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Item 1. Business

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We are a clinical-stage biotechnology company focused on unlocking the broad potential of RNA medicines (also known as oligonucleotides), or those targeting ribonucleic acid (“RNA”), to transform human health.

Our RNA medicines platform, PRISM TM , combines multiple modalities, chemistry innovation and deep insights into human genetics to deliver scientific breakthroughs that treat both rare and prevalent disorders.

Our toolkit of RNA-targeting modalities includes RNA editing, splicing, antisense silencing and RNA interference (“RNAi"), providing us with unique capabilities for designing and sustainably delivering candidates that optimally address disease biology.

Our lead programs are in rare and prevalent diseases, including alpha-1 antitrypsin deficiency (“AATD”), obesity, Duchenne muscular dystrophy (“DMD”), and Huntington’s disease (“HD”).

We are a clinical-stage biotechnology company focused on unlocking the broad potential of ribonucleic acid (“RNA”) medicines (also known as oligonucleotides), or those targeting RNA, to transform human health.

Our RNA medicines platform, PRISM ® , combines multiple modalities, chemistry innovation and deep insights into human genetics to deliver scientific breakthroughs that treat both rare and common disorders.

Our toolkit of RNA-targeting modalities includes RNA editing, splicing, silencing using RNA interference (“siRNA") and antisense silencing, providing us with unique capabilities for designing and sustainably delivering candidates that optimally address disease biology.

Our diversified pipeline includes clinical programs in obesity, alpha-1 antitrypsin deficiency (“AATD”), Duchenne muscular dystrophy (“DMD”), and Huntington’s disease (“HD”), as well as several preclinical programs utilizing our versatile RNA medicines platform.

We were founded on the recognition that there was a significant, untapped opportunity to use chemistry innovation to tune the pharmacological properties of oligonucleotides.

Today, we have more than a decade of experience challenging convention related to oligonucleotide design and pioneering novel chemistry modifications to optimize the pharmacological properties of our molecules.

We have seen preclinically and in clinical trials that these chemistry modifications enhance potency, distribution, and durability of effect of our molecules.

Our novel chemistry also allows us to avoid using complex delivery vehicles, such as lipid nanoparticles and viruses, and instead use clinically proven conjugates (e.g.

N -acetylgalactosamine or (“GalNAc”)) or free uptake for delivery to a variety of cell and tissue types.

We have more than a decade of experience challenging convention related to oligonucleotide design and pioneering novel chemistry modifications to optimize the pharmacological properties of our molecules.

We have seen in clinical trials that these chemistry modifications enhance potency, distribution, and durability of effect of our molecules.

Our novel chemistry also allows us to avoid using complex delivery vehicles, such as lipid nanoparticles and viruses, and instead use clinically proven conjugates ( e.g., N -acetylgalactosamine or (“GalNAc”)) or free uptake for delivery to a variety of cell and tissue types.

We maintain strong and broad intellectual property, including for our novel chemistry modifications.

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By opening up new areas of biology, we have also opened up new opportunities to slow, stop or reverse disease and have expanded the possibilities offered through our platform.

The inspiration for our multimodal platform is based on the recognition that the biological machinery (i.e.

enzymes) needed to address human disease already exists within our cells and can be harnessed for therapeutic purposes with the right tools.

The inspiration for our multimodal platform is based on the recognition that the biological machinery (i.e., enzymes) needed to address human disease already exists within our cells and can be harnessed for therapeutic purposes with the right tools.

We believe that we have built the most versatile toolkit of RNA-targeting modalities in the industry, with multiple means of repairing, restoring, or reducing proteins and designing best-fit solutions based on the unique biology of a given disease target.

We are actively advancing programs in all of our modalities.

We are actively advancing programs using four distinct modalities, including novel A-to-I RNA editing oligonucleotides (“AIMers”).

These modalities include:

• RNA editing, which uses AIMers that are designed to target single bases on an RNA transcript and recruit endogenous ADAR enzymes that naturally possess the ability to change an adenine (A) to an inosine (I), which cells read as guanine (G).

This approach enables both the correction of G-to-A point mutations and the modulation of RNA to either upregulate protein expression, modify protein-protein interactions, or alter RNA folding and processing.

AIMers are short in length, fully chemically modified, and use our novel chemistry, which make them distinct from other ADAR-mediated editing approaches.

• Antisense (silencing) , which uses our oligonucleotide designed to bind to a specific sequence in a target RNA strand that encodes a disease-associated protein or pathogenic RNA.

The resulting double-stranded molecule (“duplex”) is then recognized by a cellular enzyme called RNase H, which cleaves, or cuts, the target RNA in the duplex, thereby preventing the disease-associated protein from being made.

• RNA interference (RNAi ) (silencing) , which uses our double-stranded RNAs called siRNAs to engage the RNAi machinery known as the RNA-induced silencing complex (“RISC”) and to silence a target RNA that is either pathogenic itself or encodes a disease-associated protein, thereby preventing the accumulation of the pathogenic species (RNA or protein).

• Splicing / exon skipping , which is the processing of a nascent pre-mRNA transcript into mRNA by removing introns and joining exons together.

Exon skipping uses our oligonucleotide designed to bind to a particular sequence within a target pre-mRNA and direct the cellular machinery to alter the final composition of exons in mature mRNA by deleting, or splicing out, certain specific regions of that RNA.

We intentionally focus on targeting the transcriptome using oligonucleotides rather than other nucleic acid modalities such as gene therapy and DNA editing.

This focus enables us to:

• Leverage diversity of expression across cell types by modulating the many regulatory pathways that impact gene expression, including transcription, endogenous RNA interference pathways, splicing, and translation;

• Leverage diversity of expression across cell types by modulating the many regulatory pathways that impact gene expression, including transcription, endogenous RNAi pathways, splicing, and translation;

• Address diseases that have historically been difficult to treat with small molecules or biologics;

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• Leverage well-established industry manufacturing processes and regulatory, access, and reimbursement pathways.

We have a robust and diverse pipeline of potential first-or best-in-class programs, including:

We have a robust and diverse pipeline of potential first-or best-in-class programs addressing both rare and common diseases::

• GalNAc-conjugated oligonucleotides for hepatic and metabolic diseases including:

WVE-006 is a GalNAc-conjugated SERPINA1 RNA editing oligonucleotide.

Lead clinical candidate is a GalNAc-conjugated RNAi oligonucleotide targeting inhibin βE (“INHBE”).

WVE-007 is a GalNAc-conjugated siRNA targeting inhibin βE (“INHBE”);

• Alpha-1 antitrypsin deficiency ("AATD"):

WVE-006 is a GalNAc-conjugated SERPINA1 AIMer;

• Liver disease:

GalNAc-conjugated AIMer targeting PNPLA3 I148M for correction;

• Heterozygous Familial Hypercholesterolemia (“HeFH”):

GalNAc-conjugated AIMer targeting low-density lipoprotein receptor (“LDLR”) for upregulation and GalNAc-conjugated AIMer targeting apolipoprotein B (“APOB”) for correction.

• Unconjugated oligonucleotides for muscle, CNS and other disease areas including:

• Duchenne muscular dystrophy ("DMD"):

WVE-N531 is an exon 53 splicing oligonucleotide;

WVE-003 is a selective mutant huntingtin (“mHTT”)-lowering SNP3 antisense silencing oligonucleotide.

We are also building a pipeline of novel A-to-I RNA editing oligonucleotides (“AIMers”).

Our RNA editing capability affords us the dexterity to address both rare diseases, as well as those diseases impacting large patient populations.

AIMers are designed to target single bases on an RNA transcript and recruit proteins that exist in the body, called ADAR enzymes, which naturally possess the ability to change an adenine (A) to an inosine (I), which cells read as guanine (G).

AIMers enable simplified delivery and avoid the risk of permanent changes to the genome and irreversible off-target effects with DNA-targeting approaches.

AIMers are short in length, fully chemically modified, and use our novel chemistry, which make them distinct from other ADAR-mediated editing approaches.

In December 2022, we announced a strategic collaboration with GlaxoSmithKline Intellectual Property (No.

3) (“GSK”) to advance transformative oligonucleotide therapeutics, including WVE-006.

The collaboration combines GSK’s novel genetic insights, as well as its global development and commercial capabilities, with our PRISM platform and oligonucleotide expertise.

The collaboration will enable us to continue building a pipeline of first-in-class oligonucleotide-based therapeutics and unlock new areas of disease biology, as well as realize the full value of WVE-006 as a potential best-in-class treatment for AATD that has the potential to simultaneously address both liver and lung manifestations of the disease.

Our GSK collaboration has three components:

(1) A discovery collaboration which enables us to advance up to three programs leveraging targets informed by GSK’s novel insights, the first of which is our INHBE program for obesity and other metabolic disorders;

(2) A discovery collaboration which enables GSK to advance up to eight programs leveraging PRISM and our oligonucleotide expertise and discovery capabilities;

(3) An exclusive global license for GSK to WVE-006, our AATD program, that uses our proprietary AIMer technology.

We will maintain development responsibilities for WVE-006 through completion of RestorAATion-2, at which point development and commercial responsibilities will transition to GSK.

• Huntington’s disease ("HD"):

WVE-003 is an allele-selective oligonucleotide designed to lower mutant huntingtin (“mHTT”) protein and preserve healthy, wild-type huntingtin (“wtHTT”) protein.

Our Current Programs

Additional details regarding our lead therapeutic programs are set forth below.

Background and Market Opportunity

Obesity is increasingly being recognized as a growing global epidemic.

In the United States, an estimated 42% of the adult population is living with obesity, and there are an estimated 175 million adults with obesity in the United States and Europe.

Adults with obesity have higher risk for many serious health conditions, including heart disease, type 2 diabetes, and some forms of cancer;

and obesity is estimated to cost the U.S.

healthcare system almost $173 billion annually.

Current Treatments

There are two GLP-1 receptor agonists approved in the United States and the European Union (“EU”) for the treatment of obesity:

Saxenda (liraglutide, Novo Nordisk) and Wegovy (semaglutide, Novo Nordisk).

Tirzepatide (Eli Lilly), approved as Zepbound by the U.S.

Food and Drug Administration (“FDA”) and as Mounjaro by the European Medicines Agency (“EMA”) in November 2023, is a GLP-1/GIP receptor agonist.

Other FDA-approved therapies for obesity include Xenical (H2-Pharma, approved in the United States in 1999), Qsymia (Vivus, approved in the United States in 2012), and Contrave (Currax Pharmaceuticals, approved in the United States in 2014).

