Five Things you Should Know about Peanut Allergy Immunotherapy
by William R. Reisacher, MD, FACS, FAAOA
If you are reading this, it is likely that either you or a loved one are among the many afflicted with peanut allergy. In fact, approximately 5.4 million adults and 1.6 million children in the United States suffer from peanut allergy. And, until recently, there were no FDA-approved treatments for peanut allergy except for epinephrine (EPI-Pens or Auvi-Q) to treat severe allergic reactions after peanut exposure.
Just this year, the FDA approved the first-ever oral immunotherapy (OIT) treatment for peanut allergy. On January 31, 2020, the U.S. Food and Drug Administration approved PALFORZIA™ [Peanut (Arachis hypogaea) Allergen Powder] for the treatment of allergic reactions, including anaphylaxis, that may occur with accidental exposure to peanuts. This development has created interest in peanut allergy immunotherapy. But it has also caused a lot of confusion.
We hope the following helps simplify this topic and answer questions to clarify any confusion about peanut allergy immunotherapy.
How does OIT for peanut allergy work?
The principle behind OIT is to expose peanut-allergic patients to specific amounts of peanut protein over time. Studies over the past couple of decades have reported that consistent consumption of peanut powder is effective at decreasing the severity of symptoms following accidental exposure and reducing the incidence of life-threatening reactions. In addition to Palforzia, many allergy specialists are using their own, non-regulated, versions of OIT in their offices to treat their patients with peanut allergy.
Is OIT safe?
The main disadvantage of OIT is frequent adverse events during treatment, including oral rashes, gastrointestinal discomfort, sore throat, and even anaphylaxis. The frequency and severity of OIT side effects suggests the need for a safer method of delivering peanut allergy immunotherapy which will also be effective.
What is sublingual immunotherapy (SLIT) for peanut allergy?
SLIT is a form of oral mucosal immunotherapy (OMIT™) where the allergens are delivered to the tissues lining the mouth instead of being swallowed, as is the case with OIT. These tissues are designed to educate the immune system what is safe to consume, a key role they play during the first year of life. SLIT for food allergy involves placement of allergy drops under the tongue daily with the goal of desensitizing the patient to that allergen. Studies show that SLIT using peanut protein increases the tolerated consumption of peanuts by a substantial margin with fewer and less severe side effects compared to OIT. While providing similar benefits as OIT, SLIT has only been effectively used in university studies with complicated dosing requirements. Doctors drop measured liquid doses of glycerinated peanut extract under a patient’s tongue for about two minutes before spitting it out. SLIT would be a challenging treatment in the real world where most patients with peanut allergy are children.
Can you deliver peanut allergy immunotherapy through a skin patch?
Unfortunately, this option remains inconclusive. French biopharmaceutical firm DBV Technologies developed a skin patch, referred to as epicutaneous immunotherapy (EPIT), called ViaskinTM Peanut. As with most therapy patches, local irritation and skin discoloration can occur. Also, research has reported that this investigational EPIT platform may lack sufficient efficacy in adolescents and adults. In August 2020, the FDA declined to approve Viaskin Peanut citing the impact of patch-site adhesion issues on efficacy.
Are there any other peanut allergy immunotherapy methods on the horizon?
Another version of OMIT is INT301, which is a commercial-grade toothpaste under investigation by Intrommune Therapeutics that contains a specific amount of peanut protein. Compared to SLIT, INT301 delivers the proteins required for desensitization to a wider area of the oral cavity mucosa while avoiding the risks associated with swallowing them. A toothpaste may also be preferable for children or adults who have difficulty swallowing. And because INT301 has all the functionality of regular toothpaste, it can be integrated very easily into the daily routine, which is important to maintain the level of desensitization desired in the long run. It is suspected that life-long exposure to peanut protein each day may be required [for all food allergy immunotherapies] in order to maintain the proper level of desensitization.
Another possible benefit of INT301 is the ability to potentially treat multiple food allergies simultaneously. People often suffer from more than one food allergy. Allovate Therapeutics is a biopharmaceutical company which currently offers a version of this toothpaste, called Allerdent®, for patients suffering from respiratory allergies.
While peanut immunotherapy treatments utilize different delivery methods, all follow the fundamental principle of immunotherapy: peanut allergen delivery to the immune system in increasing doses to decrease the immune response to the allergen.
In addition to the OIT, EPIT, SLIT and OMIT treatments discussed, new immunotherapy strategies, such as vaccines and probiotics, are also being developed to address peanut allergy.
Additional peanut and food allergy support can be found at:
- Allergy & Asthma Network
- FARE (Food Allergy Research & Education)
- Food Allergy & Anaphylaxis Connection Team (FAACT)
William R. Reisacher, MD FACS FAAOA is an Associate Professor at Weill Cornell Medical College and the Director of Allergy Services in the Department of Otolaryngology – Head and Neck Surgery at New York-Presbyterian Hospital.
Dr. Reisacher is also an advisor and shareholder for Allovate Therapeutics and Intrommune Therapeutics.