD, and I'll let Mike continue to answer the question, but subsequently, I mean as we shared on research day, there's a lot of excitement as we think about the in vivo data we're generating across cell uptake of PN chemistry, and we'll talk about this in the context of muscle, obviously, for DMD, but as we just shared today, one can see that transitioning across neurons and other aspects.

Mike, do you want to answer the question on DMD?.

Sure. Sure, Paul, yes. So as Paul just said, I mean we're seeing something very different in terms of tissue access, distribution, and importantly durability when the PN backbones are added to identical PS/PO molecules.

So DMD, where we are, why we're thinking this could address these issues, first of all, the in vivo model, it targets exon 23, but you see a clear difference in terms of tissue, in terms of clinical effects, in terms of what we're seeing in that model, the PS/PO versus a PN. So clearly we're seeing a difference there that is encouraging.

The PN does seem, as Paul alluded to earlier, introduce a negative -- introduce neutral charges to the backbone which changes the overall potentially effect on how that molecule accesses tissues. And as I said, the durability here is clearly different.

So maybe having it in the tissues longer at higher concentrations with better access could address this change we saw, this lack of access that we saw with suvodirsen.

So the overall picture here is that there are a lot of characteristics of the molecule in the preclinical data that we are seeing that give us hope, but you can only take that so far with an exon targeting or with an ASO targeting a different exon and manual, and you just need to take it into a human study to really answer that question, and we can do that very efficiently as described..

Thank you..

Yes, just to follow-up on that. I mean I think, Joon, one of the other -- yes, as Mike alluded to with the DKO mouse study and the comparison, I think the other -- the piece that was also important was that substantial reduction in dose.

So really not just seeing that improvement, but seeing that improvement at 50% less than that PS/PO drug, so 75 milligrams per kilogram, and every other week, so not even weekly. So I think we see that as important.

I think we also see good distribution in that model which is heavily sensitive across cardiac and pulmonary phenotype with distribution to heart and diaphragm. So we're pretty excited about the characteristics there.

One other point just to bring back up to Alpha-1 antitrypsin deficiency is you were asking questions about protein augmentation, and it should be noted that that therapy is a weekly IV infusion.

So in terms of just correcting, not just in terms of the hepatic, but also being able to restore the normal protein in a lung, being able to move patients off of weekly IV administration to real correction of the physiologic protein, that's something we're pretty excited about brining forward..

Great, thank you, and looking forward to the data updates. Thank you, guys..

Your next question is from the line of Mani Foroohar with SVB Leerink..

Hi, good morning. This is Rick on the line for Mani. Congrats on all the progress. My first question is also on N531.

So I was hoping you can elaborate a little bit more on what you're seeing in the preclinical studies with the PN chemistry? And I guess besides tissue access, would you expect to see any improvements in either tolerability or therapeutic window compared to suvodirsen?.

I mean, I'm going to let Mike continue. I mean I think as we alluded, one, with the distribution we're seeing it's substantially less dose, so have the amount of drug at -- and expanding the time interval out longer.

We're seeing that -- those changes in a mouse that has a phenotype, and I think that's really important to note, because often times we talk to -- people talk about MDx data where there isn't a phenotype that is purely around dystrophin.

So I think what's exciting about this model for us is this model does have the phenotype that's being corrected with this exon 23 skipping compound, as Mike said, with the PN chemistry. So we're excited about that in terms of exposure distribution and being able to evaluate that in the model.

Mike, do you have anything you want to add to that?.

Yes, and I would say we also expect the therapeutic window to be quite different. I mean we're seeing that lower doses given less frequently are leading to effects that suggest that there's clearly a difference in that therapeutic window, as well as supported by all of the other preclinical studies between the molecules.

So we would anticipate there being a difference, but obviously until you test that hypothesis in humans you don't know, which is why we've decided that the best way to proceed here is to proceed with a study that can be focused, focusing on target engagement in a small number of patients, but definitive to give us enough information to make that determination whether there is this difference..

All right, got it.

Thanks for that, and I have a follow-up about the Huntington's program, so could you maybe discuss some of the learnings from PRECISION-HD1 and HD2 that you're brining with you into the dose escalation of WVE-003? And if you think you'll be able to start at a -- the escalation at a more clinically relevant dose than the earlier studies, or maybe could you escalate more rapidly than PRECISION-HD1 and HD2 in the newer study?.

Mike, do you want to take that question?.

Yes, sure, absolutely. So, I think we've learned a lot, obviously, from PRECISION-HD1 and 2. We've learned that how to run these studies, how to engage community, how to find patients.

