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

Background: Allergic rhinitis is a common condition often requiring treatment. Objective: We evaluated whether recombinant humanized (rhu)mAb-E25, a recombinant humanized construct of a murine antibody that binds to circulating IgE, could control symptoms and reduce intake of concomitant medication in seasonal allergic rhinitis (SAR) induced by birch pollen if given subcutaneously 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-E25 or placebo given 2 or 3 times during the season, depending on baseline IgE levels. The primary efficacy variable was the subject's average daily nasal symptom severity score (sneezing, itching, runny, and stuffy nose) from diary data collected over the double-blind treatment period. Secondary efficacy variables included the average number of rescue antihistamine tablets per day, the proportion of days with any SAR medication use, and rhinoconjunctivitis-specific quality of life (QOL), Results: Significant between-treatment differences in favor of rhumAb-E25 were observed in average daily nasal symptom severity scores, the average number of tablets of rescue antihistamines per day, the proportion of days with any SAR medication use, and all domains of QOL. Serum-free IgE levels were markedly lower in rhumAb-E25-treated subjects and were associated with clinical 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 controlling birch pollen-induced SAR symptoms, with Less concomitant medication use and improved QOL. This study shows the therapeutic potential of anti-IgE antibody in SAR.