Avidity Biosciences to Present Data from EXPLORE44® Clinical Development Program of Del-Zota in DMD44 at 30th Annual Congress of the World Muscle Society

Rhea-AI Summary

Avidity Biosciences (NASDAQ: RNA) will present late-breaking oral and poster data from the EXPLORE44 clinical development program for delpacibart zotadirsen (del-zota) at the 30th Annual World Muscle Society Congress in Vienna, October 7-11, 2025.

The company said the presentations build on September 2025 results that showed reversal of disease progression and improvements versus baseline and natural history in multiple functional measures after one year of continuous treatment in Phase 1/2 EXPLORE44 and Phase 2 EXPLORE44-OLE in Duchenne muscular dystrophy patients amenable to exon 44 skipping (DMD44). Del-zota is investigational and not approved by the FDA.

Oral presentation: Kevin M. Flanigan, M.D., on October 11, 2025, 12:33–12:45 p.m. CET. Poster 674P: Aravindhan Veerapandiyan, M.D., on October 8, 2025, 2:30–3:30 p.m. CET. Slides and poster will be posted on the company publications page.

Insights

Clinical Development Strategist

Late-breaking presentations report one-year improvements with del‑zota in DMD44; data will be presented at WMS Oct 7–11, 2025.

Avidity Biosciences will present late‑breaking oral and poster data from the EXPLORE44® and EXPLORE44‑OLE™ programs at the 30th World Muscle Society Congress on October 7-11, 2025. The announcement states delpacibart zotadirsen (del‑zota) produced reversal of disease progression and improvements versus baseline and natural history across multiple functional measures after one year in participants with DMD amenable to exon 44 skipping.

The record notes these results derive from Phase 1/2 and Phase 2 OLE trials and that del‑zota remains investigational with safety and efficacy not established. The immediate dependencies are the full datasets presented at WMS—oral presentation on October 11, 2025 and poster on October 8, 2025—and subsequent public posting on the company publications page. Watch those presentations and the posted materials for patient counts, endpoint definitions, magnitude of change, and safety details over the one‑year exposure to gauge how broadly the results apply.

SAN DIEGO, Oct. 6, 2025 /PRNewswire/ -- Avidity Biosciences, Inc. (Nasdaq: RNA), a biopharmaceutical company committed to delivering a new class of RNA therapeutics called Antibody Oligonucleotide Conjugates (AOCs™) to profoundly improve people's lives, today announced that it will deliver late-breaking oral and poster presentations at the 30th Annual International Congress of the World Muscle Society (WMS), to be held October 7-11, 2025, in Vienna, Austria.

The data to be presented at WMS will reinforce and build on the positive data announced by Avidity in September 2025 which showed reversal of disease progression and unprecedented improvement compared to baseline and natural history across multiple functional measures for participants living with Duchenne muscular dystrophy mutations amenable to exon 44 skipping (DMD44) treated continuously with delpacibart zotadirsen (del-zota) for one year in the Phase 1/2 EXPLORE44^® and Phase 2 EXPLORE44-OLE™ trials. Del-zota is investigational, and it is not approved by the FDA. Its safety and efficacy have not been established.

30th Annual World Muscle Society Congress Presentations

• Delpacibart zotadirsen (del-zota) showed trends toward improvement in functional and patient-reported outcomes in individuals with DMD amenable to exon 44 skipping
  • Oral presentation: Kevin M. Flanigan, M.D., Nationwide Children's Hospital, to present on October 11, 2025, from 12:33 - 12:45 p.m. CET
• Delpacibart Zotadirsen (Del-zota) Increased Dystrophin and Improved Muscle Integrity Markers Regardless of Ambulatory Status in Individuals with DMD44
  • Poster presentation (674P): Aravindhan Veerapandiyan, M.D., Associate Professor of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, to present on October 8, 2025, from 2:30 - 3:30 p.m. CET

The presentation and poster will be available on the publications page of Avidity's website at https://www.aviditybiosciences.com.

