CATEGORY: IMMUNE HEALTH
Four months of injections let 67% of children allergic to peanut and at least two other foods eat the equivalent of about two and a half peanuts without a serious reaction. Among children given placebo injections, 7% could. The drug is omalizumab, an antibody treatment used for two decades against severe asthma, and the same children also became far less reactive to cashew, milk and egg.1 The U.S. Food and Drug Administration approved it for food allergy in February 2024, the first medicine ever cleared to reduce reactions across many foods at once.
Why Soaking Up One Antibody Quiets Several Foods
A food allergy is a case of mistaken identity. The immune system has built IgE antibodies shaped to fit peanut, milk or egg protein, and those antibodies sit on the surface of mast cells like tripwires. Mast cells come packed with histamine and other irritant chemicals. When the food arrives the wires are pulled, the cells dump their contents, and out come hives, swelling, vomiting or, at worst, a dangerous drop in blood pressure. Omalizumab does not care which food an IgE antibody was built for. It grabs free IgE in the blood before it can settle onto a mast cell, so fewer tripwires get laid. That is why a single drug can raise the threshold for several unrelated foods at once, which no food-specific treatment can do.
Weighed Mouthfuls, Before and After
The trial, called OUtMATCH, screened 462 people and enrolled 180: 177 children and teenagers aged 1 to 17, median age 7, plus three adults. All had a confirmed peanut allergy along with allergies to at least two of cashew, milk, egg, walnut, hazelnut or wheat. A two-to-one draw decided who received the drug and who received matching placebo. No family history and no clinician’s hunch entered into that split, which is why the gap at the end belongs to the drug. Injections went under the skin every two to four weeks for 16 to 20 weeks, dosed by body weight and by the amount of IgE, the allergy antibody, in the blood. Before treatment and again at the end, every participant went through an oral food challenge: eating slowly increasing, carefully weighed amounts of each food under medical supervision until a reaction appeared or the top dose was reached. The headline question was how many could take in at least 600 mg of peanut protein, roughly two and a half peanuts, with no worse than mild symptoms. Funding came from the National Institutes of Health, with the drug and additional support supplied by its makers.
Seventy-Nine of 118 Against Four of 59
After four months, 79 of the 118 participants on omalizumab (67%) passed the 600 mg peanut challenge. On placebo, 4 of 59 did (7%). Food by food at a 1,000 mg threshold the pattern repeated: cashew 41% versus 3%, milk 66% versus 10%, egg 68% versus 0%. The first 60 participants to finish then stayed on omalizumab openly for another 24 weeks. By that point 67% could eat a cumulative 1,044 mg of peanut protein and 44% could manage 6,044 mg, about 25 peanuts, with no serious reaction. Side effects matched between the groups apart from more soreness at the injection site. One serious adverse event turned up, a rise in liver enzymes in a one-year-old, which the investigators judged unlikely to have come from the drug.
Headroom Against an Accident, Not a New Menu
What the trial measured was protection against a mistake. It never tested whether treated children could put peanut or milk back into their diets, and the investigators were explicit on the point. Lead investigator Robert Wood called the findings potentially life-changing while noting that patients “will still need to avoid the foods” and keep carrying self-injectable epinephrine. The gain is margin against the mislabeled cookie and the shared utensil, the sort of exposure behind most emergency reactions. Whether any of that margin survives once the injections stop was not tested. The drug mops up IgE rather than retraining the immune system, and throughout the trial it kept arriving every two to four weeks. A third of the children on omalizumab never reached the 600 mg mark. A smaller Danish trial leans the same way: 20 children aged 6 to 17 with severe food allergy received omalizumab or placebo, and the treated ones tolerated substantially larger amounts of food protein at three and six months.2 Twenty children cannot carry a conclusion alone, but that trial came from a separate group in a different country.
Key Takeaways
- Four months of omalizumab let 67% of children with multiple food allergies eat about two and a half peanuts’ worth of peanut protein without a serious reaction, against 7% on placebo: 79 of 118 children versus 4 of 59.
- Reaction thresholds rose for cashew, milk and egg as well, because the drug blocks the allergy antibody itself rather than the response to any one food.
- The trial measured protection against accidental exposure. It did not test putting those foods back into a diet, and about a third of treated children never reached the peanut threshold.
References
- Wood RA, Togias A, Sicherer SH, et al. Omalizumab for the Treatment of Multiple Food Allergies. New England Journal of Medicine. 2024;390(10):889–899. link
- Mortz CG, Parke L, Rasmussen HM, Kjaer HF, Bindslev-Jensen C. A randomized, double-blind placebo-controlled study on the efficacy of Omalizumab on food allergy threshold in children with severe food allergy. Allergy. 2024;79(4):964–976. link