In adolescents suffering from allergic rhinoconjunctivitis, the safety of the HDM SLIT tablet is insensitive to the geographic region or age.

A phase 3, open-label, single-arm, 28-day safety trial (MT-18) was conducted to supplement existing  safety data of house dust mite sublingual immunotherapy (HDM SLIT) tablet in adolescents with HDM allergic rhinitis with/without conjunctivitis (AR/C).

Adolescents (12-17 years old) with HDM AR/C, without or with asthma, were incorporated. Minimum one treatment-emergent adverse event (TEAE) was the major outcome ascertained. Data from 12 SQ-HDM adolescent subpopulations from previously documented 1-year phase 3 trials were compared with the results of MT-18.

In the trials, there were no instances of eosinophilic esophagitis, severe local swellings, severe throat or mouth edema, anaphylaxis related to the treatment, or epinephrine administrations. The proportion of adolescents treated with 12 SQ-HDM who reported any TEAE was 93%, 95%, and 88% for TO-203-3-2 (206 adolescents), P001 (189 adolescents), and MT-18 (253 adolescents), respectively. For the study groups, the percentage who reported any treatment-related AE (TRAE) was 66%, 93%, and 86%, respectively.

Local application site reactions were the most frequent TRAEs. The majority of TRAEs were mild in intensity and frequently occurred in the first 1–2 days after treatment initiation. With the HDM SLIT tablet, there were no TEAEs associated with asthma. At baseline, adolescents with or without asthma appear to have a comparable safety profile.

Adolescents with HDM AR/C across Europe, North America, and Japan tolerated the HDM SLIT tablet well, thus signifying that its safety is not dependent on a patient's age or location.