In new data from a phase-III study in 345 children and adolescents (ages five-17 years), patients with grass pollen allergic rhinoconjunctivitis treated with Merck's investigational sublingual grass (Phleum Pratense) allergy immunotherapy tablet (AIT) showed a 26 per cent greater improvement in the total combined score (daily symptom score and daily medication score), compared to patients receiving placebo (p=0.001). Allergic rhinoconjunctivitis, or runny nose and itchy, watery eyes due to allergies, is a common condition in children and adolescents. These data were presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting in New Orleans.

AIT is an investigational, dissolvable oral tablet that is designed to prevent allergy symptoms by inducing a protective immune response against allergies, thereby treating the underlying cause of the disease. Merck is investigating AIT for the treatment of grass pollen allergic rhinoconjunctivitis in both children and adults. AIT is currently approved in the European Union (EU) for children and adults (ages 5-65) with grass pollen allergy, marketed under the name Grazax by ALK-Abello, which discovered and developed the product in the EU.

"Patients who received AIT experienced significant reductions in allergy symptoms and allergy medication use, the combined symptom scores evaluated in the study," said Michael Blaiss, clinical professor of paediatrics and medicine, University of Tennessee Health Science Center in Memphis, Tennessee, and lead investigator for the study. "This phase-III study is the first to evaluate AIT in children and adolescents with grass pollen allergies in North America."

The randomized, placebo-controlled, phase-III study investigated the efficacy and safety of AIT versus placebo in the treatment of allergic rhinoconjunctivitis caused by pollen from Timothy grass, a type of grass common in North America. A total of 345 patients, ages five-17 years, were randomized to daily treatment with oral grass AIT (15mcg of Phl p5, which is a formulation of the timothy grass allergen) or placebo at least eight weeks prior to and throughout the 2009 grass pollen season. The primary efficacy endpoint was the total combined score, comprised of total daily symptom score and total daily medication score. Adverse events experienced by patients receiving AIT were generally local, application site reactions and included oral pruritus, throat irritation, stomatitis, ear pruritus, mouth edema, oropharyngeal pain, pharyngeal erythema, eye pruritus and lip swelling. There were no reports of anaphylactic shock in the study. Eighty-nine percent of study patients were sensitive to allergens in addition to the grass pollen allergen.

"Merck is committed to developing respiratory products that provide physicians with a wide range of treatment options to help their patients suffering from allergies," said James E Fish, executive director, Global Scientific Affairs, Merck Research Laboratories. "We are encouraged by the positive results of this study and look forward to further developing the oral allergy immunotherapy tablet for patients suffering from allergies caused by grass pollen."