Recombinant humanized mAb-E25, an anti-IgE mAb, in birch pollen-induced seasonal allergic rhinitis

Background: Allergic rhinitis is a common condition often requiring treatme nt. Objective: We evaluated whether recombinant humanized (rhu)mAb-E25, a recom binant humanized construct of a murine antibody that binds to circulating I gE, could control symptoms and reduce intake of concomitant medication in s easonal allergic rhinitis (SAR) induced by birch pollen if given subcutaneo usly in a dose schedule predicted to reduce serum free IgE levels below 25 ng/mL. Methods: We randomly assigned 251 adult subjects with a history of SAR and a positive skin test response to birch pollen to receive 300 mg of rhumAb-E 25 or placebo given 2 or 3 times during the season, depending on baseline I gE levels. The primary efficacy variable was the subject's average daily na sal symptom severity score (sneezing, itching, runny, and stuffy nose) from diary data collected over the double-blind treatment period. Secondary eff icacy variables included the average number of rescue antihistamine tablets per day, the proportion of days with any SAR medication use, and rhinoconj unctivitis-specific quality of life (QOL), Results: Significant between-treatment differences in favor of rhumAb-E25 w ere observed in average daily nasal symptom severity scores, the average nu mber of tablets of rescue antihistamines per day, the proportion of days wi th any SAR medication use, and all domains of QOL. Serum-free IgE levels we re markedly lower in rhumAb-E25-treated subjects and were associated with c linical effectiveness. Recombinant humanized mAb-E25 was well tolerated. No anti-rhumAb-E25 antibodies mere detected. Conclusion: Compared with placebo, rhumAb-E25 was safe and effective in con trolling birch pollen-induced SAR symptoms, with Less concomitant medicatio n use and improved QOL. This study shows the therapeutic potential of anti- IgE antibody in SAR.