Page 1

DESIGN THERAPEUTICS Design Therapeutics Reports GeneTACTM Portfolio Progress and Second Quarter 2021 Results August 9 , 2021 Preclinical Data Support Initiation of Clinical Development of Lead Gene TAC Program for Friedreich Ataxia in the First Half of 2022 Leadership Team Strengthened with Appointment of Elizabeth Gordon , Ph.D. , as Senior Vice President of Regulatory Affairs CARLSBAD , Calif . , Aug. 09 , 2021 ( GLOBE NEWSWIRE ) Design Therapeutics , Inc. ( Nasdaq : DSGN ) , a biotechnology company developing treatments for degenerative genetic disorders , today reported recent progress with its portfolio of novel small molecule gene targeted chimeras ( Gene TACS ™ M ) , as well as business highlights and second quarter 2021 financial results . " So far in 2021 , we've made substantial progress as a company , highlighted by the compelling new data from ongoing IND - enabling studies with our lead GeneTAC program for Friedreich ataxia . Importantly , we've observed well - tolerated GeneTAC doses in rodents and non - human primates that produced ample biodistribution into key tissues affected by the disease , including the brain , increasing our confidence in the potential of this program as a disease - modifying treatment for patients , " said João Siffert , M.D. , president and chief executive officer of Design Therapeutics . " With plans to begin clinical development in the first half of 2022 , we are pleased to welcome Dr. Elizabeth Gordon to the team , who brings decades of valuable experience in overseeing US and ex - US regulatory affairs and successful regulatory submissions . " " Design is well positioned to advance our research and development activities targeting a number of nucleotide repeat expansion diseases , enabled by a talented team that includes multiple new additions in our R & D organization and a strong balance sheet to fuel our pipeline of novel GeneTAC programs , " added Pratik Shah , Ph.D. , co - founder and executive chair of Design Therapeutics . " We are now preparing for the important transition to a clinical - stage organization , bringing us another step closer to delivering a new class of genomic medicines for a range of serious disorders currently without approved treatments . " Pipeline Progress • New Data from IND - enabling Studies with GeneTAC Product Candidate for Friedreich Ataxia ( FA ) Support Initiation of Clinical Trial in First Half of 2022 : Data from IND - enabling studies in rodents and non - human primates showed that multidose systemic administration of the company's FA Gene TAC was well tolerated and achieved higher concentrations in the CNS ( cerebrum , cerebellum , brainstem and spinal cord ) , heart , and skeletal muscle than needed to restore frataxin ( FXN ) gene expression . In addition , the company observed that exposure to low nanomolar ( nM ) concentrations of its FA GeneTAC in neurons and cardiomyocytes derived from FA patient stem cells in in vitro experiments led to robust and durable increases in FXN mRNA , as well as an increase in endogenous protein reaching levels comparable to unaffected individuals . • On - track for FA GeneTAC Initiation of Clinical Trial in First Half of 2022 : Design has received scientific advice from the European Medicines Agency consistent with the favorable feedback previously received from the U.S. Food and Drug Administration ( FDA ) , supporting the development plan for its FA GeneTAC . In addition , the company has successfully manufactured both drug substance and product at a scale sufficient for clinical use . Design anticipates initiating a Phase 1 clinical trial in patients with Friedreich ataxia in the first half of 2022 , with initial topline clinical data expected in the second half of 2022 . • Continued Progress across GeneTAC Portfolio with Myotonic Dystrophy with Preclinical Data to be Reported in Second Half of 2021 : Design has continued to advance its second GeneTAC program focused on treating myotonic dystrophy type - 1 ( DM1 ) , a genetic disorder that causes progressive muscle weakness and for which there are currently no approved treatment options . The company plans to report preclinical data supporting its potential to develop a disease modifying treatment for patients with DM1 at a medical meeting in the second half of 2021. In addition , leveraging its GeneTAC platform , Design is progressing several earlier - stage programs targeting diseases caused by inherited nucleotide repeat expansions , which represent significant pipeline opportunities to address serious unmet medical needs . Business Highlights • Leadership Team Strengthened with Appointment of Elizabeth Gordon , Ph.D. as Senior Vice President of Regulatory Affairs : Dr. Gordon is a recognized expert in regulatory affairs with over 30 years of experience in the pharmaceutical industry and at the FDA . Dr. Gordon most recently served as senior vice president of regulatory affairs at Amplyx Pharmaceuticals , and before that as vice president , regulatory affairs at Shire Pharmaceutics and vice president of regulatory affairs at Lumena Pharmaceuticals . Earlier in her career , Dr. Gordon served in the Center for Biologics