AVR-RD-01 is an investigational gene therapy that AVROBIO is developing as a potential cure for Fabry disease.

How does AVR-RD-01 work?

A mutation in the GLA gene causes Fabry. This results in the deficiency of the alpha-galactosidase A enzyme. The lack or low activity of the enzyme causes a fatty substance called globotriaosylceramide (Gb3 or GL-3) to build inside cells, leading to irreversible organ damage.

AVR-RD-01 is a gene therapy that uses a harmless virus to deliver the healthy form of the GLA gene into the body.

For the treatment, researchers isolate adult stem cells from the patient’s blood (hematopoietic stem cells) and expose them to the lentiviral vector, or modified virus. The virus inserts the gene into the stem cells, which researchers then return to the patient’s body. Because other cells in the vicinity take up the alpha-galactosidase A that the modified blood stem cells secrete, the therapy can potentially restore alpha-galactosidase A levels to normal ranges throughout the body.

AVR-RD-01 in clinical trials

Researchers are currently testing AVR-RD-01 in two separate clinical trials.

The first, called FACTS (NCT02800070), is a Phase 1 study in Canada. It aims to determine whether AVR-RD-01 can safely increase alpha-galactosidase A levels in Fabry patients.

Enrollment is complete at five participants who received AVR-RD-01. Investigators will monitor them for up to five years. The study is ongoing and researchers estimate to conclude it in February 2024.

The second trial, called FAB-GT or FAB-201 (NCT03454893), is a multinational Phase 1/2 study assessing the safety and effectiveness of AVR-RD-01 in people with Fabry who have not received any other treatments. It is taking place in Australia, Canada, and the U.S.

Researchers expect that the preparation, treatment, and initial follow-up process will take about one year, after which they will monitor patients regularly. The 64-week or about 16-month-long trial is still recruiting up to 12 participants, ages 16 to 50. It will conclude in November 2021.

Preliminary data from patients in both trials showed continued efficacy over a number of years. Patients showed increased levels of alpha-galactosidase A and reduced levels of GB3. The data suggest that the new cells have become incorporated into the patients’ bodies where they are able to continue producing working enzymes. They also suggest that patients have generally stable kidney function compared with the usual decline that Fabry patients experience.

Other information

Enzyme replacement therapy is the current standard of care for the disease, but requires lifelong weekly infusions. AVR-RD-01 offers a potentially permanent cure for the disease with only one infusion.

AVR-RD-01 has received orphan drug designation in the U.S. and the European Union.


Last updated: Jan. 22, 2021


Fabry Disease News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.