Aeglea BioTherapeutics announced the U.S. Food and Drug Administration (FDA) has granted Rare Pediatric Disease Designation to ACN00177 for the treatment of Homocystinuria, a serious metabolic disorder characterized by elevated plasma homocysteine which leads to a wide range of life-altering complications and reduced life expectancy. ACN00177 is a novel engineered human enzyme therapy designed to lower the total level of homocysteine in the plasma. Aeglea initiated a Phase 1/2 clinical trial earlier this year to investigate ACN00177 for the treatment of Homocystinuria.

"Homocystinuria is a serious and progressive disease that significantly impacts the quality of life of patients – with a high risk of life threatening blood clots, severe vision issues, skeletal abnormalities, developmental delay and intellectual disability," said Anthony Quinn, M.B Ch.B, Ph.D., president and chief executive officer of Aeglea. "There is a significant need for new and better therapies for Homocystinuria patients given the lack of effective treatment options for many patients. The Rare Pediatric Disease Designation speaks to the significant impact of this disease beginning in childhood and is an important incentive in promoting drug development to improve outcomes in this patient population."

The FDA grants rare pediatric disease designation for diseases with serious or life-threatening manifestations that primarily affect fewer than 200,000 people in the United States and who are less than 18 years old. If a Biologics License Application (BLA) for the treatment of Homocystinuria is approved by the FDA, Aeglea may be eligible to receive a Priority Review Voucher (PRV), which can be redeemed to obtain priority review for any subsequent marketing application or may be sold or transferred. This program is intended to encourage development of new drugs and biologics for the prevention and treatment of rare pediatric diseases.

Aeglea is developing ACN00177 for the treatment of patients with cystathionine beta synthase (CBS) deficiency, also known as Classical Homocystinuria. Homocysteine accumulation plays a key role in multiple progressive and serious disease-related complications, including thromboembolic vascular events, skeletal abnormalities including severe osteoporosis, developmental delay, intellectual disability, lens dislocation and severe near-sightedness. ACN00177 has been designed as a novel recombinant human enzyme, which degrades the amino acid homocysteine and its related homocystine dimer. With this mechanism, ACN00177 is intended to lower the abnormally high blood levels of homocysteine in patients with Homocystinuria. Preclinical data demonstrated that ACN00177 improved important disease-related abnormalities and survival in a mouse model of Homocystinuria. ACN00177 has received both U.S. and EU Orphan Drug Designation. Aeglea initiated a Phase 1/2 trial in the second quarter of 2020 and continues patient identification and administrative activities.