Efficacy of the SQ HDM SLIT-tablet on House Dust Mite Induced Allergic Conjunctivitis

RATIONALE: Co-existence of allergic conjunctivitis is well recognized in patients with allergic rhinitis although the co-reporting frequency may be as low as 40%. Under-recognition and treatment of house dust mite (HDM)-induced allergic conjunctivitis may be due to the under-appreciation of eye symptoms in patients with HDM-induced allergic rhinitis. We present clinical data from 2 North American trials with the SQ HDM sublingual immunotherapy (SLIT)-tablet evaluating treatment effect on ocular symptoms.

METHODS: Trial 1 included 124 adult subjects with HDM-induced allergic rhinitis/rhinoconjunctivitis (AR/C) randomized to SQ HDM SLIT-tablet (6 or 12 SQ-HDM) or placebo for 24 weeks. Efficacy was assessed during HDM exposure in an environmental exposure chamber. Trial 2 included 1,482 adult/adolescent subjects with HDM-induced AR/C randomized to SQ HDM SLIT-tablet (12 SQ-HDM) or placebo for up to 12 months. A conjunctivitis symptom score (range 0-6) was constructed based on subjects’ rating of 2 ocular symptoms (watery eyes and itchy eyes).

RESULTS: In trial 1, 40% reported perennial allergic conjunctivitis. The average conjunctivitis symptom score during the HDM exposure session after 24 weeks of treatment showed a relative difference between both active treatment groups and placebo of -41% for 6 SQ-HDM and -68% for 12 SQ-HDM. In trial 2, 65% reported perennial allergic conjunctivitis. The average conjunctivitis daily symptom score obtained during the last 8 weeks of treatment showed a difference between treatment groups of -33.3% (95% CI, -47.1%, -18.5%).

CONCLUSIONS: The SQ HDM SLIT-tablet had a significant treatment effect on ocular symptoms in patients with HDM-induced AR/C.