Early Success in Trials for Experimental Gene Therapies for Fabry Disease and Cystinosis

As reported in Business Fortnight, the top level gene therapy company AVROBIO has announced successful clinical trials for investigational drugs for Fabry disease and cystinosis. The CEO of AVROBIO, Geoff Mackay has said, “We’re excited to see continued strong results across our clinical programs for Fabry disease and cystinosis.”
So far, their Phase 2 results on four Fabry disease patients make the researchers optimistic that just one dose of their gene therapy could be enough to kick-start patients into durably producing the faulty enzyme so the body can maintain healthy cleansing on toxic matter. They found the positive effects continued six months after patients received the gene therapy.
Similarly, they found their first cystinosis patient that received their personalized treatment ‘plato’ continued to show positive trends for their key kidney functioning measures. The first patient reportedly experienced a notable reduction in plasma lyo-Gb3, and more healthy levels of leukocyte and plasma enzyme activity, at triple the level of the control group.

Fabry Disease

Fabry disease is a rare genetic disease caused by a buildup of the fat globotriaosylceramide in the cells. While every patient is affected differently, it tends to cause symptoms such as pain in the hands and feet, dark red spots, the inability to sweat, cloudy vision at the outer eye, hearing loss or ringing, and gastrointestinal issues. As the disease progresses, it can trigger life-threatening circumstances such as a heart attack, stroke, and kidney damage. There are symptomatic treatment options including a specific diet, medications, and aspirin, but there is not currently any FDA approved treatment option.


Cystinosis is a rare genetic disease that leads the build-up of cystine, an amino acid, which crystallizes in the cells, potentially causing organ damage, kidney failure, or death. There are three subtypes: nephropathic, intermediate, and non-nephropathic depending on when and how it develops. Some cases develop in infancy, while others develop later in life and patients never experience the severe symptoms.


When the Fabry phase 2 trial cut off in November of 2019, none of the participant had noted any safety events due to either of the drug’s administration. They found patients successfully maintained increased leukocyte and plasma AGA enzyme activity while others sustained decreases in plasma lyso-Gb3 and total Gb3 levels.
At six months into trials for the cystinosis patient, the researchers measured positive trends in the key measures of kidney functioning.  They found the patient experienced a drop in plasma lyso-Gb3 and leukocytes a month after the treatment. This is important because many patients suffer from potentially debilitating kidney failure, with 90% of patients requiring a kidney transplant by their 20s and 30s.  The researchers found the first dosed patient experienced improvements in their serum creatinine and glomerular filtration rate, two key measures of kidney functioning.
The researchers point to the exciting nature of the new treatment being administered in one dose, comparing it to the current method which consists of dozens of pills a day without guarantee of preventing the disease from progressing. The first patient stopped using this treatment regime before receiving the AVR-RD-04 dose, and continues to not need these medications.

What are your thoughts on the early findings from these trials? Share your stories, thoughts, and hopes with the Patient Worthy community!

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