A new treatment for Krabbe disease, PBKR03, has recently been granted the Orphan Drug and Rare Pediatric Disease designations by the FDA, according to an article in GlobeNewswire. These designations are exciting, as they not only enhance furture research into this treatment, but they mean that Krabbe disease patients may have another treatment option soon.
About Krabbe Disease
Krabbe disease, also called globoid cell leukodystrophy, is a rare disorder that causes the destruction of myelin in the brain and nervous system. It can range in severity between affected individuals, but it is typically fatal by age two. Symptoms include fever, difficulties feeding, vomiting, loss of head control, developmental delays, irritability, unexplained crying, muscle spasms, and declines in alertness. These effects are all the result of a mutated gene that is inherited in an autosomal recessive pattern. This gene is responsible for an enzyme called galactocerebrosidase (GALC), and when there is not enough of it, it allows fats to accumulate. This buildup then results in the destruction of myelin. Unfortunately, there is no cure for this condition. Treatment is symptomatic.
About the Designations
The Orphan Drug designation is reserved for medications that treat rare diseases, which are conditions that affect less than 200,000 people in the US. When a company receives this designation, they qualify for certain benefits. These include tax credits, help from the FDA during the development process, and other financial incentives.
The other designation that PBKR03 received, the Rare Pediatric Disease designation, is intended for treatments for a severe or life-threatening, rare condition that impacts those under the age of 18. The FDA gives benefits for this designation as well, such as a priority review voucher.
PBKR03 is an AAV-delivered gene therapy that encodes for the enzyme that is underproduced, GALC. Using an AAVhu68 capsid, this treatment gives a functional gene. When there is a working GALC gene, fats no longer accumulate, meaning that there will be less demyelination.
Preclinical models have showed positive results, such as improvements within the central and peripheral nervous systems. Based off of this data, researchers have decided to run a Phase 1/2 trial in the first half of 2021. As Krabbe disease patients currently face an unmet medical need, this development is very exciting.