Although GLP-1 receptor agonists induce weight loss, there remains a substantial unmet need in obesity, as GLP-1 receptors lead to weight loss at the expense of muscle mass.

For instance, in a Phase 3 study of semaglutide, 34% of total weight loss was from loss of lean mass (King 2021), and in a Phase 3 study of tirzepatide, treatment led to an approximately 34% loss in fat mass and an approximately 11% loss in lean mass (Jastreboff 2022).

GLP-1s have also been shown to suppress the general reward system and are associated with a poor tolerability profile, frequent (weekly) administration, and discontinuation rates up to 68%.

Our Obesity Program

WVE-007 is a GalNAc-siRNA that is designed to silence the INHBE gene to induce lipolysis (fat-burning) while preserving muscle mass to restore and maintain a healthy metabolic profile.

Heterozygous INHBE loss-of-function (“LoF”) human carriers exhibit a healthy metabolic profile, including reduced waist-to-hip ratio and reduced odds of developing type 2 diabetes or coronary artery disease, and reduction of INHBE by 50% or more is expected to restore a healthy metabolic profile.

In connection with our 2023 Research and Development Day, we shared in vivo proof-of-concept data in diet-induced obesity (“DIO”) mice demonstrating INHBE silencing well beyond the anticipated 50% therapeutic threshold, which led to substantially lower body weight and reduction of visceral fat as compared to controls.

These are the first data to demonstrate INHBE silencing in vivo in an animal model is consistent with the phenotypes of heterozygous loss-of-function carriers.

WVE-007 utilizes our next generation GalNAc-siRNA format.

In preclinical diet-induced obesity (“DIO”) mouse models, our INHBE GalNAc-siRNA has demonstrated highly potent INHBE silencing (ED50 < 1 mg/kg), durable silencing following one, low-single digit dose supporting every-six-month or annual subcutaneous dosing in humans, weight loss with no loss of muscle mass and reduction in fat mass, with preferential effect to the visceral fat, consistent with the profile of INHBE LoF in human genetics.

(left, middle, right) Linear Mixed Effects ANOVA with post hoc comparisons of marginal treatment effects vs.

PBS per timepoint (left) or per tissue (middle, right) * p < 0.05

In a head-to-head study in DIO mice, we have observed a weight loss effect from a single dose of our INHBE GalNAc-siRNA similar to semaglutide.

In addition, treatment with our INHBE GalNAc-siRNA prior to cessation of semaglutide treatment curtailed expected rebound weight gain.

Additionally, in a separate ongoing study in DIO mice, when administered as an add-on to semaglutide, a single dose of our INHBE GalNAc-siRNA doubled the weight loss observed with semaglutide alone, and this effect was sustained throughout the duration of the study.

10nmol/kg in mouse is equivalent to therapeutic dose of GLP-1s in human.

Linear Mixed Effects ANOVA with post hoc comparisons of marginal treatment effects of Semaglutide vs.

Semaglutide + INHBE GalNAc-siRNA per time point * p < 0.05;

Linear Mixed Effects ANOVA with post hoc comparison of Day 28 vs.

Day 56 marginal effects per treatment * p < 0.05

In February 2025, we announced that we had initiated INLIGHT, the first-in-human Phase 1 clinical trial of WVE-007 in obesity.

INLIGHT is enrolling adults living with overweight or obesity to assess safety, tolerability, pharmacokinetics (“PK”), biomarkers for target engagement, body weight and composition, and metabolic health.

Dosing in INLIGHT is underway and we expect to deliver clinical data from INLIGHT in the second half of 2025.

Alpha-1 antitrypsin deficiency (“AATD”)

Our AATD program is the first to leverage our novel RNA editing capability and uses GalNAc-conjugated AIMers (RNA editing oligonucleotides) and endogenous ADAR enzymes to correct a single base in the mutant SERPINA1 mRNA.

By correcting the single RNA base mutation that causes a majority of AATD cases with the Pi*ZZ genotype (approximately 200,000 in the United States and Europe), RNA editing may provide an ideal approach for increasing circulating levels of wild-type Alpha-1 antitrypsin (“AAT”) protein and reducing mutant protein aggregation in the liver, thus simultaneously addressing both the lung and liver manifestations of the disease.

WVE-006 is first-in-class in AATD and is the most advanced program currently in development using an oligonucleotide to harness an endogenous enzyme for RNA editing.

In the fourth quarter of 2023, we initiated our RestorAATion clinical program investigating WVE-006 as a treatment for AATD.

The RestorAATion clinical program includes both healthy volunteers (“RestorAATion-1”), as well as patients with AATD who have the homozygous Pi*ZZ mutation (“RestorAATion-2”) and is designed to provide an efficient path to proof-of-mechanism as measured by restoration of wild-type alpha-1 antitrypsin (“M-AAT”) protein in serum.

Dose escalation is ongoing in healthy volunteers in RestorAATion-1.

We expect to deliver proof-of-mechanism data in patients with AATD in 2024.

Under our GSK collaboration, GSK received an exclusive global license for WVE-006, with clinical development and commercial responsibilities transitioning to GSK after we complete the RestorAATion-2 trial.

Background and Market Opportunity

We are leveraging our RNA editing platform capability to develop a first-in-class treatment for AATD.

AATD is a rare, inherited genetic disorder that is commonly caused by a G-to-A point mutation in the SERPINA1 gene;

this mutant allele is termed the Z allele.

This mutation leads to misfolding and aggregation of Z-AAT protein in hepatocytes and a lack of functional Alpha-1 antitrypsin (“AAT”) in the lungs.

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

Weekly intravenous augmentation therapy is the only treatment option for AATD in those with the lung pathology;

there are currently no approved therapies to address the liver pathology.

Approximately 200,000 people in the United States and Europe are homozygous for the Z allele, which is the most common form of severe disease.

Current Treatments

There are five treatments currently approved in the United States for chronic augmentation and maintenance therapy in adults with emphysema due to congenital deficiency of alpha1-proteinase inhibitor (“Alpha1-PI”).

Per FDA labeling for each, the effect of augmentation therapy with any Alpha1-PI on pulmonary exacerbations and on the progression of emphysema in Alpha1-PI deficiency has not been demonstrated in randomized, controlled clinical trials.

Augmentation therapy is also approved in the EU, but reimbursement and accessibility vary by country.

Patients with AATD can also be treated with therapies used in other lung diseases including bronchodilators to open airways and corticosteroids to reduce chronic inflammation common in the lungs of patients with AATD.

There are currently no approved therapies to prevent the accumulation of the misfolded AAT protein in the liver.

Treatments are available to help deal with intestinal bleeding, fluid in the abdomen, nutritional issues, and other complications from scarring of the liver, but ultimately many patients will progress towards requiring a liver transplant.

Our AATD Program

Our AATD program uses our novel GalNAc-conjugated AIMers (RNA editing oligonucleotides) and endogenous ADAR enzymes to correct a single base in the mutant SERPINA1 mRNA.

By correcting the single RNA base mutation that causes a majority of AATD cases with the Pi*ZZ genotype (approximately 200,000 in the United States and Europe), RNA editing may provide an ideal approach for increasing circulating levels of wild-type AAT protein and reducing mutant protein aggregation in the liver, thus simultaneously addressing both the lung and liver manifestations of the disease.

WVE-006 is first-in-class in AATD and is the most advanced program currently in clinical development using an oligonucleotide to harness an endogenous enzyme for RNA editing.

Our RestorAATion clinical program investigating WVE-006 as a treatment for AATD is comprised of two parts:

RestorAATion-1, a study of healthy volunteers;

and RestorAATion-2, a study in patients with AATD who have the homozygous Pi*ZZ mutation.

We have completed multi-dosing in healthy volunteers in the top cohort of RestorAATion-1 at a dose level greater than those planned for any cohort in RestorAATion-2.

RestorAATion-2 is a Phase 1b/2a open label study designed to evaluate the safety, tolerability, pharmacodynamics (“PD”) and PK of WVE-006 in individuals with AATD who have the homozygous Pi*ZZ mutation.

The trial includes both single ascending dose (“SAD”) and multiple ascending dose (“MAD”) portions.

In October 2024, we announced positive proof-of-mechanism data from the ongoing Phase 1b/2a RestorAATion-2 study:

Following a single subcutaneous dose of 200 mg of WVE-006 in the study’s first two patients, circulating wild-type M-AAT protein in plasma reached a mean of 6.9 micromolar at day 15, representing more than 60% of total AAT.

Increases in neutrophil elastase inhibition from baseline were consistent with production of functional M-AAT.

Mean total AAT protein increased from below the level of quantification at baseline to 10.8 micromolar at day 15, meeting the level that has historically been the basis for regulatory approval for AAT augmentation therapies.

Increases in total AAT from baseline and M-AAT protein were observed as early as day 3 and through day 57.

WVE-006 was well-tolerated with a favorable safety profile.

All adverse events in RestorAATion-2, as well as in the RestorAATion-1 trial of healthy volunteers, were mild to moderate, with no serious adverse events (“SAEs”) reported.

These data were the first-ever clinical demonstration of RNA editing in humans.

In the first quarter of 2025, we initiated multi-dosing in the first cohort of RestorAATion-2, where patients are receiving 200 mg subcutaneous doses every two weeks, and initiated the second single dose cohort of RestorAATion-2 at 400 mg.

We expect to share multi-dose data from RestoraAATion-2 in 2025.

GSK has an exclusive global license for WVE-006, with clinical development and commercial responsibilities transitioning to GSK after we complete the RestorAATion trial.

Under the terms of the collaboration, we are eligible to receive up to $525 million in development, launch, and commercial milestone payments, as well as double-digit tiered royalties up to the high teens, as a percentage of net sales for WVE-006.

In December 2023, we announced that we achieved the first WVE-006 milestone in our collaboration with GSK, resulting in a $20 million payment.

Under the terms of the collaboration, we are eligible to receive up to $505 million in additional development, launch, and commercial milestone payments, as well as double-digit tiered royalties up to the high teens, as a percentage of net sales for WVE-006.

Preclinical data show that treatment with WVE-006 resulted in serum AAT protein levels of up to 30 micromolar in an established AATD mouse model (NSG-PiZ).

WVE-006 also led to restoration of approximately 50% wild-type M-AAT protein in serum and a 3-fold increase in neutrophil elastase inhibition activity, indicating that the restored M-AAT protein was functional.

