SonoThera says it delivered the full-length dystrophin gene to monkey muscle without a virus
SonoThera says it delivered the full-length dystrophin gene to monkey muscle without a virus
Delivery remains a central constraint in gene therapy. A large gene must reach the right cells, while standard viral vectors often cannot be administered repeatedly. SonoThera has demonstrated a different approach in animals. DNA is injected with microbubbles, then focused ultrasound temporarily allows it to enter cells. The company has no clinical data or peer-reviewed publication.
Duchenne muscular dystrophy is caused by defects in the dystrophin gene. Without this protein, muscle fibers gradually break down. The full-length gene is too large for a standard viral vector, so viral therapies usually carry a shortened micro-dystrophin gene.
On July 2, Elixirgen described another route to the same goal. Its local full-length dystrophin mRNA is intended to remain at the injection site. SonoThera is trying to use ultrasound to deliver DNA to several muscle tissues at once.
SonoThera is trying to bypass this limitation. According to biologist Avi Roy's account, the company injects DNA with microscopic gas bubbles and directs ultrasound at the target tissue. The bubbles briefly make cell membranes permeable, allowing the DNA to enter. This process does not require a virus and could, in theory, be repeated.
In a poster, the company reported expression of full-length human dystrophin in the skeletal muscle, heart, and diaphragm of mice with a Duchenne model. In monkey skeletal muscle, SonoThera reports protein levels reaching 50% of the normal level. This figure has a specific limitation. The antibody used in the experiment detects both the monkey's native protein and the delivered human protein. The authors therefore also looked for human RNA and a specific tag on the delivered protein in treated muscle fibers.
On July 17, STAT quoted two Duchenne researchers who considered the animal result too unusual to accept without further verification. SonoThera has not yet conducted human trials. The company plans to begin its first trial in 2027, and the disclosed evidence is currently limited to a conference poster.
In human muscle, the ultrasound method must demonstrate two properties. It must deliver large DNA molecules to enough cells, and it must allow repeat dosing without dangerous consequences. If it does, some gene therapies could move beyond the size limit imposed by viral capsids and deliver more complete repair programs to tissues.