• Initiating new Phase 2 FOX trial in boys with Duchenne who have been previously treated with gene therapy
• Continuing dose escalation of Phase 2 LYNX trial and initiating a cohort in boys with Duchenne not currently treated with corticosteroids

BOULDER, Colo. / Oct 26, 2023 / Business Wire / Edgewise Therapeutics, Inc., (Nasdaq: EWTX), a leading muscle disease biopharmaceutical company, today announced an expansion of their clinical development program of EDG-5506, an investigational orally administered small molecule designed to prevent contraction-induced muscle damage in dystrophinopathies, including Duchenne. The Company is initiating FOX, a new Phase 2 placebo-controlled trial in children and adolescent boys with Duchenne who have been previously treated with gene therapy. Further, the Company is continuing dose escalation and expanding enrollment in their Phase 2 placebo-controlled LYNX trial; one of the new LYNX cohorts will study EDG-5506 in boys with Duchenne not currently treated with corticosteroids.

With strong interest from the Duchenne community and supportive initial safety data from LYNX, the Company initiated the FOX trial, a new Phase 2 placebo-controlled trial in children and adolescents with Duchenne who have been previously treated with gene therapy. The FOX trial will assess the effect of EDG-5506 over 12 weeks on safety, pharmacokinetics (PK) and biomarkers of muscle damage. The study will also explore changes in functional measures, such as the North Star Ambulatory Assessment (NSAA) and self-reported/caregiver-reported outcomes. Approximately 24 participants, aged 6 to 14 years, are expected to be enrolled in the trial at multiple sites across the United States. Participants will then continue in an open-label extension portion of the trial for a total of 12 months to gain further insights into safety, PK, function and biomarker measures.

The LYNX trial in children with Duchenne has rapidly enrolled at 14 sites across the United States, with the first three cohorts over-enrolled. Based on the safety profile observed to date, the Company added an additional cohort to continue dose escalation of EDG-5506. LYNX is designed to identify a dose of EDG-5506 that will reduce biomarkers of muscle damage and has the potential to provide functional benefit to patients in a Phase 3 trial. The Company expects to report Phase 2 interim data in the first half of 2024, with the Phase 3 dose identified. Additionally, the Company is adding a new cohort to LYNX to include children aged 4 to 9 years with Duchenne who are not currently treated with corticosteroids. The Company also extended the open label portion of the trial for a total of 24 months.

“Having provided care for individuals with Duchenne for over 20 years, I’m excited to see Edgewise expand its clinical studies with EDG-5506 to include boys with Duchenne who are not currently treated with steroids as well as those who have received gene therapy and remain symptomatic,” said Barry J. Byrne, M.D., Ph.D., Director, Powell Gene Therapy Center, University of Florida and Chief Medical Adviser for MDA. “The patient community is desperate to find additional treatment options to curb the effects of this devastating disease.”

“We have listened to the Duchenne community and thoughtfully initiated FOX and expanded LYNX, both important advances in our EDG-5506 clinical development program. We anticipate moving towards a Phase 3 trial start in Duchenne in the second half of 2024,” said Joanne Donovan, M.D., Ph.D., Chief Medical Officer of Edgewise. “We are thrilled to open our studies of EDG-5506 to broader groups of individuals with Duchenne exploring the potential of a muscle-targeted therapeutic against the evolving treatment landscape.”

About FOX Phase 2 Trial in Children with Duchenne

FOX is a Phase 2 placebo-controlled trial to assess the effect of EDG-5506 over 12 weeks on safety, PK and biomarkers of muscle damage in children and adolescents with Duchenne who have been previously treated with gene therapy. Approximately 24 participants, aged 6 to 14 years, are expected to be enrolled in the trial at multiple sites across the United States, which is expected to start in early 2024. Participants will then continue in an open-label extension portion of the trial for a total of 12 months to gain further insights into safety, PK, function and biomarker measures. Go to clinicaltrials.gov to learn more about this trial (NCT06100887).

About LYNX Phase 2 Trial in Children with Duchenne

LYNX is a Phase 2 placebo-controlled trial to assess the effect of multiple doses of EDG-5506 over 12 weeks on safety, PK and biomarkers of muscle damage. The study will also explore changes in functional measures, such as the North Star Ambulatory Assessment (NSAA) and self-reported/caregiver-reported outcomes. Approximately 45 children with Duchenne aged 4 to 9 years are expected to be enrolled in this trial. Participants will then continue in an open-label extension portion of the trial for a total of 24 months to gain further insights into safety and functional measures. Importantly, this trial is designed to identify a dose of EDG-5506 that will reduce biomarkers of muscle damage and has the potential to provide functional benefit to patients in a Phase 3 trial. Go to clinicaltrials.gov to learn more about this trial (NCT05540860).

About Duchenne Muscular Dystrophy

Duchenne is a severe, degenerative muscle disorder with a median life expectancy of around 30 years old. People living with Duchenne begin to lose their ability to walk without assistance by their early teens and nearly all will require the use of a wheelchair by the time they are in their mid-teens. Duchenne is the most common type of muscular dystrophy, and genetic mutations in the dystrophin gene result in contraction-induced muscle damage, which is the primary driver of irreversible muscle loss and impaired motor function. Currently there is no cure for Duchenne; early, active multidisciplinary care from neuromuscular specialists, cardiologists, physical therapists, and other specialists is critical for optimized disease management. Current therapeutic options for Duchenne are inadequate to prevent significant morbidity and mortality; novel therapies in development for Duchenne, including muscle targeted interventions, aim to positively impact disease trajectory.