Wave’s AATD AIMers are highly specific to SERPINA1 RNA in vitro and in vivo based on transcriptome-wide analyses.

If we are successful in the clinic with WVE-006, we will validate our clinical approach to AATD and demonstrate the feasibility of RNA editing as a therapeutic modality in humans.

Obesity and Other Metabolic Disorders

Our first wholly owned program to emerge from our collaboration with GSK is a GalNAc-conjugated siRNA silencing program targeting INHBE for obesity.

There are approximately 174 million people in the United States and Europe with obesity, and

therapeutic options beyond GLP-1 receptor agonists are needed.

GLP-1 receptor agonists lead to weight loss at the expense of muscle, suppress the general reward system, and are associated with a poor tolerability profile, with 68% drop-off after one year.

Heterozygous INHBE loss-of-function human carriers exhibit a healthy metabolic profile, including reduced waist-to-hip ratio and reduced odds of developing type 2 diabetes or coronary artery disease, and reduction of INHBE by 50% or more is expected to restore a healthy metabolic profile.

In connection with our 2023 Research and Development Day (“R&D Day”), we shared in vivo proof of concept data in diet-induced obesity mice demonstrating INHBE silencing well beyond the anticipated 50% therapeutic threshold, which led to substantially lower body weight and reduction of visceral fat as compared to controls.

These are the first data to demonstrate INHBE silencing in vivo in an animal model is consistent with the phenotypes of heterozygous loss-of-function carriers.

In March 2024, we announced the selection of our INHBE lead clinical candidate, which utilizes our next generation GalNAc-siRNA format.

This next generation format results in more potent and durable siRNA silencing and when applied to our INHBE program resulted in:

1) highly potent INHBE silencing (ED50 < 1 mg/kg), durable silencing following one, low-single digit dose in preclinical mouse models supporting every-six-month or annual subcutaneous dosing;

3) Weight loss with no loss of muscle mass;

4) Reduction in fat mass, with preferential effect to the visceral fat, consistent with the profile of INHBE LoF in human genetics.

We expect to initiate a clinical trial for our INHBE candidate in the first quarter of 2025.

Our AATD AIMers are highly specific to SERPINA1 RNA in vitro and in vivo based on transcriptome-wide analyses.

Duchenne muscular dystrophy (“DMD”)

Background and Market Opportunity

DMD is a rare, genetic progressive neuromuscular disorder caused by mutations in the dystrophin gene on the X chromosome that affects approximately one in 5,000 newborn boys around the world (approximately 20,000 new cases annually).

The dystrophin protein is part of a protein complex called the dystrophin-associated protein complex that acts as an anchor, connecting each muscle cell’s structural framework with a lattice of proteins and other molecules outside the cell through the muscle cell membrane.

The dystrophin-associated protein complex protects the muscle from injury during contraction and relaxation.

Patients with DMD typically develop muscle weakness in the early years of life and become wheelchair-bound in their early teens.

As the disease progresses, patients with DMD typically develop respiratory, orthopedic, and cardiac complications.

Cardiomyopathy and breathing difficulties usually begin by the age of 20, and few individuals with DMD live beyond their thirties.

Current Treatments

While there are approved therapies for DMD, there is no cure, and there continues to be significant unmet medical need.

In most countries, corticosteroids are the standard drug therapy, which slows the progression of muscle weakness and delays loss of ambulation by two to three years.

In 2017, Emflaza (deflazacort) became the first corticosteroid approved by the FDA as a treatment for patients with DMD.

Santhera Pharmaceuticals’ Agamree (vamorolone), an alternative steroid, was approved in the United States and EU in 2023.

In 2024, FDA granted approval to Italfarmaco/ITF Therapeutics’ Duvyzat (givinostat), a histone deacetylase inhibitor.

Four exon skipping therapies have been approved in the United States, all under the accelerated approval pathway.

They include three products from Sarepta Therapeutics:

Exondys 51 (eteplirsen) for exon 51 skipping, approved in 2016;

Vyondys 53 (golodirsen) for exon 53 skipping, approved in 2019;

and Amondys 45 (casimersen) for exon 45 skipping, approved in 2021.

NS Pharma’s Viltepso (viltolarsen) was approved for exon 53 skipping in 2020.

All of these products require weekly IV infusion, and to date, none of these products has demonstrated clinical benefit in a confirmatory trial.

Sarepta Therapeutics’ Elevidys, a microdystrophin gene therapy, is available in the United States and select ex-EU markets.

The labeled indication in the United States is currently for ambulatory and non‑ambulatory DMD patients aged at least four years who have a confirmed mutation in the DMD gene.

The indication that includes ambulatory DMD patients was granted under a traditional approval, and the indication that includes non‑ambulatory DMD patients was approved under accelerated approval based on expression of Elevidys microdystrophin.

Continued approval for non‑ambulatory DMD patients may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

In 2014, PTC Therapeutics’ Translarna (ataluren) was the first disease-modifying treatment to receive conditional approval by the EMA for patients with DMD who have a nonsense mutation (12% of DMD cases) in the dystrophin gene.

However, in 2023, the Committee for Medicinal Products for Human Use (“CHMP”) of the EMA issued a negative opinion on the renewal of the conditional marketing authorization, and in 2024, CHMP re-confirmed this negative opinion.

Once adopted by the European Commission, this ruling will result in the withdrawal of Translarna from the EU market.

Our DMD Program

In DMD, we are advancing WVE-N531, which is designed to skip exon 53 within the dystrophin gene – a therapeutic approach that would address approximately 8-10% of DMD cases.

WVE-N531 is designed to cause the cellular splicing machinery to skip over exon 53 during pre-mRNA processing, which restores the dystrophin mRNA reading frame and enables production of a truncated, but functional, dystrophin protein.

Exon skipping produces dystrophin from the endogenous dystrophin gene (not micro or mini dystrophin expressed from a foreign vector), under the control of native gene-regulatory elements, resulting in normal expression.

WVE-N531 is our first splicing candidate incorporating PN backbone (“PN”) chemistry to be assessed in the clinic.

In December 2022 (data cut-off:

December 6, 2022), we announced a positive update from Part A of the Phase 1b/2a proof-of-concept, open label trial of WVE-N531 in three boys with DMD amenable to exon 53 skipping.

In the third quarter of 2024, the FDA granted Rare Pediatric Disease Designation and Orphan Drug Designation to WVE-N531.

In December 2022, we announced a positive update from Part A of the Phase 1b/2a proof-of-concept, open label trial of WVE-N531 in three boys with DMD amenable to exon 53 skipping.

High muscle concentrations of WVE-N531 and exon skipping were observed six weeks after initiating multi-dosing at 10 mg/kg every other week, achieving proof-of-concept in the trial.

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In December 2023, we initiated dosing of WVE-N531 in FORWARD-53, the Phase 2 portion of the open-label trial (“Part B”).

Boys are being dosed at 10 mg/kg every other week, and we plan to assess dystrophin protein after 24 and 48 weeks of dosing.

The primary endpoint will be dystrophin protein levels, and the trial will also evaluate pharmacokinetics, digital and functional endpoints, and safety and tolerability.

We expect to deliver data from FORWARD-53, including dystrophin protein expression from muscle biopsies taken after 24 weeks of treatment, in the third quarter of 2024.

The study is designed to administer 10 mg/kg infusions of WVE-N531 every two weeks (“Q2W”), and muscle biopsies are taken after 24 and 48 weeks of dosing.

The primary endpoint will be dystrophin protein levels, and the trial will also evaluate PK, digital and functional endpoints, and safety and tolerability.

In September 2024, we announced positive interim data from the ongoing Phase 2 FORWARD-53 study.

Eleven boys amenable to exon 53 skipping (age 5-11;

10 ambulatory and 1 non-ambulatory) are enrolled.

The interim analysis was conducted after 24 weeks of 10 mg/kg dosing Q2W.

WVE-N531 appeared safe and well tolerated.

We observed mean muscle content-adjusted dystrophin expression of 9.0% and unadjusted dystrophin of 5.5%, with high consistency across participants, in a prespecified analysis of ambulatory participants.

*Excluded from prespecified mean analysis of ambulatory patients;

Muscle content adjustment was done using the formula:

MHC-normalized dystrophin/(total myofiber area/total area of biopsy section);

Graph shows all patients (including non-ambulatory) with appropriate biopsy sample;

dystrophin measured by Western Blot (AB15277)

Dystrophin expression was quantified from two isoforms consistent with those observed in Becker muscular dystrophy patients who display milder disease.

In addition, we observed meaningful improvements in serum biomarkers for muscle health, with localization of WVE-N531 in myogenic stem cells and in myofibers.

Mean skeletal muscle concentrations of ~41,000 ng/g and a 61-day tissue half-life support monthly dosing going forward.

The FORWARD-53 trial is ongoing and all patients have elected to continue treatment in the planned extension portion of the study with monthly doses of WVE-N531.

In the first quarter of 2025, we expect to deliver the 48-week FORWARD-53 data and feedback from regulators on a pathway to accelerated approval.

Pending positive results from this trial, we are planning to advance a broader DMD pipeline with PN-modified splicing oligonucleotides designed to skip other exons, with the goal of providing new treatment options for a larger population of boys with DMD.

Huntington’s disease (“HD”)

In HD, we are currently advancing WVE-003, a stereopure antisense oligonucleotide designed to selectively target an undisclosed single nucleotide polymorphism (“SNP”), “mHTT SNP3”, associated with the disease-causing mHTT mRNA transcript within the Huntingtin (“HTT”) gene.

Approximately 40% of the HD population carries SNP3 according to published literature (Carroll et al., Molecular Therapy, 2011).

WVE-003 incorporates our novel PN chemistry.

Targeting mRNA with SNP3 allows us to lower expression of transcript from the mutant allele, while leaving the healthy transcript relatively intact, thereby preserving wild-type (healthy) huntingtin (“wtHTT”) protein, which is important for neuronal function.

Background and Market Opportunity

HD is a rare hereditary neurodegenerative disease that results in early death and for which there is no cure.

In patients with HD, there is a progressive loss of neurons in the brain leading to cognitive, psychiatric, and motor disabilities.

HD is caused by a mutation (an expanded cytosine-adenine-guanine (“CAG”) triplet repeat) in the Huntingtin (“ HTT”) gene, which results in production of mHTT protein and decreases the amount of wtHTT protein that is expressed.

Patients with HD still express some wtHTT protein, which is important for neuronal function, and which may be neuroprotective in an adult brain.