I think the important thing here is, as I mentioned earlier, is we're in a situation where we have in vivo data to help give us a bit more guidance on where we need to be.

So we would anticipate therefore starting at dosing levels that would be more in that window where we would expect to engage target, and a dose escalation scenario driven by those in vivo data as well as the data that we're going to be generating in an ongoing fashion from the clinical study itself, and I think what's very important is this once -- once again, every molecule that comes out of the PRISM platform has a different pharmacology, has a different characteristics in vivo and in vitro, and that's what's going to guide how we approach the next study.

So when you see the study you'll see there are elements we've adapted from our existing studies, and you'll also see some pretty meaningful differences that we have -- that have been driven by the pharmacology of the 003 molecule..

I think the other thing just to add to that in terms of identifying patients is, with -- to your point, Rick, with the ability now to have ongoing studies where we're screening for SNP, the apparatus around the phasing, we're able to do that a lot more efficiently now with the practice around SNP1 and SNP2, and also by screening those patients having a good understanding of SNP3 and where those SNP3 patients are.

So as we look at the totality of the SNP3 program beyond just the SNP3 characteristics of the medicine itself, the broader infrastructure for clinical trial operations is in place to do this..

Absolutely..

All right, great. Thanks for taking our questions..

Thank you..

Thank you..

Your next question is from the line of Salim Syed with Mizuho..

Great. Good morning, everybody, and thanks for the color, guys. Just three for me, if I can, Paul, on the PRECISION trials, in the second quarter call you had talked about site lockdowns in Australia given half of your sites are currently there.

So wondering if you could just give us an update on what you're seeing with COVID-19 in Australia, are you still seeing the site lockdowns there or are you seeing new patients coming back on -- into those trials, the ones that you identified, and are you close to finishing enrollment? Number two, on the going higher than 32 milligrams, now that we're getting close to the end of the fourth quarter here, what is your framework here, to go potentially higher than 32 milligrams given you don't need all the data from that cohort? And will you disclose this to the Street if you decide to go higher, and how will you do that? And then just lastly on 531 DMD, if you can just give us some color as to whether you plan on keeping 100% of the economics there or partnering that program out? Thanks so much..

Thank you, and I'll let Mike take the first two questions related to HD, and then I'll answer your last question on DMD.

Mike, do you want to answer the questions on HD?.

Sure. So, first of all, focusing on the environment with COVID as we said at the last call, there were lockdowns that were clearly having differences along the way and impacting our ability to recruit. That is a moving target, but I can say that as sites have closed down, others have opened up as lockdowns end, sites open up again.

So, we've been actually very fortunate that last time it was -- one of the big factors was Melbourne had just shutdown, Melbourne is up, and certainly cities and different places are opening and closing.

I mean, this is an evolving landscape where -- but we're -- what's been great is that we have really good communication with the investigators, so we can anticipate when these things are happening and then redirect if necessary, but right now with the way we're headed, none of that has impacted our ability to have the data readout in the first quarter, which is what we're reaffirming we're going to have today.

In terms of the framework to go higher with being one quarter away from the definitive multi-dose readout. At this point, we thought it may just make the most sense to wait to see that dataset in terms of degree of knockdown, in terms of the overall profile of the product before making that decision.

I mean, as we've said previously, we have the therapeutic window. We have the ability to go higher from a preclinical perspective, but being so close to the definitive readout, we just thought it was best to wait for that at this time. So that's where we are with that, and I'll pass it back to Paul for the question about the partnering..

And just, I mean, to wrap up on HD, I mean, we're excited at getting to this data readout. I mean, as you know, we provided updates. If there were any changes that impacted the updates to the readout timing and we remain on track for the first quarter of 2021 data readouts.

As far as DMD and the percent of economic, I think this is something that we thought very carefully about around where and how to partner.

I say you often partner, because you require the financial means to deliver on the data or you need to leverage some sort of operating capability or capacity to deliver that, and I think what the team has done and where we are is we can deliver this study that Mike laid out today within our runway, and therefore, I think it's important for us to continue to generate that data for both the platform and this particular program specifically, and for right now retain 100% of the economics as we push forward, but as anything, it's something that we'll continue to evaluate as we move that program forward..

Super helpful. Thanks so much, guys..

Your next question is from the line of Paul Matteis with Stifel..

Hi, thanks for taking the question. This is Alex on per Paul.

Just a couple on your AATD program, first, I was just curious if you could elaborate on how -- what proportion of the homozygous have that G-to-A mutation? And then along with that, I am curious if you can talk a little bit more about kind of the rationale for the ADAR strategy and its ability to allow for that physiologic regulation of AAT? Thanks so much..

