Updated July 18, 2025: The nasal epinephrine sprayer neffy quickly reversed moderate anaphylaxis in children undergoing food allergy challenges, a new study finds.
The children, ages 6 to 17, were taking part in oral food challenges to allergenic foods such as egg, milk, peanut, wheat and walnut under medical supervision in Japan. During these tests, children eat their allergen in gradually increasing amounts to determine how much they can tolerate.
Fifteen children experienced moderate anaphylaxis. The children’s symptoms included widespread hives, mouth swelling, abdominal pain, nausea, and wheezing.
Each child was treated with a single dose of neffy. On average, symptoms fully resolved within 16 minutes in all children. None needed a second dose to stop the initial reaction.
However, one 14-year-old boy went on to develop a biphasic reaction, meaning his symptoms returned hours later. That child was treated with a second dose of epinephrine, administered by injection, and recovered.
Dr. Jay Lieberman, a study co-author, says the findings should help patients and physicians feel comfortable in using neffy as an alternative to epinephrine auto-injectors in allergic emergencies. Lieberman is a professor of pediatrics at the University of Tennessee Health Science Center in Memphis.
“This gives more evidence that neffy works in a clinical setting, so patients and physicians can feel more confident using it,” the allergist-immunologist says.
What makes this study unique is that it’s one of the first “prospective” studies on using epinephrine during anaphylaxis, Lieberman says. Prospective means that researchers planned in advance to administer epinephrine during an allergic reaction and monitored symptom improvement in real time.
Most epinephrine studies are retrospective and look back at what happened after the fact. “In that regard, this a great study,” Lieberman says. He adds that no equivalent prospective studies have been done using auto-injectors or epinephrine delivered with a needle and syringe.
EURneffy Approved in U.K.
Neffy is the first needle-free treatment approved by the Food and Drug Administration for severe allergic reactions. The 2 milligram dose for adults and children weighing at least 66 pounds was approved in August 2024. A 1 mg dose for children as young as 4 years old and weighing 30 to 66 pounds was approved in March 2025.
Then on July 18, 2025, the United Kingdom’s Medicines and Healthcare Products Regulatory Agency approved the nasal spray device (called EURneffy) for the emergency treatment of serious allergic reactions in those weighing more than 30 kilograms (66 pounds). The European Commission previously authorized the EURneffy in 2024.
In the U.K. and Europe, pharmaceutical company ALK-Abelló A/S will be handling the commercialization of the epinephrine spray.
Studies Vs. Injector or Syringe
For safety reasons, clinical trials directly assessing epinephrine products are done in healthy volunteers, not in people experiencing anaphylaxis. These trials measure effectiveness by tracking increases in heart rate and blood pressure. These are indicators that epinephrine is being absorbed.
Across clinical trials, more than 700 children and adults have received neffy. These studies found comparable increases in heart rate and blood pressure among neffy, epinephrine given via auto-injectors and needle and syringe.
Neffy has also been tested in people with stuffy, runny noses due to colds or seasonal allergies. Those studies found nasal congestion does not interfere with nasal absorption.
Big Real-World Study Coming
More prospective data is on the way. ARS Pharmaceuticals, neffy’s manufacturer, has launched a larger study that aims to enroll 600 participants undergoing food challenges at 15 sites. If they experience anaphylaxis during a challenge, patients will receive either neffy or a dose of epinephrine by injection.
Physicians won’t know which treatment a patient is assigned to receive until the reaction occurs. The FDA requested this design to prevent any potential bias in whether a patient is given the nasal spray or injection based on symptom severity, explains Richard Lowenthal, ARS Pharma’s president and CEO. If a second dose is required, it will be the same type as the first.
The FDA requested the post-approval study to gather safety data in patients experiencing anaphylaxis, says Lowenthal. For the approval submission, “all of our safety data was in people who were relatively healthy, not having an allergic reaction.”
Lowenthal notes that people having anaphylaxis may experience fewer side effects than healthy volunteers. “With anaphylaxis, their whole throat could be closing up. They are experiencing really serious symptoms. They might not mention a tingle in their throat,” he says.
“That’s what FDA wants to know. Are there new things that might happen, and what is the true safety profile in a real-world situation? That will inform labeling.”
The study will also track how long symptoms take to resolve and how many need a second dose. The study will be the first randomized, prospective study comparing two different methods of epinephrine in people experiencing anaphylaxis, as opposed to healthy volunteers. Lowenthal says that also means it will the first time the FDA receives such head-to-head data.
Neffy in Children Findings
Children in the Japanese study were treated with either the 1 mg dose or 2 mg neffy dose, depending on their weight. Nearly all kids began showing improvement in their symptoms within five minutes.
Seven children were also given additional treatments, such as antihistamines, bronchodilators for wheezing, mast cell stabilizers, steroids, oxygen or cooling to relieve itching.
Reported side effects were mild to moderate in the study, published in the Journal of Allergy and Clinical Immunology: In Practice. Shakiness and nasal redness or irritation were the most common.
The study’s authors concluded that “the availability of a needle-free epinephrine delivery device may reduce dosing hesitancy, particularly in patients who are fearful of injections.”
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