Oral immunotherapy, a treatment for peanut allergies that involves giving children small, oral doses of the allergen, appears to desensitize them to peanuts, according to a meta-analysis of 12 clinical trials published on April 25 in The Lancet. But the intervention was also linked to a two- to threefold higher risk of participants experiencing the severe allergic reaction known as anaphylaxis, compared to those taking a placebo or avoiding peanuts.

“In our study we found that this increase occurred for all preparations of OIT [oral immunotherapy] used and for all protocols,” coauthor Derek Chu of McMaster University in Hamilton, Ontario, reports. “The bottom line is that this therapy is still experimental, and physicians and patients need to understand that.”

Chu and his colleagues gathered data from more than 1,000 kids who participated in the randomized controlled clinical trials. They found that the oral immunotherapy led to a greater tolerance of peanuts in challenge tests, but also to a much higher number of serious adverse reactions compared with children who didn’t get the intervention. Of note, there was no difference in the quality of life between the two groups.

Alkis Togias, the branch chief of allergy, asthma, and airway biology at the US National Institute of Allergy and Infectious Diseases, tells CNN the data show the intervention is at an early stage. “From our perspective as an agency that is responsible for research in the field, what it tells us is that we need to improve on the methods for treating food allergy, especially peanut allergy.”

Chu tells CBC News that oral immunotherapy for peanut allergy is still worth pursuing. “We’re not outright saying that . . . this should be denounced or that this should be abandoned. Far from it,” Chu says. “From a research standpoint this is a major advance. We’re almost there.”

Dr. Kenneth Backman of Allergy and Asthma Care of Fairfield County comments: “Studies of oral immunotherapy (desensitization) for peanut and other food allergies are ongoing. This study emphasizes that there is still much to learn. While the number of accidental reactions may be reduced by treatment, patients undergoing desensitization will have significantly more reactions than patients who choose avoidance alone.  OIT is a potentially exciting advance in food allergy treatment, but the risks and benefits still have to be fully worked out for this experimental treatment.”