Yes, great question. It's something we focused in about 5% to 15%. I know that's a reasonable range, our patients who are amenable. So, our number on the 250,000 patients are the estimated patient populations worldwide, so 250,000 patients worldwide that are amenable to the correction of this mutation.

I think we've stayed focused on this concept of correction around bringing kind of the concept around physiologic regulation, meaning restoring, and so, by correcting the transcript, therefore not knocking it out, but allowing for the production of a wild-type protein that then can be used as physiologically required.

So, oftentimes it's known that since it's engaging [indiscernible] to the lung, which can result from injury in the lung to activating and acquiring this protein. By having that protein around that enables it to be responsive as it would be under normal circumstances.

So I think the exciting aspect of bringing this program is really bringing a different way of thinking about the treatment of the disease, which is one around correction.

So, not taking away a mutant protein and or requiring weekly IV protein augmentation therapy, but rather restoring physiologic balance through the correction of the transcript, which is really the hallmark of RNA editing.

So we're excited about this space, and more broadly, we're excited about what it means as we think about different diseases in ADAR as a platform.

So, we do look at this, obviously, AATD as initial therapeutic approach, but I think when we step back and say, what are we learning about ADAR, we're investing and building this proprietary model that will now let us be able to cross it with multiple diseases and look at the human ADAR enzyme in the context of disease, we build models for therapeutic program, I think we think much more broadly about the treatments that could be possible with Alpha-1 antitrypsin deficiency..

Thanks so much..

Your next question is from the line of Eun Yang with Jefferies Jefferies..

Thank you, I have more speculative questions.

So on HD program, as we expect data in the first quarter of next year, hypothetically, if you see similar mutant HTT reduction at 32 milligram as what you saw as 16, would you make a go, no go decision at that point or still pursue a higher dose?.

I think that's exactly to Mike's point what we want to stay focused on in terms of analyzing the data.

So being data driven, there's a variety of biomarkers to look at and ascertain at that point, do we believe going higher will be there? Are we at that dose as we think about that, that's the point, I think if we see a plateauing, there's a variety of other biomarkers to assess as part of that clinical data outcome, and we'll have to do that in the first quarter, once we have that data.

Mike, any additional thoughts?.

No, nothing else there, Paul, I mean, we have a lot of things we're going to be looking at. So it's not the least of which is what's meaningful, in this setting, a very specific, knockdown as opposed to Pan selective, which is different, they have to be looked at differently, and that'll all be part of the conversation..

But I think, Eun in terms of having tools for the Allele-selective therapy, it's one advantage of why we're not getting the SNP-3 WV-003 on that readout.

So we're excited about driving that program forward independently because we do believe in this and this Allele-selective approach, the data that we're seeing in the literature continues to grow and wild-type sparing, and so, we'll have other programs to be able to assess that, but we'll have to look at the totality of the data in the first quarter..

Yes, that's informative, and a lot of questions on the DMD program exon 53 candidate, so in vitro model, you saw dose dependent increase in dystrophin production up to 70% of the normal, and I understand that we improve the durability and tissue penetration.

I mean, can you extrapolate from this in vitro study data to what you could realistically expect in humans?.

I think we're going to reserve speculation from the in vitro study, I think we see substantial dystrophin production with the candidate that's going to be tested in the clinic, that gives us a lot of confidence on dystrophin production and the preclinical data supporting exposure, I think, coupling that with the DKO data, which is here you have a phenotype that you can correct and restore.

I think that gives us confidence that, indeed, we are getting into dystrophic muscle and having an impact granted with the 23 molecule, but in vivo data at lower dose is less frequently, which give us confidence. I think the study that Mike laid out that we're going to be pursuing is measured for that exact reason.

I think we're disciplined after our Suvodirsen experience that we do need to see what happens in the DMD poise, and we've had a lot of conversations with the community, having seen the data, who are extraordinarily supportive after this approach and the data that we've generated, but we need to generate that data, and we're excited to be able to do that.

Mike, I don't know, you want to add to that?.

Yes, and the only thing I would add is, I think as you captured nicely, this entire DMD space is unfortunately lots of disappointment about what can translate preclinically to clinically, we have a lot of evidence that suggests that we have something here that could be different, but really the best way is to get it into human beings take a look judiciously at, we execute this study in a way that allows us to assess that profile and make determinations of next steps that we felt that was the most responsible way to proceed..

Okay, thank you very much..

Thanks, Eun..

Your next question is from the line of Yaron Werber with Cowen..

