Alleviation of allergic rhinoconjunctivitis symptoms in participants treated with a 0.005% tacrolimus eye drop solution

Abstract Purpose This randomized, placebo-controlled, crossover, double-blind, single site trial was aimed to evaluate efficacy and safety of Tacrosolv, a novel eye drop solution containing solubilized tacrolimus, in adult participants with grass pollen induced allergic conjunctivitis. Methods 64 adult participants with proven grass pollen allergy were randomized to either 2.5 µg or 5 µg tacrolimus/eye/day or placebo treatment for 8 days. Allergic symptoms were induced by 4h grass pollen exposure on day 1 and day 8. After a 2-week wash-out period, placebo participants crossed over to high or low dose and vice versa, and repeated treatment and exposure. During exposure, participants recorded ocular, nasal and respiratory allergy symptoms every 15 minutes. The primary endpoint was the mean ‘Total Ocular Symptom Score’ (TOSS) on Day 8. Objective ocular safety parameters were assessed before, during and after exposure. Adverse events (AEs) were recorded throughout the study. Results On Day 8, TOSS was reduced towards the end of exposure in participants receiving Tacrosolv high dose compared to placebo (p<0.05 at timepoints 3h45min and 4h). Accordingly, intensity of the single ocular symptoms like redness and watery eyes was reduced versus placebo by end of exposure on Day 8. A 26% reduction of baseline adjusted TOSS from day 1 to day 8 was observed in participants treated with high dose Tacrosolv, whereas placebo treated participants showed no difference in TOSS between day 1 and day 8. Interestingly, a significant reduction of total nasal symptoms, mainly itching and sneezing, was seen both on day 1 and day 8 in participants treated with high dose Tacrosolv (p<0.05). No safety concerns were raised upon ocular assessments by the investigator like redness of the eye, corneal and conjunctival staining. All AEs were resolved within the study period. Conclusion Treatment with Tacrosolv at the dose and frequency studied is safe and alleviates symptoms in participants suffering from allergic rhinoconjunctivitis. Trial registration NCT04532710; EudraCT No. 2019-002847-62