Abstract
Purpose :
A clinical trial was conducted with an antihistamine (ketotifen) and contact lens (CL) combination product (K-Lens) to evaluate the reduction of itch from two concentrations of ketotifen: 8 micrograms (K-Lens 8) and 19 micrograms (K-Lens 19) as compared to a control (non-medicated) contact lens.
Methods :
Itch reduction was evaluated using the Conjunctival Allergen Challenge (CAC) model. After confirming a bilateral CAC reaction, qualifying CL wearing subjects were randomized by eye to receive either K-Lens 8 or K-Lens 19 or placebo CL in each eye. They were then challenged, at separate visits, after 8 hours and 12 hours of lens wear. Post-CAC ocular itching was reported by the subject at three timepoints (3, 5, and 7 minutes post-challenge) using a validated 9-point (0-4 in 0.5 units) grading scale. The primary analysis compared the scores between the treated and placebo eyes for contralateral eye subjects using a Wilcoxon Sign Rank test for paired observations at each timepoint. In addition, ocular itching data from contralateral and parallel groups were pooled resulting in mean scores that were analyzed as three treatment groups: K-Lens 8, K-Lens 19 and placebo. The mean scores were compared at each post-CAC timepoint using the Wilcoxon Sign Rank test. All statistical tests were conducted at the two-sided, 5% significance level.
Any observed or reported adverse events were also recorded during the conduct of this trial.
Results :
Eighty subjects were enrolled. In the contralateral treatment groups, the mean ocular itching difference scores for K-Lens 19 versus placebo were clinically significant (≥ 1.0 units) after 8 and 12 hours. Additionally, the mean ocular itching scores for both K-Lens 8 and K-Lens 19 versus placebo were statistically significant (p=0.003 or less) at all timepoints after 8 and 12 hours of wear.
In the pooled treatment groups, both K-Lens 8 and K-Lens 19 demonstrated statistically significant reduction (p<0.001) in ocular itching as compared to placebo at all timepoints after 8 and 12 hours of wear.
Twenty ocular adverse events were reported during K-Lens wear while 13 adverse events were reported during placebo lens wear. All adverse events were self-limiting, mild in severity, and resolved without treatment.
Conclusions :
Ketotifen-releasing contact lenses reduced ocular itching symptoms in habitual contact lens wearers during a Conjunctival Allergen Challenge.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.