12 standard quality house dust mite sublingual lyophilisate (SQ-HDM SLIT) is recommended, within its marketing authorisation, as an option for treating moderate to severe house dust mite allergic rhinitis in people 12 to 65 years that is:
diagnosed by clinical history and a positive test of house dust mite sensitisation (skin prick test or specific immunoglobulin E [IgE]) and
persistent despite use of symptom-relieving medicine.
12 SQ‑HDM SLIT is not recommended, within its marketing authorisation, for treating house dust mite allergic asthma in adults that is:
diagnosed by clinical history and a positive test of house dust mite sensitisation (skin prick test or specific IgE) and
associated with mild to severe house dust mite allergic rhinitis and
not well controlled by inhaled corticosteroids.
This recommendation is not intended to affect treatment with 12 SQ‑HDM SLIT that was started in the NHS before this guidance was published. People having treatment outside this recommendation may continue without change to the funding arrangements in place for them before this guidance was published, until they and their NHS healthcare professional consider it appropriate to stop.
Why the committee made these recommendations
Standard care for moderate to severe allergic rhinitis caused by house dust mites for people 12 to 65 years includes treatments to relieve symptoms such as intranasal corticosteroids and antihistamines. Standard care for allergic asthma caused by house dust mites in adults includes inhaled corticosteroids and short-acting beta agonists. It may also include additional long-acting beta agonists and leukotriene receptor antagonists.
Clinical trial evidence suggests that, compared with placebo plus standard care, 12 SQ‑HDM SLIT plus standard care may reduce:
rhinitis symptoms and medicine use in people with house dust mite allergic rhinitis, and
asthma exacerbations in people with house dust mite allergic asthma.
But these results are uncertain. It is unclear exactly how much the treatment would benefit people in clinical practice because the way the trials were done does not reflect NHS clinical practice. There is more uncertainty about the clinical effectiveness of 12 SQ-HDM SLIT for allergic asthma than for allergic rhinitis.
There are uncertainties in the economic modelling. This is because of uncertainties in the clinical evidence and because the model structures do not completely reflect how people would have treatment in NHS clinical practice. Taking into account the uncertainties, 12 SQ-HDM SLIT is cost effective for treating allergic rhinitis caused by house dust mites, but is not cost effective for treating allergic asthma caused by house dust mites. So, 12 SQ-HDM SLIT is recommended only for persistent moderate to severe house dust mite allergic rhinitis. Some of the eligible population may also have allergic asthma, which would not prevent them having 12 SQ-HDM SLIT to treat their allergic rhinitis.