Published Online: August 17, 2015
Allergy to house dust mite (HDM) is the most common respiratory allergy caused by inhalant allergens and HDM allergic rhinitis is associated with an increased risk of developing asthma. Allergy immunotherapy is the practice of treating the underlying cause of the allergic disease by exposing patients to definite amounts of the substance they are allergic to, which increases the body’s tolerance towards the allergens. A few studies have shown benefit of allergy immunotherapy in HDM allergy but there has been a need for more rigorous studies confirming the benefit.
In a study recently published in The Journal of Allergy and Clinical Immunology (JACI), P. Demoly and colleagues report the results of a large clinical trial with a sublingual immunotherapy tablet (SQ HDM SLIT-tablet, ALK) used to treat HDM allergic rhinitis. Over the course of 1 year, 992 adult subjects from 12 European countries were treated daily with one of two doses of the HDM SLIT-tablet (6 or 12 SQ-HDM) or placebo. At inclusion the subjects had moderate to severe allergic rhinitis symptoms due to HDM despite frequent use of symptomatic medications such as antihistamines and nasal steroid spray ascertained during a 2 week-baseline period. The subjects scored their symptoms and medication use at 5 different time points across the 1year HDM SLIT-tablet treatment period.
Already after 14 weeks of treatment there was a significant improvement in the combined rhinitis symptoms and medication score in the subjects receiving the HDM SLIT-tablet compared to placebo. The subjects had fewer symptoms despite also using less symptomatic medication to relieve their symptoms. The improvement increased in magnitude until 24 weeks of treatment and from there remained stable throughout the remainder of the one-year treatment period. Improvements fulfilled the pre-defined criteria for clinical relevance with both doses, with the most robust effect for 12 SQ-HDM. The most common side effects with both doses of the HDM SLIT-tablet were mild to moderate local reactions (itching, mild swelling) in the mouth and throat irritation for a short time after tablet intake during the first weeks.
The results of this study confirm that the HDM SLIT-tablet effectively reduces allergic rhinitis symptoms and need for symptomatic medication year-round in an adult population with moderate to severe allergic rhinitis with or without concomitant asthma. The results also showed that the HDM SLIT-tablet was well tolerated, supporting self-administration at home after the first tablet is taken under medical supervision.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.