Phase III studies
Participants in the phase III CAC studies had a history of allergic conjunctivitis. They were treated with vehicle or cetirizine, challenged with the allergen 15 minutes and 8 hours later, and evaluated for signs and symptoms of an allergic response at various intervals post-allergen challenge.
Ocular itching, the primary efficacy endpoint, was evaluated using a 5-point severity rating scale at 3-, 5-, and 7-minute, post-allergen challenge. Evaluation of secondary endpoints showed that cetirizine demonstrated statistical superiority to vehicle at 15 minutes and 8 hours after administration for chemosis, eyelid swelling, and ear or palate itching.
In total, topical cetirizine was evaluated in 7 clinical trials in which 840 patients with allergic conjunctivitis or at risk of developing allergic conjunctivitis received the active medication or vehicle. The most commonly reported adverse reactions, which occurred in about 1% to 7% of subjects treated with either topical cetirizine or vehicle, were ocular hyperemia, instillation site pain, and reduced visual acuity.
Animal models show that cetirizine is selective for H1 receptors and has negligible anticholinergic and antiserotonergic activity.
The ophthalmic formulation of cetirizine was developed by Aciex Therapeutics, a company founded by Ora (Andover, MA). Nicox (Paris, France) acquired Aciex Therapeutics in 2014. Nicox intends to partner the commercialization rights to cetirizine in the United States.