FDA Grants Orphan Drug Designation to GTX-101 for Potential Angelman Treatment

The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to GTX-101, GeneTx Biotherapeutics’s investigational compound for the treatment of Angelman syndrome.

GTX-101, which is GeneTx’s first drug candidate, is an antisense therapy that can silence gene expression by binding to the RNA molecule that converts the gene into a functional protein. Antisense therapies have shown promise to treat other diseases, including spinal muscular atrophy and amyotrophic lateral sclerosis (ALS).

The orphan drug designation means the company receives incentives, including a seven-year period of U.S. marketing exclusivity, if the drug is approved. Additional benefits include tax credits for clinical research costs, annual grant funding, the FDA’s assistance on clinical trial design, and the waiver of Prescription Drug User Fee Act (PDUFA) filing fees.

“No approved treatments for Angelman syndrome exist today,” Allyson Berent, chief operating officer of GeneTx Biotherapeutics, said in a press release. “The FDA’s orphan drug designation for GTX-101 highlights the significant need for treatments for individuals with Angelman syndrome, and we believe that targeted delivery of GTX-101 represents a promising, novel approach to treat this devastating disorder,” she added.

“This is a new area of medicine, known as a targeted therapy,” said Scott Dindot, PhD, associate professor, Texas A&M College of Veterinary Medicine & Biomedical Sciences. “Historically, clinicians have treated symptoms of a disease or disorder with medication but not the cause of the condition. A targeted therapy goes after the cause of the condition and attempts to fix it,” he added.

“The FDA’s orphan drug designation for GTX-101 is an important next step in bringing effective treatments to individuals with Angelman syndrome,” said Paula Evans, GeneTx CEO. “Activation of the normally silent paternal UBE3A gene has the potential to mitigate many of the disorder’s debilitating symptoms.”

GeneTx Biotherapeutics was launched by FAST, the Foundation for Angelman Syndrome Therapeutics, to accelerate the development of a potential cutting-edge treatment for Angelman syndrome. FAST is the majority owner of GeneTx Biotherapeutics; Texas A&M University, where early work was done into this potential therapy, is a minority owner.

Depending on the outcomes of investigational new drug studies and interactions with regulatory agencies, the company hopes to test GTX-101 in clinical trials by late 2019.