DURHAM, N.C. — Precision BioSciences Inc. reported new preclinical data supporting the advancement of PBGENE-DMD into clinical testing for Duchenne muscular dystrophy.
The company presented the data at the American Society of Gene & Cell Therapy 2026 Annual Meeting in Boston. Precision BioSciences is developing PBGENE-DMD using its ARCUS gene-editing platform.
The new preclinical findings showed that PBGENE-DMD produced higher dystrophin protein restoration in early-juvenile mice than in late-juvenile mice over a comparable period. The company said the results support evaluating the therapy in younger Duchenne muscular dystrophy patients, including boys as young as 2 years old.
PBGENE-DMD is being evaluated in the ongoing Phase 1/2 FUNCTION-DMD trial in boys ages 2 to 7.
“These new data give us a clear preclinical rationale for treating DMD as early as possible. By directly comparing early- and late-juvenile mice, we showed that intervening earlier translated into substantially greater dystrophin restoration in the skeletal and respiratory muscles that matter most for long-term outcomes. This is important because the FUNCTION-DMD trial is designed to treat children between the ages of two and seven years,” said Cassie Gorsuch, Ph.D., Chief Scientific Officer of Precision BioSciences. “These results also reinforce a meaningful point of differentiation for PBGENE-DMD. Because we are correcting the gene rather than delivering a synthetic transgene, the durability of effect would not be expected to be subject to the AAV dilution that affects microdystrophin approaches as young patients grow, a limitation that becomes more pronounced the younger the patient.”
Precision BioSciences said PBGENE-DMD achieved up to three times higher dystrophin protein restoration in skeletal muscle and up to 12 times higher restoration in respiratory muscle in early-juvenile mice compared with late-juvenile mice at equivalent dose levels.
The company said the therapy also exceeded the expected dystrophin protein restoration therapeutic threshold of 5% in respiratory muscle tissue. Early-juvenile mice achieved up to 12% dystrophin restoration in the diaphragm and up to 30% in the intercostal muscles, which are important for respiratory function in Duchenne muscular dystrophy.
Precision BioSciences said PBGENE-DMD also drove high levels of dystrophin-positive fibers in early-juvenile mice, reaching up to 70% dystrophin-positive fibers. The company said cardiac muscle efficacy was similar in early- and late-juvenile mice.
The new data build on earlier preclinical findings from the company. Precision BioSciences said a toxicology study in a humanized Duchenne muscular dystrophy mouse model showed PBGENE-DMD treatment led to a greater than 45% reduction in serum creatine kinase across multiple dose levels, along with improvements in muscle pathology compared with vehicle-treated controls.
The company also said treated mice maintained up to 92% of the maximum force output of non-diseased animals, while untreated diseased mice showed progressive declines in force output.
