Trial Enrollment Upcoming for GTX-102 Following FDA Activation of Its New Drug Application

GTX-102, a potential treatment for Angelman syndrome, is cleared for clinical trials, thanks to the activation of its investigational new drug (IND) application by the U.S. Food and Drug Administration.

Enrollment in an upcoming Phase 1/2 trial is due to begin in the first half of 2020.

The investigational therapy is an antisense oligonucleotide designed to target the molecule that causes Angelman syndrome and prevent it from working. Antisense oligonucleotides (ASOs) are small molecules that can bind to RNA to change how it is spliced.

The FDA granted GTX-102 both orphan drug and rare pediatric disease designations in September 2019 to help speed its advancement.

A rare neurologic disorder, Angelman is caused by the loss or dysfunction of the maternal copy of the UBE3A gene in central nervous system neurons. All people inherit two copies of the gene, one each from their mothers and fathers. Without the maternal copy, the body relies on only the paternal copy.

Angelman syndrome occurs when the paternal UBE3A is silenced by a molecule called the UBE3A antisense transcript (UBE3A-AS). In theory, inhibiting UBE3A-AS should restore the function of UBE3A.

Unsilencing the paternal  UBE3A in mouse models has lessened some of the neurological symptoms associated with the syndrome.

Symptoms include developmental delay, poor balance, motor impairment, seizures, anxiety, and disturbed sleep. Some individuals are unable to walk and most do not speak. Although Angelman syndrome does not typically shorten one’s lifespan, those with the condition require continuous care and cannot live independently.

The upcoming trial, named KIK-AS — Knockdown of UBE3A-antisense in Kids with AS — will enroll 20 patients at multiple sites. The open-label study will analyze multiple doses and dose escalation. The goal is to determine the safety, tolerability, and pharmacokinetics (how a medicine moves throughout the body) of GTX-102 in pediatric patients with Angelman syndrome.

GTX-102 is being developed by GeneTx Biotherapeutics and Ultragenyx Pharmaceutical, who entered a partnership in August 2019.

“The FDA’s clearance of the IND to evaluate GTX-102 in patients with Angelman syndrome represents a significant milestone for the Angelman community,”  Paula Evans, CEO of GeneTx, said in a press release.  “Assessing an investigational therapy that aims to address the underlying cause of this devastating disorder has the potential to meaningfully alter the clinical course of patients’ lives.”

GeneTx was launched by the Foundation for Angelman Syndrome Therapeutics (FAST), the largest non-governmental funder of Angelman research in the world.