Epinephrine Nasal Spray Shows Comparable Efficacy to Injection, With Thomas Casale, MD

ARS Pharmaceuticals recently reported that epinephrine nasal spray (neffy) performed as effectively as epinephrine injections in treating anaphylaxis during routine clinical practice.1,2 Findings from this large-scale real-world analysis will be published later this year in Annals of Allergy, Asthma, and Immunology, the official journal of the American College of Allergy, Asthma, and Immunology.

The company announced that the epinephrine nasal spray successfully treated about 9 out of 10 patients. A single 2 mg dose successfully treated 486 patients, with 59 patients requiring a second dose.

This finding was identical to the historic response rate found with epinephrine injection. Compared to the epinephrine injection’s 88.9% success rate, a single dose of epinephrine nasal spray resulted in an 89.2% success rate.

HCPLive spoke with investigator Thomas B. Casale, professor of Medicine and Pediatrics and chief of Clinical and Translational Research in the USF Health Morsani College of Medicine at the University of South Florida, about what this means for allergists.

“[The biggest benefit [of this study] is even though neffy, through a number of…trials to get FDA approval, show equivalent levels of epinephrine in the blood and relevant PD changes—that is, changes in pulse rate and blood pressure—a lot of physicians want to make sure: does it really work? And I think this study is very important in showing that it did,” Casale said. “Before this, there [were] only a couple of small clinical studies. One was 15 patients doing oral food challenges that showed that [epinephrine nasal spray] treated them successfully.”

The US Food and Drug Administration (FDA) approved epinephrine nasal spray, marketed as neffy, for type 1 allergic reactions in adults and children aged ≥ 4 years who weigh > 33 lbs. The approval opened a new anaphylaxis treatment for patients who fear needles or experience portability issues.

Many patients delayed or avoided auto-injectors due to their fears. In 2023, of the 20 million patients treated for severe reactions, only 3.2 million filled an auto-injector prescription, and half consistently carried it. Now, seen with this large analysis, epinephrine nasal spray not only eliminates many patients' fears but is as effective as having an injection.

“We know from a number of pieces of data that about 90% of patients get better with a single dose of epinephrine, and of the 10% that need a second dose, more than half of those get better with the second dose,” Casale said. “These data show that the numbers were very similar, and that with the first dose of neffy, 90% of patients got better when they had signs and symptoms of anaphylaxis. So again, very reassuring that have performed similar to what we've seen and noted with injectable epinephrine.”

References

1. Real-World Evidence Supports Clinical Effectiveness of neffy® (epinephrine nasal spray) in Patients Experiencing Anaphylaxis - ARS Pharmaceuticals. ARS Pharmaceuticals. Published 2025. Accessed September 12, 2025. https://ir.ars-pharma.com/news-releases/news-release-details/real-world-evidence-supports-clinical-effectiveness-neffyr

2. Derman, C. Epinephrine Nasal Spray as Effective as Injection for Anaphylaxis in Real-World Data. HCPLive. September 12, 2025. https://www.hcplive.com/view/epinephrine-nasal-spray-effective-as-injection-anaphylaxis-real-world-data. Accessed September 15, 2025.