Appointments strengthen company’s capabilities across drug discovery, development and manufacturing WALTHAM, Mass. – Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced the addition of three key members to its leadership team: Oxana Beskrovnaya, Ph.D., senior vice president and head of research; Chris Mix, M.D., senior vice president, clinical development; and John Najim, vice president, chemistry, manufacturing and controls (CMC). “Dyne is establishing a leadership position in muscle disease therapeutics by combining transformative science with an organizational passion for changing the lives of patients,” said Joshua Brumm, president and chief executive officer of Dyne. “We are thrilled to welcome Oxana, Chris and John to our growing team. Leveraging their collective experience in the discovery and development of novel medicines, we are poised to rapidly advance our programs toward the clinic and are fully focused on execution.” Dr. Beskrovnaya is an accomplished R&D leader with a strong track record of discovering and developing first-in-class therapeutics for rare genetic diseases. Prior to joining Dyne, she served as head of musculoskeletal and renal research in Sanofi’s rare disease and neurological unit, where she advanced a pipeline of drug candidates using multiple therapeutic modalities, including nucleic acids, proteins and small molecules. Dr. Beskrovnaya is the author of numerous patents, invited reviews, editorials, book chapters and original research articles in major scientific journals. She received her Ph.D. in genetics from Moscow Genetics Institute, followed by postdoctoral fellowship training in neuromuscular diseases at the Howard Hughes Medical Institute at the University of Iowa. Dr. Mix brings extensive clinical development experience to Dyne, most recently serving as vice president of rare genetic disease clinical development at Agios Pharmaceuticals, where he oversaw development across several hemolytic anemia indications. In his previous role as vice president of clinical development at Sarepta Therapeutics, he focused on advancing candidate therapies for rare neuromuscular disease. Dr. Mix received his B.A. in chemistry from Haverford College and his M.D. from the University of Massachusetts Medical School. He completed his residency in internal medicine at Tufts Medical Center, a fellowship in nephrology at the Beth Israel Deaconess Medical Center in Boston and an M.S. in clinical care research at the Tufts School of Biomedical Sciences. Mr. Najim brings a wealth of CMC biopharmaceutical development and cGMP manufacturing experience across multiple biologic expression systems and small molecules. Mr. Najim previously held roles of increasing responsibility at Proteon Therapeutics, including most recently as vice president of manufacturing and process development, and also served as associate director of manufacturing at Dyax Corporation. He received his B.S. in biochemistry from Merrimack College and his MBA from Bentley University. About Dyne Therapeutics Dyne Therapeutics is pioneering life-transforming therapies for patients with serious muscle diseases. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle with unprecedented precision to restore muscle health. Dyne is advancing treatments for myotonic dystrophy type 1 (DM1), Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Dyne was founded by Atlas Venture and is headquartered in Waltham, Mass. For more information, please visit www.dyne-tx.com, and follow us on Twitter and LinkedIn.   Media Contact Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com Industry veteran brings extensive experience leading biotech companies through periods of growth WALTHAM, Mass.– Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced the appointment of Joshua Brumm as President and Chief Executive Officer. “Josh brings extraordinary skills and experience to further our mission of creating life-transforming therapies for patients with serious muscle diseases,” said Jason Rhodes, partner with Atlas Venture and Dyne founder and executive chairman of the board of directors. “This positions us strongly to pursue the next phase of growth and product development, and we are thrilled to have him joining us.” “Dyne’s FORCE therapeutic platform achieves a unique combination of tissue-specific delivery, high potency and tolerability to enable a broad product pipeline,” said Joshua Brumm. “I look forward to working closely with the board and talented team at Dyne to maximize the potential of our platform by advancing our pipeline and exploring new partnerships.” “On behalf of everyone here, I am excited to welcome Josh,” said Romesh Subramanian, Dyne founder and chief scientific officer. “We look forward to working together to realize the therapeutic power of oligonucleotides for patients with rare muscle diseases and fulfilling Dyne’s mission.” Prior to joining Dyne, Mr. Brumm served as chief operating officer and chief financial officer of Kaleido Biosciences, where he led the company’s financings including its initial public offering and helped bring the lead program into Phase 2 development.  