Studies suggest a multifaceted mechanism by which gain of mHTT protein and a concurrent loss of wtHTT protein may drive the pathophysiology of HD.

Accordingly, therapeutic approaches for HD that aim to lower mHTT but that also suppress wtHTT may have detrimental long-term consequences.

Wild-type HTT is important both for normal neuronal function in the adult CNS and for protection against HD.

It can protect against stress-induced neurodegeneration in multiple model systems:

in cultured neurons, wtHTT is protective against stress-induced apoptosis;

in mice, postnatal deletion of wtHTT leads to progressive neurological phenotypes, neurodegeneration, and premature death, whereas overexpression of wtHTT conveys neural protection during stress, including ischemia and other types of CNS injury, as well as NMDA-induced excitotoxicity.

In the YAC128 mouse model of HD, overexpression of wtHTT ameliorates striatal neuropathology, whereas loss of the wild-type mouse Htt worsens motor performance, survival, and striatal neuronal size.

In patients with HD, a variant in a regulatory element impacts expression of the associated HTT gene.

An A variant decreases expression relative to a G variant at this position.

Accordingly, when the A variant associates with mHTT, expression of mHTT is reduced and disease onset is delayed (on average, 10 years).

By contrast, when the A variant associates with wtHTT, expression of wtHTT is reduced and disease onset is earlier (on average, four years), indicating that increased expression of wtHTT can be protective against HD in patients.

Together, these studies provide evidence that wtHTT is both neural protective during stress and is specifically protective against HD;

thus, we believe an allele-selective therapeutic, one that can diminish the production of mHTT while sparing wtHTT, may be ideal.

In patients with HD, a variant in a regulatory element impacts expression of the associated HTT gene.

Accordingly, the variant that decreases expression of mHTT associates with delayed onset of disease (on average by 10 years compared with the variant that increases mHTT expression).

By contrast, the same variant that decreases expression of wtHTT associates with earlier onset (on average four years compared with increased wtHTT expression), indicating that increased expression of wtHTT can be protective against HD in patients.

Together, these studies provide evidence that wtHTT is both neural protective during stress and is specifically protective against HD;

thus, we believe an allele-selective therapeutic, one that can diminish the production of mHTT while sparing wtHTT, may be ideal.

Symptoms of HD typically appear between the ages of 30 and 50 and worsen over the next 10 to 20 years.

Many describe the symptoms of HD as similar to having amyotrophic lateral sclerosis, Parkinson’s Disease and Alzheimer’s Disease simultaneously.

Patients experience a reduction in motor function and psychological disturbances.

Life expectancy after symptom onset is approximately 20 years.

In the most symptomatic stages, often lasting over 10 years, affected persons become fully dependent upon others to manage all activities of daily living;

they lose the ability to make decisions, feed themselves and walk, and often require premature placement in a long-term care facility.

It is estimated that there are over 200,000 individuals with HD across all disease stages in the United States and Europe;

~160,000 are pre-symptomatic and ~65,000 are symptomatic.

Our allele-selective approach may enable us to address both the symptomatic and pre-symptomatic populations.

Medium spiny neurons in a deep brain region called the striatum, which is composed of caudate and putamen, are particularly sensitive to death in HD.

Caudate volume, as measured by magnetic resonance imaging (“MRI”), is an imaging biomarker that consistently shows atrophy at the earliest stages of disease, and it is one of the biomarkers that serves as a landmark for disease progression (Tabrizi et al., 2022 Lancet Neurol).

Our evaluation of longitudinal natural history data from TRACK-HD and PREDICT-HD demonstrate that an absolute reduction of 1% in the rate of caudate atrophy is associated with a delay of onset of disability for individuals with HD of at least 7.5 years.

TRACK-HD (n=366) and PREDICT-HD (n=1,078) are longitudinal HD natural history studies that include MRI brain imaging, clinical outcome assessments.

Paulson et al., Neurosci.2014, Tabrizi et al., Lancet Neurol 2009, Tabrizi et al., Lancet Neurol 2012, Tabrizi et al., Lancet Neurol.

Current Treatments

There are currently no approved treatments that can reverse or slow HD progression.

Current pharmacological therapies only address HD symptoms.

Antipsychotics are used to manage depression, irritability, and chorea (involuntary movements).

Xenazine (tetrabenazine), Austedo (deutetrabenazine), and as of August 2023, Ingrezza (valbenazine) are the only therapies approved for the treatment of chorea associated with HD in the United States.

In the EU, Xenazine, Haldol (haloperidol), and Tiapridal (tiapride) are approved for the treatment of chorea associated with HD.

Our HD Program

In HD, we are currently advancing WVE-003, a stereopure allele-selective oligonucleotide designed to selectively target rs362273, a variant of the single nucleotide polymorphism (“SNP”), “mHTT SNP3”, associated with the disease-causing mHTT mRNA transcript within the HTT gene (Iwamoto et al., MTNA).

Approximately 40% of the HD population carries SNP3 according to published literature (Carroll et al., Molecular Therapy, 2011), and up to 80% of HD may be addressed in the future with other SNP-targeted candidates.

WVE-003 incorporates our proprietary PN chemistry.

Targeting mRNA through SNP3 allows us to lower expression of transcript from the mutant allele, while leaving the healthy transcript relatively intact, thereby preserving wild-type (healthy) huntingtin (“wtHTT”) protein, which is important for neuronal function.

Only an allele-selective approach to mHTT lowering has the potential to both protect the reservoir of wtHTT protein and decrease the mHTT to wtHTT ratio in neurons, potentially releasing wtHTT from the inhibitory actions of mHTT.

Our allele-selective approach may also enable us to address the premanifest HD patient population in the

In preclinical studies, WVE-003 showed dose-dependent and selective reduction of mHTT mRNA in vitro , as well as potent and durable knockdown of mHTT mRNA and protein in vivo in mouse models.

The SELECT-HD trial, which incorporates learnings from our prior HD programs, is a multicenter, randomized, double-blind, placebo-controlled Phase 1b/2a clinical trial to assess the safety and tolerability of intrathecally administered WVE-003 for patients with early manifest HD.

Additional objectives include measurement of mHTT and wtHTT protein in cerebrospinal fluid (“CSF”) and exploratory pharmacokinetic, pharmacodynamic, clinical and magnetic resonance imaging (“MRI”) endpoints.

The SELECT-HD trial is designed to be adaptive, with dose level and dosing frequency being guided by an independent committee.

In September 2022 (data cut-off:

August 29, 2022), we announced a positive update from SELECT-HD driven by the observation of reductions in mean CSF mHTT protein in cerebrospinal fluid (“CSF”) after trial participants received either a single 30 or 60 mg dose of WVE-003.

Additionally, wtHTT protein levels appeared consistent with allele-selectivity.

Single doses (30 mg, 60 mg, and 90 mg) of WVE-003 appeared generally safe and well-tolerated.

Based on the SELECT-HD data, we adapted the trial to expand the single-dose cohorts, and the multi-dose portion is underway.

We have completed enrollment in the 30 mg multi-dose cohort, which is evaluating doses of WVE-003 administered every eight weeks, and we plan to evaluate the completed single-dose and multi-dose cohorts simultaneously.

We expect to report data from the 30 mg multi-dose cohort with extended follow-up, along with all single-dose data, in the second quarter of 2024.

These data are expected to form the basis for decision making for our advancement of this program, including supporting an opt-in package for Takeda Pharmaceutical Company Limited (“Takeda”).

In the third quarter of 2023, we achieved a milestone in our collaboration with Takeda, which pertained to the positive results from a non-clinical study of WVE-003 in non-human primates (“NHPs”) and resulted in a payment of $7.0 million to us in the fourth quarter of 2023.

In the third quarter of 2023, we achieved a milestone in our collaboration with Takeda Pharmaceutical Company Limited (“Takeda”), which pertained to the positive results from a non-clinical study of WVE-003 in non-human primates and resulted in a payment of $7.0 million to us.

This study showed significant tissue exposure levels of WVE-003 in the deep brain regions, including striatum and bolstered our existing datasets that confirm the ability of our oligonucleotides to distribute to the areas of the CNS important for HD.

SELECT-HD was a global, multicenter, randomized, double-blind, placebo-controlled Phase 1b/2a clinical trial to assess the safety and tolerability of WVE-003 in people with a confirmed diagnosis of HD who are in the early stages of the disease and carry SNP3 in association with their CAG expansion.

Additional objectives included assessing PK and exploratory PD and clinical endpoints.

In June 2024, we announced positive clinical data from the Phase 1b/2a SELECT-HD study of WVE-003.

Results from the multi-dose portion of the trial, which evaluated three doses of 30 mg WVE-003 administered every eight weeks, showed clear translation of target engagement to clinic with statistically significant, potent, durable and allele-selective reductions in cerebrospinal fluid (“CSF”) mHTT of up to a mean 46% with preservation of wtHTT protein.

* p<0.05, **p<0.01, ***p<0.001, ****p<0.0001

The multi-dose cohort also revealed a statistically significant correlation between mHTT reduction and slowing of caudate atrophy, indicating a potential benefit of allele-selective mHTT reductions.

Caudate atrophy, as measured by MRI, is a well-characterized measures of disease progression in HD.

Baseline MRI single-dose day 1-3 MRI;

final MRI multi-dose day 169;

Volumes derived through Jacobian integration after normalization in MNI space.

Results are from mixed model repeated measures (MMRM) analysis;

CSF mHTT concentration:

single-dose baseline, multi-dose day 141

In the multi-dose cohort, WVE-003 was generally safe and well-tolerated, with mild-to-moderate adverse events (“AEs”) and no SAEs.

In November 2024, five months after a patient completed their final safety visit, an SAE was reported that we assessed to be not related to WVE-003.

Following our positive clinical results, we initiated engagement with the FDA.

In November 2024, we received supportive initial feedback from the FDA, who recognize the severity of HD and are receptive to and engaged with us regarding a potential pathway to accelerated approval.

The FDA is open to our plan to evaluate biomarkers, including caudate atrophy, as an endpoint to assess HD progression with the potential to predict clinical outcome.

Also in November 2024, the FDA granted Orphan Drug Designation to WVE-003.

Preparation is ongoing for a global, potentially registrational Phase 2/3 study of WVE-003 with caudate atrophy as a primary endpoint.

We expect to submit an Investigational New Drug (“IND”) application for WVE-003 in the second half of 2025.

