Mevonlerbart

This study is researching 2 experimental drugs, REGN1908 and REGN1909, which are called REGN1908-1909 when mixed together (called "study drug") to reduce eye allergy signs and symptoms from cat allergy.
The aim of the study is to see how safe and effective the study drug is at lowering allergic eye signs and symptoms compared with placebo. A placebo looks like a treatment but does not contain any real medicine.
The study is looking at several other research questions, including:
* What side effects may happen from taking the study drug
* How much study drug is in the blood at different times
* Whether the body makes antibodies against the study drug (which could make the drug less effective or could lead to side effects)