About EDG-5506 for Becker and Duchenne Muscular Dystrophies

EDG-5506 is an orally administered small molecule designed to prevent contraction-induced muscle damage in dystrophinopathies including Duchenne and Becker. EDG-5506 presents a novel mechanism of action designed to selectively limit the exaggerated muscle damage caused by the absence or loss of functional dystrophin. By minimizing the progressive muscle damage that leads to functional impairment, EDG-5506 has the potential to benefit a broad range of patients suffering from debilitating neuromuscular disorders Its unique mechanism of action provides the potential to establish EDG-5506 as a foundational therapy in dystrophinopathies, either as a single agent therapy or in combination with available therapies and those in development. In August 2021, the U.S. Food and Drug Administration (FDA) granted Fast Track designation to EDG-5506 for the treatment of individuals with Becker.

The Company has advanced EDG-5506 through the clinic including completed a Phase 1 trial evaluating safety, tolerability, PK and pharmacodynamics of EDG-5506 in adult healthy volunteers (Phase 1a) and in adults with Becker (Phase 1b) (NCT04585464). In ARCH, an open-label, single-center trial (NCT05160415) assessing long-term safety and PK, decreases in biomarkers of muscle damage and trends toward improvement in NSAA have been observed following 12 months of treatment with EDG-5506. A Phase 2 cohort of EDG-5506 in Becker (CANYON) is fully enrolled and has now been expanded to include an additional 120 adult participants in a pivotal cohort called GRAND CANYON, which is currently enrolling (NCT05291091). In Duchenne, the Company is advancing its Phase 2 studies, LYNX (NCT05540860) and FOX (NCT06100887), both assessing safety, PK and biomarkers of muscle damage in individuals with Duchenne. The Company is also continuing to advance the DUNE Phase 2 exercise challenge study, to evaluate the effect of EDG-5506 on biomarkers of muscle damage following exercise in adults with LGMD2I, Becker or McArdle disease at a single site in Denmark.

About Edgewise Therapeutics

Edgewise Therapeutics is a leading muscle disease biopharmaceutical company developing novel therapeutics for muscular dystrophies and serious cardiac conditions. The company’s deep expertise in muscle physiology is driving a new generation of first-in-class therapeutics. EDG-5506 is an orally administered skeletal myosin inhibitor in clinical trials in patients with Becker, Duchenne, and Limb-Girdle muscular dystrophies as well as McArdle Disease. EDG-7500, currently in a Phase 1 trial, is a novel cardiac sarcomere modulator for the treatment of HCM and other disorders of cardiac diastolic dysfunction. The entire team at Edgewise is dedicated to our mission: changing the lives of patients and families affected by serious muscle diseases. To learn more, go to: www.edgewisetx.com or follow us on LinkedIn, X (formerly Twitter), Facebook, Instagram and Threads.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Statements in this press release that are not purely historical are forward-looking statements. Such forward-looking statements include, among other things, statements regarding the potential of, and expectations regarding EDG-5506; statements regarding Edgewise’s expectations relating to its clinical trials, including the timing of reporting data (including the Phase 2 interim data from the LYNX clinical trial of EDG-5506) and commencement of trials (including the FOX clinical trial and Phase 3 clinical trial of EDG-5506 Duchenne); statements regarding Edgewise’s pipeline of product candidates and programs; and statements by Edgewise’s Chief Medical Officer. Words such as “believes,” “anticipates,” “plans,” “expects,” “intends,” “will,” “goal,” “potential” and similar expressions are intended to identify forward-looking statements. The forward-looking statements contained herein are based upon Edgewise’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results could differ materially from those projected in any forward-looking statements due to numerous risks and uncertainties, including but not limited to: risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and operating as an early clinical stage company including the potential for Edgewise’s product candidates to cause serious adverse events; Edgewise’s ability to develop, initiate or complete clinical trials for, obtain approvals for and commercialize any of its product candidates; the timing, progress and results of clinical trials for EDG-5506; Edgewise’s ability to enroll and maintain patients in clinical trials; Edgewise’s ability to raise any additional funding it will need to continue to pursue its business and product development plans; the timing, scope and likelihood of regulatory filings and approvals; the potential for any clinical trial results to differ from preclinical, interim, preliminary, topline or expected results; Edgewise’s ability to develop a proprietary drug discovery platform to build a pipeline of product candidates; Edgewise’s manufacturing, commercialization and marketing capabilities and strategy; the size of the market opportunity for Edgewise’s product candidates; the loss of key scientific or management personnel; competition in the industry in which Edgewise operates; Edgewise’s reliance on third parties; Edgewise’s ability to obtain and maintain intellectual property protection for its product candidates; general economic and market conditions; and other risks. Information regarding the foregoing and additional risks may be found in the section entitled “Risk Factors” in documents that Edgewise files from time to time with the U.S. Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Edgewise assumes no obligation to update the forward-looking statements, or to update the reasons why actual results could differ from those projected in the forward-looking statements, except as required by law.

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