{"success":true,"data":{"pressRelease":{"id":"168940","rtpr_id":"nBwChrwha-20261014","ticker":"SRPT","exchange":"NASDAQ","all_tickers":["SRPT"],"title":"Sarepta Therapeutics Presents New Preclinical Data Demonstrating Robust Knockdown of Pathogenic DMPK RNA in the Nucleus with SRP-1003 in DM1 at 2026 Oligonucleotide Therapeutics Society Annual Meeting","author":"Business Wire","published_at":"2026-10-14T12:30:00.710Z","article_body":"Sarepta Therapeutics Presents New Preclinical Data Demonstrating Robust\nKnockdown of Pathogenic DMPK RNA in the Nucleus with SRP-1003 in DM1 at 2026\nOligonucleotide Therapeutics Society Annual Meeting\n\n\n * Correction of MBNL- dependent mis-splicing provides functional evidence that\nSRP-1003 is degrading disease-causing RNA within the nucleus.\n\n * In a preclinical model, SRP-1003 reduced pathogenic DMPK mRNA in both the\ncytoplasm and nucleus in a dose-dependent manner, achieving up to\napproximately 80% knockdown in each compartment\n\n * Nuclear target engagement supported by three independent methodologies,\nincluding compartment-fractionated ddPCR, RNA FISH, and RNAscope\n\n * SRP-1003 remained detectable across multiple muscle groups for up to 16 weeks\nfollowing a single intravenous dose\n\nSarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic\nmedicine for rare diseases, today presented new preclinical data at the 22nd\nAnnual Meeting of the Oligonucleotide Therapeutics Society (OTS) demonstrating\nthat SRP-1003, the company's investigational small interfering RNA (siRNA)\nprogram for the treatment of myotonic dystrophy type 1 (DM1), can directly\nreduce pathogenic DMPK transcripts within the nucleus, where the molecular\ndrivers of DM1 pathology originate.\n\nIn the analysis, correction of muscleblind-like (MBNL)-dependent mis-splicing\nprovide functional evidence of nuclear activity. Direct measurement of the\nnuclear and cytoplasmic transcripts pools further demonstrated the efficiency\nof that activity, with SRP-1003 producing comparable, dose-dependent DMPK in\nboth compartments and achieving up to approximately 80% knockdown in each. The\nresults were confirmed via three independent and complementary methods: RNA\nfluorescence in situ hybridization (FISH) foci quantification,\ncompartment-fractionated ddPCR with purity controls, and in situ RNAscope in\nintact cells.\n\nDM1 is caused by a CTG repeat expansion in the DMPK gene that leads to the\nbuildup of toxic CUG-repeat RNA transcripts within the nucleus. This toxic RNA\ntraps MBNL proteins and disrupts the normal processing, or splicing, of many\nother RNAs, leading to disease across multiple organ systems. Since both MBNL\nsequestration and pre-mRNA splicing occur in the nucleus, correcting MBNL\nmis-splicing is functional evidence that the therapy has reached and reduced\nthe disease-causing RNA in the nucleus.\n\n“For an siRNA approach to address the underlying biology of DM1, it must\nreduce the toxic DMPK in the nucleus,” said Louise Rodino-Klapac, Ph.D.,\npresident, Research & Development and Technical Operations, Sarepta.\n“These results provide two complementary lines of evidence that SRP-1003\neffectively and efficiently gets into the nucleus. We observed correction of\nMBNL-dependent mis-splicing, a functional readout that requires degradation of\nthe nuclear transcript and measured comparable levels of DMPK knockdown in the\nnucleus and cytoplasm. Together with the reductions in toxic nuclear RNA foci\nacross multiple models and methods, these data strengthen the biological\nrationale for SRP-1003 and support the continued advancement of the program in\nour ongoing Phase 1/2 clinical study, from which we expect to share results\nlater this year.”\n\nDetails from the SRP-1003 poster presentation:\n\nP-066: Preclinical Evaluation of SRP-1003: An αvβ6 Integrin-Targeting siRNA\nPlatform for Targeted Knockdown of DMPK in Myotonic Dystrophy Type 1 (C.\nGreer, et al.)\n\nIn DM1 patient-derived myotubes, compartment fractioned ddPCR directly\nmeasured DMPK mRNA in the nuclear and cytoplasmic transcript pools. SRP-1003\nproduced dose dependent reductions in both compartments, achieving up to\napproximately 80% knockdown in each, with nuclear knockdown comparable to\ncytoplasmic knockdown. Fractional purity was validated using established\ncytoplasmic and nuclear RNA controls, and DMPK knockdown was specific to\nSRP-1003 and was not observed with a scrambled siRNA control.