Oral House Dust Mite Immunotherapy Safe, Effective in Allergic Rhinitis

The trials enrolled 2,138 patients with HDM allergic rhinitis, with or without conjunctivitis
The trials enrolled 2,138 patients with HDM allergic rhinitis, with or without conjunctivitis

ATLANTA, GA—House dust mite (HDM) sublingual immunotherapy (SLIT) tablet (MK-8237, Merck/ALK) offers consistent efficacy and safety among patients with HDM allergic rhinitis, with or without conjunctivitis (AR/C), according to a post-hoc analysis of data pooled from double-blind, multicenter clinical trials conducted in North America (P001) and Europe (MT-06). The findings were presented at the 2017 AAAAI Annual Meeting.

“The 12 SQ-HDM SLIT-tablet consistently improved symptoms and was well tolerated in relevant subgroups of patients with HDM AR/C,” reported Jose A. Bardelas, MD, FAAAI, of Moses H. Cone Memorial Hospital in Greensboro, NC, and coauthors.

The trials enrolled a total of 2,138 patients for efficacy analysis and 2,923 patients for safety analysis. Patients included in the study were aged at least 12 years (P001) or 18 years (MT-06) old with HDM AR/C with or without asthma symptoms. Patients were randomly assigned then to receive placebo or 12 SQ-HDM SLIT tablets for up to 52 weeks. Total combined rhinitis score (TCRS) during the final 8 weeks of therapy were pooled for subgroup efficacy analysis for age, ethnicity, gender, baseline asthma and allergen sensitization, Dr. Bardelas and coauthors reported. The study authors stated that safety data were pooled from "P001 and MT-06, as well as an asthma trial (MT-04) and an environmental chamber trial", where local AEs were solicited daily in P001 and unsolicited in the other three trials.

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“In the two individual trials, treatment with 12 SQ-HDM improved TCRS 17% and 18% vs. placebo,” the authors reported. “Across the subgroups there were consistent trends of significant numeric superiority with 12 SQ-HDM vs. placebo. The lowest observed TCRS improvement was 15% in subjects without asthma, and the greatest improvement was 25% in subjects aged 12–17 years.”

Adverse events were “generally similar” within subgroups. Drug-related adverse events in the SQ-HDM study arms “appeared numerically higher” in teenagers (aged 12–17 years) than 18–49-year-olds, they noted. Subgroup analysis found that 92% of patients aged 12–17 years receiving 12 SQ-HDM experienced any treatment-related adverse event (TRAE) compared to 68% of patients aged 18–49 years receiving the treatment. Study data also found that 0.2% of patients in the treatment group experienced a serious TRAE, compared to 0.1% of patients in the placebo group. Discontinuation rates due to TRAE was 7% in the 12 SQ-HDM group vs. 1% in the placebo group.  

Results of this analysis demonstrated that the 12 SQ-HDM SLIT-tablet is not only efficacious but is well tolerated as well.