About Avidity  
Avidity Biosciences, Inc.'s mission is to profoundly improve people's lives by delivering a new class of RNA therapeutics - Antibody Oligonucleotide Conjugates (AOCs™). Avidity is revolutionizing the field of RNA with its proprietary AOCs, which are designed to combine the specificity of monoclonal antibodies with the precision of oligonucleotide therapies to address targets and diseases previously unreachable with existing RNA therapies. Utilizing its proprietary AOC platform, Avidity demonstrated the first-ever successful targeted delivery of RNA into muscle and is leading the field with clinical development programs for three rare muscle diseases: myotonic dystrophy type 1 (DM1), Duchenne muscular dystrophy (DMD) and facioscapulohumeral muscular dystrophy (FSHD). Avidity is also advancing two wholly-owned precision cardiology development candidates addressing rare genetic cardiomyopathies. In addition, Avidity is broadening the reach of AOCs with its advancing and expanding pipeline including programs in cardiology and immunology through key partnerships. Avidity is headquartered in San Diego, CA. For more information about our AOC platform, clinical development pipeline and people, please visit www.aviditybiosciences.com and engage with us on LinkedIn and X.

Forward-Looking Statements
Avidity cautions readers that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. These statements are based on the company's current beliefs and expectations. Such forward-looking statements include, but are not limited to, statements regarding: the characterization of the data presented by Avidity in September 2025 and the impact of that data on the advancement of del-zota; the potential for del-zota to reverse the progression of DMD44; the status of the clinical study of del-zota; Avidity's plans to present additional data from the EXPLORE44® program and the timing thereof; and Avidity's platform, planned operations and programs. The inclusion of forward-looking statements should not be regarded as a representation by Avidity that any of these plans will be achieved. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in Avidity's business and beyond its control, including, without limitation: preliminary results of a clinical trial are not necessarily indicative of final results; further analysis of existing clinical data and analysis of new data may lead to conclusions different from those established as of the data cutoff dates in the clinical trial of del-zota, and such data may not meet Avidity's or regulators' expectations; unexpected adverse side effects to, or inadequate efficacy of, del-zota that may delay or limit its development, regulatory approval and/or commercialization; later developments with the FDA and other global regulators that could be inconsistent with the feedback received to date regarding del-zota and which could delay its currently anticipated timelines; Avidity's approach to the discovery and development of product candidates based on its AOC™ platform is unproven; potential delays in the EXPLORE44-OLE™ study; Avidity's dependence on third parties in connection with clinical testing and product manufacturing; legislative, judicial and regulatory developments in the United States and foreign countries; Avidity could exhaust its available capital resources sooner than it currently expects; and other risks described in Avidity's Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and subsequent filings with the SEC. Avidity cautions readers not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and the company undertakes no obligation to update such statements to reflect events that occur or circumstances that arise after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

Investor Contact:
Kat Lange
(619) 837-5014
investors@aviditybio.com 

Media Contact:
Kristina Coppola
(619) 837-5016
media@aviditybio.com

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SOURCE Avidity Biosciences, Inc.

FAQ

When will Avidity Biosciences (RNA) present EXPLORE44 data at the World Muscle Society Congress?

Avidity will present at WMS in Vienna during October 7–11, 2025, with an oral talk on October 11, 2025 and a poster on October 8, 2025.

What EXPLORE44 results will Avidity (RNA) report at WMS on del-zota for DMD44?

Presentations will highlight one-year data showing reversal of disease progression and functional improvements versus baseline and natural history in participants amenable to exon 44 skipping.

Who is presenting Avidity's (RNA) EXPLORE44 del-zota data at WMS?

Oral presenter Kevin M. Flanigan, M.D., on October 11, 2025, and poster presenter Aravindhan Veerapandiyan, M.D., on October 8, 2025.

Is delpacibart zotadirsen (del-zota) approved by the FDA?

No. Del-zota is investigational and has not been approved by the FDA; its safety and efficacy have not been established.

Where can investors access the presentation slides and poster for Avidity (RNA)?

Slides and the poster will be posted on Avidity Biosciences' publications page on the company's website after the presentations.