Asthma med facilitates food immunotherapy in multi-allergic kids

Last Updated: 2017-12-14

By Reuters Staff

NEW YORK (Reuters Health) - The combination of the anti-IgE asthma medication omalizumab with oral immunotherapy facilitates rapid oral densitization in children with multiple food allergies, according to a phase 2 randomized controlled trial.

"Despite progress in single food oral immunotherapy, there is little evidence concerning the safety and efficacy of treating individuals with multiple food (multifood) allergies," Dr. Sharon Chinthrajah and colleagues from the Center for Allergy and Asthma Research at Stanford University in California note in their December 11 report in Lancet Gastroenterology and Hepatology.

"The study showed significant efficacy and safety improvements in multi-allergic patients treated with omalizumab and food immunotherapy," co-author Dr. Kari Nadeau of Stanford University said in a statement. "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."

Omalizumab, a humanized monoclonal antibody, reduces levels of circulating IgE (immunoglobulin E) and ramps down the allergic response. The study included 48 children (ages 4 to 15 years) with two or more allergies to various foods including peanuts, cashews, walnuts, hazelnuts, almonds, eggs, soy, and wheat.

For 16 weeks, 36 children received omalizumab injections and 12 received placebo injections. Eight weeks after starting the injections, all children began oral immunotherapy with two to five trigger foods until week 36, with up-dosing to a maintenance of 2 grams of protein for each trigger food. Oral immunotherapy was continued without omalizumab or placebo for the next 20 weeks. At this point, the children underwent standard food challenge to 2 grams of food protein.

At 36 weeks, significantly more children treated with omalizumab than placebo passed food challenges to 2 grams of protein for at least two offending foods (83% vs. 33%). The likelihood of achieving tolerance to these food triggers was 10-fold higher with omalizumab than placebo (P=0.0044), the investigators report.

"Every participant who tolerated 2 grams of at least two foods in the week 36 food challenges also tolerated 4 grams for at least two foods in the same challenges," they further report.

In addition, a significantly larger proportion of children in the omalizumab arm achieved the secondary efficacy endpoints of passing food challenges to 2 grams of each of three, four, or five foods compared with the placebo arm.

Omalizumab also appeared to increase the pace of desensitization, with children in the omalizumab arm reaching their maintenance dose as early as 12 weeks versus 20 weeks for children in the placebo arm.

All children completed the study, and there were no serious or severe (grade 3 or worse) adverse events. Children who received omalizumab had fewer gastrointestinal and respiratory side effects during oral immunotherapy.

These results "suggest that multifood oral immunotherapy in combination with a short initial course of omalizumab (16 weeks) will permit effective desensitization to be achieved rapidly in the majority of multifood allergic participants," the researchers conclude in their article.

In a linked Comment, Dr. Lars Poulsen from the Allergy Clinic, Copenhagen University Hospital at Gentofte in Hellerop, Denmark, says this study addresses "the most severely affected and thus difficult-to-treat part of the food allergic population," namely those with not a single but multiple food allergies.

"The good news is that the anti-IgE cover conferred a much improved safety profile on the multiple-food oral immunotherapy, and this allowed for a higher success rate in the patients who received omalizumab pretreatment compared with those who received placebo," Dr. Poulsen writes.

"As discussed by the authors, the study has limitations," Dr. Poulsen points out. "Whether tolerance was sustained was not addressed, and this question will require future studies. Furthermore, not all patients can be treated adequately with omalizumab due to very high levels of serum IgE, and this might in particular cause problems in the substantial subset of patients with atopic dermatitis, a condition often seen in conjunction with food allergy. On the other hand, new molecules targeting IgE are in the pipeline that might further improve the anti-IgE cover."

The study had no commercial funding. Two authors reported financial relationships with Aimmune Therapeutics and DBV Technologies, which develop treatments for food allergies. Dr. Poulsen has declared no competing interests.

SOURCES: http://bit.ly/2ASxZm4 and http://bit.ly/2AB5A7d

Lancet Gastroenterol Hepatol 2017.