\n\nSRP-1003 also reduced toxic nuclear RNA foci in patient-derived myotubes, as\ndemonstrated by RNA fluorescence in situ hybridization (RNA FISH). In the\nDMSXL mouse model of DM1, treatment reduced nuclear RNA foci in skeletal\nmuscle, diaphragm, and myocardium and was associated with significant\nreductions in both human and mouse DMPK mRNA.\n\nIn a second DM1 mouse model expressing a pathogenic human DMPK transgene, an\nSRP-1003 surrogate siRNA reduced pathogenic human DMPK RNA in the nucleus and\nproduced dose-dependent correction of MBNL-dependent mis-splicing as assessed\nby RNA sequencing.\n\nThis splicing correction is an important functional readout of nuclear\nactivity: because the trapped MBNL proteins and the affected splicing\nmachinery are located in the nucleus, the observed correction indicates that\nthe disease-causing nuclear RNA was degraded rather than only in the\ncytoplasm.\n\nIn separate pharmacokinetic studies, SRP-1003 demonstrated sustained exposure\nacross multiple upper and lower body muscle groups for up to 16 weeks\nfollowing a single intravenous dose in preclinical models.\n\nAbout DM1 and SRP-1003\n\nMyotonic dystrophy type 1 (DM1) is the most common form of adult-onset\nmuscular dystrophy and is caused by a repeat expansion in the DMPK gene. DM1\nis a progressive, multisystem disorder that affects skeletal and smooth\nmuscle, as well as the heart, respiratory system, eye, endocrine,\ngastrointestinal, and central nervous systems. The disease is commonly\nassociated with muscle weakness, daytime sleepiness, breathing difficulties,\nand cardiac conduction abnormalities. There is currently no cure for DM1, and\nno disease modifying treatments are available.\n\nSRP-1003 is an investigational siRNA treatment for DM1 and is designed to\ntarget and knockdown, or silence, the DMPK mRNA in target cells. SRP-1003 is\ncurrently being studied in a first-in-human, Phase 1/2, single ascending dose\n(SAD)/multiple ascending dose (MAD), randomized, placebo-controlled clinical\ntrial (Study SRP-1003-101) that is being conducted in individuals with DM1\naged 18 to 65.\n\nAbout Sarepta Therapeutics\n\nSarepta is on an urgent mission: engineer precision genetic medicine for rare\ndiseases that devastate lives and cut futures short. We hold a leadership\nposition in Duchenne muscular dystrophy (Duchenne) and are building a robust\nportfolio of programs across muscle, central nervous system, and cardiac\ndiseases. For more information, please visit www.sarepta.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.sarepta.com&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=www.sarepta.com&index=1&md5=b77db4071db2eda48cfebe70e110685d)\nor follow us on LinkedIn\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.linkedin.com%2Fcompany%2Fsarepta-therapeutics&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=LinkedIn&index=2&md5=dfe934c31afe9b20d9ab68611146884f)\n, X\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Ftwitter.com%2FSarepta&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=X&index=3&md5=cd68e14ee5d355f61dbeb0a561824f03)\n, Instagram\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.instagram.com%2Fsareptatherapeutics%2F&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=Instagram&index=4&md5=c85a9f2aa07831caf08fb88629073485)\nand Facebook\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.facebook.com%2FSarepta-Therapeutics-208950446535427%2F&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=Facebook&index=5&md5=ae72591b0945cc846365d16ebec9c0f1)\n.\n\nInternet Posting of Information\n\nWe routinely post information that may be important to investors in the 'For\nInvestors' section of our website at www.sarepta.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.sarepta.com%2F&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=www.sarepta.com&index=6&md5=b3f20f72623d2d7a0aeaa56e30d28d52)\n. We encourage investors and potential investors to consult our website\nregularly for important information about us.\n\nForward-Looking Statements\n\nThis press release contains forward-looking statements. Any statements\ncontained in this press release that are not statements of historical fact may\nbe deemed to be forward-looking statements. Words such as \"believes,\"\n\"anticipates,\" \"plans,\" \"expects,\" \"will,\" \"intends,\" \"potential,\" \"possible\"\nand similar expressions are intended to identify forward-looking statements.\nThese forward-looking statements include statements related to our priorities,\ntechnologies and research and development programs; the potential benefits of\nSRP-1003; and our plan to share data later this year from our Phase 1/2 trial.\n\nThese forward-looking statements involve risks and uncertainties, many of\nwhich are beyond Sarepta’s control. Known risk factors include, among\nothers: success in preclinical and clinical trials, especially if based on a\nsmall patient sample, does not ensure that later clinical trials will be\nsuccessful, and the results of future research may not be consistent with past\npositive results; differences in trial design between early-stage clinical\ntrials and later-stage clinical trials make it difficult to extrapolate the\nresults of earlier clinical trials to later clinical trials; pre-clinical and\nclinical data are often susceptible to varying interpretations and analyses,\nand the different methodologies, assumptions and applications we utilize to\nassess particular safety or efficacy parameters may yield different\nstatistical results; even if we believe data collected from clinical trials of\nour product candidates are promising, these data may not be sufficient to\nsupport approval, including that FDA or foreign regulatory authorities could\ninterpret these data in different ways from us; we rely on third parties,\nincluding in some cases our strategic partners, to conduct some aspects of our\nearly-stage research and pre-clinical and clinical development, and\naccordingly, the inadequate performance by or loss of any of these third\nparties could affect the development and commercialization of our product\ncandidate development, including delayed timelines; certain programs may never\nadvance in the clinic or may be discontinued for a number of reasons,\nincluding regulators imposing a clinical hold and us suspending or terminating\nclinical research or trials; our product candidates may cause undesirable side\neffects, result in new safety signals or have other properties that could\ndelay or prevent regulatory approval of product candidates; we may not be able\nto execute on our business plans, including meeting expected or planned\nregulatory milestones and timelines, clinical development plans, and bringing\nproducts to markets for various reasons including possible limitations of\nfinancial and other resources, manufacturing limitations that may not be\nanticipated or resolved for in a timely manner, and regulatory, court or\nagency decisions, such as decisions by the United States Patent and Trademark\nOffice with respect to patents that cover our product candidates; and those\nrisks identified under the heading “Risk Factors” in Sarepta’s most\nrecent Quarterly Report on Form 10-Q filed with the Securities and Exchange\nCommission (SEC) as well as other SEC filings made by the Company which you\nare encouraged to review.\n\nAny of the foregoing risks could materially and adversely affect the\nCompany’s business, results of operations and the trading price of\nSarepta’s common stock. For a detailed description of risks and\nuncertainties Sarepta faces, you are encouraged to review the SEC filings made\nby Sarepta. We caution investors not to place considerable reliance on the\nforward-looking statements contained in this press release. Sarepta does not\nundertake any obligation to publicly update its forward-looking statements\nbased on events or circumstances after the date hereof, except as required by\nlaw.\n\n\n\nView source version on businesswire.com:\nhttps://www.businesswire.com/news/home/20261014708948/en/\n(https://www.businesswire.com/news/home/20261014708948/en/)\n\nInvestor Contacts:\n\nIan Estepan, 617-274-4052, iestepan@sarepta.com \n(mailto:iestepan@sarepta.com) \nRyan Wong, 617-800-4112, rwong@sarepta.com \n(mailto:rwong@sarepta.com) \nTam Thornton, 617-803-3825, tthornton@sarepta.com\n(mailto:tthornton@sarepta.com)\n\nMedia Contacts:\n\nTracy Sorrentino, 617-301-8566, tsorrentino@sarepta.com \n(mailto:tsorrentino@sarepta.com)\n\n\nCopyright Business Wire 2026","article_body_html":"","raw_payload":{"data":{"id":"nBwChrwha-20261014","title":"Sarepta Therapeutics Presents New Preclinical Data Demonstrating Robust Knockdown of Pathogenic DMPK RNA in the Nucleus with SRP-1003 in DM1 at 2026 Oligonucleotide Therapeutics Society Annual Meeting","author":"Business Wire","ticker":"SRPT","created":"2026-10-14T12:30:00.710Z","tickers":["SRPT"],"exchange":"NASDAQ","article_body":"Sarepta Therapeutics Presents New Preclinical Data Demonstrating Robust\nKnockdown of Pathogenic DMPK RNA in the Nucleus with SRP-1003 in DM1 at 2026\nOligonucleotide Therapeutics Society Annual Meeting\n\n\n * Correction of MBNL- dependent mis-splicing provides functional evidence that\nSRP-1003 is degrading disease-causing RNA within the nucleus.\n\n * In a preclinical model, SRP-1003 reduced pathogenic DMPK mRNA in both the\ncytoplasm and nucleus in a dose-dependent manner, achieving up to\napproximately 80% knockdown in each compartment\n\n * Nuclear target engagement supported by three independent methodologies,\nincluding compartment-fractionated ddPCR, RNA FISH, and RNAscope\n\n * SRP-1003 remained detectable across multiple muscle groups for up to 16 weeks\nfollowing a single intravenous dose\n\nSarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic\nmedicine for rare diseases, today presented new preclinical data at the 22nd\nAnnual Meeting of the Oligonucleotide Therapeutics Society (OTS) demonstrating\nthat SRP-1003, the company's investigational small interfering RNA (siRNA)\nprogram for the treatment of myotonic dystrophy type 1 (DM1), can directly\nreduce pathogenic DMPK transcripts within the nucleus, where the molecular\ndrivers of DM1 pathology originate.\n\nIn the analysis, correction of muscleblind-like (MBNL)-dependent mis-splicing\nprovide functional evidence of nuclear activity. Direct measurement of the\nnuclear and cytoplasmic transcripts pools further demonstrated the efficiency\nof that activity, with SRP-1003 producing comparable, dose-dependent DMPK in\nboth compartments and achieving up to approximately 80% knockdown in each. The\nresults were confirmed via three independent and complementary methods: RNA\nfluorescence in situ hybridization (FISH) foci quantification,\ncompartment-fractionated ddPCR with purity controls, and in situ RNAscope in\nintact cells.\n\nDM1 is caused by a CTG repeat expansion in the DMPK gene that leads to the\nbuildup of toxic CUG-repeat RNA transcripts within the nucleus. This toxic RNA\ntraps MBNL proteins and disrupts the normal processing, or splicing, of many\nother RNAs, leading to disease across multiple organ systems. Since both MBNL\nsequestration and pre-mRNA splicing occur in the nucleus, correcting MBNL\nmis-splicing is functional evidence that the therapy has reached and reduced\nthe disease-causing RNA in the nucleus.\n\n“For an siRNA approach to address the underlying biology of DM1, it must\nreduce the toxic DMPK in the nucleus,” said Louise Rodino-Klapac, Ph.D.,\npresident, Research & Development and Technical Operations, Sarepta.\n“These results provide two complementary lines of evidence that SRP-1003\neffectively and efficiently gets into the nucleus. We observed correction of\nMBNL-dependent mis-splicing, a functional readout that requires degradation of\nthe nuclear transcript and measured comparable levels of DMPK knockdown in the\nnucleus and cytoplasm. Together with the reductions in toxic nuclear RNA foci\nacross multiple models and methods, these data strengthen the biological\nrationale for SRP-1003 and support the continued advancement of the program in\nour ongoing Phase 1/2 clinical study, from which we expect to share results\nlater this year.”\n\nDetails from the SRP-1003 poster presentation:\n\nP-066: Preclinical Evaluation of SRP-1003: An αvβ6 Integrin-Targeting siRNA\nPlatform for Targeted Knockdown of DMPK in Myotonic Dystrophy Type 1 (C.\nGreer, et al.)\n\nIn DM1 patient-derived myotubes, compartment fractioned ddPCR directly\nmeasured DMPK mRNA in the nuclear and cytoplasmic transcript pools. SRP-1003\nproduced dose dependent reductions in both compartments, achieving up to\napproximately 80% knockdown in each, with nuclear knockdown comparable to\ncytoplasmic knockdown. Fractional purity was validated using established\ncytoplasmic and nuclear RNA controls, and DMPK knockdown was specific to\nSRP-1003 and was not observed with a scrambled siRNA control.\n\nSRP-1003 also reduced toxic nuclear RNA foci in patient-derived myotubes, as\ndemonstrated by RNA fluorescence in situ hybridization (RNA FISH). In the\nDMSXL mouse model of DM1, treatment reduced nuclear RNA foci in skeletal\nmuscle, diaphragm, and myocardium and was associated with significant\nreductions in both human and mouse DMPK mRNA.\n\nIn a second DM1 mouse model expressing a pathogenic human DMPK transgene, an\nSRP-1003 surrogate siRNA reduced pathogenic human DMPK RNA in the nucleus and\nproduced dose-dependent correction of MBNL-dependent mis-splicing as assessed\nby RNA sequencing.\n\nThis splicing correction is an important functional readout of nuclear\nactivity: because the trapped MBNL proteins and the affected splicing\nmachinery are located in the nucleus, the observed correction indicates that\nthe disease-causing nuclear RNA was degraded rather than only in the\ncytoplasm.\n\nIn separate pharmacokinetic studies, SRP-1003 demonstrated sustained exposure\nacross multiple upper and lower body muscle groups for up to 16 weeks\nfollowing a single intravenous dose in preclinical models.\n\nAbout DM1 and SRP-1003\n\nMyotonic dystrophy type 1 (DM1) is the most common form of adult-onset\nmuscular dystrophy and is caused by a repeat expansion in the DMPK gene. DM1\nis a progressive, multisystem disorder that affects skeletal and smooth\nmuscle, as well as the heart, respiratory system, eye, endocrine,\ngastrointestinal, and central nervous systems. The disease is commonly\nassociated with muscle weakness, daytime sleepiness, breathing difficulties,\nand cardiac conduction abnormalities. There is currently no cure for DM1, and\nno disease modifying treatments are available.\n\nSRP-1003 is an investigational siRNA treatment for DM1 and is designed to\ntarget and knockdown, or silence, the DMPK mRNA in target cells. SRP-1003 is\ncurrently being studied in a first-in-human, Phase 1/2, single ascending dose\n(SAD)/multiple ascending dose (MAD), randomized, placebo-controlled clinical\ntrial (Study SRP-1003-101) that is being conducted in individuals with DM1\naged 18 to 65.\n\nAbout Sarepta Therapeutics\n\nSarepta is on an urgent mission: engineer precision genetic medicine for rare\ndiseases that devastate lives and cut futures short. We hold a leadership\nposition in Duchenne muscular dystrophy (Duchenne) and are building a robust\nportfolio of programs across muscle, central nervous system, and cardiac\ndiseases. For more information, please visit www.sarepta.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.sarepta.com&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=www.sarepta.com&index=1&md5=b77db4071db2eda48cfebe70e110685d)\nor follow us on LinkedIn\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.linkedin.com%2Fcompany%2Fsarepta-therapeutics&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=LinkedIn&index=2&md5=dfe934c31afe9b20d9ab68611146884f)\n, X\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Ftwitter.com%2FSarepta&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=X&index=3&md5=cd68e14ee5d355f61dbeb0a561824f03)\n, Instagram\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.instagram.com%2Fsareptatherapeutics%2F&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=Instagram&index=4&md5=c85a9f2aa07831caf08fb88629073485)\nand Facebook\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.facebook.com%2FSarepta-Therapeutics-208950446535427%2F&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=Facebook&index=5&md5=ae72591b0945cc846365d16ebec9c0f1)\n.\n\nInternet Posting of Information\n\nWe routinely post information that may be important to investors in the 'For\nInvestors' section of our website at www.sarepta.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.sarepta.com%2F&esheet=54621655&newsitemid=20261014708948&lan=en-US&anchor=www.sarepta.com&index=6&md5=b3f20f72623d2d7a0aeaa56e30d28d52)\n. We encourage investors and potential investors to consult our website\nregularly for important information about us.\n\nForward-Looking Statements\n\nThis press release contains forward-looking statements. Any statements\ncontained in this press release that are not statements of historical fact may\nbe deemed to be forward-looking statements. Words such as \"believes,\"\n\"anticipates,\" \"plans,\" \"expects,\" \"will,\" \"intends,\" \"potential,\" \"possible\"\nand similar expressions are intended to identify forward-looking statements.\nThese forward-looking statements include statements related to our priorities,\ntechnologies and research and development programs; the potential benefits of\nSRP-1003; and our plan to share data later this year from our Phase 1/2 trial.\n\nThese forward-looking statements involve risks and uncertainties, many of\nwhich are beyond Sarepta’s control. Known risk factors include, among\nothers: success in preclinical and clinical trials, especially if based on a\nsmall patient sample, does not ensure that later clinical trials will be\nsuccessful, and the results of future research may not be consistent with past\npositive results; differences in trial design between early-stage clinical\ntrials and later-stage clinical trials make it difficult to extrapolate the\nresults of earlier clinical trials to later clinical trials; pre-clinical and\nclinical data are often susceptible to varying interpretations and analyses,\nand the different methodologies, assumptions and applications we utilize to\nassess particular safety or efficacy parameters may yield different\nstatistical results; even if we believe data collected from clinical trials of\nour product candidates are promising, these data may not be sufficient to\nsupport approval, including that FDA or foreign regulatory authorities could\ninterpret these data in different ways from us; we rely on third parties,\nincluding in some cases our strategic partners, to conduct some aspects of our\nearly-stage research and pre-clinical and clinical development, and\naccordingly, the inadequate performance by or loss of any of these third\nparties could affect the development and commercialization of our product\ncandidate development, including delayed timelines; certain programs may never\nadvance in the clinic or may be discontinued for a number of reasons,\nincluding regulators imposing a clinical hold and us suspending or terminating\nclinical research or trials; our product candidates may cause undesirable side\neffects, result in new safety signals or have other properties that could\ndelay or prevent regulatory approval of product candidates; we may not be able\nto execute on our business plans, including meeting expected or planned\nregulatory milestones and timelines, clinical development plans, and bringing\nproducts to markets for various reasons including possible limitations of\nfinancial and other resources, manufacturing limitations that may not be\nanticipated or resolved for in a timely manner, and regulatory, court or\nagency decisions, such as decisions by the United States Patent and Trademark\nOffice with respect to patents that cover our product candidates; and those\nrisks identified under the heading “Risk Factors” in Sarepta’s most\nrecent Quarterly Report on Form 10-Q filed with the Securities and Exchange\nCommission (SEC) as well as other SEC filings made by the Company which you\nare encouraged to review.\n\nAny of the foregoing risks could materially and adversely affect the\nCompany’s business, results of operations and the trading price of\nSarepta’s common stock. For a detailed description of risks and\nuncertainties Sarepta faces, you are encouraged to review the SEC filings made\nby Sarepta. We caution investors not to place considerable reliance on the\nforward-looking statements contained in this press release. Sarepta does not\nundertake any obligation to publicly update its forward-looking statements\nbased on events or circumstances after the date hereof, except as required by\nlaw.\n\n\n\nView source version on businesswire.com:\nhttps://www.businesswire.com/news/home/20261014708948/en/\n(https://www.businesswire.com/news/home/20261014708948/en/)\n\nInvestor Contacts:\n\nIan Estepan, 617-274-4052, iestepan@sarepta.com \n(mailto:iestepan@sarepta.com) \nRyan Wong, 617-800-4112, rwong@sarepta.com \n(mailto:rwong@sarepta.com) \nTam Thornton, 617-803-3825, tthornton@sarepta.com\n(mailto:tthornton@sarepta.com)\n\nMedia Contacts:\n\nTracy Sorrentino, 617-301-8566, tsorrentino@sarepta.com \n(mailto:tsorrentino@sarepta.com)\n\n\nCopyright Business Wire 2026"},"type":"article","timestamp":"2026-10-14T12:30:00.759712242Z","server_sent_at_ms":1791981000759},"received_at":"2026-10-14T12:30:00.810Z","source_url":"https://www.businesswire.com/news/home/20261014708948/en/"},"analysis":{"id":"157189","press_release_id":"168940","analysis_json":{"industry":{"label":"Biotechnology","sector":"Health Care"},"redFlags":[],"eventType":"clinical_trial","narrative":"Sarepta presented new preclinical data at the Oligonucleotide Therapeutics Society meeting showing its DM1 siRNA candidate SRP-1003 reduces pathogenic DMPK RNA in the nucleus, achieving up to approximately 80% knockdown in both nuclear and cytoplasmic compartments in a dose-dependent manner.\n\nNuclear target engagement was confirmed by three independent methods (RNA FISH, compartment-fractionated ddPCR, and RNAscope), and MBNL-dependent mis-splicing correction provided functional evidence of nuclear activity.\n\nSRP-1003 showed sustained exposure across multiple muscle groups for up to 16 weeks after a single IV dose in preclinical models. The company continues its first-in-human Phase 1/2 study (SRP-1003-101) and expects to share results later this year.","sentiment":"bullish","agentHooks":{"shouldPost":true,"suggestedAngle":"Mechanistic validation for SRP-1003 in DM1 -- sets up Phase 1/2 data readout later this year as the near-term catalyst."},"keyFigures":{"drugName":"SRP-1003","phaseOfTrial":"Phase 1/2","customDimensions":{"dmpk_knockdown":"up to approximately 80% in nucleus and cytoplasm","muscle_exposure_duration":"up to 16 weeks after single IV dose"}},"quotedText":"For an siRNA approach to address the underlying biology of DM1, it must reduce the toxic DMPK in the nucleus","namedEntities":{"people":[{"name":"Louise Rodino-Klapac, Ph.D.","role":"President, Research & Development and Technical Operations, Sarepta"},{"name":"Ian Estepan","role":"investor contact"},{"name":"Ryan Wong","role":"investor contact"},{"name":"Tam Thornton","role":"investor contact"},{"name":"Tracy Sorrentino","role":"media contact"}],"products":["SRP-1003"],"companies":[{"name":"Sarepta Therapeutics, Inc.","ticker":"SRPT"},{"name":"Oligonucleotide Therapeutics Society","relationship":"conference organizer"}],"dollarAmounts":[]},"materialImpact":{"score":2,"reasoning":"Preclinical data supporting SRP-1003's nuclear mechanism of action in DM1; scientifically meaningful but early-stage with no clinical readout yet. Phase 1/2 results expected later this year are the real catalyst."},"tickerRelevance":{"others":[],"primary":"SRPT"},"globalImportance":30,"audienceRelevance":35,"eventTypeSecondary":[],"importanceComponents":{"tickerTier":"large-cap biotech","eventGravity":"preclinical data presentation","issuerAuthored":true,"catalystProximity":"Phase 1/2 data expected later this year"}},"event_type":"clinical_trial","event_type_secondary":null,"sentiment":"bullish","material_impact_score":2,"narrative":"Sarepta presented new preclinical data at the Oligonucleotide Therapeutics Society meeting showing its DM1 siRNA candidate SRP-1003 reduces pathogenic DMPK RNA in the nucleus, achieving up to approximately 80% knockdown in both nuclear and cytoplasmic compartments in a dose-dependent manner.\n\nNuclear target engagement was confirmed by three independent methods (RNA FISH, compartment-fractionated ddPCR, and RNAscope), and MBNL-dependent mis-splicing correction provided functional evidence of nuclear activity.\n\nSRP-1003 showed sustained exposure across multiple muscle groups for up to 16 weeks after a single IV dose in preclinical models. The company continues its first-in-human Phase 1/2 study (SRP-1003-101) and expects to share results later this year.","key_figures":{"drugName":"SRP-1003","phaseOfTrial":"Phase 1/2","customDimensions":{"dmpk_knockdown":"up to approximately 80% in nucleus and cytoplasm","muscle_exposure_duration":"up to 16 weeks after single IV dose"}},"named_entities":{"people":[{"name":"Louise Rodino-Klapac, Ph.D.","role":"President, Research & Development and Technical Operations, Sarepta"},{"name":"Ian Estepan","role":"investor contact"},{"name":"Ryan Wong","role":"investor contact"},{"name":"Tam Thornton","role":"investor contact"},{"name":"Tracy Sorrentino","role":"media contact"}],"products":["SRP-1003"],"companies":[{"name":"Sarepta Therapeutics, Inc.","ticker":"SRPT"},{"name":"Oligonucleotide Therapeutics Society","relationship":"conference organizer"}],"dollarAmounts":[]},"model_name":"glm-5.3-flashx","prompt_hash":"sha256:5c812bd9e28b810d","schema_hash":"sha256:05005c02d9cffac9","created_at":"2026-10-14T12:30:13.935Z","global_importance":30,"audience_relevance":35,"importance_components":{"tickerTier":"large-cap biotech","eventGravity":"preclinical data presentation","issuerAuthored":true,"catalystProximity":"Phase 1/2 data expected later this year"}},"durationMs":5230,"modelName":"glm-5.3-flashx"}}