A groundbreaking treatment offers hope to people with peanut allergy
When Sharon Wong’s 8-year-old son developed hives, puffy eyes and difficulty breathing while sitting next to a friend who’d eaten peanuts hours earlier, it was alarming. The potentially life-threatening reaction—anaphylaxis—was traced to a tiny amount of peanut residue left on the friend’s clothing. Until then, Wong hadn’t realized just how severe her son’s peanut allergy was. How would she ever keep him safe?
“Allergen avoidance wasn’t enough to protect him and we needed help,” says Wong, a food allergy advocate and author of the blog Nut Free Wok.
Help came in the form of the Viaskin peanut patch, a promising new way to treat food allergies. Developed by France-based DBV Technologies, a clinical-stage biopharmaceutical company, the peanut patch resembles a small, round bandage. It’s applied daily to the skin where the allergen (peanut protein) is delivered by means of a technology called epicutaneous immunotherapy. Continuous exposure via the patch has the potential to promote tolerance to the allergen, says Pierre-Henri Benhamou, MD, co-founder, chairman and chief executive officer of DBV Technologies.
The peanut patch isn’t commercially available but it recently entered Phase III clinical trials, the last major step in bringing a new drug or device to market.
The patch is eliciting excitement because of its convenience (it’s changed daily at home, not at the doctor’s office); its safety (no serious adverse reactions were reported in early studies, only redness and itchiness on the skin at the patch site); and its encouraging results in early clinical trials.
Wong’s son is among over 3 million Americans allergic to peanuts and/or tree nuts, according to the Journal of Allergy and Clinical Immunology. In addition to peanuts, he’s allergic to tree nuts, eggs and some fruits. (He outgrew allergies to shellfish and almonds during the trial.)
In 2012, the boy, then 9, enrolled in the Phase IIb trial of the peanut patch study (known by the acronym, VIPES) at Stanford University School of Medicine. After the year-long trial, he participated in a two-year follow-up study to continue to investigate the patch’s long-term efficacy and safety.
“Our ultimate goal wasn’t to eat a serving of peanuts every day but to have a safer life without seemingly random reactions to minute amounts of peanuts,” Wong says.
How It Works
Soon after Benhamou teamed up with an engineer and a pediatrician to found DBV Technologies in 2002, they realized that a patch they had developed for an allergy test might actually be a safe and effective method to treat food allergies by inducing desensitization in allergic patients.
“Our main focus in developing Viaskin was to offer a treatment that could influence the immune system but wouldn’t require the patients to take any risk,” says Benhamou, a French physician specializing in pediatric gastroenterology.
Because the allergen is not ingested, the patch differs from other treatments for food allergy currently being studied, such as oral immunotherapy and sublingual immunotherapy.
When the patch, which contains small amounts of peanut protein, is placed on intact skin, it seals the area. Moisture then develops between the skin and the patch and the allergen enters the outer layer of the skin through the moisture, explains Hugh A. Sampson, MD, director of Jaffe Food Allergy Institute at Kravis Children’s Hospital at Mount Sinai Hospital in New York City. Sampson has been overseeing research at DBV Technologies as the chief scientific officer since November 2015.
The method targets Langerhans cells, specific skin cells that capture the antigen and transport it to the lymph nodes. This activates the immune system without the allergen passing into the bloodstream, says Sampson. The cells educate other cells, which then desensitize and, in principle, create more permanent tolerance throughout the body. When this happens, the immunoglobulin E (IgE) level to peanut starts to go down and there’s an increase in the levels of IgG4, the antibody associated with protection following immunotherapy, he explains.
Wong’s son began his participation in the peanut patch trial with an oral food challenge. This test, which involves eating small but escalating amounts of a food allergen under careful medical supervision, had two purposes. First, it confirmed the boy’s peanut allergy. Second, it determined his baseline level of reactivity (i.e., how little peanut would trigger an allergic response). During his three years in the trial, the youngster underwent a peanut challenge each year to determine any change in his reaction threshold.
Each day during the trial, Wong’s son removed the patch before showering and applied a new one afterward. Although the patch can be worn on the arm, the boy wore it on his back where it was less itchy for him. (The patch can be itchy. Younger kids are instructed to wear it on their backs so they won’t scratch or accidentally remove it.)
Initially, the boy reacted to 1 milligram of peanut protein (similar to the size of a grain of sand). By December 2015 when the trial ended, he tolerated the equivalent of about two peanuts, only reacting when given the equivalent of an additional four peanuts or 1 gram.
Wong’s son wasn’t alone in making big gains. After one year in the study, half the kids tolerated at least 1 gram of peanut or at least 10 times the amount they initially tolerated*. After two years, about 80 percent tolerated that amount.
In December 2015, DBV Technologies announced the launch of a Phase III study of the Viaskin peanut patch. It will treat over 300 peanut-allergic children, ages 4 to 11, aiming to further confirm the patch’s effectiveness.
When will Viaskin treatment for peanut allergy be available on the market? It’s too early to tell, says Benhamou. “We’re committed to bringing it forward as soon as possible and as safely as possible.”
Wong says her son now has a sense of freedom from his peanut allergy. He feels safer and worries less about reacting to traces of peanuts in the air or in food. However, he still avoids peanuts and continues to carry epinephrine with him at all times.
It’s too early to know how long tolerance to peanuts is sustained or the best practices for maintaining that tolerance, such as whether patients must eat peanuts regularly or continue wearing the patch on a daily basis, says Sampson. Studies with mice showed that when treatment was stopped and the mice were re-challenged (i.e., they ate peanuts), they didn’t react. This suggests that a different type of cell is activated through the skin as opposed to the gut, Sampson explains.
“We really want to bring hope to the families who are navigating these allergies,” says Benhamou. “And we’re getting closer every day.”
Health correspondent Wendy Mondello lives in New York.