A Phase 1 Research Trial to Evaluate the Safety and Effectiveness of Intranasal Botulinum Toxin Type A Spray for Patients With Rhinitis.

[BACKGROUND] Botulinum toxin type A is a potent neurotoxin and was first approved for use in 1989; since there has been a surge in its uses. The latest international trend is the unapproved use of botulinum toxin for allergic and nonallergic rhinitis, being advertised as "Haytox."

[METHODS] A single-group open-label non-randomized Phase 1 clinical trial was completed. Rhinitis and nonallergic rhinitis were confirmed via formalized examination and testing with total IgE and radioallergosorbent test (RAST). Participants received 40 units of botulinum toxin type A, administered topically intranasally, 20 units per nostril, using the LMA MAD Nasal Intranasal Mucosal Atomization Device. Safety of the intervention was assessed with adverse event tracking logs. Symptom scores were used to assess symptom reduction, including total nasal symptom score (TNSS), visual analog scale (VAS) measurements at Weeks 0, 2, 4, and 12. In addition, peak nasal inspiratory flow (PNIF) was measured at Weeks 0 and 4, with the minimum clinically important difference (MCID) being used to demonstrate any clinically significant change in the TNSS score.

[RESULTS] A TOTAL OF: 15 participants enrolled, of which 14 participants received treatment, with no serious adverse or related adverse events reported. There was a statistically and clinically significant reduction in TNSS and a statistically significant reduction in VAS from Weeks 0 to 12.

[CONCLUSION] In this Phase 1 trial, topical application of botulinum toxin via spray was shown to be safe, without any significant adverse events. It reduced the TNSS and VAS across the cohort. However, the treatment efficacy should be taken in context as there was no blinding, alternative dosing, or comparison against placebo or recognized active treatment options. This safety data should embolden future research trials.

[TRIAL REGISTRATION] TGA number: CT-2024-CTN-02905-1; ANZCTR number: ACTRN12624000772549.