Efficacy and safety of grass sublingual immunotherapy tablet, MK-7243: A large randomized controlled trial

Background In North America, few studies have evaluated sublingual immunotherapy for allergic rhinitis with or without conjunctivitis (AR/C); pediatric data are sparse. The authors report findings from the largest published immunotherapy trial yet conducted in adults and children. Objective To evaluate grass sublingual immunotherapy tablet (MK-7243) treatment in subjects with AR/C. Methods North American subjects (5-65 years old) with grass allergy were randomized 1:1 to once-daily MK-7243 (2,800 BAU Phleum pratense) or placebo. The first dose was given at the investigator's office; subsequent doses were self-administered at home. The primary end point was total combined score (TCS; rhinoconjunctivitis daily symptom score [DSS] plus daily medication score [DMS]) over the entire grass pollen season (GPS). Key secondary end points included entire-season DSS, DMS, peak-season TCS, and rhinoconjunctivitis quality-of-life questionnaire scores. Safety outcomes included adverse events (AEs). Results One thousand five hundred one subjects were randomized (85% polysensitized, 25% had asthma). MK-7243 yielded improvements vs placebo of 23% in entire-season TCS (median difference -0.98, P <.001), 29% in peak-season TCS (median difference -1.33, P <.001), 20% in entire-season DSS (median difference -0.64, P =.001), 35% in entire-season DMS (mean difference -0.48, P <.001), and 12% in peak-season rhinoconjunctivitis quality-of-life questionnaire (median difference -0.13, P =.027). Efficacy between children and adults was similar. Most AEs were transient local application-site reactions, with no serious treatment-related AEs or anaphylactic shock. Three subjects (1 placebo, 2 MK-7243) had moderate systemic allergic reactions. Conclusion MK-7243 was effective in polysensitized grass-allergic North American children and adults with AR/C in this large trial, confirming previous research.