According to an article published in Yahoo, the FDA has recently granted the Rare Pediatric Disease designation to AVR-RD-05, a gene therapy for Hunter syndrome. This designation is reserved for medications created to treat rare disorders that impact children, as it is meant to facilitate development. Companies that are granted this designation and receive approval for a Biologics License Application (BLA) are then eligible for a priority review voucher.
AVR-RD-05 is an ex vivo lentiviral gene therapy intended for the treatment of Hunter syndrome, also referred to as mucopolysaccharidosis type II. AVROBIO developed this therapy to provide “durable expression of therapeutic protein,” which should stop or even reverse disease in a single dose.
This gene therapy is also in development for the treatment of cystinosis, Gaucher disease type 1 and 3, Pompe disease, and Fabry disease. It is various stages of preclinical and clinical trials for different conditions.
Looking specifically to AVR-RD-05’s development for Hunter syndrome, AVROBIO expects to initiate its Phase 1/2 clinical trial in the second half of 2022.
About Hunter Syndrome
Hunter syndrome, also known as mucopolysaccharidosis II (MPS II), is an extremely rare, genetic disorder caused by a lack of the enzyme iduronate 2-sulfatase. This enzyme is responsible for breaking down complex molecules, and without it these molecules build up and damage the body. This damage gets progressively worse as time passes, and it eventually causes permanent damage that affects appearance, mental development, organ function, and physical abilities. This disorder is inherited through a chromosome from the mother and is far more common in males than females.
Due to the buildup of harmful molecules, symptoms do not begin to present until age two to four. They can be mild to severe depending on the person who has it. Symptoms include an enlarged head, thicker lips, a broad nose with flared nostrils, a protruding tongue, a deep or hoarse voice, abnormalities in the skeletal system, a distended abdomen due to enlarged internal organs, chronic diarrhea, white skin growths, joint stiffness, aggressive behavior, stunted growth, and delayed development. Along with these symptoms, Hunter syndrome can bring other complications depending on its severity. Respiratory, cardiac, brain, nervous system, skeletal, and connective tissue complications are all possible when one has this syndrome. There are currently no cures for this disorder, although numerous therapies are currently being investigated, and treatment is symptomatic.