Aqueous Sublingual Allergen Immunotherapy Looks Promising

Sublingual immunotherapy (SLIT) can be administered using tablets, aqueous allergen extracts, or microencapsulated preparations. SLIT is used widely in Europe, and U.S. clinicians are beginning to prescribe off-label aqueous SLIT preparations. The most promising U.S. studies have involved grass tablets; aqueous preparations have yielded varying results.

In an industry-sponsored U.S. trial, researchers randomized 381 adults with ragweed allergies to sublingual allergen immunotherapy extract (SAIL) or placebo. The SAIL or placebo drops were administered daily by holding them under the tongue for 2 minutes and then swallowing. Therapy was started 8 to 16 weeks before, and continued through, ragweed season. The SAIL-treated group scored signific…