Avidity's DMD Candidate Shows Promise in Latest Data Release

Avidity Biosciences has unveiled new data for its RNA-based Duchenne muscular dystrophy (DMD) candidate, delpacibart zotadirsen (del-zota), addressing previous safety concerns and demonstrating encouraging efficacy results.

Safety Profile Assuages Earlier Concerns

The phase 1/2 trial, known as Explore44, has reported that most adverse events following del-zota treatment were mild to moderate. This update comes after earlier data had sparked questions from analysts due to instances of anaphylaxis and an infusion-related reaction, which led to two patient dropouts.

Since those initial discontinuations, no other patients have withdrawn from the trial due to adverse events. The most common side effects observed were procedural pain and headache. Analysts from Evercore ISI commented that the "safety is clean," noting that this update has alleviated potential concerns regarding anaphylaxis and infusion-related reactions.

Promising Efficacy Data Across Multiple Doses

The latest data release includes results from patients receiving either 5 milligrams or 10 milligrams of del-zota per kilogram of body weight, with consistent outcomes across both dosages. Key findings include:

• A 25% increase in dystrophin production, restoring total dystrophin levels by 58%
• Reduction in creatine kinase, a marker of muscle damage, by up to 80% from baseline

Evercore analysts described the creatine kinase reduction as "very intriguing," expressing hope that it may indicate functional benefit.

Future Developments and Regulatory Progress

Avidity Biosciences has outlined several upcoming milestones for del-zota:

1. Presentation of functional benefit data in Q4 2025
2. Submission of a biologics license application by the end of the year
3. Continuation of an open-label extension trial

The company has determined that future clinical trials will use a dosing regimen of 5 milligrams per kilogram of body weight every six weeks.

Del-zota has already received rare pediatric disease and fast track designations from the FDA, as well as orphan drug designation from both the FDA and the European Medicines Agency, highlighting its potential significance in the treatment of DMD.