Reproxalap Improves Signs and Symptoms of Allergic Conjunctivitis in an Allergen Chamber: A Real-World Model of Allergen Exposure. To assess the prophylactic and treatment activity of reproxalap, a novel reactive aldehyde species inhibitor, in a real-world model of allergen exposure. In a randomized, double-masked, vehicle-controlled, crossover Phase 2 trial, 70 adult patients with ≥2 years of moderate to severe allergic conjunctivitis history, a positive skin test to ragweed pollen, and allergen chamber-induced ocular itching and redness scores of ≥2.5 and ≥2 (both scales range from 0 to 4), respectively, were randomized 1:1:1 to one of three sequences: 0.25% reproxalap, 0.5% reproxalap, and placebo; 0.5% reproxalap, placebo, and 0.25% reproxalap; or placebo, 0.25% reproxalap, and 0.5