An estimated 1.5 million children in the US are allergic to peanuts, an allergy that can cause drastic consequences if the nuts are ingested.

To counter that extreme reaction, researchers are working on a patch that works to lessen that severity. And it's just become the first of its kind to enter phase 3 clinical trials, the last human trial needed before the US FDA gets a chance to evaluate and (hopefully for the company) approve it.

DBV Technologies, the French biotechnology company behind the patch, calls the approach to treating severe allergies an "epicutaneous immunotherapy," which means the immune-system-targeting drug is delivered through the skin. DBV is the first company to use this technology.

Inside each patch is a sprayed-on sample of peanut protein. Once you put it on, the protein makes its way into your immune system through your skin. Since it's delivered this way, the allergen never makes it to the blood stream, which would cause the allergic reaction you're trying to avoid. Ideally, when worn daily for a year or so, the patch makes it possible for people with peanut allergies to consume a small amount of peanuts, according to David Schilansky, the company's chief operating officer.

For example, if someone who started using the patch initially couldn't tolerate eating 1/10th of one whole peanut, they could ideally eat roughly a handful of peanuts without any reaction after a few years of daily use (the exact timeline for the patch to take effect is still being pinned down, says Schilansky).

Still, a small improvement could make a big difference. "When you cannot afford more than a 10th of a peanut that's really progress," Schilansky told Business Insider.

That's very different from the way allergies are typically treated in practice: Before this immunotherapy method, the only way to lessen an allergic reaction was through 'desensitisation', a process in which you gradually introduce small amounts of the allergen into your body, in the case of peanut allergies, by eating the peanut outright.

The problem with this method is that it can be very risky since it can cause an allergic reaction that spreads throughout the body via the blood stream. Other, more common methods, for treating allergies have been focused around treating the symptoms of the allergic reaction, ie. using antihistamines like Benadryl or shots of epinephrine in extreme cases.

What causes allergies?

Allergies are your immune system's response to a substance that may not be harmful to others. They're the sixth leading cause of chronic disease in the US. According to the CDC, an estimated 4 to 6 percent of children in the US have food allergies, with peanuts being one of the worst offenders.

The patch is being studied for its effects on children aged four to 11 who can benefit the most from having less severe allergies.

Allergies can be constant and life-threatening, Schilansky said. With children, the problem can be even scarier. Schilansky said that the peace of mind that comes with knowing your child won't have an extreme allergic reaction is what DBV's Viaskin is all about.

"This is a new method of immunotherapy," Pierre-Henri Benhamou, DBV's CEO, told Business Insider, which means there will be a lot of room to expand. Up next, Benhamou said the company is continuing research on using the patch for other food allergies such as milk and eggs - among the most common food allergies - and other non-food allergies that are connected to asthma. And after that, DBV plans to explore allergy vaccines that would ideally keep allergies from happening.

The Phase 3 trial, which will set DBV up for the FDA to decide whether it wants to approve the patch, is taking place in five different countries, and DBV plans to enroll more than 330 children.

This article was originally published by Business Insider.