Efficacy and Safety of a Drug-Free, Barrier-Forming Nasal Spray for Allergic Rhinitis: Randomized, Open-Label, Crossover Noninferiority Trial

Abstract

<b><i>Introduction:</i></b> Symptoms of allergic rhinitis can be reduced by nonpharmacological nasal sprays that create a barrier between allergens and the nasal mucosa. A new nasal spray (AM-301) containing the clay mineral bentonite was tested for its ability to reduce symptoms of grass pollen. <b><i>Methods:</i></b> This open-label, crossover, noninferiority trial compared the efficacy and safety of AM-301 to that of hydroxypropyl methylcellulose (HPMC; Nasaleze® Allergy Blocker), an established barrier method. Adults with seasonal allergic rhinitis were exposed to <i>Dactylis glomerata</i> pollen, in a controlled setting, the Fraunhofer allergen challenge chamber, first without protection and then protected by HPMC or AM-301 (7 days apart). Efficacy was assessed from total nasal symptom score (TNSS), nasal secretion weight, and subjective rating. The primary endpoint was the difference, between AM-301 and HPMC, in least square mean change in TNSS over a 4-h exposure to allergen. <b><i>Results:</i></b> The study enrolled 36 persons, and 35 completed all study visits. The mean TNSS was 5.91 (SD = 1.45) during unprotected exposure, 5.20 (SD = 1.70) during protection with HPMC, and 4.82 (SD = 1.74) during protection with AM-301. The difference in least square means between the two treatments was −0.39 (95% CI: −0.89 to 0.10), establishing the noninferiority of AM-301. No difference in mean weight of nasal secretions was observed between the treatments. Efficacy was rated as good or very good for AM-301 by 31% and for HPMC by 14% of subjects. Sixteen subjects reported adverse events with a relationship to AM-301 or HPMC; most adverse events were mild, and none was serious. <b><i>Discussion/Conclusion:</i></b> AM-301 demonstrated noninferiority toward HPMC in the primary endpoint and was perceived better in subjective secondary endpoints. Both barrier-forming products had a persisting protective effect over 4 h and were safe.

Barrier‐forming, drug‐free nasal spray reduces allergic symptoms induced by house dust mite allergen

“…The favorable safety and tolerability profile of AM-301 reported before 21,22 was confirmed in this study. Both subjects and investigator rated global tolerability as "very good" or "good" in >80% of cases, irrespective of the number of sprays.…”

“…21 In an earlier clinical study, AM-301 was efficacious in reducing symptoms to at least the same extent as the comparator (cellulose powder) during controlled exposure to grass pollen in Allergen Exposure Chamber (AEC), while showing a faster onset of action. 22 In the present study, the efficacy of the AM-301 device in patients with another allergy (HDM-related Perennial Allergic Rhinitis (PAR)) was also assessed in an AEC in a randomized, 3-period crossover design. The prevalence of HDM allergy is also high with 60 to 130 million persons worldwide.…”

“…In an earlier clinical study, AM‐301 was efficacious in reducing symptoms to at least the same extent as the comparator (cellulose powder) during controlled exposure to grass pollen in Allergen Exposure Chamber (AEC), while showing a faster onset of action 22 …”

Carrageenan-Containing Nasal Spray Alleviates Allergic Symptoms in Participants with Grass Pollen Allergy: A Randomized, Controlled, Crossover Clinical Trial

“…Other barrier-forming nasal sprays that prevent allergen contact are currently on the market or under development for the treatment of AR. Tested substances include cellulose derivatives, 22 clay mineral bentonite, 23 thixotropic gel, 24 petrolatum-based ointment, 25 and lipid-based ointment. 26 Of these, a hydroxypropyl methylcellulose powder (HPMC) nasal spray on sale since 1994 has been backed up by over 20 clinical studies.…”

Carrageenan-containing nasal spray alleviates allergic symptoms in subjects with grass pollen allergy: A randomized, controlled, crossover clinical trial

“…Other barrier-forming nasal sprays that prevent allergen contact are currently on the market or under development for the treatment of AR. Tested substances include cellulose derivatives 11 , clay mineral bentonite 12 , thixotropic gel 13 , petrolatum-based ointment 14 , and lipid-based ointment. 15 Of these, a hydroxypropyl methylcellulose powder (Nasaleze ® ), on sale since 1994, has been backed up by over 20 clinical studies.…”