ARS Pharmaceuticals and Neffy: Assessing Transformative Potential in Chronic Rhinosinusitis Amid Evolving Allergy Therapies

The biopharmaceutical landscape for chronic rhinosinusitis (CRS) is undergoing a seismic shift, driven by breakthroughs in biologic therapies targeting inflammatory pathways. While ARS Pharmaceuticals' neffy (epinephrine nasal spray) has garnered attention as a needle-free alternative for anaphylaxis, its role in CRS remains unproven. This analysis evaluates neffy's potential in CRS against the backdrop of transformative biologics like tezepelumab and depemokimab, while dissecting ARS's strategic positioning in allergy care.

Neffy's Current Role: Anaphylaxis and Beyond

Neffy, ARS Pharmaceuticals' flagship product, has demonstrated robust clinical efficacy in treating anaphylaxis. Real-world data from 2025 show that 90% of patients experienced successful resolution of symptoms with a single dose, aligning with historical success rates for epinephrine injections ARS Pharmaceuticals Reports Second Quarter 2025 Financial Results^[1]. The product's pharmacokinetic (PK) and pharmacodynamic (PD) profiles are comparable to intramuscular epinephrine, with advantages for patients with higher body weight or BMI Development of neffy, an Epinephrine Nasal Spray, for Severe Allergic Reactions^[2]. By Q2 2025, neffy generated $12.8 million in U.S. net revenue, driven by expanded payor access and a national DTC campaign that boosted consumer awareness to 49% ARS Pharmaceuticals Files for Approval of neffy® in Canada and United Kingdom^[3].

However, neffy's label remains restricted to anaphylaxis and allergic reactions. Clinical trials and regulatory filings explicitly exclude CRS as an indication. A 2025 review of ARS's regulatory submissions confirmed that neffy is not being studied for CRS, with the company's focus instead on chronic urticaria and global expansion ARS Pharmaceuticals Highlights neffy Regulatory Progress^[4]. This raises a critical question: Can neffy's nasal delivery mechanism be repurposed for CRS, or does its future lie in addressing unmet needs in allergic emergencies?

The CRS Revolution: Biologics Outpacing Neffy

Chronic rhinosinusitis, a condition affecting millions globally, has seen paradigm-shifting advancements in 2025. The Phase 3 WAYPOINT study of tezepelumab, a monoclonal antibody targeting thymic stromal lymphopoietin (TSLP), demonstrated a 92% reduction in the need for nasal polyp surgery or corticosteroids in patients with severe CRS with nasal polyps (CRSwNP) #AAAAI2025: Must-know Updates in Chronic Rhinosinusitis^[5]. Similarly, depemokimab, an ultra-long-acting anti-IL-5 biologic, showed sustained improvements in nasal polyp scores over 52 weeks, with twice-yearly dosing #AAAAI2025: Must-know Updates in Chronic Rhinosinusitis^[5]. These therapies, alongside dupilumab for CRS without nasal polyps (CRSsNP), are redefining treatment paradigms and capturing significant market share.

For investors, the contrast is stark: while neffy excels in acute allergic emergencies, CRS biologics are engineered for chronic disease management. Neffy's nasal delivery mechanism, though innovative, lacks the targeted anti-inflammatory action required for CRS. This underscores a strategic gap for ARS Pharmaceuticals—if the company seeks to enter the CRS space, it would need to pivot toward biologic development, a costly and time-intensive endeavor.

Regulatory and Commercial Momentum for Neffy

ARS Pharmaceuticals has navigated regulatory hurdles to secure neffy's U.S. approval in November 2024 and expanded its global footprint to the UK and Germany under the EURneffy brand ARS Pharmaceuticals Reports Fourth Quarter and Full Year 2024 Financial Results^[6]. The company's $240.1 million cash reserves as of June 2025 provide flexibility for further commercialization and research ARS Pharmaceuticals Reports Fourth Quarter and Full Year 2024 Financial Results^[6]. Notably, neffy's pediatric approval for children aged four and older (finalized in March 2025) has broadened its market reach to 2 million at-risk patients ARS Pharmaceuticals Reports Second Quarter 2025 Financial Results^[1].

Yet, the company's pipeline beyond anaphylaxis is limited. While a Phase 2b trial for chronic urticaria is planned, neffy's potential in CRS remains speculative. This raises concerns about over-reliance on a single indication in a competitive allergy market.

Investment Implications

ARS Pharmaceuticals' stock has benefited from neffy's commercial success and favorable regulatory updates. However, the company's long-term growth hinges on diversifying its therapeutic portfolio. For CRS, the biologic landscape is dominated by established players like GSK (tezepelumab) and Amgen (depemokimab), leaving little room for neffy to disrupt.

Investors should prioritize ARS's near-term catalysts: the potential U.S. launch of neffy in H2 2024, expansion into international markets, and the Phase 2b urticaria trial. While neffy's transformative potential in CRS is unproven, its role in allergic emergencies is well-established. The key question is whether ARS can leverage its expertise in nasal delivery to innovate beyond anaphylaxis—or remain a niche player in a crowded allergy space.