Lower doses of oral immunotherapy may successfully desensitize peanut allergy patients

For patients who have difficulty completing peanut oral immunotherapy (OIT), long-term treatment with lower maintenance doses may bring about complete desensitization, according to study results presented at the 2018 American Academy of Allergy, Asthma & Immunology (AAAAI) and World Allergy Organization (WAO) Joint Congress, held March 2-5, 2018, in Orlando, FL.

Researchers in Israel conducted this study to determine the long-term therapeutic efficacy of lower maintenance doses of oral immunotherapy.

The study included 145 patients who underwent peanut OIT. The treatment protocol consisted of an in-hospital initial induction-desensitization phase, where the maximal individualized tolerated dose was identified and then given to the patient to consume daily at home.

 “The doses were gradually increased on a monthly basis [in a day-hospital care setting] as patients were able to tolerate more peanut protein,” said senior author Arnon Elizur, MD, Department of Pediatrics, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel, and Institute of Asthma Allergy & Immunology, Zerifin, Israel.

A lower daily maintenance dose was given to patients who were having technical difficulty ingesting the maintenance dose or who were limited by allergic reactions.

“Eleven patients, ranging from 6 to 19 years old, were unable to reach the target maintenance dose and were placed on lower maintenance doses of peanut protein, as tolerated,” said Dr. Elizur.

These patients reached a median maintenance dose of 1,200 mg (range: 600-1,500 mg). The median duration was 5 months (range: 3-13 months).

All patients had a reaction during induction, and 45% had reactions during home treatment, including one patient who required an Epi-Pen injection.

After 6 to 68 months of low-maintenance therapy, patients were given an oral food challenge of 3,000 mg of peanut protein (PP). One patient on a maintenance dose of 600 mg reacted to 2,100 mg PP, but all others successfully passed.

Average skin prick test-wheal size was reduced from 8.9 mm to 3.6 mm, and only four subjective reactions were reported. In 90.9% of patients, oral food challenges of up to 3,000 mg PP were successful. A full 73% of patients were fully compliant to their daily dose consumption, and 27% occasionally stopped treatment for more than 1 week.

“A small portion of patients will not be able to reach the 3,000 mg target maintenance dose,” said Dr. Elizur. “However, this study shows that even lower doses, are not only protective against severe reactions in the case of accidental exposure to peanut, but also can enable free peanut consumption long-term.”