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Advocacy Awareness

Pegzilarginase (Loargys):

What Canadians with ARG1-D Should Know

Pegzilarginase, marketed as Loargys, is an enzyme therapy developed for people living with arginase 1 deficiency (ARG1-D), also known as hyperargininemia. It has already received regulatory approval in the European Union and the United States, and it is currently moving through the Canadian review process.[1][4][5]

Drug type
Recombinant human arginase 1 enzyme therapy for adults and children aged 2 years and older.[1][3]
Clinical finding
In the Phase 3 PEACE trial, pegzilarginase lowered plasma arginine from 354.0 to 86.4 umol/L at Week 24, and 90.5% of treated participants reached normal levels versus 0% on placebo.[3]
Canada status
As of early 2026, the product is under review in Canada and had not yet received a Notice of Compliance at filing.[1][2]
Jump to:
Timeline Trial information Company information Arrival to Canada References
Timeline: From clinical development to treatment
April 10, 2019
The Phase 3 PEACE trial began. ClinicalTrials.gov lists the study start date as April 10, 2019, with 32 participants enrolled in a randomized, double-blind, placebo-controlled study sponsored by Aeglea BioTherapeutics.[3]
January 2024
The Phase 3 PEACE trial was published in EClinicalMedicine, reporting major reductions in plasma arginine and clinically relevant functional mobility improvements with pegzilarginase.[3]
December 18, 2023
Immedica announced that the European Commission granted marketing authorization for Loargys for adults, adolescents, and children aged 2 years and older with ARG1-D.[4]
October 31, 2025
Immedica announced that Health Canada accepted its New Drug Submission (NDS) for Loargys for review. The company described this as its first regulatory filing in Canada, and Health Canada granted the submission priority review.[1]
December 18, 2025
Canada's Drug Agency (CDA-AMC) opened the call for patient and clinician input for pegzilarginase. The project is listed as active, with NOC status at filing recorded as Pre NOC.[2]
February 17, 2026
The CDA-AMC patient and clinician input window closed.[2]
February 2026 and beyond
The U.S. FDA issued an accelerated approval letter for Loargys, in February 2026, NICE recommends use in England March 4 2026[6,7] , while the Canadian process continued through Health Canada review and CDA-AMC reimbursement review milestones scheduled through August 2026.[5][2] CDA: https://www.cda-amc.ca/pegzilarginase Patient and clinician group input: Access it here
Trial information: What did the research show?

The key evidence for pegzilarginase comes from the Phase 3 PEACE trial, a randomized, double-blind, placebo-controlled, multicentre study in children and adults with ARG1-D. ClinicalTrials.gov lists 32 enrolled participants and identifies Aeglea BioTherapeutics as the sponsor.[3]

Study design
Phase 3, randomized, double-blind, placebo-controlled, multicentre trial.[3]
Enrollment
32 participants total; search and publication records describe 21 on pegzilarginase and 11 on placebo.[3]
Primary biochemical result
Plasma arginine fell from 354.0 to 86.4 umol/L at Week 24 in the treatment group versus 464.7 to 426.6 umol/L with placebo.[3]
Normalization
90.5% of treated participants reached normal plasma arginine levels versus 0% on placebo.[3]

The published trial summary also reported clinically relevant functional mobility improvements with pegzilarginase treatment, and the search summary notes that these effects were sustained through an additional 24 weeks of exposure.[3]

Company information: Who developed and manufactures it?

Pegzilarginase was developed in clinical trials under the sponsorship of Aeglea BioTherapeutics, which is identified as the sponsor on ClinicalTrials.gov for the Phase 3 PEACE study.[3]

The therapy is now being advanced commercially by Immedica Pharma AB, a pharmaceutical company headquartered in Stockholm, Sweden. In its Health Canada submission announcement, Immedica states that it focuses on rare diseases and has a global distribution network serving patients in more than 50 countries.[1]

The U.S. FDA accelerated approval letter was issued to Immedica Pharma AB and authorizes manufacture and sale of Loargys (pegzilarginase-nbln) for hyperargininemia in adults and pediatric patients 2 years of age and older with ARG1-D, in conjunction with dietary protein restriction.[5]

Arrival to Canada: Where is it in the process now?

As of early 2026, Loargys had not yet received a formal Notice of Compliance (NOC) in Canada. Health Canada's review was underway, and CDA-AMC listed the project as Pre NOC at filing.[1][2]

What we know so far

  • Immedica announced on October 31, 2025 that its New Drug Submission was accepted for review by Health Canada.[1]
  • Health Canada granted the submission priority review.[1]
  • CDA-AMC opened patient and clinician input on December 18, 2025 and closed it on February 17, 2026.[2]
  • CDA-AMC shows the reimbursement review as active and lists milestone dates through August 14, 2026 for the final recommendation to sponsor and drug plans.[2]

What still has to happen

Before public access is in place across Canada, there are usually several steps:

1. Health Canada review
2. Notice of Compliance, if approved
3. CDA-AMC recommendation
4. pCPA pricing negotiations
5. Provincial funding decisions

This means that even after regulatory approval, there can still be additional steps before routine publicly funded access is available in every province or territory.

Why this matters for Canadians living with ARG1-D

ARG1-D is a progressive rare metabolic condition. The clinical evidence published to date shows that pegzilarginase can substantially lower plasma arginine and may improve real-world mobility and function for some patients.[3]

For Canadian families, the current review period is an important time to build awareness, share lived experience, and explain why timely and equitable access matters.

This page is intended as an advocacy and awareness resource and should not replace individualized medical advice from a metabolic specialist or care team.

Sources and references
  1. Immedica. Immedica submits New Drug Submission (NDS) for Loargys (pegzilarginase) to Health Canada. October 31, 2025.
    https://www.immedica.com/en/press/immedica-submits-new-drug-submission-nds-loargysr-pegzilarginase-health-canada-2402056
  2. Canada's Drug Agency (CDA-AMC). pegzilarginase reimbursement review page. Active project listing with patient input dates, NOC status at filing, and key milestones.
    https://www.cda-amc.ca/pegzilarginase
  3. Sanchez Russo R, Gasperini S, Bubb G, et al. Efficacy and safety of pegzilarginase in arginase 1 deficiency (PEACE): a phase 3, randomized, double-blind, placebo-controlled, multi-centre trial. EClinicalMedicine. 2024;68:102405. ClinicalTrials.gov record NCT03921541.
    https://clinicaltrials.gov/study/NCT03921541
    https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370%2823%2900582-5/fulltext
  4. Immedica. Loargys (pegzilarginase) approved in the EU for treatment of arginase 1 deficiency (ARG1-D). December 18, 2023.
    https://www.immedica.com/en/press/loargysr-pegzilarginase-approved-eu-treatment-arginase-1-deficiency-arg1-d-2185053
  5. U.S. Food and Drug Administration. Loargys (pegzilarginase-nbln) injection accelerated approval letter. 2026.
    https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2026/761211Orig1s000ltr.pdf
  6. Metabolic Support UK. (2026). NICE committee recommends pegzilarginase for ARG1-D pending final approval. https://metabolicsupport.org/news-and-events/latest-news/nice-committee-recommends-pegzilarginase-for-arg1-d-pending-final-approval/
  7. National Institute for Health and Care Excellence (NICE). (Mar 4 2026). Pegzilarginase for treating arginase-1 deficiency in people 2 years and over (HST35)  https://www.nice.org.uk/guidance/hst35