Abstract
Purpose:
: In this phase 3, multicenter, vehicle-controlled, double-blinded, randomized trial we evaluated the onset and duration of action of topical cetirizine 0.24% using the conjunctival allergen challenge model of allergic conjunctivitis.
Methods:
The trial (NCT01881113) was conducted between June and September of 2013, and enrolled a total of 101 subjects; this number constituted the intent-to-treat and safety populations, while the per-protocol population included 87 subjects. Qualified subjects exhibited reproducible allergic responses to bilateral instillation of allergen. Following randomization, they were challenged with allergen on 2 separate visits, 15 minutes or 8 hours after receiving bilateral instillation of test compound or vehicle. Primary efficacy measures were ocular itching scores (at 3, 5, and 7 minutes post-challenge) and ocular hyperemia (at 7, 15, and 20 minutes post-challenge). Secondary endpoints included ciliary and episcleral redness, chemosis, eyelid swelling, and ear/palate pruritis; each of these were scored at 7, 15, and 20 minutes post challenge.
Results:
For the primary endpoint of ocular itching, Cetirizine was statistically superior to vehicle for the onset of action (challenge 15 minutes post-instillation; p < 0.0001) at all measured time points; the drug was also statistically superior to vehicle 8 hours after instillation (p < 0.0001). In a subgroup analysis, the drug exhibited highest efficacy in those subjects with the most severe baseline itch scores. Cetirizine was superior to vehicle for all secondary endpoints, including all measures of hyperemia. Of particular note, drug treatments were statistically superior to vehicle for prevention of eyelid swelling and ear/palate pruritis at all measured time points (p< 0.001), suggesting a unique spectrum of efficacy. The study drug was safe and well tolerated; no subjects withdrew from the study due to any adverse event.
Conclusions:
Cetirizine is one of the most commonly used oral agents for treatment of allergic rhinitis, but its re-formulation for topical use in treatment of allergic conjunctivitis is novel. This study demonstrates the efficacy of the drug for prevention of ocular itching associated with allergic conjunctivitis, and also establishes its unique spectrum of action against other allergic symptoms.
Keywords: 475 conjunctivitis •
557 inflammation •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials