Xolair, an antibody asthma drug, was recently approved for severe food allergic reactions. It is not the first biological drug to treat multiple conditions. But it is the first to treat severe food allergies - a growing problem.
As much as we hate having our collective lives polluted by the ceaseless and nauseating prescription drug ads (See No, I Don't Want To Hear About Your Bent Penis While Dining) as well as being toyed with by insurance companies that seemingly create arbitrary rules to avoid paying for new, high priced drugs, there is a definite upside to many of the new products that drug companies are discovering and developing.
One area I've covered extensively is the discovery of biological drugs that have revolutionized the treatment of asthma (See I'm A Human Pincushion And A Damn Lucky One and Dupilumab, A Miracle Drug For Eczema. And Now Asthma, Too). Dupixent (dupilumab) has a dual purpose; it was approved for severe eczema – not something you want to experience – in 2017, and 2018 for severe asthma (no picnic either). (1)
Given that the drug, a monoclonal antibody, inhibits cytokines interleukin-3 and interleukin-4 it is not unreasonable that it is able to treat multiple conditions. This is because asthma, eczema, and allergic rhinitis (aka hay fever)– the so-called atopic triad – are all caused by a hyperimmune response caused by excessive quantities of an allergenic antibody called IgE. (2,3,4)
The atopic triad refers to the tendency of asthma, eczema, and allergies to occur together. The progression begins with eczema, followed by food allergies, and then the development of asthma and allergic rhinitis, which causes sneezing and a runny nose. Doctors also call this progression the atopic march.
Medical News Today, November 2021
Nor is it a coincidence that other biological immune modulators can likewise treat more than one condition. Omalizumab (Xolair), which was the first antibody drug approved for allergic asthma in 2003 recently received FDA approval for protection against food allergies in people who are at high risk of having severe reactions:
Today, the U.S. Food and Drug Administration approved Xolair (omalizumab) injection for immunoglobulin E-mediated food allergy in certain adults and children 1 year or older for the reduction of allergic reactions (Type I), including reducing the risk of anaphylaxis, that may occur with accidental exposure to one or more foods.
FDA Press release, February, 2024
While Xolair is not 100% effective in preventing severe allergic reactions to food it does a rather good job. Below are some of the clinical trial highlights of a study published in NEJM that led to the FDA's nod last month.
- The trial involved 180 participants, aged 1-55, who were allergic to peanuts and at least two other foods from the list of cashew nuts, milk, eggs, walnuts, wheat, and hazelnuts.
- Participants received injections of either omalizumab or a placebo every 2-4 weeks for a duration of 16-20 weeks. The dose of Xolair administered was based on the participant's body weight and IgE count (2).
- The primary endpoint was the percentage of subjects who were able to eat a single dose (600+ milligrams) of peanut protein (equal to 2.5 peanuts) without developing an allergic skin reaction or respiratory, or gastrointestinal symptoms.
- In the Xolair-treated group, 75 of 110 participants (68%) were able to eat peanuts without developing symptoms such as hives, persistent coughing, or vomiting)
- In the placebo group, only 6% of the subjects were without symptoms.
- However, the drug wasn't perfect; 17% of participants receiving Xolair could still not tolerate peanuts, so people who take Xolair still must avoid allergy-producing foods. The drug is not a free pass but represents an important advance for the treatment of food allergies, which have soared in the past 15 years.
While it will not eliminate food allergies or allow patients to consume food allergens freely, its repeated use will help reduce the health impact if accidental exposure occurs.
Kelly Stone, M.D., Ph.D., associate director of the Division of Pulmonology, Allergy, and Critical Care in the FDA’s Center for Drug Evaluation and Research
There are six approved biological drugs now approved for different varieties of asthma and two of them have utility for different, but related conditions. It's a pretty good bet that as more biological drugs for allergic and inflammatory responses are developed and studied this trend of expanded utility of such drugs will become more common.
Perhaps then we can all breathe easier.
NOTES:
(1) Before Dupixent was approved for the management of allergic asthma some patients had to take an approved asthma drug like Xolair in addition to Dupixent for their eczema. I was one of them. I discontinued the Xolair without any adverse impact.
(2) Excess IgE is the hallmark of asthma and eczema, but the antibody once had a critical function in fighting intestinal parasites. Those of us who inherited an immune system with high IgE counts would have had a survival advantage over those who did not. But in the absence of the parasites, IgE reacts to other allergens, causing immune-based allergies and asthma.
(3) IL-4 plays a central role in promoting IgE production.
(4) IL-3 plays a role in the maturation and activation of mast cells, which are involved in allergic reactions. Excessive IL-3 levels contribute to the hypersensitivity of the cells, leading to exaggerated allergic responses.
