Real-World Data Support Effectiveness of Neffy (epinephrine nasal spray) for Acute Treatment of Anaphylaxis

A real-world study evaluating the efficacy of neffy (epinephrine nasal spray) for treatment of acute anaphylaxis found the novel delivery mechanism achieved rapid symptom resolution for nearly 90% (89.2%) of participants treated during oral food challenge or allergen immunotherapy, with no need for a second dose.1

The study is the first large-scale analysis of treatment outcomes with epinephrine nasal spray during routine clinical practice, according to developer ARS Pharmaceuticals. The findings were accepted in August for publication in the Annals of Allergy, Asthma and Immunology.1

Neffy was approved by the FDA in August 2024 as the first needle-free epinephrine product in the US indicated for emergency treatment of type 1 allergic reactions, including anaphylaxis.2 neffy was designed to overcome barriers associated with epinephrine autoinjectors including needle phobia, parental fear of using the current standard of care administration method, and errors when using the device, ARS has stated.2

The results of this study are a near perfect match with findings from meta-analyses in which a similar proportion of patients (88.9%) were treated successfully with a single dose of epinephrine delivered via autoinjector or intramuscular injection by a health care professional for food-induced anaphylaxis.3

Confirmation of Clinical Interchangeability

“The finding that about 9 out of every 10 patients were successfully treated with a single dose of neffy in more than 500 patients is essentially identical to the historic response rates observed with epinephrine injection,” Thomas B. Casale, MD, professor of medicine and pediatrics and chief of clinical and translational research at the USF Health Morsani College of Medicine at the University of South Florida, said in a statement.1 “We believe these real-world outcomes data support the clinical interchangeability of neffy and epinephrine injection, building on the clinical studies conducted for FDA approval that showed neffy achieved blood levels and pharmacodynamic responses within the range of approved injection products.”1

neffy Experience Program

The real-world retrospective observational analysis used data collected from 301 US healthcare professionals participating in the neffy experience program who reported outcomes for 545 patients who received neffy for acute anaphylaxis symptoms during clinical procedures.1 As participants in the program, clinicians received 6 doses of neffy to be used as rescue therapy for anaphylactic reactions during oral food challenge and allergen immunotherapy. The data reported by ARS reflect collection through the cutoff date of March 2025. The program remains active and participants now have access to both the 2 mg and 1 mg doses of epinephrine nasal spray, according to the ARS statement.1

The new real-world outcomes build on previously published clinical studies, including a phase 3 prospective trial in which all 15 participants undergoing oral food challenge responded to neffy, with no need for second doses to control an initial reaction.4 The initial indication in 2024 for use of epinephrine nasal spray 2 mg in children weighing at least 66 lbs was expanded on March 5, 2025, to include a 1 mg dose for children aged 4 years and older weighing at least 33 lbs.3

Clinical Implications

Anaphylaxis is a rapid-onset, potentially life-threatening systemic allergic reaction requiring prompt epinephrine therapy. Limitations of traditional approaches, including needle anxiety, device complexity, and inconsistent carrying or administration of autoinjectors, contribute to undertreatment in emergencies, ARS stated. Further the company cites data revealing that in 2023, only 3.2 million out of an estimated 20 million Americans at risk filled an active autoinjector prescription, and fewer than half consistently carried the device. Among those who did, more than half delayed or omitted administration in actual emergencies.1

neffy prescribing information recommends that a second dose may be administered in the same nostril starting 5 minutes after the first if symptoms persist or worsen.5 Users should always carry 2 neffy sprays to ensure preparedness for potential recurrence or inadequate initial response.5

References

1. ARS Pharmaceuticals announces real-world evidence of neffy (epinephrine nasal spray) effectiveness in patients experiencing anaphylaxis symptoms. News release. ARS Pharmaceuticals, Inc. September 8, 2025. Accessed September 15, 2025. https://ir.ars-pharma.com/news-releases/news-release-details/real-world-evidence-supports-clinical-effectiveness-neffyr

2. Halsey G. FDA approves first intranasal epinephrine for emergency treatment of allergic reactions. Patient Care. August 9, 2024. https://www.patientcareonline.com/view/fda-approves-first-intranasal-epinephrine-for-emergency-treatment-of-allergic-reactions

3. Patel N, Chong KW, Yip AYG, et al. Use of multiple epinephrine doses in anaphylaxis: a systematic review and meta-analysis. J Allergy Clin Immunol. 2021;148(5):1307-1315. doi:10.1016/j.jaci.2021.03.042

4. Ebisawa M, Takahashi K, Takahashi KK, et al. Epinephrine nasal spray improves allergic symptoms in patients undergoing oral food challenge, phase 3 trial. J Allergy Clin Immunol. 2025; doi:10.1016/j.jaip.2025.06.038

5. neffy. Prescribing information. ARS Pharmaceuticals; 2025. Accessed September 15, 2025. https://www.ars-pharma.com/wp-content/uploads/pdf/Prescribing_Information.pdf