Sangamo Therapeutics has reported positive top line results from their Phase I/II clinical trial which investigated ST-920, a gene therapy for Fabry disease.

The company’s press release has outlined that several patients experienced meaningful improvements in disease severity, quality of life, and gastrointestinal symptoms after receiving the gene therapy. Some were able to reduce or stop pain medications and resume activities like exercise, indicating enhanced daily functioning.

Fabry disease is a rare genetic lysosomal disorder which can present with a wide range of symptoms. Mild symptoms may include pain, skin rashes, gastrointestinal issues, and reduced sweating. More serious symptoms can include kidney failure, heart problems (like hypertrophic cardiomyopathy), and neurological complications such as stroke.

“Fabry disease is a debilitating and multifaceted condition, for which there is a serious unmet medical need,” said Nathalie Dubois-Stringfellow, Chief Development Officer at Sangamo.

The disorder is caused by mutations in the galactosidase alpha (GLA) gene which leads to a deficiency in the activity of the enzyme alpha-galactosidase (α-Gal A). In healthy individuals, this enzyme is responsible for the metabolism of the molecule globotriaosylceramide (Gb3). Gb3 builds up in the cells of Fabry patients which can cause serious damage to vital organs including the heart and kidneys.

ST-920, or isaralgagene civaparvovec, is an investigational gene therapy for Fabry disease, requiring just one infusion without preconditioning. The therapy uses an AAV viral vector to deliver a working copy of human GLA cDNA to the liver.

The Phase I/II trial was named STAAR, an open-label, one time infusion, dose variable, multicentre clinical study which evaluated ST-920 in 32 patients over the course of 52 weeks.

“We are thrilled to see these compelling topline STAAR study results, including the positive mean annualized eGFR slope at both 52 and 104 weeks, alongside notable improvements in a range of secondary endpoints,” said Dubois-Stringfellow.

“Taken together these data demonstrate the potential for a single dose of ST-920 to provide meaningful clinical benefits above current standards of care and to treat the underlying pathology of Fabry disease.”

Fierce Biotech have reported that Sangamo are now preparing an FDA application for the therapy through the regulator’s accelerated approval pathway.