The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to Prevail Therapeutics‘ investigational therapy PR001 for the treatment of Gaucher disease.
In addition, the regulatory agency granted this potential gene therapy rare pediatric disease designation specifically for treating neuronopathic Gaucher, which includes types 2 and 3.
Gaucher is caused by mutations in the GBA1 gene, which lead to a defective version of an enzyme called beta-glucocerebrosidase and toxic accumulation of fatty molecules inside the cells of multiple organs.
Neuronopathic Gaucher disease presents early in life and involves various neurological manifestations, such as seizures and motor abnormalities.
Type 2 Gaucher begins in early infancy and is characterized by rapidly progressive neurodegeneration. In turn, type 3 is usually milder and has slower progression than seen in patients with type 2.
PR001 is an investigational treatment designed to deliver a fully working version of the GBA1 gene to patients’ nerve cells. Given in a single dose, the therapy seeks to restore production of normal beta-glucocerebrosidase in brain cells and modify the disease course.
The newly awarded designations are intended to facilitate PR001’s development.
Orphan drug designation is given to treatment candidates for diseases that affect fewer than 200,000 people in the United States. This designation includes partial tax credits for clinical trial expenses, waives user fees, and makes a compound eligible for seven years of marketing exclusivity if approved.
Rare pediatric disease designation is granted for the treatment of life-threatening diseases affecting fewer than 200,000 children in the country. If the therapy is granted FDA approval, the company qualifies for priority review of a future marketing application for a different product.
“These designations support our conviction that new gene therapies for Gaucher disease are urgently needed — especially for the severe, neuronopathic form of the disease, for which there are no FDA-approved therapies,” Asa Abeliovich, MD, PhD, founder and CEO of Prevail, said in a press release.
Prevail will conduct two Phase 1/2 trials for types 2 and 3 Gaucher disease. Following clearance from the FDA, dosing in the type 2 trial is expected to start in the first half of 2020. Prevail plans to start the study in type 3 Gaucher later this year.
The company had been awaiting a decision by the FDA to test higher doses of PR001 than initially planned. Preclinical studies had suggested that PR001 would be both safe and more efficient at the higher doses.
Earlier this year, one patient with type 2 Gaucher was granted treatment with PR001 under a compassionate use program.
In addition to its development for neuronopathic Gaucher disease, Prevail is also testing PR001 in Parkinson’s disease involving GBA1 mutations. Recruitment for that Phase 1/2 trial, named PROPEL (NCT04127578), remains open. Prevail is seeking 16 participants with Parkinson’s, ages 40 to 75.