Hi guys, this is Brendan on for Yaron. Thanks very much for taking on the question. Just a couple quick ones from me, I guess. First in HD, I just wanted to check in on the wild-type huntingtin as and kind of see where this stands.

I know in the past, there has been talk of maybe some updates to the assay, it felt just to make sure you're really able to see differences and kind of little sparing effect and just kind of -- I just wanted to check in on that.

And then, for DMD, as we're kind of looking across the space, obviously, between the exon skippers and like gene therapy, for example, we're seeing kind of different, the five different mechanisms, just different results here.

So, just kind of trying to get your thoughts on where your bar is for this Phase 1, are you really hoping to see level of protein restoration or maybe improve NSA that we've seen with gene therapy, or you're really aiming for the bar closer to where we stand with exon skipping ASS? Thanks..

Excellent, I mean, the short answer on the first question is, we continue to do the work, as we alluded to earlier on the wild-type assay and we anticipate and we're working hard to deliver that with our data in the first quarter.

We agree that's an important way of driving that assessment, as it relates to the bar, I think what we were excited about now is restoring dystrophin and having an impact, this study is initially anticipated, it is not a clinical outcome study, we're not right now looking at this in the context of that would be something that would follow-up, as you pointed out, the NSA and other metrics, that's something that we could continue to follow.

I think the first question we want to ask is dystrophic muscle exposure, dystrophin production and safety, those are the key drivers to give us a sense moving forward, and we're excited about the prospects based on the preclinical work, but we also want to be really measured on where we are, I think if we see what we're seeing in the DKO mouse, which is these mice that should actually not be living, we're restoring a survival phenotype in them, and that's not just about skeletal muscle, and I think one nuance that we're excited about with the prospects of the addition of PN chemistry now is exposure to heart and diaphragm.

So these might have, the full phenotypes and are dying from cardiac and respiratory complications. So the ability to access both those other tissues beyond skeletal muscle is really what excites us about this program and at the dosing intervals and doses that we're using.

So I think there's a lot to be excited about to go forward, but again, this first study is about that measured approach to assessing that, and I'll pass to Mike, is there anything you want to add to either of those points?.

No, nothing to add to that. Thanks, Paul..

Great. Thanks, guys..

Your next question is from the line of Luca Issi with RBC Capital..

Terrific. Thank you for taking my question, congratulation on all the progress here. Two quick one for me; one, it is my understanding that all five studies that are ongoing in 2021 will be actually ex-U.S. One, is that correct? Two, if so, are you planning to open an IND in the U.S.

for any of the programs, and how should we think about timelines there, two, I think Ionis showed their initial data for SOD1-ALS was actually more impressive for fast progressors. I do suspect the same for C9 and if so, are you planning to enrich your trials for such patient? Thank you..

Thank you for your questions.

Mike, do you want to take the question?.

Sure. Yes, so regarding first question about where we're conducting the study, it's our intention for I mean as you know, PRECISION HD1, PRECISION HD2 we have some sites in the U.S., and we have some sites outside the U.S. So multidose is outside the U.S., as we've always talked about.

So regarding other programs, we anticipate that these are going to be global studies, and we anticipate conducting these studies in the U.S., except for in N531, as we've already said will be just a small proof-of-concept study ex-U.S. So I would, so that is our intention. We're very optimistic that we'll be able to do that.

Regarding the second question, which was again….

I was just wondering about SOD1, I think as Ionis for this study. Yes, go ahead..

I'm sorry, yes, thank you. No, sorry about that. Yes, so we'll give more details of the study design early next year, but what I can say is that, I mean one thing about C9orf72 disease in ALS patients, it is a fairly rapidly progressive, they progress it a little more rapid rate than other groups of ALS patients.

So, that's going to be something that will just be a factor of the population itself.

The way we're approaching our C9orf72 program is really focusing on C9 disease, if you will, these are patients that could have ALS, they could have FTD, they can have the overlap condition, which is actually fairly, not unusual, and that we're really looking to target the disease itself at its origins in both population focusing on a biomarker readout that will allow us then to make those decisions on how we progress clinically.

So that's how we're approaching it. Again, we're approaching it as a single, rapidly progressive thing focused on target engagement at the biomarker level..

Great, thanks guys..

Thank you..

I'm showing no further questions at this time. I would now like to turn the conference back to Dr. Paul Bolno..

Thanks everyone for joining the call this morning to review our third quarter update, and thanks to our employees for their hard work and commitment to patients. We look forward to speaking with you all again soon. Have a nice day. Thank you..

Ladies and gentlemen, this concludes today's conference. Thank you for your participation and have a wonderful day. You may all disconnect..