Immunotherapy may ease grass allergy symptoms

NEW YORK (Reuters Health) - Once-daily sublingual therapy with grass allergen tablets, which are dissolved under the tongue (sublingual), moderately reduce the symptoms of seasonal grass allergy, also referred to as "hay fever," according to a report in the Journal of Allergy and Clinical Immunology.

Topical nasal corticosteroids and antihistamines are the recommended treatments for allergic rhinitis, the authors explain, but these agents bring only partial relief in more than 40 percent of patients with hay fever.

A course of desensitizing injections with small doses of the offending substance can be effective, but the process is inconvenient and can be uncomfortable. A quick-dissolve grass allergen tablet taken sublingually is intended to produce the same results but with advantage that it can be taken at home.

Dr. Stephen R. Durham from the Royal Brompton and Harefield Hospitals, London, and colleagues investigated the effects of a sublingual tablet for grass allergen (GRAZAX; ALK-Abello, Denmark) in 855 patients in eight countries with grass pollen-induced allergic rhinoconjunctivitis.

Compared with placebo, daily treatment with the grass allergen tablet for an average of 18 weeks provided a 16-percent improvement in symptom scores and a 28-percent reduction in medication use during the pollen season, the investigators report. The study participants also had a significantly increased number of well days.

A subgroup of patients who were treated 8 weeks or longer before the grass pollen season began had ever better responses, the team found.

Although the levels of grass pollen increased by three-fold by the time of the post-treatment visit, the patients did not experience the expected increase in symptoms.

Patients generally tolerated the treatment well, the report indicates, and only 2 percent of patients withdrew from the study because of probable or possible treatment-related side events.

"This study provides "proof-of-concept for" the use of the grass allergen tablet in seasonal allergic rhinoconjunctivitis," the authors conclude. "It is likely that a more prolonged preseasonal treatment phase will enhance efficacy, and such studies are currently in progress."

SOURCE: Journal of Allergy Clinical Immunology, April 2006.