According to a press release from the Massachusetts-based biotechnology company Avrobio, Inc., clinical tests of the Company’s experimental Fabry disease gene therapy, AVR-RD-01, have yielded impressive preliminary results. Though the studies in question involved only a small number of participants, the promising findings will doubtlessly prompt further investigation into the treatment’s potential.
About Fabry Disease
Fabry disease is an inherited genetic disorder characterized by the buildup of a substance called globotriaosylceramide in cells throughout the body. Globotriaosylceramide is a type of globoside, a kind of fat molecule with attached carbohydrates. As globotriaosylceramide builds up over time, it can cause serious problems around the body — potentially leading to tinnitus, kidney damage, heart attack, or even stroke.
Fabry disease is caused by a mutation to the gene GLA, which codes the production of an enzyme called alpha-galactosidase A. This enzyme breaks down globotriaosylceramide in lysosomes — sacks of digestive enzymes found in nearly every animal cell. Mutations to GLA may cause alterations to the unique structure of alpha-galactosidase A, leaving it unable to effectively bind to and break down globotriaosylceramide molecules.
The most serious cases of Fabry disease are seen in individuals completely lacking alpha-galactosidase A activity. Some people with limited enzyme activity may only develop a mild, late-onset form of the condition that affects fewer areas of the body.
Treatment for Fabry disease is mostly focused on the management of its symptoms, including the often-reported episodes of pain. Patients are advised to identify and avoid their “pain triggers” (e.g. heat, sun exposure, exercise, etc.). Patients may undertake enzyme replacement therapy (ERT), but in the United States there’s currently only one approved ERT treatment. Effective treatments are badly needed — Fabry disease can result in significantly reduced life expectancy, especially for men.
If it wasn’t obvious, AVR-RD-01 is still only an experimental drug. So far, Avrobio has conducted phase 1 and 2 clinical studies of the drug in a total of eight patients. The phase 2 study in question involved only three patients — a far lower number than is usually preferred by clinical researchers. However, some of the findings have been encouraging.
The phase 2 trial found that one patient experienced an 87% reduction in kidney globotriaosylceramide levels a year following treatment with AVR-RD-01. Six of the eight patients have experienced a stabilization in their alpha-galactosidase A levels up to six months after cessation of treatment.
The phase 2 trial is still open to recruitment. Only time, and more data, will tell if AVR-RD-01 is truly as promising as it looks in these early stages.
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