The FDA created the Rare Pediatric Disease Designation and Priority Review Voucher Program to stimulate the development of therapies intended to treat, diagnose, or prevent rare pediatric diseases. These are conditions affecting fewer than 200,000 children (under 18 years old) within the United States. If this product then becomes approved, the company then becomes eligible to be granted a Priority Review voucher for another product. According to a news release from gene therapy company AVROBIO, AVR-RD-02 recently earned Rare Pediatric Disease designation for the treatment of Gaucher disease. 

AVR-RD-04 is being developed for Gaucher diseases types 1 and 3. In a previous article published in Gaucher Disease News in 2021, the author explains that AVR-RD-04:

uses a harmless lentiviral vector as a vehicle to deliver a working copy of the GBA gene to patients’ own blood cell precursors, called hematopoietic stem cells, [which] are isolated from the patient, modified in the lab, and then infused back to the person. The gene therapy aims to permanently restore the production of the beta-glucocerebrosidase – the enzyme produced from the GBA gene – lowering the accumulation of fatty toxic substances inside cells.

More data from the Phase 1/2 study should be available by the end of this year or early next year.

What is Gaucher Disease?

Gaucher disease is a rare genetic lysosomal storage disorder in which patients have low levels of beta-glucocerebrosidase, or even none at all. It is inherited in an autosomal recessive pattern, meaning individuals must inherit one mutated gene from each parent. Normally, beta-glucocerebrosidase breaks down glucocerebroside (a lipid) into glucose and ceramide. However, in Gaucher disease, glucocerebroside accumulates in cells. Gaucher disease is more common in those of Ashkenazi Jewish descent. 

There are three main forms of Gaucher disease (I, II, and III). In the first type, symptoms can include anemia, easy bruising and bleeding, arthritis, lung disease, an enlarged liver and/or spleen, and bone pain or fractures. Next, Gaucher disease types II and III affects the central nervous system (CNS). Symptoms may include some from type I, as well as brain damage, unusual eye movements, and seizures. Type III typically progresses at a slower rate, while type II may be fatal in infancy. However, other forms of this disease do exist, including cardiovascular and perinatal lethal.