Aeglea BioTherapeutics Launches THINK ARGININE™, a Disease Education Initiative to Improve Awareness and Diagnosis of Arginase 1 Deficiency

AUSTIN, Texas – Aeglea BioTherapeutics, Inc. (NASDAQ:AGLE), a clinical-stage biotechnology company developing a new generation of human enzyme therapeutics to benefit people with rare metabolic diseases, today announced the launch of THINK ARGININE, a disease education initiative focused on improving the awareness and diagnosis of Arginase 1 Deficiency (ARG1–D), a devastating and progressive rare metabolic disease. People living with ARG1-D are faced with debilitating, progressive disease manifestations that create significant challenges in daily life, including mobility issues, intellectual disability, developmental delays and seizures.

The THINK ARGININE campaign consists of a comprehensive program to educate healthcare providers on when to suspect ARG1-D, the significance of persistently high levels of arginine as the driver of the disease, and the benefits of early diagnosis. In order to support healthcare providers in making diagnoses, THINK ARGININE also includes no-charge diagnostic testing for adults and children with suspected ARG1-D. The diagnostic testing program includes amino acid testing working with Mayo Clinic Laboratories and genetic testing partnered with Invitae.
“Like many rare diseases, patients with ARG1-D frequently experience a frustrating and prolonged diagnostic journey before receiving the correct diagnosis. The uncertainties introduced by the challenges in getting a diagnosis and the limited knowledge of the disorder create an additional burden for the patient and their family as they manage this debilitating disease,” said Anthony G. Quinn, M.B. Ch.B., Ph.D., president and chief executive officer of Aeglea. “Our THINK ARGININE initiative is the result of input from those in the ARG1-D community, including patients, caregivers and clinicians. It provides a platform to increase awareness of ARG1-D among the healthcare professional community and to equip healthcare providers with the tools needed to diagnose this rare disease early in childhood. Together, greater awareness and earlier diagnosis can lead to more effective disease management strategies earlier in life.”

“Arginase 1 Deficiency is a debilitating cause of spasticity that can be missed due to lack of awareness and experience with the condition or misdiagnosed as a more common condition with a similar presentation, like cerebral palsy or hereditary spastic paraplegia. Yet, the condition can be diagnosed with a simple amino acid or genetic test,” said Roberto T. Zori, MD, chief of clinical genetics and metabolism, Department of Pediatrics, University of Florida, Gainesville, FL. “Because Arginase 1 Deficiency is a progressive disease, delays in diagnosis and treatment can lead to worse clinical outcomes. By ending the diagnostic odyssey and securing the first step in disease management, we have the potential to change the course of the lives of these patients.”

While newborn screening is available in some states, it has limited effectiveness due to low levels of plasma arginine in newborns and inconsistent testing standards. Plasma amino acid panels and genetic tests are considered to be more reliable and are readily available. Through THINK ARGININE, Aeglea will provide no-charge sponsored testing for adults and children with suspected ARG1-D. These tests must be ordered by a healthcare professional and are only available in the United States.

Visit to learn more about ARG1-D, the significant impact it has on patients and their families, and information on how to order a test.

About Arginase 1 Deficiency

ARG1-D is a debilitating, progressive, inherited, rare metabolic disease characterized by persistently high levels of arginine. ARG1-D is a urea cycle disorder that typically presents in early childhood with spasticity, intellectual disability, developmental delays and seizures and cognitive impairment, and may lead to a reduced quality of life and even early mortality. Due to the rarity of the condition and the general lack of awareness within the healthcare professional community, ARG1-D is commonly undiagnosed or misdiagnosed, which can lead to disease progression and suboptimal clinical outcomes. Although ARG1-D has overlapping features with other urea cycle disorders, it has distinct characteristics and manifestations – severe hyperammonemia is rare and spasticity is common. There are currently no effective treatment options or approved therapeutics for ARG1-D. Current disease management strategies focus on severe dietary protein restriction, which commonly does not allow patients to achieve target arginine levels due to adherence challenges and its inability to address non-dietary sources of arginine.

About Aeglea BioTherapeutics

Aeglea BioTherapeutics is a clinical-stage biotechnology company redefining the potential of human enzyme therapeutics to benefit people with rare metabolic diseases with limited treatment options. Aeglea’s lead product candidate, pegzilarginase, is in a pivotal Phase 3 trial for the treatment of Arginase 1 Deficiency and has received both Rare Pediatric Disease and Breakthrough Therapy Designation. The Company initiated a Phase 1/2 clinical trial of AGLE-177 for the treatment of Homocystinuria in 2020. AGLE-177 has also been granted Rare Pediatric Disease Designation. Aeglea has an active discovery platform focused on engineering small changes in human enzymes to have big impact on the lives of patients and their families. For more information, please visit


Media Contact: Kelly Boothe, Ph.D., Senior Director, Corporate Communications, Aeglea BioTherapeutics , 512.399.5458, [email protected]; Investor Contact: Joey Perrone, Vice President, Finance & Investor Relations, Aeglea BioTherapeutics, [email protected]