Limb-Girdle Muscular Dystrophy, Type 2C

Atamyo has received approval to initiate a clinical trial of ATA-200 gene therapy in France and Italy ATA-200 is a single-injection gene therapy aimed to treat LGMD2C/R5 caused by mutations in the γ-sarcoglycan gene The phase 1b, dose-escalation study will evaluate the safety and efficacy of ATA-200 in children EVRY, France--(BUSINESS WIRE)-- Atamyo Therapeutics, a clinical-stage biotechnology company focused on the development of new-generation gene therapies targeting muscular dystrophies and cardiomyopathies, today announced the first authorization of a Clinical Trial Application (CTA) in Europe for ATA-200, its gene therapy for the treatment of the γ-sarcoglycan related limb-girdle muscular dystrophy Type 2C/R5 (LGMD2C/R5). This authorization was first granted by the Italian Medicines Agency (AIFA), then by the French Medicines Agency (ANSM). “We are thrilled to obtain our CTA approval in France and Italy for the devastating LGMD2C/R5 disease affecting primarily a pediatric population and for which there is no approved treatment,” said Dr Sophie Olivier, Chief Medical Officer of Atamyo. “Atamyo plans to initiate dosing in patients for ATA-200 in third quarter 2024.” “LGMD 2C/R5 is a severe muscular dystrophy with an onset in early childhood and loss of ambulation generally occurring before adolescence,” said Pr. Giacomo Comi, Full Professor of Neurology at the University of Milan (Italy), and principal investigator of this trial. “It is a great motivation to know that the work we are doing has the potential to make a life-changing difference for the patients affected by this disease.” “This is a significant milestone for LGMD-2C/R5 patients and for Atamyo as ATA-200 is the first treatment targeting LGMD-2C/R5 to enter clinical trials,” said Stéphane Degove, CEO of Atamyo Therapeutics. “With the ongoing clinical trial of ATA-100 in LGMD2I/R9, the initiation of the clinical program for ATA-200 confirms our unique capabilities in bringing to patients suffering from limb-girdle muscular dystrophies a new generation of safe and effective gene therapies.” This clinical trial (NCT05973630) is a multicenter, Phase 1b, open-label, dose escalation study evaluating safety, pharmacodynamic, efficacy, and immunogenicity of intravenous ATA-200, a single-dose Adeno-Associated Virus (AAV) vector carrying the human γ-sarcoglycan transgene. LGMD2C/R5 is a rare genetic disease caused by mutations in the gene that produces γ-sarcoglycan, a transmembrane protein that is involved in the connection between muscle fibers and their environment. It affects an estimated 2,000 people in Europe. In the classical form, symptoms appear in early childhood and patients suffer from progressive muscular weakness leading to loss of ambulation before adulthood. Cardiac involvement, typically presenting as dilated cardiomyopathy is reported in approximately half of patients. There is no curative treatment. The management of LGMD2C/R5 is solely supportive. ATA-200, a gene therapy candidate for LGMD2C/R5, delivers a normal copy of the gene for production of γ-sarcoglycan protein. In preclinical models, a single systemic injection of ATA-200 demonstrated its tolerability and capability to correct symptoms and biomarkers of the pathology. ATA-200 has been granted Orphan Medicinal Product Designation by the European Medicines Agency (EMA). The therapy is based on the research of Atamyo Chief Scientific Officer Isabelle Richard, Ph.D., Research Director at National Center of Scientific Research (CNRS) in France and head of the Progressive Muscular Dystrophies Laboratory at Genethon. In addition to its LGMD2C/R5 gene therapy, Atamyo is developing a clinical trial with ATA-100 gene therapy for LGMD2I/R9, related to deficiencies in FKRP; and is in IND-enabling studies for LGMD2A/R1, related to deficiencies in calpain protein. About Atamyo Therapeutics Atamyo Therapeutics is a clinical-stage biopharma focused on the development of a new generation of effective and safe gene therapies for neuromuscular diseases. A spin-off of gene therapy pioneer Genethon, Atamyo leverages unique expertise in AAV-based gene therapy and muscular dystrophies from the Progressive Muscular Dystrophies Laboratory at Genethon. Atamyo’s most advanced programs address different forms of limb-girdle muscular dystrophies (LGMD), with two clinical-stage programs targeting respectively LGMD2I/R9 and LGMD2C/R5. The name of the company is derived from two words: Celtic Atao which means “Always” or “Forever” and Myo which is the Greek root for muscle. Atamyo conveys the spirit of its commitment to improve the life of patients affected by neuromuscular diseases with life-long efficient treatments. For more information visit . View source version on businesswire.com: Contacts U.S. Contact: Charles Craig, Opus Biotech Communications Charles.s.craig@gmail.com, 404-245-0591 European Contact: contact@atamyo.com Source: Atamyo Therapeutics View this news release online at:

Participation in Chardan’s 7th Genetic Medicines Conference Participation in Cell and Gene Therapy on the Mesa 2023 Meeting Five upcoming communications on LGMD programs at WMS congress, ESGCT annual meeting and 2023 International Limb-Girdle Muscular Dystrophy Conference EVRY, France--(BUSINESS WIRE)-- Atamyo Therapeutics, a biotechnology company focused on the development of new-generation gene therapies targeting neuromuscular disease, today announced its participation to forthcoming conferences and scientific communications on its programs targeting limb-girdle muscular dystrophies (LGMDs). Atamyo to participate in Chardan's 7th Annual Genetic Medicines Conference and in Cell & Gene Meeting on the Mesa 2023 Stephane Degove, Atamyo CEO, will provide a corporate overview at two forthcoming conferences in October: • Chardan's 7th Annual Genetic Medicines Conference, held in New York City: - Presentation on October 2, at 10:30 AM, in the Embassy room • Cell & Gene Meeting on the Mesa, held in Carlsbad, CA, on October 10-12, 2023: - Presentation on October 10, at 5:15pm, at the Rentschler ATMP Ballroom Two upcoming communications at the 28th Annual Congress of the World Muscle Society (3-7 October 2023 in Charleston, SC) Two communications describing Atamyo’s LGMD programs will be presented at the 28th International Annual Congress of the World Muscle Society (WMS): 1) Evaluation of gene transfer efficiency in a mild model of dystrophic muscle disorder performed by machine learning and linear discriminant analysis • Oral Presentation by A. Brureau (Genethon), at Ballroom C2 on October 4, 2023 from 18h15 to 18h45 • Poster Board Number 282 at Ballroom C, on October 4, 2023, 17h15-18h15 2) Natural history of limb girdle muscular dystrophy R9: one-year follow-up of a European cohort • Oral Presentation by J. Vissing (Copenhagen Neuromuscular Center, Rigshospitale) at Ballroom C2 on October 4, 2023 from 18h15 to 18h45 • Poster Board Number 283 at Ballroom C, on October 4, 2023, 17h15-18h15 Two upcoming communications at the European Society of Gene & Cell Therapy 30th annual congress (24-27 October 2023 in Brussels - Belgium): Two communications describing Atamyo’s LGMD programs will be presented at the 30th Annual Congress of the European Society of Gene & Cell Therapy (ESGCT) that will take place on October 24-27, 2023 in Brussel (Belgium): 1) Gene therapy for LGMDR9: preliminary results of a dose-escalation study • Oral presentation by Nicolai Preisler, MD, Rigshospitalet, Copenhagen, during the Cardiovascular and muscular diseases session, on Friday October 27, 11h30-13h00 – Le BEL, Tour & Taxis 2) A micro-RNA regulated AAV vector prevents the cardiotoxicity induced by transgene overexpression following FKRP gene transfer • E. Gicquel (Genethon) et al., poster number P060, poster sessions October 25 and 26 Oral presentation on Atamyo’s LGMD-R9 program at the 2023 International Limb-Girdle Muscular Dystrophy Conference (28-29 October 2023, Washington DC) 1) Preliminary experiences with Atamyo’s FKRP gene therapy • Oral presentation by John Vissing, MD, Rigshospitalet, Copenhagen, during the Clinical Trials Updates (Part 1) Session, on October 29, 11h00am-12h10pm – Constitution Ballroom, Grand Hyatt About Atamyo Therapeutics Atamyo Therapeutics is a clinical-stage biopharma focused on the development of a new generation of effective and safe gene therapies for neuromuscular diseases. A spin-off of gene therapy pioneer Genethon, Atamyo leverages unique expertise in AAV-based gene therapy and muscular dystrophies from the Progressive Muscular Dystrophies Laboratory at Genethon. Atamyo’s most advanced programs address different forms of limb-girdle muscular dystrophies (LGMD), with two clinical-stage programs targeting respectively LGMD-R9 and LGMD-R5. The name of the company is derived from two words: Celtic Atao which means “Always” or “Forever” and Myo which is the Greek root for muscle. Atamyo conveys the spirit of its commitment to improve the life of patients affected by neuromuscular diseases with life-long efficient treatments. For more information visit View source version on businesswire.com: Contacts U.S. Contact: Charles Craig, Opus Biotech Communications charles.s.craig@gmail.com, 404-245-0591 European contact: contact@atamyo.com Source: Atamyo Therapeutics View this news release online at:

A multicenter phase 1b study will evaluate safety, pharmacodynamic and efficacy of ATA-200 ATA-200 is the second Atamyo’s next generation gene replacement therapy entering the clinic ATA-200 is eligible to receive up to €8m ($8.6m) of non-dilutive financing from France 2030 program EVRY, France--(BUSINESS WIRE)-- Atamyo Therapeutics, a biotechnology company focused on the development of new-generation gene therapies targeting neuromuscular diseases, today announced the filing of a Clinical Trial Application (CTA) in Europe for ATA-200, its gene therapy targeting γ-sarcoglycan (SGCG) related limb-girdle muscular dystrophy Type 2C/R5 (LGMD2C/R5). The company also announced that ATA-200 has been granted a non-dilutive financing up to €8m ($8.6m) from France 2030 public program managed by Bpifrance, to support its clinical trials and manufacturing development programs. This clinical trial (EUCT 2023-506440-16-00) is a multicenter, Phase 1b, open-label, dose escalation study evaluating safety, pharmacodynamic, efficacy, and immunogenicity of intravenous ATA-200, a single-dose Adeno-Associated Virus (AAV) vector carrying the human γ-sarcoglycan transgene. “LGMD-R5 is the most rapidly progressive and debilitating form of LGMDs with onset of symptoms in early childhood, a loss of ambulation before adulthood, and frequent cardiac impairment. No curative treatment exists for this disease,” said Dr Sophie Olivier, Chief Medical Officer of Atamyo. “ATA-200 incorporates a new promoter that enhances the liver and cardiac safety of gene therapy,” said Isabelle Richard, Ph.D., Co-founder and Chief Scientific Officer of Atamyo. “This first-in-class experimental treatment represents a new hope for the patients.” “We are thrilled to European Clinical trial and to receive such a strong public financing for the devastating LGMD2C/R5 disease,” said Stephane Degove, Co-Founder and Chief Executive Officer of Atamyo. “With the ongoing clinical trial in LGMD-R9, the initiation of the clinical program for LGMD-R5/2C confirms our unique capabilities in bringing to patients suffering from limb-girdle muscular dystrophies a new generation of safe and effective gene therapies.” LGMD2C/R5 is a rare genetic disease caused by mutations in the gene that produces γ-sarcoglycan, a transmembrane protein that is involved in the connection between muscle fibers and their environment. It affects an estimated 2,000 people in Europe only. In the classical form, symptoms appear in early childhood and patients suffer from progressive muscular weakness leading to loss of ambulation before adulthood. Cardiac involvement, typically presenting as dilated cardiomyopathy is reported in approximately half of patients. There is no curative treatment. The management of LGMDR5 is solely supportive. ATA-200, the gene therapy for LGMD2C/R5, delivers a normal copy of the gene for production of γ-sarcoglycan. In preclinical mice models, ATA-200 demonstrated its tolerability and capability to correct symptoms and biomarkers of the pathology. Atamyo plans to initiate dosing in patients for ATA-200 in the first half of 2024. In addition to its LGMD2C/R5 gene therapy, Atamyo is developing a clinical trial with ATA-100 gene therapy for LGMD2I/R9, related to deficiencies in FKRP; and is in IND-enabling studies for LGMD2A/R1, related to deficiencies in calpain protein. About Atamyo Therapeutics Atamyo Therapeutics is a clinical-stage biopharma focused on the development of a new generation of effective and safe gene therapies for neuromuscular diseases. A spin-off of gene therapy pioneer Genethon, Atamyo leverages unique expertise in AAV-based gene therapy and muscular dystrophies from the Progressive Muscular Dystrophies Laboratory at Genethon. Atamyo’s most advanced programs address different forms of limb-girdle muscular dystrophies (LGMD), with two clinical-stage programs targeting respectively LGMD-R9 and LGMD-R5. The name of the company is derived from two words: Celtic Atao which means “Always” or “Forever” and Myo which is the Greek root for muscle. Atamyo conveys the spirit of its commitment to improve the life of patients affected by neuromuscular diseases with life-long efficient treatments. For more information visit About France 2030 Launched by the President of France Republic in October 2021, France 2030 is a €54 ($58) billion program which aims to accelerate the transformation of key sectors of the French economy through innovation. From fundamental research, emergence of an idea, and up to the production of a new product or service, France 2030 supports the entire life cycle of innovation until its industrialization. More information on : france2030.gouv.fr View source version on businesswire.com: Contacts U.S. Contact: Charles Craig, Opus Biotech Communications charles.s.craig@gmail.com, 404-245-0591 European contact: contact@atamyo.com Source: Atamyo Therapeutics View this news release online at: