{"filing":{"accession_number":"0001818794-26-000009","cik":"0001818794","ticker":"DYN","company_name":"Dyne Therapeutics, Inc.","form":"8-K","filing_date":"2026-09-29","report_date":"2026-09-29","primary_document":"dyn-20260929.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/1818794/000181879426000009/dyn-20260929.htm"},"events":[{"id":35747,"run_id":32945,"accession_number":"0001818794-26-000009","anchor_item_number":"8.01","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"summary":"Dyne Therapeutics announced additional one-year clinical data from its Phase 1/2 ACHIEVE trial of zeleciment basivarsen (DYNE-101) for myotonic dystrophy type 1, demonstrating functional improvement across multiple measures including myotonia, function, strength, and patient-reported outcomes. The company disclosed baseline data from the registrational expansion cohort and reiterated expectations for topline data in Q1 2027 to support a potential U.S. Accelerated Approval submission in Q3 2027.","company_name":"Dyne Therapeutics, Inc.","ticker":"DYN","filing_date":"2026-09-29","form":"8-K","submitted_at":null,"items":[{"id":39911,"accession_number":"0001818794-26-000009","item_number":"7.01","item_title":"Regulation FD Disclosure.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"Dyne Therapeutics announced additional one-year clinical data from its Phase 1/2 ACHIEVE trial of zeleciment basivarsen (DYNE-101) for myotonic dystrophy type 1, showing functional improvement across multiple measures and a mean baseline vHOT of 8.3 seconds for the registrational expansion cohort. This is a material clinical milestone disclosure—the company expects topline data in Q1 2027 intended to support a potential U.S. Accelerated Approval submission in Q3 2027—but does not fit the specific categories of earnings release, M\u0026A, restatement, or other named event types. It is a material operational/clinical development event for a clinical-stage biopharmaceutical company.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-29T20:11:50.347401+00:00","company_name":"","ticker":null,"filing_date":""},{"id":39912,"accession_number":"0001818794-26-000009","item_number":"8.01","item_title":"Other Events.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"Dyne announced additional one-year clinical data from the Phase 1/2 ACHIEVE trial of z-basivarsen for myotonic dystrophy type 1, showing functional improvement across multiple measures (myotonia, function, strength, and patient-reported outcomes) compared to baseline, placebo, and natural history cohorts. The company also disclosed baseline data from the registrational expansion cohort (REC) and reiterated expectations for topline REC data in Q1 2027 to support a potential BLA submission for U.S. Accelerated Approval in Q3 2027. This is a material clinical milestone disclosure that would affect investor assessment of the company's pipeline progress and regulatory pathway, but it does not fit neatly into the specific financial, governance, legal, or terminal categories—it is a clinical/operational development that is clearly material to a biopharmaceutical company's prospects.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-29T20:11:50.347401+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":39911,"accession_number":"0001818794-26-000009","item_number":"7.01","item_title":"Regulation FD Disclosure.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"Dyne Therapeutics announced additional one-year clinical data from its Phase 1/2 ACHIEVE trial of zeleciment basivarsen (DYNE-101) for myotonic dystrophy type 1, showing functional improvement across multiple measures and a mean baseline vHOT of 8.3 seconds for the registrational expansion cohort. This is a material clinical milestone disclosure—the company expects topline data in Q1 2027 intended to support a potential U.S. Accelerated Approval submission in Q3 2027—but does not fit the specific categories of earnings release, M\u0026A, restatement, or other named event types. It is a material operational/clinical development event for a clinical-stage biopharmaceutical company.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-29T20:11:50.347401+00:00","company_name":"Dyne Therapeutics, Inc.","ticker":"DYN","filing_date":"2026-09-29"},{"id":39912,"accession_number":"0001818794-26-000009","item_number":"8.01","item_title":"Other Events.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"Dyne announced additional one-year clinical data from the Phase 1/2 ACHIEVE trial of z-basivarsen for myotonic dystrophy type 1, showing functional improvement across multiple measures (myotonia, function, strength, and patient-reported outcomes) compared to baseline, placebo, and natural history cohorts. The company also disclosed baseline data from the registrational expansion cohort (REC) and reiterated expectations for topline REC data in Q1 2027 to support a potential BLA submission for U.S. Accelerated Approval in Q3 2027. This is a material clinical milestone disclosure that would affect investor assessment of the company's pipeline progress and regulatory pathway, but it does not fit neatly into the specific financial, governance, legal, or terminal categories—it is a clinical/operational development that is clearly material to a biopharmaceutical company's prospects.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-29T20:11:50.347401+00:00","company_name":"Dyne Therapeutics, Inc.","ticker":"DYN","filing_date":"2026-09-29"}]}