Omalizumab Facilitates Rapid Oral Desensitization for Peanut Allergy
Sunday, March 6, 2016: 4:45 PM
Concourse Foyer (Convention Center)
Andrew J. Macginnitie, MD PhD, Rima A. Rachid, MD FAAAAI, Antonella Cianferoni, MD PhD FAAAAI, Tina L.R. Dominguez, Jennifer Heimall, MD, Melanie M. Makhija, MD, MS, Rachel Robinson, MD, Sara V. Little, Hana Gragg, Paul Lakin, Tanya Logvinenko, PhD, Jennifer S. LeBovidge, PhD, Jennifer Koss, Megan T. Ott, Courtney B. Rooney, Dale T. Umetsu, MD PhD FAAAAI, Jacqueline A. Pongracic, MD FAAAAI, Jonathan M. Spergel, MD PhD FAAAAI, Kari C. Nadeau, MD PhD FAAAAI, Lynda C. Schneider, MD FAAAAI
Rationale:  Peanut oral immunotherapy (OIT) is a promising approach to peanut allergy but reactions frequently occur and some patients cannot be desensitized.  The anti-IgE medication omalizumab (Xolair) may allow accelerated up-dosing and reduced reactions during peanut OIT.

Methods:  In this multicenter, randomized, double blind, placebo controlled trial, 37 subjects who failed a food challenge to <100 mg of peanut protein were randomized to omalizumab (n=29) or placebo (n=8).  After 12 weeks of treatment subjects underwent a rapid desensitization to 250 mg of peanut protein over 6 hours, followed by weekly dose increases up to 2000 mg.  Omalizumab or placebo was discontinued and subjects continued on 2000 mg of peanut protein daily.  12 weeks after stopping omalizumab or placebo, subjects underwent an open challenge to 4000 mg of peanut protein.  If tolerated, subjects continued on this dose daily.

Results:   Median age of enrolled patients was 10 years and median peanut-specific IgE was 90 kU/L.  Of 29 patients randomized to omalizumab (27 of whom received peanut OIT) 23 tolerated 2000 mg peanut protein 6 weeks after stopping study drug versus 1 of 8 receiving placebo (p=0.0011).   Similarly, the median peanut dose tolerated on initial desensitization was 250 mg for omalizumab versus 22.5 mg for placebo.  22 patients on omalizumab versus 1 on placebo successfully tolerated 4000 mg of peanut protein 12 weeks after discontinuing study drug.

Conclusions:   Omalizumab allows patients with peanut allergy to be rapidly desensitized. Additional studies are needed to confirm these observations and identify the most appropriate patients for this approach.