Discovery Pipeline

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Building on our work in AATD, we have demonstrated our ability to address more prevalent diseases by editing RNA to upregulate or increase the stability of the mRNA transcript, thereby increasing endogenous protein production.

Utilizing our proprietary “edit-verse,” which is powered by genetic datasets and deep learning models, we have identified several RNA editing targets that leverage easily accessible biomarkers, offer efficient paths to proof-of-concept in humans, and represent meaningful commercial opportunities.

We demonstrated preclinical proof-of-concept data on several of these new targets in 2023, achieving at least 2-fold mRNA upregulation in liver and kidney targets and more than 60% mRNA correction in liver and lung targets.

Through our collaboration with GSK, we are leveraging GSK’s novel genetics insights to expand our wholly owned pipeline, with the first being our INHBE program.

In addition, we and GSK are actively working on multiple target validation programs for our GSK-partnered programs, for which all of our costs and expenses are prepaid by GSK.

We expect to select five new clinical candidates by the end of 2025, including our INHBE candidate for obesity.

Utilizing our proprietary “edit-verse,” which is powered by genetic datasets and deep learning models, we have identified several RNA editing targets in indications that leverage easily accessible biomarkers, offer efficient paths to proof-of-concept in humans, and represent meaningful commercial opportunities.

Our wholly owned discovery-stage pipeline includes hepatic and extra hepatic targets, including three RNA editing programs in liver that leverage GalNAc conjugates and have efficient clinical paths to proof-of-concept.

- PNPLA3, which uses mRNA correction to restore the heterozygous phenotype for those at high risk for genetically defined liver disease.

Homozygous PNPLA3-I148M patients are at high risk for a variety of liver diseases and there are more than nine million impacted individuals in the United States and Europe.

- LDLR and APOB, which utilize first-in-class mRNA upregulation and mRNA correction approaches, respectively, to achieve target low-density lipoprotein cholesterol (LDL-c) levels in people with heterozygous familial hypercholesterolemia.

Combined, LDLR and APOB AIMers could address approximately one million HeFH patients in the United States and Europe.

LDLR upregulation also offers significant expansion opportunities in patients with statin intolerance or prior cardiovascular events which represent approximately 30 million patients in the United States and Europe.

Through our collaboration with GSK, we are also leveraging GSK’s novel genetic insights to expand our wholly owned pipeline.

In addition, we and GSK are actively working on multiple target validation programs as GSK-partnered programs, for which all of our costs and expenses are prepaid by GSK.

In April 2024, GSK selected its first two programs to advance to development candidates following achievement of target validation, triggering an aggregate initiation payment to us of $12.0 million from GSK.

These programs utilize our next generation GalNAc-siRNA format and are in hepatology.

We plan to share new preclinical data from our wholly owned hepatic and extra-hepatic RNA editing programs in 2025.

In 2026, we expect to initiate clinical development of additional RNA editing programs, including PNPLA3, LDLR, and APOB.

We are building a leading RNA medicines company by leveraging PRISM to design, develop and commercialize optimized disease-modifying medicines for indications with a high degree of unmet medical need.

We have a robust and diverse pipeline of first- or best-in-class RNA medicines using our RNA editing, RNAi, splicing, and antisense modalities.

Our lead programs aim to address both rare and prevalent diseases, including AATD, obesity, DMD and HD.

In addition to driving clinical and preclinical programs, we are continuously investing in PRISM to fully unlock the potential of our unique and expanding platform capabilities and conducting discovery research on multiple targets where we have the potential to deliver first-in-class therapeutics, starting with RNA editing.

We have a robust and diverse pipeline of first- or best-in-class RNA medicines using our RNA editing, splicing, silencing using siRNA, and antisense silencing modalities.

Our lead programs aim to address both rare and common diseases, including obesity, AATD, DMD, and HD, as well as preclinical programs for liver diseases and HeFH.

In addition to driving clinical and preclinical programs, we are continuously investing in PRISM to fully unlock the potential of our unique and expanding platform capabilities.

The key components of our strategy are as follows:

• Extend our leadership in RNA medicines .

We intend to establish a dominant position in the field of oligonucleotides, advancing basic research and pharmacology using stereochemistry and novel modifications across multiple therapeutic modalities and target classes.

Our work has already led to the development of AIMers for RNA editing, as well as the introduction of PN backbone chemistry modifications for potential therapeutic use.

Through PRISM, our efforts continue to reveal structure-activity relationships among sequence, chemistry and backbone stereochemistry that may allow us to further tune the activity of our oligonucleotides in a previously unexplored, modality-specific manner.

We intend to establish a dominant position in the field of oligonucleotides, advancing basic research and pharmacology using stereochemistry and other novel modifications across multiple therapeutic modalities and target classes.

Our work has already led to the development of AIMers for RNA editing, as well as the introduction of PN backbone chemistry modifications for potential therapeutic use and novel base modifications such as N3U.

Through PRISM, our efforts continue to reveal structure-activity relationships among base modifications and sequence, chemistry and backbone stereochemistry that may allow us to further tune the activity of our oligonucleotides in a previously unexplored, modality-specific manner.

• Rapidly advance and sustainably grow our differentiated portfolio of RNA medicines.

We are committed to transforming the care of devastating diseases where patients have limited treatment options.

Our current and future portfolio is focused on novel therapeutic approaches that optimally address disease biology and which offer biomarkers for target engagement and to provide insights into clinical effects early in development.

We are currently advancing multiple programs:

WVE-006 (AATD), INHBE lead clinical candidate (obesity), WVE-N531 (DMD), and WVE-003 (HD), which were all designed with novel PN backbone chemistry modifications developed from our PRISM platform.

We are also conducting our own discovery-stage research on novel therapeutic approaches, and will have the opportunity through our GSK collaboration to advance programs leveraging GSK’s novel genetic insights.

Our current and future portfolio is focused on novel therapeutic approaches that optimally address disease biology, that offer biomarkers for target engagement, and that inform on clinical effects early in development.

We are currently advancing multiple clinical programs:

WVE-007 (obesity), WVE-006 (AATD), WVE-N531 (DMD), and WVE-003 (HD), which were all designed with novel PN backbone chemistry modifications and developed from our PRISM platform.

We continue to conduct discovery-stage research on novel therapeutic approaches, and have the opportunity, through our GSK collaboration, to advance programs leveraging GSK’s novel genetic insights.

We expect these activities will add multiple first-in-class therapeutics to our pipeline over the next several years.

• Expand our pipeline of high-value programs.

In 2023, we made meaningful progress in advancing our RNA editing modality, AIMers, including demonstrating upregulation across several targets.

With these therapeutic modalities, we are positioned to unlock new biology and develop first-in-class therapeutics.

In 2024, we made meaningful progress in advancing preclinical programs utilizing our versatile PRISM platform.

With multiple modalities at our disposal, we are positioned to unlock new biology and develop first-in-class therapeutics.

To build on our demonstration of first-ever RNA editing in humans with WVE-006 (AATD), we announced three wholly owned GalNAc-AIMer programs that offer first-in-class approaches to address unmet needs in cardiometabolic diseases.

These new programs include PNPLA3, which uses mRNA correction for those at high risk for a genetically defined liver disease, and LDLR and APOB, which utilize first-in-class mRNA upregulation and mRNA correction, respectively, to achieve target LDL-c levels in people with heterozygous familial hypercholesterolemia.

• Leverage manufacturing leadership in oligonucleotides.

We have built a hybrid internal / external manufacturing model that gives us the capability to produce stereopure oligonucleotides at scales from one micromole to potential commercial scale.

Through our internal manufacturing, based in our Lexington, Massachusetts facility, we have the capacity to support multiple discovery, preclinical, and early clinical-stage programs and have the established expertise to efficiently conduct manufacturing runs for oligonucleotides across a spectrum of modalities.

Through our internal manufacturing, based in our Lexington, Massachusetts facility, we have the capacity to support multiple discovery, preclinical, and early clinical-stage programs, and we have the expertise to conduct manufacturing runs for oligonucleotides spanning multiple modalities.

We believe that leveraging our internal manufacturing capabilities along with expertise from contract manufacturing organizations (“CMOs”) facilitates our growth and enhances our ability to secure drug substance for current and future development activities.

RNA Medicines

Nucleic acid therapeutics, including oligonucleotides, are an innovative class of drugs that can modulate the function of target RNAs to ultimately affect the production of disease-associated proteins or prevent the accumulation of pathogenic RNA species, which are emerging as important factors in human disease.

Oligonucleotides can regulate protein and RNA via several different molecular mechanisms.

These mechanisms can be broadly categorized as RNA editing, those that bind to a target RNA and modify its base sequence;

splicing, those that bind to a target RNA and promote exon skipping;

and silencing, those that promote degradation of the target RNA, including antisense and siRNA.

The unique capability of oligonucleotides to address a wide range of genomic targets that impact multiple therapeutic areas creates potentially significant market opportunities for us to develop molecules to treat a broad spectrum of human diseases, including diseases where no medicines currently exist or for which existing treatments are not optimal.

The investigational oligonucleotides we are currently developing employ the following molecular mechanisms:

• RNA editing, which involves an oligonucleotide that uses endogenous ADAR (adenosine deaminases acting on RNA) enzymes to edit adenosines in target RNAs.

This technology can be used to correct missense and nonsense mutations to restore protein activity.

It can also be used to modulate protein activity, for example correcting a disease-causing mutation, altering a post-translational modification site, a protease cleavage site, or a protein-protein interaction interface.

Other applications of this technology include the ability to target regulatory elements in RNA that impact its stability or function, for example, AUGs in the 5’-UTR for translational upregulation or AG splice acceptor sites to modify exon splicing.

• RNA interference (RNAi ) (silencing) , which uses double-stranded RNAs called siRNAs to engage the RNAi machinery known as the RNA-induced silencing complex (“RISC”) and to silence a target RNA that is either pathogenic itself or encodes a disease-associated protein, thereby preventing the accumulation of the pathogenic species (RNA or protein).

• Splicing / exon skipping , which is the processing of a nascent pre-mRNA transcript into mRNA by removing introns and joining exons together.

Exon skipping uses an oligonucleotide designed to bind to a particular sequence within a target pre-mRNA and direct the cellular machinery to delete, or splice out, certain specific regions of that RNA.

Often, the underlying mutation leads to non-productive mRNA, yielding no functional protein.

Use of the exon-skipping modality permits the cellular machinery to bypass and assemble a partially functional protein, thereby mitigating or alleviating the disease that would otherwise result.

