The University of Kansas (KU) Medical Center in the US has released preliminary data from the Phase I/II trial of Avidity Biosciences’ drug, del-brax (delpacibart braxlosiran), for the treatment of facioscapulohumeral muscular dystrophy (FSHD).
KU Medical Center is the study site for the trial, the early findings of which indicate that del-brax could significantly decrease the expression of the DUX4 gene.
DUX4 is usually not expressed or remains inactive in healthy people while it makes toxic proteins in the muscle cells of FSHD patients.
Del-brax showed an average reduction of over 50% in DUX4 expression and a 25% decrease in DUX4-related proteins after four months.
In addition, the drug lowered creatine kinase levels, a muscle damage indicator.
Participants who were given del-brax also demonstrated improvements in muscle strength and function versus those treated with the placebo.
These improvements were also notable when compared to individuals from the ReSolve natural history study, which tracks the disease's progression without treatment.
Affecting approximately one in 20,000 people, FSHD leads to muscle weakness and atrophy, particularly in the face, shoulders, upper arms, and lower legs.
With no medications currently approved by the US Food and Drug Administration for FSHD, the ailment is managed through various treatments.
Commenting on the asset, KU Medical Center neurology professor and trial investigator Jeffrey Statland said: “It’s the first molecularly designed, gene-targeted trial that has been specifically designed to go in the muscle and hit this DUX4 protein and knock it down.
“We’re really excited about these gene-targeted therapies, and there’s also a trial going on right now for muscle regenerative therapy and a repurposed drug that’s in a Phase III study.
“So for FSHD, we have studies that are in Phases I-III, all going on at the same time with multiple approaches to therapy. That’s what you want to see for drug development for a rare disease.”