Today, Avidity Biosciences announced that it has submitted a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) seeking approval of delpacibart zotadirsen (del-zota) for individuals living with Duchenne who are amenable to exon 44 skipping.

The application is being reviewed through the FDA’s Accelerated Approval pathway and is supported by data from the Phase 1/2 EXPLORE44 and EXPLORE44-OLE clinical trials. According to Avidity, the submission includes data from participants enrolled in the EXPLORE44 clinical development program. The company has also initiated SAFARI44, a global Phase 3 trial intended to serve as the confirmatory study and further evaluate the long-term safety and clinical benefit of del-zota.

The FDA will now determine whether to accept the application for review. PPMD will continue to monitor developments and share updates as they become available.

Read Avidity’s community letter below: 

June 25, 2026

Dear DMD Community:

We are pleased to share that we have submitted an application to the U.S. Food and Drug Administration (FDA) seeking approval of delpacibart zotadirsen (also known as “del-zota” or AOC 1044) as a treatment option for people living with Duchenne muscular dystrophy (DMD) who have a genetic variant that may be treated through exon 44 skipping (DMD44).

This application, known as a Biologics License Application (BLA), includes data from the Phase 1/2 EXPLORE44® and EXPLORE44-OLETM clinical trials. The application was submitted through the FDA’s Accelerated Approval pathway, which is designed to help bring therapies for serious diseases to patients sooner while additional confirmatory data continue to be collected.

A global phase 3 trial (SAFARI44TM) is initiated as a confirmatory trial and is intended to further evaluate the long-term safety of del-zota and help confirm its clinical benefit. The study will be conducted outside the United States. You can learn more about the phase 3 trial by visiting the study’s page on clinicaltrials.gov.

This important milestone would not have been possible without the participation and dedication of the individuals and families who took part in the EXPLORE44® clinical development program. We extend our sincere gratitude to all trial participants, their caregivers and families, advocacy organizations, investigators, and study teams. Your commitment has helped advance the development of a potential new treatment option for the DMD44 community.

If you have questions about del-zota or the EXPLORE44® or EXPLORE44-OLETM clinical trials, please speak with your healthcare provider.

Sincerely,
The AOC1044 Clinical Development team

medinfo@aviditybio.com