Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced data for its investigational Timothy grass sublingual allergy immunotherapy tablet (MK-7243) from a study involving 1,501 North American adult and pediatric patients. Results showed that MK-7243 demonstrated significant improvement in Total Combined Score (TCS) averaged over the entire grass pollen season (the primary endpoint), which was the sum of the rhinoconjunctivitis daily symptom score (DSS) and the daily medication score (DMS), compared to placebo. Researchers will present findings at the American College of Allergy, Asthma & Immunology Annual Scientific Meeting, Nov. 7-11, in Baltimore. “Patients in this study who took the investigational Timothy grass sublingual allergy immunotherapy tablet showed a significant improvement in common allergy symptoms during the entire grass season,” said Dr. David Bernstein, professor of Medicine and Environmental Health, Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, who was one of the study investigators. “Few large studies have evaluated sublingual immunotherapy for allergic rhinitis in both adults and children, and we are proud that Merck is exploring this potential new option for Timothy grass pollen-induced allergic rhinitis treatment in North America,” said Dr. Sean Curtis, vice president, Respiratory and Immunology, Merck Research Laboratories. Study design This multicenter, double-blind, randomized, placebo-controlled, parallel-group study evaluated the efficacy and safety of the investigational MK-7243 sublingual tablet (2800 BAU) in 1,501 pediatric and adult patients (ages 5-65) with a clinical history of Timothy grass pollen-induced allergic rhinitis with or without conjunctivitis, with or without asthma (FEV 1 ≥70 percent of predicted value). As baseline characteristics, 25 percent of patients in the study had asthma; patients with a history of severe asthma were excluded. Additionally, 85 percent of patients in the study were sensitized to multiple allergens. Patients received either MK-7243 or placebo once daily for at least 12 weeks prior to and during the grass pollen season. The primary efficacy assessment of the study was total combined score (TCS), which was the sum of the rhinoconjunctivitis daily symptom score (DSS) and the daily medication score (DMS) averaged over the entire grass pollen season. The DSS consisted of daily ratings of four nasal symptoms (runny nose, blocked nose, sneezing and itchy nose) and two eye symptoms (gritty eyes and watery eyes) on a scale from zero (no symptoms) to three (severe symptoms). The DMS was based on the type and amount of allergy rescue medication (oral antihistamines, ocular antihistamines, intranasal corticosteroids or oral corticosteroids) used each day during the grass pollen season, which patients in both arms of the study were permitted to use.