NICE Guidance: Pegzilarginase for Arginase-1 Deficiency

NICE Highly Specialised Technology Evaluations

Published March 4th, 2026

Detected March 12th, 2026

Summary

NICE has published guidance recommending pegzilarginase (Loargys) for treating arginase-1 deficiency in individuals aged 2 years and over. The guidance includes evidence-based recommendations and details a commercial access agreement for the treatment.

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What changed

NICE has issued final guidance (HST35) recommending the use of pegzilarginase (Loargys) for the treatment of arginase-1 deficiency in patients aged 2 years and older. This guidance is based on evidence and outlines the recommendations for its application within the NHS. It also notes the existence of a commercial access agreement with a discount patient access scheme, with details available through specific portals or direct contact.

Healthcare professionals are expected to consider this guidance when making treatment decisions, in consultation with patients. Commissioners and providers are responsible for ensuring the necessary funding is available. All adverse events related to the treatment should be reported to the MHRA via the Yellow Card Scheme. The guidance also highlights the responsibility of commissioners and providers to assess and reduce the environmental impact of implementing the recommendations.

What to do next

Review NICE guidance HST35 on pegzilarginase for arginase-1 deficiency.
Ensure patient treatment decisions align with guidance recommendations and individual patient needs.
Report any adverse events related to pegzilarginase via the MHRA Yellow Card Scheme.

Source document (simplified)

Pegzilarginase for treating arginase-1 deficiency in people 2 years and over

Highly specialised technologies guidance
HST35
Published:

04 March 2026

Download guidance (PDF)

Overview

Evidence-based recommendations on pegzilarginase (Loargys) for treating arginase-1 deficiency in people 2 years and over.

Last reviewed: 4 March 2026

Next review: This guidance will be reviewed if there is new evidence that is likely to change the recommendations.

Commercial arrangement

There is a commercial access agreement with a simple discount patient access scheme for pegzilarginase. NHS organisations can get details on the Commercial Access and Pricing (CAP) Portal. Non-NHS organisations can contact orders-uk@immedica.com for details.

Guidance development process

How we develop NICE highly specialised technologies guidance

Your responsibility

The recommendations in this guidance represent the view of NICE, arrived at after careful consideration of the evidence available. When exercising their judgement, health professionals are expected to take this guidance fully into account, alongside the individual needs, preferences and values of their patients. The application of the recommendations in this guidance is at the discretion of health professionals and their individual patients and do not override the responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or their carer or guardian.

All problems (adverse events) related to a medicine or medical device used for treatment or in a procedure should be reported to the Medicines and Healthcare products Regulatory Agency using the Yellow Card Scheme.

Commissioners and/or providers have a responsibility to provide the funding required to enable the guidance to be applied when individual health professionals and their patients wish to use it, in accordance with the NHS Constitution. They should do so in light of their duties to have due regard to the need to eliminate unlawful discrimination, to advance equality of opportunity and to reduce health inequalities.

Commissioners and providers have a responsibility to promote an environmentally sustainable health and care system and should assess and reduce the environmental impact of implementing NICE recommendations wherever possible.