A pilot study conducted at Boston Children’s Hospital Division of Allergy and Immunology and Harvard Medical School shows promise that treatment combining the asthma drug Xolair® with oral desensitization therapy facilitates rapid desensitization in children with severe peanut allergies.
The study, published in the Journal of Allergy and Clinical Immunology (JACI), followed 8 boys and 5 girls aged 8-16 years with histories of significant allergic reactions to peanuts.
Method
The children were first given customary dosages of Xolair for their weight every 2-4 weeks. Beginning in week 12, they were given 11 successively higher doses of peanut flour ranging from 0.1mg to 500mg over a six hour period. The following day they began the dosage escalation phase starting with 500mg doses of peanut flour for 6 days, then successively higher daily doses increasing from 750mg to 4000mg over the next 8 weeks. At week 20, the Xolair was discontinued but the daily doses of peanut flour continued.
Challenge
In week 32 of the study, 12 weeks after discontinuing the Xolair administration, the children were challenged with successively increasing doses of peanut flour every 15 minutes ranging from 500mg to 3500mg dose for a total of 8000mg (equivalent to 20 peanuts.) If the children passed the challenge, they were given a single 8000mg dose 16 hours later. Afterward, the children were told to consume 10-20 peanuts daily as a maintenance dose and followed over the remainder of the 52 week study.
Results
One child withdrew from the study at week 15 due to persistent nausea and vomiting caused by increased oral mucus production. Of the other 12 children, 11 passed the final 8000mg challenge outright. One vomited at the 3500mg challenge but ultimately passed the final 8000mg challenge.
All 13 children passed the 500mg challenge with minimal or no symptoms, a dose that may be sufficient to protect against accidental ingestion.
During the 52 week study period, 6 patients had no or mild symptoms treated with antihistamines, 5 suffered grade 2 (“moderate”) symptoms and 2 suffered grade 3 (“severe”) symptoms, though all responded quickly to treatment (presumably with epinephrine.)
While the study was small, it does suggest that this treatment may provide a means for oral immunotherapy to proceed at an accelerated pace with fewer reactions. Larger studies are currently underway.
