Omalizumab May Help Desensitization for Multiple Food Allergies

Veronica Hackethal, MD

December 12, 2017

Combining the asthma medication omalizumab with oral immunotherapy may improve the speed, effectiveness, and safety of allergy desensitization in children with multiple food allergies, researchers report.

The pilot study is the first phase 2, double-blind, randomized controlled trial to evaluate the efficacy and safety of omalizumab added to oral immunotherapy in children with multiple food allergies. The results were published online December 11 in The Lancet Gastroenterology & Hepatology.

"The study showed significant efficacy and safety improvements in multi-allergic patients treated with omalizumab and food immunotherapy," coauthor Kari Nadeau, MD, PhD, director of the Parker Center and professor of medicine and of pediatrics at Stanford University in Palo Alto, California, said in a press release. "Multi-allergic patients are at much higher risk for anaphylactic reactions since they are allergic to more foods, and omalizumab can help change the course of therapy by making it safer and faster."

About 30% of people with allergies are allergic to multiple foods, which puts them at increased risk for fatal or near-fatal food reactions.

Oral immunotherapy involves daily ingestion of small doses of proteins from trigger foods, with dose escalations over time to achieve tolerance. Many studies have evaluated oral immunotherapy in treating allergies to single foods. However, because the technique can cause allergic reactions, its use in people with multiple allergies is riskier. For this reason, few studies have evaluated it in this population.

Omalizumab (Xolair, Genentech) may improve the situation. A humanized monoclonal antibody, omalizumab both decreases the amount of circulating IgE and dampens its activity in stimulating allergic responses.

However, the authors stressed that more research is needed before the combination can be used in clinical practice.

"While our results are promising, they are preliminary and suggest that children with multiple food allergies might one day be safely desensitised to their trigger foods using this treatment combination," lead author, Sharon Chinthrajah, MD, also from Stanford University, said in a press release.

The study included 48 children aged 4 to 15 years with multiple food allergies, as confirmed on food challenge tests (the gold standard for diagnosing food allergy).

Researchers randomly assigned participants to 16 weeks of injections with omalizumab (36 children) or placebo (12 children). Eight weeks after starting injections, children started oral immunotherapy with two to five of their trigger foods. These foods included cashews, walnuts, hazelnuts, almonds, sesame, cow's milk, hen's eggs, peanuts, soy, and wheat. Over time, food dosages were increased up to a maintenance dose of 2 g per food, or the amount commonly eaten during an accidental ingestion.

After discontinuing omalizumab or placebo, children continued oral immunotherapy for 20 more weeks, after which they underwent a food challenge. 

At week 36, 83% of children treated with omalizumab tolerated a food challenge with 2 g of protein from two or more or their trigger foods, compared with 33% of those treated with placebo. The odds of achieving tolerance were 10 times higher with omalizumab than placebo (odds ratio, 10.0; 95% confidence interval, 1.8 - 58.3; P = .0044).

The same children who tolerated 2 g of their trigger foods also tolerated 4 g, or an average serving (about 1 tablespoon of peanut butter). This finding is noteworthy, according to the authors, because being able to eat an average serving is important for nutrition and quality of life.

"Patients and families say they're so grateful," Dr Chinthrajah said. "They can broaden their food variety and participate in more social activities without fear of a bad allergic reaction. Kids say things like 'I no longer sit at the allergen-free table at lunch; I can sit with my usual friends.' These tiny things that others take for granted can open their social world."

Omalizumab also appeared to speed desensitization. Children in the omalizumab group reached their maintenance dose at 12 weeks, compared with 20 weeks with placebo.

In addition, receiving omalizumab seemed to improve the safety of oral immunotherapy. In weeks 8 to 16 (during the food challenge and omalizumab or placebo dosing), the most common adverse events were gastrointestinal problems, which were significantly more common with placebo (54%) than with omalizumab (22%; P = .044).  Respiratory adverse events were also significantly fewer with omalizumab (0%)  than with placebo (1%; P  = .023). No participants  experienced serious side effects, such as anaphylactic shock.

In a linked comment, Lars Poulsen, PhD, from Copenhagen University Hospital at Gentofte in Hellerop, Denmark, discussed several limitations of the study. Most important, the study could not evaluate whether tolerance is sustained over time. However, the authors noted they intend to conduct future studies to look at this issue.

Nevertheless, Dr Poulsen writes that the study is noteworthy.

"By including participants with a high level of sensitisation…the study addresses the most severely affected and thus difficult-to-treat part of the food allergic population," he emphasized.

The study was funded by the National Institutes of Health (NIH). One or more authors reports grants, nonfinancial support, sponsored research, and/or advisory board fees from one or more of the following: NIH, National Institute of Allergy and Infectious Diseases, Novartis, AnaptysBio, Aimmune, DBV Biosciences, Astellas, DBV Technologies, and/or Astellas Pharma Global Development. Dr Poulsen has disclosed no relevant financial relationships.

Lancet Gastroenterol Hepatol. Published online December 11, 2017. Abstract, Comment

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