Anti-IgE Drug Speeds Up Allergy Therapy

Two more groups reported here that the anti-IgE biologic drug omalizumab (Xolair) was helpful in speeding immunotherapy for allergies, suggesting that the approach may be gaining momentum.

Omalizumab eliminates IgE from circulation and is approved as an adjunctive treatment for allergic asthma. Previous reports had indicated that the drug was helpful in preventing anaphylaxis during "rush" desensitization treatments for severe allergies.

Researchers at Duke University, testing omalizumab in teens undergoing oral immunotherapy for peanut allergy, said here that the strategy shortened the time needed to achieve a reasonable degree of peanut tolerance.

And clinicians in Boston found that omalizumab helped stave off anaphylactic reactions in a colon cancer patient who needed oxaliplatin but was severely allergic to the drug and had to undergo desensitization therapy with it.

Both reports were presented at the annual meeting of the American Academy of Allergy, Asthma, and Immunology (AAAAI).

At last year's AAAAI meeting, Kari Nadeau, MD, of Stanford University, reported that starting omalizumab in milk-allergic children nine weeks before starting oral immunotherapy allowed most of them to complete the entire first phase in just one day, such that they could tolerate two grams of powdered milk.

The Duke study reported this year involved nine adolescents (age 12 to 19) with longstanding peanut allergies. Michele Henson, MD, said omalizumab was started four months before initiating the desensitization therapy in a modified rush protocol.

The immunotherapy was a two-day process with a target of 475 mg of peanut powder. In comparison, the regular oral immunotherapy procedure at Duke is a one-day protocol that seeks to work patients up to ingesting 6 mg.

Following these initial procedures, patients then take peanut powder daily with dose escalations every two weeks as tolerated. The ultimate target is 4,000 mg, equivalent to about 13 peanuts.

The omalizumab was continued for one month after the maintenance dose was reached, then stopped.

One of the nine patients stopped the therapy prematurely, and three others are still in the buildup phase, Henson said. For the five that have reached the maintenance dose of 4,000 mg/day, the time needed to reach it ranged from 233 to 276 days.

In contrast, the median time to reach maintenance dosing for 28 patients undergoing the regular oral immunotherapy program at Duke has been 350 days (P<0.01), she reported.

Reactive symptoms such as hives and chest tightness during the rush procedure and on dose escalation days also were less common and less severe than with the regular protocol.

Henson said the group was interested next in pursuing a larger, randomized, double-blinded trial with omalizumab in peanut allergy therapy.