A new genetic therapy, WVE-N531, has shown promise in improving muscle health in boys with Duchenne muscular dystrophy (DMD), according to results from a phase 2 clinical trial.
The findings were reported in a press release published by the study sponsor, Wave Life Sciences.
Muscle biopsy results showed that the treatment helped boys produce dystrophin, a protein needed for muscle function. Dystrophin levels stayed steady between 24 and 48 weeks of therapy, averaging about 7.8%. Most boys (88%) had more than 5% average dystrophin during this time.
What is dystrophin?
Dystrophin is the protein that mutates and leads to DMD. It is found in small quantities in muscle cells, where its role is to protect the cell from daily damage.
When it mutates, it causes muscle cell degeneration and inflammation, leading to damage in the tissue of the bones, lungs and heart.
WVE-N531 was safe and well-tolerated during the 48 weeks of treatment. Any side effects that occurred were mild to moderate, and none of the boys had to stop the treatment because of any issues.
Read more about DMD treatment and care
This type of treatment works by changing how cells read genetic instructions, helping the body produce dystrophin. WVE-N531 is an exon 53-skipping therapy. The U.S. Food & Drug Administration (FDA) has given it special recognition to support its development as a treatment for DMD.
About 8%-10% of boys with DMD have a genetic change that may be helped by exon 53 skipping therapy. The study looked at how these boys responded to WVE-N531 over 48 weeks.
Eleven boys ages 5 to 11 participated — 10 could walk, and one could not. They received a dose of WVE-N531 every two weeks. Researchers studied muscle biopsies from eight boys who could walk, taken at 24 and 48 weeks, to see how the treatment affected their muscles. They also monitored all 11 boys for safety and changes in functional outcomes.
Besides an improvement in dystrophin protein levels, biopsy results also showed significant improvements in muscle health over 48 weeks. There was a reduction in muscle damage and inflammation, a decrease in markers of muscle injury, and the muscle fibers became more organized and mature.
In the Time-to-Rise (TTR) test, which measures how long it takes a person lying on their back to stand up, the treated boys improved by 3.8 seconds, a meaningful difference compared to the untreated control group. The minimal change considered important was 1.4 seconds, so the improvement in the treated group was well above that.
In the North Star Ambulatory Assessment (NSAA), which measures overall muscle function, the treated boys showed a positive trend with a 1.2-point improvement, though it wasn’t statistically significant.
The treated boys also showed positive trends in grip strength.
Now, all of the boys have moved into the next phase of the study, where they are receiving the treatment once a month.
Based on feedback from the FDA and the data from the 48-week study, Wave Life Sciences plans to submit an application in 2026 to the FDA to get accelerated approval for WVE-N531. This would allow the treatment to be available to patients sooner. Additionally, there will be a global trial to further confirm how well WVE-N531 works.
“These data demonstrate a promising continuum from dystrophin restoration, to regeneration and maturation of muscle tissue, to functional improvement,” Pat Furlong, founder and president of Parent Project Muscular Dystrophy, was quoted as saying in the press release. “Paired with monthly administration and a continued favorable safety profile, WVE-N531 represents a significant step forward.”
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