Acarizax has been accepted for use in NHS Scotland for adults with persistent moderate to severe house dust mite allergic rhinitis despite symptom-relieving medication.

SMC changes recommendation on Acarizax

The Scottish Medicines Consortium (SMC) has accepted Acarizax (12 SQ-HDM sublingual immunotherapy) for eligible adults with house dust mite allergic rhinitis, changing the treatment’s previous status in NHS Scotland.

The SMC published its latest advice on 10 August 2026 following a full submission from ALK. The decision applies to adults aged 18-65 diagnosed through clinical history and a positive test for house dust mite sensitisation, including a skin prick test and/or specific immunoglobulin E test.

Eligible patients must have persistent moderate to severe house dust mite allergic rhinitis despite using symptom-relieving medication. The SMC advice also covers adults with house dust mite allergic asthma that is not well controlled by inhaled corticosteroids and is associated with mild to severe house dust mite allergic rhinitis, although the supplied announcement focuses on allergic rhinitis.

The decision is notable because Acarizax was previously not recommended for use in NHS Scotland. In 2023, the SMC said it could not recommend the treatment because the marketing authorisation holder had not submitted an application for the indication under review.

Evidence from three Phase 3 studies

Acarizax is a once-daily sublingual immunotherapy tablet containing house dust mite allergen extracts. Unlike medicines that primarily control allergy symptoms, allergen immunotherapy aims to modify the immune response to the allergen.

ALK said the SMC’s decision followed a review of three double-blind Phase 3 studies. The studies found that one year of treatment with 12 SQ-HDM, alongside standard care, significantly improved a combined measure of rhinitis symptoms and medication use compared with placebo.

The company also said adverse events were generally mild to moderate, with relatively few patients stopping treatment because of adverse events.

The SMC listing confirms that the new submission was a full submission, with the medicine listed as D. pteronyssinus and D. farinae allergen extracts and the pharmaceutical company identified as ALK-Abello Ltd.

House dust mite allergic rhinitis can cause symptoms including sneezing, a blocked or runny nose and breathing difficulties, with persistent symptoms affecting sleep and quality of life.

Dr George Raptis, paediatric allergy consultant at NHS Greater Glasgow and Clyde, said: “House dust mite allergic rhinitis presents a significant burden and ongoing challenge in daily clinical practice across Scotland.”

He added that the condition can affect quality of life and day-to-day wellbeing, while saying the SMC decision provides another treatment option for patients whose symptoms remain poorly controlled.

Potential change in access to allergy immunotherapy

The SMC decision could expand access to allergen immunotherapy in Scotland, where Acarizax had previously not been routinely available through NHS Scotland.

Anne Biggs, deputy head of clinical services at Allergy UK, said: “Uncontrolled house dust mite allergy severely impacts daily life, sleep, and overall wellbeing.”

She added that Allergy UK welcomed the SMC decision and said it could provide another option for patients who have not achieved sufficient relief from existing medicines.

Acarizax has already received a recommendation from NICE for persistent, moderate to severe house dust mite allergic rhinitis in adults and adolescents in England, Wales and Northern Ireland. NICE’s recommendation in 2025 made it eligible for general reimbursement through those NHS systems.

Emil Stage Olsen, general manager UK & Republic of Ireland at ALK, said: “The SMC’s acceptance of ACARIZAX marks a major milestone in transforming airborne allergy management for patients in Scotland.”

The Scottish decision therefore represents a further step in expanding NHS access to allergen immunotherapy for house dust mite allergy across the UK.