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Duchenne Exon 44 Drug Del-zota: Phase 1/2 Results Published

In short: Peer-reviewed Phase 1/2 results for del-zota, an experimental Duchenne drug for people with exon 44 skipping-amenable gene changes, appeared in The Lancet Neurology. The drug raised dystrophin and had an acceptable safety profile in a small trial. It is not approved, and Duchenne has no cure.

Duchenne Exon 44 Drug Del-zota: Phase 1/2 Results Published

What was published

The Lancet Neurology published results from EXPLORE44, a Phase 1/2 trial of delpacibart zotadirsen (del-zota). The paper was added to PubMed on October 14, 2026, and its print issue is dated November 2026.

Del-zota is for Duchenne muscular dystrophy caused by gene changes that can be treated by skipping exon 44 of the DMD gene. The paper says no exon-skipping treatment is approved for this group. It is an antibody linked to a molecule that skips exon 44, and it is designed to deliver that molecule to muscle.

What the trial found

Part B of the trial included 26 boys and men with Duchenne aged 7 to 27. They were randomly assigned to del-zota or placebo and received three infusions. Neither they nor the staff knew who got the drug. The trial also tested 45 healthy adult volunteers in Part A.

  • Exon 44 skipping rose by an average of 36.6% at 5 mg/kg and 43.4% at 10 mg/kg, versus 1.6% on placebo.
  • Dystrophin levels rose by an average of 25.0% at 5 mg/kg and 25.6% at 10 mg/kg, versus a 0.7% drop on placebo.
  • Most side effects were mild or moderate. Two people on the 5 mg/kg dose stopped treatment because of side effects, one with an anaphylactic reaction and one with an infusion-related reaction.
  • The authors also report lower levels of markers of muscle damage.

How to read these results

This was a small, early trial built mainly to test safety. Part B had 19 people on del-zota and 7 on placebo. The measured outcomes were exon skipping and dystrophin, not walking or strength. A higher dystrophin level is a lab result, and the paper does not show that people moved or felt better. The authors say the findings support a larger Phase 3 study to look at benefit and long-term safety.

The trial was sponsored by Avidity Biosciences, now part of Novartis.

Where del-zota stands

Del-zota is not approved. Our Duchenne report lists a September 2026 report from patient groups that the FDA accepted the company's application for accelerated approval with priority review, and that a Phase 3 confirmatory trial called SAFARI44 has started. Acceptance for review is not approval, and the FDA may or may not approve it.

Where to read more

Our Duchenne report covers this paper and the other drugs under review. This post is AI-written from the sources below, has not been reviewed by a doctor, and is not medical advice. Duchenne muscular dystrophy has no cure.

Frequently asked questions

Is del-zota approved for Duchenne?

No. As of October 16, 2026, our report lists it as under FDA review for accelerated approval. Acceptance for review is not approval.

Does del-zota help boys with Duchenne move better?

This trial did not measure that. It showed more exon skipping and more dystrophin, and the authors say a larger Phase 3 study is needed to look at benefit.

Is there a cure for Duchenne muscular dystrophy?

No. Treatments aim to slow the disease or replace missing dystrophin, but there is no cure today.

Read the full Duchenne muscular dystrophy (DMD) report: latest studies, treatments, trials near you, expert care centers and support groups, updated daily.

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This post was written with AI from the sources listed above and has not been reviewed by a doctor. It is not medical advice. Talk with your doctor before changing treatment. See our Terms of Use.