Prior to joining Kaleido, Mr. Brumm was COO and CFO at Versartis, where he oversaw the company’s financial strategy including the successful completion of its IPO, played an integral role in product strategy, and helped negotiate the company’s first product partnership. His previous roles include serving as executive vice president of finance and principal financial officer at Pharmacyclics; CFO at ZELTIQ Aesthetics, where he led the company through its initial public offering, led the international product launch for CoolSculpting and also served in corporate development; and director of finance at Proteolix, Inc., assisting in the sale of the company to Onyx Pharmaceuticals. He also held investment banking roles at Citigroup Global Markets, Inc. and Morgan Stanley. Over the course of his career, Mr. Brumm has raised approximately $1 billion in capital. In 2014, he was named Silicon Valley Business Journal’s CFO of the Year for companies under $500 million. He holds a B.A. in business administration from the University of Notre Dame. About Dyne Therapeutics Dyne Therapeutics is pioneering life-transforming therapies for patients with serious muscle diseases. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle with unprecedented precision to restore muscle health. Dyne is advancing treatments for myotonic dystrophy type 1 (DM1), Duchenne muscular dystrophy (DMD), and facioscapulohumeral muscular dystrophy (FSHD). Dyne was founded in 2018 and is based in Waltham, Mass. For more information, please visit www.dyne-tx.com. Media Contact Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com WALTHAM, Mass.– Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced its support for the ReSolve study, an ongoing natural history study designed to inform the development of therapies for facioscapulohumeral muscular dystrophy (FSHD). ReSolve (Clinical Trial Readiness to Solve Barriers to Drug Development in FSHD) is an observational study run by the FSHD Clinical Trial Research Network (CTRN), a network of medical centers across the U.S. and Europe that aims to validate new clinical outcome assessments and refine trial planning strategies in FSHD. “Dyne is working to deliver life-changing therapies to patients with serious muscle diseases, including FSHD, by leveraging our muscle-targeted FORCE™ platform technology,” said Romesh Subramanian, Ph.D., president and chief executive officer of Dyne. “We are proud to contribute to initiatives like the ReSolve study that seek to accelerate the development of new therapeutic options.” The 18-month, longitudinal ReSolve study is enrolling approximately 160 patients with FSHD across eight sites in the U.S., plus an additional 60 patients across three sites in Europe. The specific goals of the study are to validate new clinical outcome assessments and evaluate physiological biomarkers to support the design and implementation of future clinical trials. To date, approximately 140 patients have been enrolled in the study. Funding from Dyne will lead to an expansion of the number of sites and participants in Europe, as well as fund a muscle biopsy study to advance biomarker development. In addition to Dyne, supporters of the ReSolve study and the CTRN include the National Institutes of Health, Muscular Dystrophy Association, FSHD Society, AFM, Fulcrum Therapeutics and Friends of FSH Research. “With the advancement of targeted treatments for FSHD, it is now more critical than ever to develop reliable clinical outcome assessments and methodologies,” said Dr. Jeffrey Statland, M.D., co-principal investigator of the ReSolve study. “We are grateful for Dyne’s support and look forward to working with them to advance this important work.” For more information about the ReSolve study, including eligibility criteria and a full list of study locations and contacts, please visit clinicaltrials.gov. About Dyne Therapeutics Dyne Therapeutics is pioneering therapies that target muscle tissue with unprecedented precision to restore muscle health. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle to treat a range of serious muscle diseases. Dyne is advancing a treatment for myotonic dystrophy type 1 (DM1) in addition to programs for Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Dyne launched in 2019 and is based in Waltham, Mass. For more information, please visit www.dyne-tx.com. Contacts Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com CAMBRIDGE, Mass.– Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced the appointment of Lawrence Klein, Ph.D., to its Board of Directors. “Dyne’s FORCE therapeutic platform achieves a unique combination of tissue-specific delivery, high potency and tolerability to enable a broad product pipeline,” said Dr. Klein. “I look forward to working closely with the board and leadership team to execute our growth strategy and explore new partnerships to develop life-transforming therapies.” “We are pleased to welcome Lawrence to the Board as we rapidly advance our platform of targeted therapies for serious muscle diseases, including DM1, DMD and FSHD,” said Jason P. Rhodes, Dyne executive chairman and partner at Atlas Venture. “Lawrence’s deep experience across both corporate strategy and business development will be invaluable assets as we move through our next phases of growth.” Dr. Klein is currently chief business officer at CRISPR Therapeutics, where he previously served as vice president of strategy and corporate development. Before joining CRISPR, he was an associate partner at McKinsey & Company, where he was a leader in the biotech practice and served a number of biotech companies on a wide range of topics, from strategy to operations. He received his B.S. in biochemistry and physics from the University of Wisconsin-Madison and his Ph.D. in biophysics from Stanford University. About Dyne Therapeutics Dyne Therapeutics is pioneering therapies that target muscle tissue with unprecedented precision to restore muscle health. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle to treat a range of serious muscle diseases. Dyne is advancing a treatment for myotonic dystrophy type 1 (DM1) in addition to programs for Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Dyne launched in 2019 and is based in Waltham, Mass. For more information, please visit www.dyne-tx.com. Media Contact Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com CAMBRIDGE, Mass.– Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced the appointment of Catherine Stehman-Breen, M.D., to its Board of Directors. “This is an exciting time at Dyne as we advance our platform of targeted therapies for patients with serious muscle diseases, including DM1 and DMD,” said Stehman-Breen. “I look forward to working closely with the Board and leadership team as we build on the company’s progress to date including Dyne’s support of END-DM1, a natural history study to advance the understanding of DM1 disease progression.” “Catherine has played an instrumental role in Dyne’s launch and product strategy and in establishing relationships with the patient communities that we strive to serve,” said Jason P. Rhodes, Dyne executive chairman and partner at Atlas Venture. “We are fortunate to have her joining the Board as we pursue our mission of developing life-transforming therapies.” Dr. Stehman-Breen is currently an independent board member at Generation Bio and is an entrepreneur-in-residence with Atlas Venture. She previously served as chief medical officer of Sarepta Therapeutics, a biopharmaceutical company focused on RNA-targeted therapeutics, as vice president, clinical development at Regeneron Pharmaceuticals, and held senior leadership positions at Amgen, including as vice president, global development, where she led several therapeutic areas. About Dyne Therapeutics Dyne Therapeutics is pioneering therapies that target muscle tissue with unprecedented precision to restore muscle health. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle to treat a range of serious muscle diseases. Dyne is advancing a treatment for myotonic dystrophy type 1 (DM1) in addition to programs for Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Dyne launched in 2019 and is based in Cambridge, Mass. For more information, please visit www.dyne-tx.com. Media Contact Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com Study sponsored by Myotonic Dystrophy Clinical Research Network will advance understanding of disease progression and enable development of clinical outcome assessments­ Patients with DM1 aged 18-70 encouraged to enroll at study sites in U.S. and Europe CAMBRIDGE, Mass.­ – Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced its support for END-DM1, a natural history study to advance the understanding of disease progression in patients with myotonic dystrophy type 1 (DM1) and enable the development of clinical outcome assessments. END-DM1 (Establishing Biomarkers and Clinical Endpoints in Myotonic Dystrophy Type 1) is a non-interventional study sponsored by the Myotonic Dystrophy Clinical Research Network (DMCRN), a network of medical centers that aims to support future clinical trials of potential therapies for DM1 through the standardization of testing methods. The END-DM1 study will enroll approximately 650 people with DM1 aged 18-70 across nine DMCRN study sites in the U.S. and seven sites in Europe. Financial support from Dyne Therapeutics enables the expansion of the study to Europe. In addition to