• Subjects must:

‣ be at least 10 years of age of either sex and any race;

⁃ provide written informed consent and sign a HIPAA form. Subjects who are under the age of 18 will need to sign an assent form as well as having a parent or legal guardian sign an informed consent;

⁃ be willing and able to follow all instructions and attend all study visits;

⁃ (If female and of childbearing potential) agree to have urine pregnancy testing performed at visits 2, 4a (must be negative) and at exit visit (Visit 5); must not be lactating; and must agree to use at least 1 medically acceptable form of birth control throughout the study duration, for at least 14 days prior to the first dose of investigational drug (Visit 4a) and for 1 month after the last dose of investigational drug (Visit 5). Acceptable forms of birth control are true abstinence (when this is in line with the preferred and usual lifestyle of the subject), spermicide with barrier, oral contraceptive, injectable or implantable method of contraception, transdermal contraceptive, intrauterine device, or surgical sterilization of male partner at least 3 months prior to the first dose of investigational drug (Visit 4a). Note: Women considered capable of becoming pregnant include all females who have experienced menarche and have not experienced menopause (as defined by amenorrhea for greater than 12 consecutive months) or have not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy);

⁃ (If male and with female partner of childbearing potential) must use at least 1 medically acceptable form of birth control. throughout the study duration, for at least 14 days prior to the first dose of investigational drug (Visit 4a) and for 1 month after the last dose of the study drug (Visit 5) Note: Acceptable forms of birth control are true abstinence (when this is in line with the preferred and usual lifestyle of the subject) or vasectomy at least 3 months prior to the first dose of investigational drug (Visit 4a). Without a vasectomy, must use condoms with spermicidal foam/gel/film/cream/suppository.

⁃ have a history of ocular allergies and a positive skin test reaction to a seasonal (grass, ragweed, tree pollen) or perennial (cat dander, dog dander, dust mites, cockroach) allergen as confirmed by an allergic skin test conducted at Visit 1 or within the past 24 months;

⁃ have a calculated best-corrected visual acuity of 0.7 LogMar or better in each eye as measured using an ETDRS chart at Visit 2;

⁃ have a positive bilateral CAC reaction (defined as having scores of ≥ 2 for ocular itching and ≥ 2 for conjunctival redness) within 10 minutes of instillation of the last titration of allergen at Visit 2;

⁃ have a positive bilateral CAC reaction (defined as having scores of ≥ 2 for ocular itching and ≥ 2 for conjunctival redness) in at least 2 out of 3 timepoints at following the challenge at Visit 3;

‣ be able and willing to discontinue wearing contact lenses for at least 72 hours prior to Visit 2 and during the study trial period.