Peanut allergies find new adversary in sublingual immunotherapy

When it comes to severe food-induced allergic episodes, peanuts play a pretty mammoth part. As of now, the only way for patients to avoid suffering an acute, potentially fatal, reaction to peanuts is through dietary elimination. If that fails, there’s always the last-ditch, epinephrine injection, but aside from such reinforcement, the options have been few — until now.

According to a new study conducted by David M. Fleischer, MD, of National Jewish Health in Denver, and Wesley Burks, MD, Curnen Distinguished Professor and Chair of the Department of Pediatrics in the University of North Carolina School of Medicine, sublingual immunotherapy (SLIT) could be the next best thing in treatment for the peanut-susceptible. SLIT requires patients to take a daily dose of liquid containing peanut powder — the liquid is held under the tongue for 2 minutes, then swallowed. As the therapy progresses, the amount of peanut powder involved increases steadily.

Fleischer and Burks observed 40 patients with peanut allergies, aged 12 to 37 years old. Some were given the SLIT content, while others took placebo pills. All study participants underwent baseline oral food challenges where they were administered up to two grams of peanut powder to gauge how much could be consumed without symptoms arising. Following the 44-week mark, subjects were given a second oral food challenge, in which consumption amounts were upped; 70 percent of those who had received actual SLIT pills were able to ingest either 5 grams or up to 10-fold more peanut powder than their original baseline amount compared to the 15 percent of placebo participants who were able to do so.

According to the study outline: “Among the peanut-SLIT responders, the median amount of peanut powder they could successfully consume increased from 3.5 to 496 milligrams. After 68 weeks, that amount increased significantly, to 996 milligrams. Of 10,855 peanut doses given through week 44 of the study, 63.1 percent were symptom-free. When oral/pharyngeal symptoms were excluded from the analysis, 95.2 percent of doses were symptom-free.”

"These results are encouraging," Burks said in a news release. "The immune response was stronger than we thought it might be, and the side effects of this treatment were relatively small. However, the magnitude of the therapeutic effect was somewhat less than we had anticipated. That's an issue we plan to address in future studies."

Both Burks and Fleischer agreed that while the findings are promising, it’s not a treatment meant for patients or physicians to try on their own until more clinical trials have been completed.