A clinical research consortium sponsored by NIAID and JDRF
Casale TB, Kline JN, Busse WW, Ballas ZK, Mokhtarani M, Seyfert-Margolis V, Bateman K, Moss MH, Townley RG.
Creighton University, Omaha, NE University of Wisconsin, Madison, WI Univ. of Iowa, Iowa City, IA Immune Tolerance Network, San Francisco, CA PPD Development, Wilmington, NC NIAID, NIH, Bethesda, MD
Rationale: To examine whether omalizumab given 9 weeks prior to RIT makes RIT safer.
Methods: Adult patients with a positive history and skin test for ragweed sensitivity were enrolled in a double-blinded, parallel-group, 3-center, placebo-controlled trial. Patients received either 9 weeks of omalizumab (0.016 mg/kg/IgE [IU/mL]/mo) or placebo, followed by 1 day RIT (1.2 to 4.0 mcg ambA1 maximum dose) or placebo over 3 to 5 hours. RIT placebo contained increasing amounts of histamine, 6 to 62.5 mcg, to aid in the blinding process. Patients received 180mg fexofenadine the day before and morning of RIT.
Results : One hundred fifty-nine patients were randomized: 150 received all omalizumab or placebo pretreatments and 149 received at least 1 dose of RIT. IgE levels decreased > 90% in the omalizumab treated patients. The percentage of patients with adverse events in the omalizumab plus RIT versus placebo plus RIT groups, respectively, were: wheezing, 0 versus 7.7; flushing, 13.9 versus 41.0; urticaria, 8.3 versus 28.2; angioedema, 2.8 versus 7.7; drops in BP>15mm, 11.1 versus 7.7; lightheadedness, 5.6 versus 17.9; itching 13.9 versus 30.8. Overall, the reaction rates during RIT for the 4 groups were: 33.3% omalizumab plus RIT; 29.7% omalizumab plus placebo RIT; 56.4% placebo omalizumab plus RIT and 34.9% placebo plus placebo. Over twice as many patients required epinephrine and/or prednisone in the placebo plus RIT arm versus the omalizumab plus RIT arm.
Conclusion : Omalizumab pretreatment may be an effective strategy to permit more rapid and higher doses of allergen IT.
J Allergy Clin Immunol 115(2): S65, 2005.
