U.S. FDA has granted accelerated approval of Loargys® (pegzilarginase-nbln) for the treatment of hyperargininemia in patients 2 years and older with arginase 1 deficiency (ARG1-D)

STOCKHOLM, Sweden, February 23, 2026 -  Immedica Pharma today announced that the U.S. Food and Drug Administration (FDA) has granted accelerated approval of Loargys® (pegzilarginase-nbln), an arginine specific enzyme indicated for the treatment of hyperargininemia in adult and pediatric patients 2 years of age and older with Arginase 1 Deficiency (ARG1-D), in conjunction with dietary protein restriction.

This indication is approved under accelerated approval based on reduction of plasma arginine. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

“Today’s FDA accelerated approval of Loargys is an important milestone for Immedica and for patients and families affected by ARG1-D in the U.S.,” said Anders Edvell, CEO of Immedica. “This outcome is the result of collaborative efforts across the entire ARG1-D community including patients, advocacy groups, researchers, and clinicians. We are proud to be able to deliver a treatment option for patients and families who have long awaited progress.”

ARG1-D affects an estimated 250 people living in the U.S. and current standard of care relies primarily on symptom management, including dietary protein restriction, arginine-free amino acid supplementation and nitrogen scavenging agents if necessary.

“Until now, the care of patients with ARG1-D has been limited to symptomatic management and strict dietary control. The accelerated approval of Loargys offers a fundamentally new approach that addresses the enzyme deficiency itself.  Since persistently elevated arginine and its metabolites have been reported to be the proximal or direct driver of disease progression, this is a major advancement in metabolic medicine” said Dr. Stephen Cederbaum, Professor Emeritus of Human and Medical Genetics at UCLA.

Loargys is the first and only treatment to address persistently elevated levels of plasma arginine, the primary driver of ARG1-D.

About ARG1-D 
ARG1-D is an ultra-rare and serious inherited metabolic disorder. The principal defect in ARG1-D leads to accumulation of plasma arginine (hyperargininemia) and its toxic metabolites. Patients are often diagnosed in late infancy or early childhood, and the symptoms include spasticity, seizures, developmental delay, intellectual disability, and early mortality. ARG1-D is one of the eight urea cycle disorder (UCD) subtypes. It shares some overlapping features with other UCDs, including impaired nitrogen excretion. However, in ARG1-D, hyperammonemia is generally less severe. 

About Loargys® (pegzilarginase-nbln) 
Pegzilarginase is a novel, recombinant, human arginase-1 enzyme that has been shown to rapidly and sustainably lower levels of the amino acid arginine and its toxic metabolites in plasma, making it the first and only therapy proven to lower plasma arginine. Loargys is approved in the EU, UK, US, and Oman for the treatment of arginase 1 deficiency (ARG1-D), also known as hyperargininemia, in adults, adolescents, and children 2 years and older.

In the US, Loargys® (pegzilarginase-nbln) is approved for the treatment of hyperargininemia in adult and pediatric patients 2 years of age and older with Arginase 1 Deficiency (ARG1-D), in conjunction with dietary protein restriction. This indication is approved under accelerated approval based on reduction of plasma arginine. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

About Immedica
Immedica is a pharmaceutical company, headquartered in Stockholm, Sweden, focused on the commercialization of medicines for rare diseases and specialty care products. Immedica’s capabilities cover marketing and sales, compliance, pharmacovigilance, quality assurance, regulatory, medical affairs and market access, as well as a global distribution network serving patients in more than 50 countries. Immedica is fully dedicated to helping those living with diseases which have a large unmet medical need. Immedica’s therapeutic areas are within RARE metabolic, RARE hematology & oncology, RARE neurology, RARE endocrinology and specialty care. Immedica was founded in 2018 and employs today around 180 people across Europe, the Middle East and the United States. Immedica is backed by the investment firms KKR and Impilo.

For more information visit www.immedica.com.

Immedica contact:
Linda Holmström
VP, Head of HR & Communication
[email protected]