Abstract
Purpose :
The randomized double-blinded, placebo-controlled crossover trial was conducted to evaluate the treatment efficacy of a novel eye drop solution containing solubilized tacrolimus on allergy symptoms.
Methods :
Adult subjects with clinically proven grass pollen allergy were allocated to either 5µg tacrolimus/eye (two drops/eye/day; N=32) or 2.5µg tacrolimus/eye (one drop/eye/day; N=32) and the respective placebo, for 8 days. Allergy symptoms were induced by 4h grass pollen challenges in the Vienna Challenge Chamber on day 1 and day 8. Subjects recorded ocular and nasal allergy symptoms every 15 minutes during the challenges. Primary endpoint was the mean total ocular symptom score (= TOSS; sum of itchy eye, redness, watery eye and gritty feeling assessed on a categorical scale from 0 to 3) between 0 and 4h of the allergen challenge on day 8. Secondary endpoint was the Total Nasal Symptom Score (=TNSS; sum of itchy nose, runny nose, sneezing, nasal congestions). First dose was applied 30 min before subjects underwent grass pollen challenge on day 1. From day 2 to day 7 subjects applied the respective eye drop dosages once a day in the morning. On day 8 last treatment was taken 30 minutes before entering the challenge chamber.
Results :
Although no statistical difference in mean TOSS calculated from 0-4h during the grass pollen challenge was found, the 5µg group showed lower values compared to placebo starting at 2h, which differed significantly after 3.5h (p<0.05). Accordingly, intensity of the main single ocular symptoms (itchy eyes, redness, watery eyes) started to separate after 2 – 2.5h. Reduction of redness was significantly reduced compared to placebo treatment after 3.5h of the challenge (p<0.05).
A 26% reduction of baseline adjusted TOSS from day 1 to day 8 was observed in subjects treated with 5µg tacrolimus whereas placebo treated subjects showed no difference.
Interestingly, a significant reduction of total nasal symptoms, mainly itching and sneezing, was seen on day 1 and day 8 in subjects treated with 5µg tacrolimus (p<0.05) only.
Lower dose of tacrolimus (2.5µg/eye/day) had no effect on nasal symptoms.
Conclusions :
Anti-inflammatory activity of solubilized tacrolimus was observed in subjects suffering from rhinoconjunctivitis at doses as low as 5µg tacrolimus/eye/day.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.