Reproxalap Is Effective for Allergic Conjunctivitis
By Lynda Seminara
Selected by Richard K. Parrish II, MD
Journal Highlights
American Journal of Ophthalmology, October 2021
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Although histamine is a key contributor to allergic conjunctivitis, topical antihistamines often can’t relieve ocular itching or inflammation. For the first time in decades, a new mechanism of action is being explored for this condition. In a phase 3 trial, Clark et al. assessed the postacute activity and clinical utility of topical reproxalap, a novel reactive aldehyde species inhibitor, in treating seasonal allergic conjunctivitis. They found that both 0.25% and 0.5% reproxalap were superior to the control vehicle for reducing ocular itching and achieving faster resolution of symptoms. Both concentrations of reproxalap were safe and well tolerated.
Participants of this parallel-group, double-masked, randomized trial were adults with a history of allergic conjunctivitis, a positive skin test result for seasonal allergies, and itching/redness scores of 2.5 or higher during conjunctival allergen challenge. Patients were assigned randomly (1:1:1) to receive reproxalap topical ophthalmic solution (0.25% or 0.5%) or vehicle 10 minutes before the challenge. The primary end point was area under the postacute ocular itching score curve (range of 0-4) from 10 to 60 minutes after the challenge. The main secondary end point was improvement of at least two points in the peak ocular itching score obtained at baseline.
Altogether, 318 patients were treated (62% women; mean age, 45.7 years). Area under the ocular itching score curve from 10 to 60 minutes was lower for both 0.25% and 0.5% reproxalap than for the vehicle control (p < .0001 and p = .003, respectively). Similarly, the proportion of patients with improvement of at least two points in their peak baseline itching score was greater for both concentrations of reproxalap (p = .0005 and p = .02 vs. vehicle, respectively). The time to achieve an ocular itching score of 0 was faster with 0.25% and 0.5% reproxalap than with vehicle (p < .0001 and p = .001, respectively), and the degree of ocular redness was lower in the active treatment arms. No major safety or tolerability issues occurred.
Reproxalap 0.25% not only resolved allergic conjunctivitis symptoms more quickly than vehicle but also increased the clinical response at least twofold. Although it outperformed the 0.5% solution in most analyses, the authors found no significant differences between the two concentrations. They urged further testing of reproxalap in other allergen-challenge models.
The original article can be found here.