• Antisense (silencing) , which uses an oligonucleotide designed to bind to a specific sequence in a target RNA strand that encodes a disease-associated protein or pathogenic RNA.

The resulting two-stranded molecule (“duplex”) is then recognized by a cellular enzyme called RNase H, which cleaves, or cuts, the target RNA in the duplex, thereby preventing the disease-associated protein from being made.

Our proprietary discovery and drug development platform

Our PRISM platform was built on the recognition that a significant opportunity exists to tune the pharmacological properties of oligonucleotides by leveraging three key features of these molecules:

sequence, chemistry, and stereochemistry.

Our PRISM platform demonstrates the powerful convergence of best-in-class chemistry with human genetics.

The platform was built on the recognition that a significant opportunity exists to tune the pharmacological properties of oligonucleotides by leveraging three key features of these molecules:

base modifications and sequence, chemistry, and stereochemistry.

Our unique ability to control stereochemistry provides the resolution necessary to optimize pharmacological profiles and develop and manufacture stereopure oligonucleotides.

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Our rational process for designing stereopure oligonucleotides allows us to selectively optimize chemical modifications to a specific therapeutic modality in order to generate best-in-class oligonucleotides.

With PRISM, we leverage the diversity created by backbone stereochemistry to expand the parameters that we explore to optimize oligonucleotides.

Moreover, through continued exploration of these interactions using iterative analysis of in vitro and in vivo outcomes and machine learning-driven predictive modeling, we also continue to refine our design principles that we deploy across subsequent programs.

We are using these ongoing discoveries to guide our drug development activities, which we believe will lead to medicines that are more specific, can be dosed at lower concentrations, less frequently, or some combination of these characteristics, as well as with improved therapeutic profiles.

Advantages of PRISM

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• Ability to rationally design product candidates with optimized pharmacological properties .

Our platform combines our unique ability to construct stereopure oligonucleotides with a deep understanding of how the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry impacts key pharmacological properties.

Our platform combines our unique ability to construct stereopure oligonucleotides with a deep understanding of how the interplay among oligonucleotide base modifications and sequence, chemistry and backbone stereochemistry impacts key pharmacological properties.

By exploring these interactions through iterative analysis of in vitro and in vivo outcomes and machine learning-driven predictive modeling, we continue to define design principles that we deploy across programs to rapidly develop and manufacture clinical candidates that meet pre-defined product profiles.

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• Broad applicability .

PRISM is applicable to oligonucleotides acting via multiple therapeutic modalities, including RNA editing, splicing, and silencing (including RNAi and antisense).

PRISM is applicable to oligonucleotides acting via multiple therapeutic modalities, including RNA editing, splicing, and silencing (including siRNA and antisense).

It is also compatible with a broad range of chemical modifications and targeting moieties.

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Unlike PS modifications, PN modifications are neutral, meaning that the negative charge of the oligonucleotide is reduced with every PN modification added to the backbone.

In preclinical experiments, we have demonstrated that judicious use of PN backbone chemistry modifications in stereopure oligonucleotides have generally increased potency, tissue exposure and durability of effect across our RNA editing, splicing and silencing modalities.

We have also investigated the impact of PN chemistry and performed experiments under gymnotic or free uptake conditions.

In the graph labeled one below, the data demonstrate the contrast between AIMer uptake in cells, depending on whether it incorporates PN chemistry, shown in light blue, or not, shown in dark blue.

To the right, in the graph labeled two, the data demonstrate the proportion of AIMer released from endosomes inside the cell.

The addition of PN chemistry drove a greater than 2-fold increase in cellular uptake and an over 4-fold increase in endosomal release compared with PS chemistry.

Below, we also demonstrated the benefits of PN chemistry on cellular residency, with a higher percentage of PN-containing molecules persisting within the cell, a 5-fold benefit on nuclear uptake, and ultimately, evidence this modification leads to a dramatic 30-fold improvement in target engagement in a cell free lysate system.

Base Modifications

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For example, we have shown that the introduction of an N3U at the “orphan position” of an RNA editing oligonucleotide, which is across from the edit site in the transcript, enhances RNA editing across a diversity of sequences in preclinical studies.

In our 2024 Nucleic Acids Research paper (Lu et al., 2024 Nuc Acid Res;

doi.org/10.1093/nar/gkae681 N), we described the development of new AIMer designs with base modifications and sequence, sugar and backbone modifications that improve RNA editing efficiency over our previous design.

AIMers incorporating a novel pattern of backbone and 2′ sugar modifications support enhanced editing efficiency across multiple sequences.

Further efficiency gains were achieved through incorporation of N3U in place of cytidine (C) in the orphan position.

Molecular modeling suggested that N3U might enhance ADAR catalytic activity by stabilizing the AIMer-ADAR interaction and potentially reducing the energy required to flip the target base into the active site.

Supporting this hypothesis, AIMers containing N3U consistently enhanced RNA editing over those containing C across multiple sequences and multiple nearest neighbor sequence combinations.

These modifications to AIMers improved RNA editing both in vitro and in vivo .

We continuously explore how new modifications and new combinations of modifications from our expansive repertoire can redefine what’s possible with oligonucleotide therapeutics.

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The addition of PN chemistry substantially improves both potency and editing efficiency.

In our Nature Biotechnology paper (Monian P, et.

doi.org/10.1038/s41587-022-01225-1), we demonstrated efficient RNA editing in vitro with our AIMers across a variety of cell lines, including non-human primate and human primary hepatocytes, as shown

in the figures below.

In our foundational RNA editing paper published in Nature Biotechnology (Monian P, et.

doi.org/10.1038/s41587-022-01225-1), we demonstrated efficient RNA editing in vitro with our AIMers across a variety of cell lines, including non-human primate (“NHP”) and human primary hepatocytes, as shown in the figures below.

We observed potent, dose-dependent RNA editing with three chemically distinct stereopure AIMers (ACTB 1, ACTB 2, ACTB 3) via GalNAc-mediated uptake.

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we continued to see significant editing 45 days after the last dose.

The pharmacokinetic data, shown in the figure below on the left, confirmed that a significant amount of AIMer was still detectable in the liver at that time.

The PK data, shown in the figure below on the left, confirmed that a significant amount of AIMer was still detectable in the liver at that time.

To assess off-target editing for the whole transcriptome, a mutation-calling software was used to call edit sites.

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We also observed potent, durable, and specific editing across multiple additional tissues following systemic administration of a single dose of an unconjugated UGP2 AIMer in mice.

These additional tissues in mice include heart, kidney, lung, and spleen, as well as liver cells beyond hepatocytes.

These additional tissues in mice include heart, kidney, lung, pancreas and spleen, as well as liver cells beyond hepatocytes.

The application of PRISM to RNA editing opens the door to therapeutic applications extending beyond precise correction of genetic mutations, including upregulation of expression, modification of protein function, or alteration of protein stability.

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Using PRISM, we can produce stereopure PN-modified oligonucleotides that promote potent and specific RNA transcript silencing activity in preclinical experiments.

We have applied our stereopure PS and PN modifications to the RNAi modality using double-stranded siRNAs and demonstrated potent and durable silencing in vivo in transgenic mice, leveraging GalNAc to enhance delivery to liver hepatocytes.

We have applied our stereopure PS and PN modifications to the siRNA modality using double-stranded siRNAs and demonstrated potent and durable silencing in vivo in transgenic mice, leveraging GalNAc to enhance delivery to liver hepatocytes.

In April 2023, we announced the publication of preclinical data for our novel siRNA formats in the journal of Nucleic Acids Research .

The preclinical data demonstrated unprecedented Argonaute2 (“Ago2”) loading following administration of single subcutaneous GalNAc-siRNA doses, leading to improved potency and durability in vivo in mice versus comparator siRNA formats.

The data, shown below, illustrate a GalNAc-siRNA, with controlled stereochemistry and PN backbone chemistry, that led to remarkably durable transcript silencing in mice three months after a single dose, compared with mice treated with a siRNA based on

state-of-the-art designs, where expression levels had recovered to control levels (left).

The data below (middle and right) also highlight that siRNAs developed with PRISM show improved activity profiles because they support more Ago2 loading than controls.

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As shown in the figure below, our next generation GalNAc-siRNA (shown in dark blue) further improves on the potency and duration of silencing in mice over our first generation GalNAc-siRNA format (shown in light blue) and the benchmark, which is based on a clinically proven format.

As a reminder, translation from preclinical experiments to the clinic is well understood for RNAi, and we expect our next generation siRNA format may support six month or annual subcutaneous dosing.

Translation from preclinical experiments to the clinic is well understood for RNAi, and we expect our next generation siRNA format may support six month or annual subcutaneous dosing.

2018, 26(3), 708.

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PCR assays for RNA PD, relative fold changes of App to Hprt mRNA normalized to % of PBS;

Three-way ANOVA followed by Bonferroni-adjusted post hoc test comparing condition to PBS (data not shown), Next gen siRNA significantly lower than PBS at both time points for all tissues at P < 0.0001 level;

derived from Three-way ANOVA (treatment, tissue, time point) followed by Bonferroni-adjusted post hoc test comparing condition to PBS (data not shown), Next gen siRNA significantly lower than PBS at week 16 for all tissues at P < 0.0001 level;

Immunohistochemical analysis of FFPE Mouse Brain tissue labeling App protein (Color Brown) with CS#19389 followed by a ready to use Polymer-HRP 2nd Detection antibody.

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Single 100 ug ICV injection

We further demonstrated how our PN chemistry allows us to access new tissues through eight-week mouse experiments using siRNAs to silence gene expression.

On the far left, we highlight the well-described impact of using GalNAc to access hepatocytes in the liver.

This graph also highlights the limits of a conjugate, as it is cell and tissue specific, so it does not enable silencing in other tissues of interest, like white adipose, muscle or cardiac tissue.

To the right, we demonstrate our ability to alternate designs with PN variants to enable access to new and various combinations of tissues, including liver, adipose and muscle, in the absence of any targeting ligand.

Depending on the target and indication, we can deploy the design that best fits the biology.

Using PRISM, we can change the physicochemical properties of our oligos to deliver to numerous extrahepatic tissues and achieve potent and durable silencing with a single dose.

With PRISM, we have optimized stereopure oligonucleotides that promote efficient splicing in vitro , ex vivo , and in vivo to restore protein production.

In our splicing programs, as with our other modalities, the sequence, chemistry and backbone stereochemistry of oligonucleotides impact their activity.

