The First Patient Has Been Treated in a Gene Therapy Study for MPS I

The first patient has been treated in the Empowers study, a clinical trial investigating an experimental gene editing therapy for the treatment of mucopolysaccharidosis type I. The source article, which contains more information, can be found here, at PR Newswire.

About Mucopolysaccharidosis Type I (MPS I)

MPS I, also known as Hurler syndrome, occurs when a person’s body isn’t able to properly break down mucopolysaccharides (a type of sugar molecule), causing them to accumulate in cells and cause damage. This is because people affected by MPS I typically have an alteration in the IDUA gene. This gene codes for an enzyme (the IDUA enzyme) that is involved in the breakdown of mucopolysaccharides. Alterations to the IDUA gene can disrupt the functioning of the IDUA enzyme, and therefore mucopolysaccharide breakdown.

According to the MPS Society, MPS I can vary a lot in severity between patients. The condition can cause developmental delay and progressive physical problems, although the speed of progression varies between individuals. Approximately one in every 100,000 newborns is believed to have MPS I.

About the Investigational Genome Editing Therapy

Sangamo Therapeurics Inc. is evaluating an investigational in vivo (in the body) genome-editing therapy called SB-318 for the possible treatment of MPS I.

In this genome editing therapy, a new copy of the IDUA gene is inserted into targeted liver cells. The therapy is designed to help the liver produce a functioning version of the enzyme. According to the source article, this genome editing therapy is thought to insert the therapeutic gene precisely into the DNA, whereas conventional AAV cDNA gene therapies do not integrate the therapeutic gene into the cell’s genome.

The Empowers Study

The Empowers Study is a Phase 1/2 clinical trial that will study the effects of SB-318 in patients diagnosed with MPS I. The researchers will investigate how safe, tolerable, and effective SB-318 is. It will be an open-label and ascending dose study that involves up to nine adult patients with attenuated MPS I.

So far, the US FDA has awarded SB-318 Orphan Drug, Rare Pediatric Disease, and Fast Track designations, and the European Medicines Agency has awarded it Orphan Medical Product designation.