Dyne has announced that the first participant has been dosed in the Phase 1/2 DELIVER clinical trial of DYNE-251 in participants with Duchenne amenable to skipping exon 51.

Dyne-251 is an exon skipping product that combines a PMO to enable skipping of exon 51 with a fragment antibody (Fab) to increase targeted delivery of the product to skeletal muscle.

Read the announcement from Dyne:

WALTHAM, Mass., Sept. 06, 2022 (GLOBE NEWSWIRE) — Dyne Therapeutics, Inc. (Nasdaq: DYN), a clinical-stage muscle disease company focused on advancing innovative life-transforming therapeutics for people living with genetically driven diseases, today announced that the first patient has been dosed in its Phase 1/2 clinical trial, DELIVER, evaluating DYNE-251 for the treatment of Duchenne muscular dystrophy (DMD) mutations amenable to exon 51 skipping.

“We are excited to bring our FORCE™ platform to the clinic for the first time with the initiation of patient dosing in the DELIVER trial. This is a significant milestone for Dyne and our efforts to build a global franchise of DMD exon skipping therapies. We have designed the DELIVER trial with the potential to be registrational and are focused on driving toward meaningful clinical data, including dystrophin, to understand the potential of DYNE-251 in DMD. We thank the Duchenne community for their continued partnership as we work to expand the DELIVER trial globally, and advance toward our ultimate goal of developing new, transformative therapeutic options for individuals living with this devastating disease,” said Wildon Farwell, M.D., MPH, chief medical officer of Dyne.

The DELIVER trial is a Phase 1/2 global clinical trial evaluating DYNE-251, consisting of a 24-week multiple ascending dose (MAD) randomized placebo-controlled period, a 24-week open-label extension and a 96-week long-term extension. The trial, which is designed to be registrational, is expected to enroll approximately 46 ambulant and non-ambulant males with DMD who are ages 4 to 16 and have mutations amenable to exon 51 skipping therapy. The primary endpoints are safety, tolerability and change from baseline in dystrophin levels as measured by Western blot. Secondary endpoints include measures of muscle function, exon skipping, and pharmacokinetics. Dyne anticipates reporting data from the MAD placebo-controlled portion of the DELIVER trial on safety, tolerability and dystrophin in the second half of 2023.

“There is a significant need for new therapies for people living with Duchenne. The comprehensive preclinical data supporting DYNE-251 demonstrate the magnitude of dystrophin expression in cardiac and skeletal muscle. We look forward to being a part of the DELIVER trial to understand the potential of DYNE-251,” said Kevin Flanigan, M.D., Robert F. and Edgar T. Wolfe Foundation Endowed Chair in Neuromuscular Research and director of the Center for Gene Therapy in The Research Institute at Nationwide Children’s Hospital in Columbus, Ohio.

In the MAD placebo-controlled portion of the DELIVER trial, patients will be randomized to receive DYNE-251 or placebo every four weeks intravenously based on a global protocol designed to incorporate feedback from multiple regulatory authorities, including on starting dose. Patient cohorts will be dosed from 0.7 mg/kg to 40 mg/kg (approximate PMO dose) in the U.S. Outside the U.S., starting doses and number of cohorts will vary by region. Following the placebo-controlled period, patients will transition to DYNE-251 treatment in the open-label portion of the trial and in the long-term extension.

Visit https://www.clinicaltrials.gov/ (NCT05524883) to learn more about the DELIVER trial.

Virtual Event on September 12, 2022

Dyne will host a “Spotlight on the Clinic” virtual event on Monday, September 12, 2022 from 7:30-9:00 a.m. ET. The Company will review its pipeline with a focus on the clinical programs and opportunity for DYNE-101 in myotonic dystrophy type 1 (DM1) and DYNE-251 in DMD and be joined by leading neuromuscular disease experts. The event will feature presentations, discussion and Q&A with the following speakers:

• Valeria Sansone, M.D., Ph.D., Clinical and Scientific Director at Clinical Center NeMO, Milan; Professor of Neurology, University of Milan
• Richard Finkel, M.D., Director, Center for Experimental Neurotherapeutics, St. Jude Children’s Research Hospital, Memphis, TN
• Joshua Brumm, President and Chief Executive Officer
• Wildon Farwell, M.D., MPH, Chief Medical Officer

A live webcast of the event will be available in the Events & Presentations page of the Investors & Media section of Dyne’s website and a replay will be accessible for 90 days following the presentation. An accompanying slide presentation will also be available. To register for the live webcast and replay, please visit https://investors.dyne-tx.com/news-and-events/events-and-presentations.

About DYNE-251

DYNE-251 is Dyne’s product candidate being developed for people living with Duchenne muscular dystrophy (DMD) who are amenable to exon 51 skipping. DYNE-251 consists of a phosphorodiamidate morpholino oligomer (PMO) conjugated to a fragment antibody (Fab) that binds to the transferrin receptor 1 (TfR1) which is highly expressed on muscle. It is designed to enable targeted muscle tissue delivery and promote exon skipping in the nucleus, allowing muscle cells to create a truncated, functional dystrophin protein, with the goal of stopping or reversing disease progression. In preclinical studies with Dyne’s FORCE™ platform, robust and durable exon skipping and dystrophin expression were observed in the mdx mouse model in skeletal and cardiac muscle as well as reduced muscle damage and increased muscle function. DYNE-251 demonstrated a favorable safety profile and achieved impressive exon skipping in non-human primates, especially in the heart and diaphragm, muscles in people living with DMD that weaken over time leading to mortality.

In addition to DYNE-251, Dyne is building a global DMD franchise with preclinical programs for patients with mutations amenable to skipping other exons, including 53, 45 and 44.