In our splicing programs, as with our other modalities, the base modifications and sequence, chemistry and backbone stereochemistry of oligonucleotides impact their activity.

In our Nucleic Acids Research paper (Kandasamy et al., 2022;

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The more potent molecules are shifted upwards as they are restoring expression.

The navy dots represent the impact of a few stereopure PN modifications in compounds with otherwise identical sequences and 2’-ribose

chemical modifications.

The navy dots represent the impact of a few stereopure PN modifications in compounds with otherwise identical sequences and 2’-ribose chemical modifications.

There is an overall shift upwards in activity among the PS / PO / PN compounds, representing a substantial potency gain in most cases.

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Moving in vivo , we have demonstrated potent silencing activity of multiple targets in the CNS of non-human primates with stereopure, PN-modified oligonucleotides.

In the results shown below, non-human primates received a single 12 mg dose of PN-modified MAPT silencing oligonucleotide by intrathecal injection.

This single dose led to substantial and widespread mRNA reduction in the CNS one month after administration, as well as potent silencing (as shown on the right).

In a separate study (shown below), NHPs were treated with four monthly intrathecal doses of a stereopure PN-modified MAPT silencing oligonucleotide across three dose levels.

This repeat dosing led to reduced tau in the NHP CSF, which can serve as a clinical biomarker, and correlates to reduced tau within the brain.

80-90% knockdown in target tissues were detected at no observed adverse effect level (“NOAEL”).

Therapeutic Programs

Our pipeline programs are designed to treat serious, life-altering diseases, including those with targets in liver, muscle, and the CNS.

These programs include:

- GalNAc-conjugated oligonucleotides for hepatic and metabolic diseases including:

RNA editing oligonucleotide (WVE-006)

o Obesity (INHBE):

siRNA (lead clinical candidate)

- Unconjugated oligonucleotides for muscle, CNS and other disease areas including:

Exon skipping oligonucleotide (WVE-N531)

antisense silencing oligonucleotide (WVE-003)

See below for more information on these programs and the diseases we are targeting.

Alpha-1 Antitrypsin Deficiency

Background and Market Opportunity

We are leveraging our RNA editing platform capability to develop a potentially novel treatment for AATD.

AATD is a rare, inherited genetic disorder that is commonly caused by a G-to-A point mutation in the SERPINA1 gene;

this mutant allele is termed the Z allele.

This mutation leads to misfolding and aggregation of Z-AAT protein in hepatocytes and a lack of functional AAT in the lungs.

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

Weekly intravenous augmentation therapy is the only treatment option for AATD in those with the lung pathology, there are no approved therapies to address the liver pathology.

Approximately 200,000 people in the United States and Europe are homozygous for the Z allele, which is the most common form of severe disease.

Current Treatments

Food and Drug Administration (“FDA”) labeling for each, the effect of augmentation therapy with any Alpha1-PI on pulmonary exacerbations and on the progression of emphysema in Alpha1-PI deficiency has not been demonstrated in randomized, controlled clinical trials.

Augmentation therapy is

also approved in the European Union (“EU”), but reimbursement and accessibility vary by country.

There are currently no approved therapies to prevent the accumulation of the misfolded AAT protein in the liver.

Our AATD Program

ADAR editing may provide an ideal approach for increasing circulating levels of wild-type AAT protein and reducing aggregation in the liver, thus simultaneously addressing both the lung and liver manifestations of the disease.

WVE-006 is first-in-class in AATD and is the first RNA editing therapeutic candidate ever to be evaluated in humans.

RestorAAtion clinical program:

In the fourth quarter of 2023, we announced the initiation of our RestorAATion clinical program investigating WVE-006 as a treatment for AATD and approval of multiple CTAs for WVE-006.

The RestorAATion clinical program includes both healthy volunteers (RestorAATion-1), as well as patients with AATD who have the homozygous Pi*ZZ mutation (RestorAATion-2) and is designed to provide an efficient path to proof-of-mechanism as measured by restoration of M-AAT protein in serum.

In December 2023, we announced that we had initiated dosing in healthy volunteers.

We expect to deliver proof-of-mechanism data in patients with AATD in 2024.

Alpha-1 antitrypsin Strnad et al., 2020 N Engl J Med 382:1443-55;

Blanco et al., 2017 Int J Chron Obstruct Pulmon Dis 12:561-69;

Remih et al., 2021 Curr Opin Pharmacol 59:149-56.

Preclinical data

Preclinical data for WVE-006 demonstrated that WVE-006 supports dose-dependent RNA editing in human preclinical model systems, as shown in the figure below.

We observed efficient SERPINA1 editing in donor-derived primary human hepatocytes (MZ genotype) after 48 hours, as well as a dose-dependent increase in RNA editing in iPSC-derived human hepatocytes (ZZ genotype) eight days after a single dose.

In an in vivo preclinical study in NSG-PiZ mice, we demonstrated restoration of functional AAT protein with every-other-week doses of 10 mg/kg.

WVE-006 treatment resulted in serum AAT protein levels of up to 30 micromolar.

At 13 weeks, AAT protein levels with WVE-006 were approximately 7-fold greater than PBS-administered controls and well above the predicted protective threshold of up to 11 uM, as shown below.

This increase was observed at week 13 both in mice that received a loading dose, as well as mice that did not.

WVE-006 also resulted in approximately 50% RNA editing of SERPINA1 transcript at 13 weeks in this same model, regardless of whether a loading dose was used.

We then sought to determine whether the restored serum AAT protein from the mouse experiment described above was wild-type M-AAT protein.

WVE-006 led to restoration of approximately 50% wild-type M-AAT protein in serum, as measured by mass spectrometry, as shown below (left), as well as a 3-fold increase in neutrophil elastase inhibition activity, as shown below (right), indicating the restored M-AAT protein was functional.

WVE-006 treatment led to a decrease in lobular inflammation and PAS-D globule size, preventing an increase in mitoses (turnover) of hepatocytes, as indicated below.

To evaluate the specificity of our GalNAc-AIMers (specifically “SA1-4 AIMer”), we performed RNA-seq on liver biopsies from treated animals.

The figure below on the left shows total sequence coverage across the entire SERPINA1 transcript for the AIMer-treated samples.

The percentage of unedited “T” and edited “C” reads 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.

This also confirms there is no editing of bystander residues, as has been seen with DNA targeting approaches.

To assess off-target editing for the whole transcriptome, we applied a mutation-calling software to search edit sites.

From this analysis, we observed minimal off-target editing across the transcriptome.

Sites where potential off-target editing occurred had either low read coverage in the analysis or occurred at low percentages (less than 10%), indicating that these are rare events, as shown below on the right.

In both analyses, we find a high percentage of editing that is specific for the target site in the SERPINA1 transcript.

Obesity and Other Metabolic Disorders

Background and Market Opportunity

Obesity is increasingly being recognized as a growing global epidemic.

In the United States, an estimated 42% of the adult population is obese, and there are an estimated 174 million obese adults in the United States and Europe.

Adults with obesity have higher risk for many serious health conditions, including heart disease, type 2 diabetes, and some forms of cancer;

and obesity is estimated to cost the U.S.

healthcare system almost $173 billion annually.

Current Treatments

There are two GLP-1 receptor agonists approved in the United States and the EU for the treatment of obesity:

Saxenda (liraglutide, Novo Nordisk) and Wegovy (semaglutide, Novo Nordisk).

Tirzepatide (Eli Lilly), approved as Zepbound by the FDA and as Mounjaro by EMA in November 2023, is a GLP-1/GIP receptor agonist.

Other FDA-approved therapies for obesity include Xenical (H2-Pharma, approved in US in 1999), Qsymia (Vivus, approved in US in 2012), and Contrave (Currax Pharmaceuticals, approved in US in 2014).

Although GLP-1 receptor agonists induce weight loss, there remains a substantial unmet need in obesity, as GLP-1 receptors lead to weight loss at the expense of muscle mass.

For instance, in a Phase 3 study of semaglutide, 36% of total weight loss was from loss of lean mass (Wilding 2021), and in a Phase 3 study of tirzepatide, treatment led to an approximately 34% loss in fat mass and an approximately 11% loss in lean mass (Jastreboff 2022).

GLP-1s have also been shown to suppress the general reward system and are associated with a poor tolerability profile and discontinuation rates up to 68%.

Our Obesity Program

INHBE lead clinical candidate :

In obesity, we are advancing our INHBE lead clinical candidate, a GalNAc-conjugated siRNA oligonucleotide targeting INHBE mRNA (Inhibin βE) that utilizes our next generation siRNA format.

INHBE loss-of-function (LoF) heterozygous human carriers exhibit a healthy metabolic profile, including reduced waist-to-hip ratio and reduced odds of type 2 diabetes and coronary artery disease.

Our lead clinical candidate is designed to silence the INHBE gene through RNA knockdown with a goal of inducing lipolysis (fat burning) while preserving muscle mass to restore and maintain a healthy metabolic profile.

Silencing INHBE is expected to recapitulate the cardiometabolic profile of these LoF carriers and may also address the limitations of GLP1s as a monotherapy or be used as an adjunct therapy with GLP1s.

We expect to initiate a clinical trial for our INHBE candidate in the first quarter of 2025.

Preclinical data

We have utilized young diet-induced obesity, or (“DIO”), mice to evaluate in vivo if INHBE silencing would impact body weight and reduce visceral fat.

After five weeks, we observed substantial INHBE silencing with our first generation GalNAc-siRNA format, exceeding the anticipated therapeutic threshold.

We then looked at the body weight of these mice over time and saw a 16% lower body weight as compared to PBS after five weeks, as shown below on the left.

A similar effect size was reported for semaglutide in a preclinical study.

We then investigated how body weight changes were reflected in different types of adipose tissues.

We observed substantial reduction in visceral fat tissues, including mesenteric, as shown below on the right, and epididymal fat, as well as subcutaneous fat.

high-fat diet.

In March 2024, we announced the selection of our INHBE lead clinical candidate, which utilizes our next generation GalNAc-siRNA format.

This next generation format results in more potent and durable siRNA silencing and when applied to our INHBE program resulted in:

1) highly potent INHBE silencing (ED50 < 1 mg/kg), durable silencing following one, low-single digit dose in preclinical mouse models supporting every-six-month or annual subcutaneous dosing;

3) Weight loss with no loss of muscle mass;

4) Reduction in fat mass, with preferential effect to the visceral fat, consistent with the profile of INHBE LoF in human genetics.

