This study is a multicenter, randomized, double-blind, placebo-controlled Phase III clinical trial aimed at evaluating the efficacy, safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of SHR-1819 injection in patients with Seasonal Allergic Rhinitis (SAR).
Age 18 to 75 years (inclusive) at the time of signing the Informed Consent Form, of any sex;
Meet the diagnostic criteria for Seasonal Allergic Rhinitis (SAR) as defined in the "Chinese Guidelines for Diagnosis and Treatment of Allergic Rhinitis (2022, Revised Edition)", with or without allergic conjunctivitis;
The investigator assesses that the participant has had a poor response to intranasal corticosteroids and/or other medications for allergic rhinitis (antihistamines, leukotriene receptor antagonists, etc.) during the same pollen season in previous years;
Participants exhibit an immunoglobulin E-mediated hypersensitivity reaction to at least one seasonal pollen allergen;
At screening or within 2 weeks prior to the screening visit, the participant has other active rhinitis besides SAR;
At screening or within 2 weeks prior to the screening visit, there may be other nasal comorbidities or concurrent diseases/conditions that could affect the efficacy assessment, acute/chronic sinusitis, or upper respiratory tract infection;
Has glaucoma, cataract, ocular herpes simplex, other ocular infections such as infectious conjunctivitis, acute conjunctivitis, or acute keratitis at screening;
History of Vernal Keratoconjunctivitis (VKC) and/or Atopic Keratoconjunctivitis (AKC) within 6 months prior to the screening visit;