Parents of kids with peanut allergies worry about school and sleepovers. A new drug therapy may offer peace of mind.

Five-year-old Claire Mancuso smiled and threw her arms in the air after finishing a course of medicine that has set her on a path to freedom from her debilitating peanut allergy.

The new drug, Palforzia, was approved by the U.S. Food and Drug Administration earlier this year, and Claire is the first patient in San Antonio to to complete a key phase of the treatment that will help her develop a low-level tolerance to the food, said her doctor, Dr. Lukena Karkhanis at AllergySA.

Palforzia is an oral immunotherapy drug that is essentially just ground-up peanut powder, mixed into food and delivered in precise, timed doses, in a clinical setting under medical supervision. Karkhanis said the medicine works by delivering gradually larger doses to the patient over a space of about six months, with the goal of getting a patient able to tolerate a dose of 300 milligrams of peanut powder, which is equal to about half of a typical peanut. This is the build-up phase that Claire completed Monday.

“It’s meant to decrease the risk of severe or fatal reactions,” Karkhanis said. “[Patients are] not supposed to eat peanuts outside of their daily Palforzia dose. They still avoid it, they still keep an EpiPen on hand, but it’s supposed to take away the worry that comes with birthday parties and potlucks and school and sleepovers.” 

According to statistics from the FDA, peanut allergies affect about 1 million children in the U.S., and only one in five children outgrow that allergy.

Claire can’t remember the first time she had a bad reaction to peanuts because she was only 18 months old, but her physician mom, Lauren Tarbox, will never forget the traumatic moment. 

After eating a piece of peanut butter candy during a New Year’s celebration, Claire broke out in hives and then began vomiting, and when she began wheezing her parents rushed her to the emergency room.

“That’s when we figured out that we had to be very careful,” Tarbox said. “We went home and we took everything peanut out of the house, even things that may have been in a peanut factory, like Goldfish [crackers].”

Claire is a kindergartner this year at St. Luke’s Episcopal School, where teachers are on guard about her allergy, an EpiPen is always close by, and Claire knows the one question she always has to ask before eating anything: “Does this have peanuts in it?”

With vigilant parents, Claire hasn’t had any bad reactions since that initial episode, but Tarbox said she has lived in constant fear of forgetting to check an ingredients list or unknowingly eating at a restaurant that uses peanut oil. She knew she didn’t want Claire to bear that burden for the rest of her life, so when Karkhanis told her about Palforzia she was eager to get her daughter started on the new medicine. 

“The main reason we wanted to do this was not so much for 5-year-old Claire but for 20-year-old Claire, so that that Claire doesn’t have to be constantly afraid,” Tarbox said.

If a patient can build up a tolerance to small amounts of peanut powder, it gives them time to realize that they are consuming peanuts and stop before ingesting a dangerous amount, Karkhanis said. In a typical situation when a patient has an allergic reaction to peanuts, they have already consumed so many milligrams of the allergen that by the time they realize it, the allergic response often becomes life-threatening, she said.

Studies conducted before the drug was approved by the FDA showed that after patients stayed on the 300 milligram dose for 12 to 18 months, most could tolerate consuming three to four peanuts with mild to no reaction, Karkhanis said.

 A follow-up study showed that more than 80 percent of patients who took Palforzia for two years were able to tolerate as much as 2,000 milligrams of peanut powder, which is equal to about six whole peanuts.

“It’s just incredible,” Tarbox said of the drug’s longer-term effects. “That will keep her safe from taking one bite, realizing it and then not potentially dying, but getting to the help she needs. And that’s just two years from now. We don’t even know what it could be when she’s in college, 13 years from now. She could be completely immune to it.”

Claire Mancuso, 5, and mom Lauren Tarbox celebrate after Claire received her final build-up dose of a new medicine for people with severe peanut allergies. Credit: Jennifer Norris for the San Antonio Report

Karkhanis said while nothing is certain, there’s reason to hope people with severe peanut allergies can build up a tolerance to the allergen based on what studies have shown so far. 

“What we know right now is that they should continue to take [Palforzia] indefinitely,” Karkhanis said. “But studies are ongoing. Once the earliest volunteers have been on Palforzia for five, seven, 10 years, that recommendation might change, because we don’t know what exactly will happen to their bodies’ tolerance until we study it.”

Food allergies are on the rise in developed countries, Karkhanis said. While there are many theories as to why that’s happening, evidence shows that the best way to avoid developing food allergies is to carefully begin introducing babies as young as four months to the foods most likely to trigger allergic reactions. 

“If your child is not fed any peanuts for the first two years of their life, you may be increasing their risk of developing an allergic reaction to that peanut because their body didn’t see the peanut and learn that it’s a normal part of life when the immune system was just beginning to develop,” Karkhanis said.

For kids like Claire who have severe peanut allergies, the new drug therapy offers an opportunity for a more carefree existence. Claire showed how she felt about reaching the important milestone in her peanut allergy battle with lots of bright smiles and just one word: “happy.” She will remain at the maintenance level of 300 milligrams of peanut powder every day for the foreseeable future.

Tarbox said Claire did not experience any significant side affects while taking the medicine and believes that starting her on the therapy at such a young age could be part of the reason her body has responded so well.

Karkhanis said fewer than a hundred patients are currently on Palforzia worldwide but she hopes more will learn about the treatment and its life-changing possibilities.

“There is a big need for awareness about peanut allergies and Palforzia,” Karkhanis said. “Parents and children with food allergies are not aware that there is an option. There is an unmet need for this drug and it can really make a lot of people’s lives drastically easier.”

Jennifer Norris has been working in journalism since 2005. She's a native Texan, but a new San Antonian who is excited to get to know the city.