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Last updated: September 2026
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Treatment Access & Advocacy

Pegzilarginase (Loargys®): What Canadians with ARG1-D Should Know

Loargys® (pegzilarginase) is an enzyme therapy for people living with Arginase 1 Deficiency (ARG1-D). In Canada, the treatment has now moved through major regulatory and health technology assessment milestones, including a positive final reimbursement recommendation from Canada's Drug Agency (CDA-AMC). The next phase is focused on reimbursement negotiations and public drug-plan funding decisions.

Canada Status
Positive CDA-AMC reimbursement recommendation

CDA-AMC has issued a final recommendation that Loargys® be reimbursed with conditions for eligible patients living with ARG1-D. A positive recommendation is an important milestone, but it does not mean that public coverage is automatically available across Canada. Additional reimbursement and drug-plan decisions are still required.

Drug type
Recombinant human arginase 1 enzyme therapy for adults and children aged 2 years and older.
Clinical finding
In the Phase 3 PEACE trial, pegzilarginase substantially reduced plasma arginine, with 90.5% of treated participants reaching normal levels at Week 24.
Where we are now
The CDA-AMC review has resulted in a positive final reimbursement recommendation. Reimbursement and public drug-plan decisions follow.

The Canadian access pathway

Loargys has progressed through several important steps in the Canadian treatment-access process.

✓ Health Canada review
✓ CDA-AMC review
✓ Positive recommendation
→ Reimbursement negotiations
Provincial & territorial funding
Jump to:
Timeline CanPKU+ Advocacy Trial Information Company Information What Happens Next? Sources
Timeline: From clinical development toward Canadian access
April 10, 2019
The Phase 3 PEACE trial began. The randomized, double-blind, placebo-controlled study enrolled 32 participants with ARG1-D.
December 18, 2023
The European Commission granted marketing authorization for Loargys for adults, adolescents and children aged 2 years and older with ARG1-D.
January 2024
Results from the Phase 3 PEACE trial were published in EClinicalMedicine, reporting substantial reductions in plasma arginine and functional mobility findings.
October 31, 2025
Immedica announced that Health Canada accepted its New Drug Submission for Loargys for priority review.
December 18, 2025
CDA-AMC opened its call for patient and clinician input as part of the reimbursement review.
February 17, 2026
The CDA-AMC patient and clinician input period closed.
2026 – CanPKU+ community input
CanPKU+ participated in the CDA-AMC reimbursement review on behalf of the rare metabolic community, bringing patient and caregiver perspectives into the assessment of Loargys.
Draft recommendation & feedback
Following release of the draft reimbursement recommendation, CanPKU+ provided additional feedback, including concerns about how treatment response and meaningful clinical benefit would be assessed for people living with a progressive condition.
Final CDA-AMC recommendation
CDA-AMC issued a final recommendation that Loargys be reimbursed with conditions for eligible patients with ARG1-D. The final guidance reflects several important issues raised through CanPKU+ advocacy.
Next: Reimbursement and public access
The focus now moves toward reimbursement negotiations and funding decisions by participating public drug plans.
CanPKU+ Advocacy: Community voice in the review

CanPKU+ participated in the CDA-AMC review on behalf of the community and provided feedback after the draft recommendation was released. Several important issues raised through that advocacy are reflected in the final guidance.

Stability matters
The final guidance recognizes that in a progressive disease, stabilization and prevention of further decline can represent meaningful treatment benefit.
The whole clinical picture matters
Temporary increases in arginine should not automatically mean treatment has failed when the patient's broader clinical picture remains stable.
Meaningful change can take time
The final recommendation recognizes that changes in mobility, cognition and development may take 12 to 24 months or longer to become apparent.
Community language reflected in the final recommendation

Language submitted by CanPKU+ about what meaningful treatment benefit looks like, including preserving mobility, maintaining communication and participating in school and community life, is reflected directly in the final CDA-AMC implementation guidance. It is a powerful example of why patient and caregiver voices belong in reimbursement decisions.

Want to see the changes in more detail? Our advocacy update compares what CanPKU+ raised during consultation with the final recommendation.

Read: What We Asked. What Changed. View the CDA-AMC Review
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 involving children and adults with ARG1-D. The study enrolled 32 participants.

Study design
Phase 3, randomized, double-blind, placebo-controlled, multicentre trial.
Enrollment
32 participants: 21 received pegzilarginase and 11 received placebo.
Arginine reduction
Plasma arginine fell from 354.0 to 86.4 µmol/L at Week 24 in the treatment group.
Normalization
90.5% of treated participants reached normal plasma arginine levels versus 0% receiving placebo.

The published trial also reported clinically relevant functional mobility findings with pegzilarginase treatment.

Company information: Who developed Loargys?

Pegzilarginase was developed in clinical trials under the sponsorship of Aeglea BioTherapeutics, which sponsored the Phase 3 PEACE study.

The therapy is now being advanced commercially by Immedica Pharma AB, a pharmaceutical company headquartered in Stockholm, Sweden that focuses on rare diseases.

What happens next? From recommendation to reimbursement

The positive CDA-AMC recommendation is a major milestone, but recommendation and reimbursement are not the same thing.

The next phase involves reimbursement processes and decisions by participating federal, provincial and territorial public drug plans. Timing and coverage criteria can differ between jurisdictions.

Where CanPKU+ will focus next

CanPKU+ will continue to follow the reimbursement process and advocate for fair, timely and consistent access for Canadians living with ARG1-D.

We will update this page as additional reimbursement and public coverage milestones are reached.

Why this matters for Canadians living with ARG1-D

ARG1-D is a progressive rare metabolic condition. For people living with a progressive disease, treatment benefit can include not only improvement but also maintaining abilities and preventing further deterioration.

The movement of Loargys through Canada's review process represents progress toward another treatment option for the Canadian ARG1-D community. The next challenge is translating a positive recommendation into meaningful and equitable access.

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

Sources and further reading
  1. Canada's Drug Agency (CDA-AMC). Pegzilarginase reimbursement review.
    View the CDA-AMC review
  2. CanPKU+. What We Asked. What Changed. Loargys Advocacy Update.
    Read the CanPKU+ advocacy update
  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 NCT03921541
  4. Immedica Pharma AB. Loargys® (pegzilarginase) regulatory and product information.
    Immedica
  5. National Institute for Health and Care Excellence (NICE). Pegzilarginase for treating arginase-1 deficiency in people 2 years and over (HST35).
    View NICE guidance
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