UPDATE 1-Asthma med facilitates food immunotherapy in multi-allergic kids

Last Updated: 2017-12-26

(Updates Dec 14 story with quotes from research team and editorialist. (Replaces last 4 paragraphs of original story with new paras 12 through 22.))

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.

"This is a growing and exciting field," Dr. Chinthrajah told Reuters Health.

"The therapy we tested is still experimental and not FDA-approved," she said in an email on behalf of her coauthors. "There are many new drugs on the horizon to test in food allergies. More studies are needed to further understand the best use of combination therapy to help (these) patients."

"We are very interested in understanding the science and mechanisms of immunotherapy to help develop safer and better therapies," she added, "and to start to understand what approach might be best for a particular individual, and what might lead to tolerance or long-lasting effects on the immune system."

Dr. Lars Poulsen of Copenhagen University Hospital at Gentofte in Hellerup, Denmark, author of an accompanying editorial, told Reuters Health by email, "In the study, a successful treatment outcome was defined as the ability to ingest the offending foods at a dose corresponding to two grams of protein."

"While tolerance to such a dose will drastically reduce the risk of adverse reactions to foods containing hidden traces of allergens, it will not necessarily allow the patient a free diet full of all the offending foods," Dr. Poulsen said.

"Also, we still do not know when or if to stop the oral immunotherapy treatment and still maintain an enduring effect," he added. "As discussed by the investigators, the study was not designed to address this issue, and further studies will have to look into this."

Is cost a concern?

"Omalizumab certainly comes with a price tag, but so does the whole concept of oral immunotherapy, which will necessitate a considerable number of patient visits," Dr. Poulson said.

"On the other hand," he noted, "we are facing many children who have a substantially reduced quality of life due to their - and their caretakers' - anxiety about serious food-induced allergic reactions."

"The direct costs and benefits for families will vary (based on) the health care system under which they live," he concluded.

(With reporting by Marilynn Larkin.)

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

Lancet Gastroenterol Hepatol 2017.