We expect to initiate a clinical trial for our INHBE candidate in the first quarter of 2025.

Duchenne Muscular Dystrophy

Background and Market Opportunity

The dystrophin-associated protein complex protects the muscle from injury during contraction and relaxation.

Patients with DMD typically develop muscle weakness in the early years of life and become wheelchair-bound in their early teens.

As the disease progresses, patients with DMD typically develop respiratory, orthopedic, and cardiac complications.

Cardiomyopathy and breathing difficulties usually begin by the age of 20, and few individuals with DMD live beyond their thirties.

Current Treatments

While there are approved therapies for DMD, there is no cure, and there continues to be significant unmet medical need.

In most countries, corticosteroids are the standard drug therapy, which slows the progression of muscle weakness and delays loss of ambulation by two to three years.

In February 2017, Emflaza (deflazacort) became the first corticosteroid in the United States approved by the FDA as a treatment for patients with DMD older than five years of age.

In October 2023, the FDA granted approval to Santhera Pharmaceuticals’ Agamree (vamorolone) for the treatment of DMD in patients 2 years of age and older, and in December 2023, approval was granted in the EU for patients with DMD 4 years of age and older.

Agamree is an alternative steroid with data suggesting a reduction in adverse events compared to currently available corticosteroids.

In 2016, Sarepta Therapeutics’ Exondys 51 ( eteplirsen) received accelerated approval in the United States for the treatment of patients with DMD, who have a confirmed mutation of the dystrophin gene amenable to exon 51 skipping.

Two drugs have received accelerated approval in the United States for patients with DMD with a confirmed mutation of the dystrophin gene amenable to exon 53 skipping:

Sarepta Therapeutics’ Vyondys 53 (golodirsen) in 2019 and NS Pharma’s Viltepso (viltolarsen) in 2020.

NS Pharma has also received Marketing Authorization for Viltepso in Japan.

In 2021, Sarepta’s Amondys 45 (casimersen) received accelerated approval for patients with DMD with a mutation amenable to exon 45 skipping.

According to U.S.

accelerated approval guidelines, approval is based on a surrogate endpoint that is likely to predict clinical benefit, but no clinical benefit needs to be established at the time of FDA approval.

No clinical benefit has yet been established for eteplirsen, golodirsen, viltolarsen, or casimersen.

Thus, in accordance with the U.S.

accelerated approval regulations, the FDA is requiring Sarepta to conduct clinical trials to verify and describe the clinical benefit of eteplirsen, golodirsen, and casimersen.

Similarly, NS Pharma is required to conduct a clinical trial to verify and describe the clinical benefit of viltolarsen.

If any of these confirmatory trials fail to verify clinical benefit, the FDA could initiate proceedings to withdraw approval of the respective drug(s).

In June 2023, the FDA granted accelerated approval to Sarepta Therapeutics’ Elevidys, a microdystrophin gene therapy, for ambulatory pediatric patients aged 4 through 5 years with a confirmed mutation in the DMD gene.

This includes patients who have a DMD mutation amenable to exon 53 skipping.

The accelerated approval was based on expression of Elevidys microdystrophin, and in December 2023, Sarepta submitted its post-marketing requirement for Elevidys to the FDA requesting conversion from accelerated approval to traditional approval, along with an efficacy supplement to its biologics license application (“BLA”), seeking to remove age and ambulation restrictions from the approved indication.

FDA decisions on the accelerated approval conversion and label expansion are expected in 2024.

In 2014, PTC Therapeutics’ Translarna (ataluren) was the first disease-modifying treatment to receive conditional approval by the European Medicines Agency (“EMA”) for the treatment of ambulatory patients with DMD over 5 years of age who have a nonsense mutation (12% of DMD cases) in the dystrophin gene.

In 2016, the EMA did not allow Translarna to convert to full marketing authorization;

rather, it granted a renewal of the conditional approval.

In 2018, the EMA expanded the conditional approval for Translarna to include treatment of ambulatory patients with DMD ≥2 years of age who have a nonsense mutation in the dystrophin gene.

However, in September 2023, the Committee for Medicinal Products for Human Use (“CHMP”) of the EMA issued a negative opinion on the renewal of the conditional marketing authorization, and in January 2024, CHMP confirmed the negative opinion

following a re-examination procedure.

Once adopted by the European Commission, this ruling will result in the withdrawal of Translarna from the EU market.

In January 2023, the National Institute for Health and Care Excellence (“NICE”) in the United Kingdom recommended Translarna for reimbursement and use across the National Health Service in England and Wales.

Our DMD Program

In DMD, we are advancing WVE-N531, which is designed to skip exon 53 within the dystrophin gene.

WVE-N531 is both our first splicing candidate and our first systemically administered candidate incorporating PN chemistry to be assessed in the clinic.

WVE-N531 clinical data :

In December 2022 (data cut-off:

December 6, 2022), we announced a positive update for WVE-N531 from Part A of the Phase 1b/2a proof-of-concept study, which was an open-label, intra-patient dose escalation clinical trial where three boys received single escalating doses of 1, 3, 6 and 10 mg/kg;

in the multidose portion of the study, the same boys received three doses of 10 mg/kg every other week.

A muscle biopsy was taken two weeks after the third and final dose (six weeks after the first dose).

WVE-N531 resulted in a mean tissue concentration of 42 micrograms/gram (6.1 micromolar), and RNAscope results indicated WVE-N531 is reaching the nucleus in muscle cells.

WVE-N531 resulted in mean exon skipping of 53% (range:

48-62%) as measured by RT-PCR, as shown in the figure below.

Mean dystrophin production was 0.27% of normal as measured by western blot, which was below the level of quantification (BLQ:

While dystrophin was below the lower limit of detection, it is expected that dystrophin protein production would lag splicing of the RNA transcript.

Plasma concentrations and other pharmacokinetic parameters following a single dose of 10 mg/kg demonstrate a half-life of 25 days.

Adverse events were all mild, except for a COVID-19 infection of moderate intensity.

There were no serious adverse events, no trends in labs, and no oligonucleotide class-related safety events.

In an analysis of the muscle biopsies from the three patients, WVE-N531 demonstrated clear uptake in myogenic stem cells in all three patients as evaluated by a dual PAX7 (stem cell marker) immunohistochemistry and WVE-N531 RNAscope chromogenic assay.

This finding represents the first clinical evidence of a potential therapeutic for DMD having the ability to access stem cells.

FORWARD-53 clinical trial :

In December 2023, we initiated dosing of WVE-N531 in FORWARD-53, the Phase 2 portion of the open-label trial (“Part B”).

Boys are being dosed at 10 mg/kg every other week, and we plan to assess dystrophin protein after 24 and 48 weeks of dosing.

The primary endpoint will be dystrophin protein levels, and the trial will also evaluate pharmacokinetics, digital and functional endpoints, and safety and tolerability.

We expect to deliver data from FORWARD-53, including dystrophin protein expression from muscle biopsies taken after 24 weeks of treatment, in the third quarter of 2024.

Preclinical data

In vitro , WVE-N531 induced dose-dependent exon 53 skipping up to 49% and dystrophin protein restoration up to 71% in DMD patient-derived myoblasts carrying a deletion of exons 45-52.

In these experiments, cells were exposed to WVE-N531 at 0.1 µM-10 µM under gymnotic conditions.

After four days of oligonucleotide treatment, efficiency at skipping exon 53 was determined by quantitative RT-PCR.

After six days of oligonucleotide treatment, protein lysate was analyzed by western blot for dystrophin protein expression.

In NHPs, plasma and tissue concentrations of WVE-N531 were significantly higher than suvodirsen (our first generation PS/PO molecule).

WVE-N531 concentrations in heart and diaphragm were substantially higher than skeletal muscle concentrations.

We also observed higher plasma Cmax, AUC, and Ctrough levels compared with suvodirsen.

To understand the effects of PN backbone chemistry modifications in vivo , we conducted a study in a dKO mouse model, which has a mutation in exon 23 leading to a lack of dystrophin, as well as a mutation leading to a lack of utrophin.

We compared the effects of a PS/PO-containing molecule dosed at 150 mg/kg weekly to a PN-containing compound dosed at the same level, a PN-containing compound at 75 mg/kg every other week and a control group dosed with PBS.

Other than the placement of the three PN backbone linkages, these molecules have the same sequence and chemistry.

There is a significant increase in survival in those animals treated

with PN containing compounds as compared with the other treatment groups.

As shown in the figure below, both cohorts of mice receiving the PN-containing molecules (shown in dark blue and light green) had 100% survival at the time of study termination, with a median age of approximately 40 weeks.

By comparison, the median survival for the mice receiving the PS/PO-containing molecule dosed at 150 mg/kg weekly was approximately 12 weeks, and the dKO control animals that received PBS had a median survival of approximately seven weeks.

These results were published in Nucleic Acids Research (Kandasamy et al., 2022;

101.1093/nar/gkac018).

Huntington’s Disease

Background and Market Opportunity

Huntington’s Disease (“HD”) :

HD is a rare hereditary neurodegenerative disease that results in early death and for which there is no cure.

In patients with HD, there is a progressive loss of neurons in the brain leading to cognitive, psychiatric, and motor disabilities.

HD is caused by a defect (an expanded CAG triplet repeat) in the HTT gene, which results in production of mHTT protein.

Patients with HD still possess some wtHTT protein, which is important for neuronal function, and which may be neuroprotective in an adult brain.

Studies suggest a multifaceted mechanism by which gain of mHTT protein and a concurrent loss of wtHTT protein may drive the pathophysiology of HD.

Accordingly, therapeutic approaches for HD that aim to lower mHTT but that also suppress wtHTT may have detrimental long-term consequences.

Wild-type HTT is important both for normal neuronal function in the adult CNS and for protection against HD.

It can protect against stress-induced neurodegeneration in multiple model systems:

in cultured neurons, wtHTT is protective against stress-induced apoptosis;

In the YAC128 mouse model of HD, overexpression of wtHTT ameliorates striatal neuropathology, whereas loss of the wild-type mouse HTT worsens motor performance, survival, and striatal neuronal size.

In patients with HD, the A variant of a non-coding SNP disrupts a binding site for the transcription factor NF-κB and decreases expression of the associated HTT gene:

when the A variant associates with mHTT, disease onset is late (on average, 10-years later than when the G variant associates with mHTT);

when the A variant associates with wtHTT, disease onset is earlier (on average, four years earlier than when the G variant associates with wtHTT), indicating that increased expression of wtHTT can be protective against HD in patients.