Dyne, supporters of END-DM1 include the FDA, the Myotonic Dystrophy Foundation, the Wyck Foundation and the Muscular Dystrophy Association. “At Dyne, we are striving to transform the lives of patients and families affected by DM1 by developing the first disease-modifying therapies,” said Romesh Subramanian, Ph.D., President and CEO of Dyne. “As we rapidly advance our development programs, we are proud to support this critical initiative that facilitates a global DM1 patient community and provides the foundation for clinical trial readiness.” END-DM1 will be the third and largest natural history study sponsored by DMCRN since the network was established in 2012. Building on current knowledge of DM1 pathogenesis and therapeutic targets, the END-DM1 study will aim to: “This is an exciting time for the development of targeted RNA-based therapies in DM1, but our understanding of this disease is still growing,” said Nicholas Johnson, M.D., a co-principal investigator for END-DM1 at VCU Health in Richmond, Virginia. “Information collected during this study will allow improved assessment of the efficacy of potential new treatment options, and we encourage patients and caregivers to consider participating.” For more information about END-DM1, including study requirements and a list of participating sites, please visit the Myotonic Dystrophy Foundation website. About Dyne Therapeutics Dyne Therapeutics is pioneering therapies that target muscle tissue with unprecedented precision to restore muscle health. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle to treat a range of serious muscle diseases. Dyne is advancing a treatment for myotonic dystrophy type 1 (DM1) in addition to programs for Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Dyne launched in 2019 and is based in Cambridge, Mass. For more information, please visit www.dyne-tx.com. Media Contact Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com Data demonstrates clinically relevant levels of gene knockdown in nonhuman primates with a single dose of Dyne-102 Company is developing pipeline of targeted therapies for patients with serious muscle diseases including DM1, DMD and FSHD CAMBRIDGE, Mass. – Dyne Therapeutics, a biotechnology company pioneering targeted therapies for patients with serious muscle diseases, today announced preclinical data at the 12th edition of the International Myotonic Dystrophy Consortium Meeting (IDMC-12) demonstrating the tissue specificity, potency and tolerability of its FORCE™ therapeutic platform in nonhuman primates. The company is advancing a treatment for myotonic dystrophy type 1 (DM1), a rare, inherited muscle disorder caused by a genetic mutation in the DMPK gene, in addition to programs for Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Mo Qatanani, Ph.D., Dyne’s Vice President of Discovery and Translational Research, presented data demonstrating clinically relevant levels of gene knockdown in nonhuman primates. Key findings include: “Existing oligo therapeutic programs for muscle diseases have demonstrated the potential to knockdown target RNA in preclinical studies. However, systemic exposure resulted in dose-limiting toxicities, restricting their clinical development,” said Mo Qatanani. “Our nonhuman primate data offers compelling evidence that the FORCE therapeutic platform enables tissue-specific delivery that can potentially lead to the development of highly potent and tolerable medicines for a variety of muscle diseases.” “These preclinical results showcase the enormous therapeutic potential of Dyne’s FORCE therapeutic platform and represent a significant step toward advancing targeted therapies for muscle diseases to the clinic,” added Romesh Subramanian, Ph.D., President and CEO of Dyne. “We are proud to lead the effort to bring life-changing oligo therapeutics to patients with myotonic dystrophy and other serious muscle diseases including DMD and FSHD.” Details on Dyne’s presentation at IDMC-12 are as follows: Title: Targeted Delivery of Oligonucleotide Therapeutics to Muscle Reduces Toxic DMPK RNA Time and Date: Thursday, June 13, 2019 at 3:30 PM CEST (9:30 AM ET) Location: The Swedish Exhibition and Congress Centre, Main session hall – G2+G3 About Dyne Therapeutics Dyne Therapeutics is pioneering therapies that target muscle tissue with unprecedented precision to restore muscle health. The company’s FORCE™ platform delivers oligonucleotides and other molecules to skeletal, cardiac and smooth muscle to treat a range of serious muscle diseases. Dyne is advancing a treatment for myotonic dystrophy type 1 (DM1) in addition to programs for Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Dyne launched in 2019 and is based in Cambridge, Mass. For more information, please visit www.dyne-tx.com. Contact Ten Bridge Communications Max Stendahl, 508-277-8117 max@tenbridgecommunications.com