AM‐301, a barrier‐forming nasal spray, versus saline spray in seasonal allergic rhinitis: A randomized clinical trial

Abstract Rationale Saline nasal sprays are frequently used in the management of seasonal allergic rhinitis (SAR) for the cleansing and clearing of aeroallergens from the nasal cavity. Also using a drug‐free approach, AM‐301 nasal spray is forming a thin film barrier on the nasal mucosa to prevent contact with allergens, trap them, and facilitate their discharge. A clinical trial compared the efficacy, safety, and tolerability of AM‐301 and saline spray in SAR. Methods A total of 100 patients were randomized 1:1 to self‐administer AM‐301 or saline 3 × daily for 2 weeks. Primary efficacy endpoint: reduction in mean daily reflective Total Nasal Symptom Score (rTNSS). Secondary efficacy endpoints: reduction in mean instantaneous TNSS and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), global impression of efficacy. Safety and tolerability: adverse events, relief medication use, symptom‐free days, global impression of tolerability. Results AM‐301‐treated patients achieved a significantly lower rTNSS than the saline group (LS square means difference −1.1, 95% CI −1.959 to −0.241, p = .013) with improvement observed across all individual nasal symptoms. Likewise, all secondary endpoints showed statistical significance in favor of AM‐301; for example, quality of life was significantly improved overall ( p < .001) as well as for each individual RQLQ domain. Both treatments showed similarly good safety and tolerability. With AM‐301, fewer patients used relief medication and more enjoyed symptom‐free days compared to saline treatment. Conclusions AM‐301 was more effective than saline in improving SAR nasal symptoms and related quality of life while offering similar tolerability, demonstrating the benefits of a barrier approach.