Study of CM310 in Subjects With Allergic Rhinitis

Inclusion Criteria:

• Able to understand the study and voluntarily sign the ICF;

• Males or females, ≥ 18 and ≤ 65 years old;

• Diagnosed SAR according to the Criteria stated in the Chinese Guidelines for theDiagnosis and Treatment of Allergic Rhinitis (2022, Revised Edition), with orwithout allergic conjunctivitis, and have SAR history in the same pollen season forat least two years;

• Have immunoglobulin E (IgE)-mediated hypersensitivity to at least one pollenallergen in the current environment, as confirmed by the result of the specific IgEtest during the screening/run-in period;

• Adequate pollen exposure during the pollen season: Participants are expected to bein the pollen season for the entire study period and have no travel plans to leavethe geographic region more than 48 hours. Definition of a pollen season: thebeginning of a pollen season is defined as local pollen count of more than 20/1000mm2 for three consecutive days, and the end of a pollen season is defined as localpollen count of less than 20/1000 mm2 for three consecutive days.

• Prior to screening, the SAR symptoms of participants remained inadequatelycontrolled (at least one moderate or above SAR symptom) after nasal spraycorticosteroids or other SAR medications (antihistamines, leukotriene receptorantagonists, etc.) treatment throughout the same pollen season previously;

• The AM iTNSS ≥ 6 points prior to screening; at the baseline visit, the AM iTNSS ≥ 6points and the average of the last 6 rTNSS scores ≥ 6 points (i.e., 3 AM and 3 PMassessments over the last three 24-hour periods, including the AM assessment at thebaseline visit), with nasal congestion ≥ 2 points and one of the three symptoms ofrhinorrhea, nasal itching, and sneezing ≥ 2 points;

• Peripheral blood eosinophils count ≥ 0.3×109/L during the screening/run-in periodand baseline visit;

• During the screening/run-in period, participants must complete at least 80% of theassessments in the diary card;

• The participants agree to use highly effective contraception methods from signing ofthe ICF to 3 months after the last dose of the investigational product.

Exclusion Criteria:

• Use of anti-interleukin 4 receptor alpha subunit (IL-4Rα) monoclonal antibody,thymic stromal lymphopoietin (TSLP) monoclonal antibody, anti-IgE monoclonalantibody, other monoclonal antibodies, or other biologics within 10 weeks or 5half-lives (whichever is longer) prior to the screening visit;

• Use of any investigational product within 4 weeks prior to the screening visit orplanning to participate in other clinical studies during this study;

• Use of systemic immunosuppressants (including but not limited to methotrexate,cyclosporine, mycophenolate mofetil, tacrolimus, penicillamine, sulfasalazine,hydroxychloroquine, azathioprine, cyclophosphamide) for the treatment ofinflammatory or autoimmune diseases (e.g., rheumatoid arthritis, inflammatory boweldisease, primary biliary cirrhosis, systemic lupus erythematosus, multiplesclerosis, etc.) within 8 weeks or 5 half-lives (whichever is longer) prior to thescreening visit;

• Infections requiring treatment with systemic antibacterial, antiviral, antifungal,antiparasitic, or antiprotozoal medications within 7 days prior to the screeningvisit;

• Received short-medium-acting systemic corticosteroids (SCS, including oral,intravenous, or intramuscular glucocorticoids), systemic traditional Chinesemedicine preparations for the treatment of allergic rhinitis within 4 weeks prior toscreening, or long-acting SCS (such as triamcinolone acetonide injection) within 6weeks prior to screening, or planning to receive the above drugs during the study;

• Use of monoamine oxidase inhibitors within 14 days prior to the screening visit;

• Participants who initiate immunotherapy within 4 weeks prior to the screening visit,or who plan to initiate immunotherapy during the study; Participants who have beenreceiving immunotherapy at a stable dose within 4 weeks prior to the screening visitand are able to remain this fixed dose throughout the study can be enrolled;

• Participants with concomitant asthma who start treatment with inhaledcorticosteroids within 4 weeks prior to screening: Participants who have beentreated with a stable dose of inhaled glucocorticoids (≤ 1000 μg/day of fluticasonepropionate or equivalent dose of other inhaled glucocorticoids) for at least 4 weeksprior to screening and the dose remains unchanged throughout the study, is in astable condition at the investigator's discretion, can be enrolled;

• Forced expiratory volume in 1 second (FEV1) ≤ 50% of the predicted value during thescreening/run-in period;

• Have active rhinitis of other type except for SAR, such as acute or chronic rhinitisand non-allergic rhinitis;

• Participants with perennial allergic rhinitis (PAR) who are allergic to pet hair.Participants can be enrolled if they stop exposing to pet hair or are allergic toother indoor allergens;

• Patients with active nasal diseases other than SAR, such as acute or chronicrhinosinusitis or nasal septal deviation, which may affect the efficacy evaluationof the investigational product at the investigator's discretion;

• History of any nasal or sinusoidal surgery within 1 year prior to screening;

• Have acute sinusitis, nasal infection, or upper respiratory tract infection atscreening or within 2 weeks prior to screening;

• Have benign or malignant tumors in the nasal cavity;

• Previously received an anti-IL-4Rα monoclonal antibody (e.g., dupilumab) for thetreatment of AR with poor response (e.g., treatment failure or intolerance);

• Participants who are allergic to MFNS, loratadine, any anti-IL-4Rα monoclonalantibody or any component of CM310;

• Comorbidity of other poorly controlled serious diseases or chronic diseases,including but not limited to active infection, cardiovascular and cerebrovasculardiseases, pulmonary tuberculosis or other pathogen infections, diabetes, autoimmunediseases, human immunodeficiency virus infection, treponema pallidum infection,active hepatitis B, hepatitis C or parasitic diseases;

• Participants with malignancy within 5 years prior to screening (except forcompletely cured cervical carcinoma in situ and non-metastatic squamous cell orbasal cell carcinoma of the skin);

• Participants with severe hepatic or renal impairment, such as aspartateaminotransferase (AST) or alanine aminotransferase (ALT) > 2 times the upper limitof normal (ULN), total bilirubin > 1.5 times the ULN, or serum creatinine > 1.2times the ULN;

• Have received a live-attenuated vaccine within 12 weeks prior to randomization orplanning to receive one during the study;

• Known or suspected immunosuppression, including but not limited to a history ofinvasive opportunistic infections (eg, tuberculosis, histoplasmosis, listeriosis,coccidioidomycosis, pneumocystosis, aspergillosis), even after this infectioncondition has recovered; or with unusually frequent, recurrent, or long-terminfections at the investigator's discretion;

• Pregnant or breast-feeding women, or women who plan to become pregnant orbreast-feeding during the study;

• Heavy alcohol consumption [i.e., more than 14 units of alcohol per week (1 unit = 360 mL of beer or 45 mL of distilled spirits with 40% alcohol or 150 mL of wine)] orhistory of drug abuse within 3 months prior to screening;

• Participants with any other conditions that are considered by the investigator asunsuitable to participate in this study.