A Trial of HRS-7085 Tablets in Patients With Moderate to Severe Active Ulcerative Colitis

Inclusion Criteria: 1. At least 18 years old and not more than 75 years old at the time of signing the Informed Consent Form (ICF), regardless of their sex. 2. Body mass index \[BMI = weight (kg)/height2(m2)\] ≥ 18 kg/m2 at screening. 3. Participants with active UC who have a modified 9-point Mayo score of 5 to 9 and an endoscopic subscore of 2 to 3 at baseline (the interval between screening endoscopy and baseline cannot exceed 14 days), with a rectal bleeding subscore of at least 1. 4. At the time of first dose, the participant is diagnosed with UC for at least 90 days, and UC is confirmed by investigation during the screening visit. 5. The investigator considers that the participant has an inadequate response, loss of response, or intolerance to conventional therapy (oral 5-ASA, immunomodulators, or corticosteroids), anti-tumor necrosis factor (TNF) or other biologic therapy, JAK inhibitor therapy, or is unable to receive these treatments for other reasons. Note: definitions of insufficient response, loss of response, or intolerance are provided in Appendix 13.5. 6. If the participant is currently receiving the following UC therapy at screening, a stable dosage should be administered within the specified time: 1. Oral 5-ASA (mesalazine) (with stable dosage at least 2 weeks before baseline and during the study treatment period), AND/OR 2. Oral corticosteroids (prednisone or prednisolone ≤ 20 mg/day) (with stable dosage for at least 2 weeks prior to baseline and during the treatment period). All other systemic corticosteroid routes are prohibited. 7. The participant voluntarily signs the Informed Consent Form (ICF) before any study-related procedures, can communicate smoothly with the investigator, understands and is willing to strictly comply with the requirements of this clinical study protocol to complete the study. Women of childbearing potential must agree to use highly effective contraceptive methods during the trial and within 3 months after the last dose of trial intervention. Serum or urine pregnancy tests must be negative before and during the trial. Females who are lactating are not eligible to participate in the trial (see Section 13.1 for details). Males must use highly effective contraceptive methods during the trial and within 3 months after the last dose of trial intervention during intercourse with a female of childbearing potential. Donation of sperm during this period is prohibited. Exclusion Criteria: 1. Any of the following medical histories or concomitant diseases: 1. Participants clinically diagnosed with unclassified colitis or suggestive of Crohn's disease. 2. Participants with UC, limited to proctitis (distal ≤15 cm). 3. Participants diagnosed with UC who are treatment-naive (no prior treatment received). 4. Participants presenting with clinical symptoms of ischemic colitis, fulminant colitis, or toxic megacolon. 5. Participants who have previously undergone surgery for UC or might require surgery during the study phase. 6. Screening investigation finds that the participant has a medical history of gastrointestinal dysplasia (atypical hyperplasia)/cancer or dysplasia (atypical hyperplasia)/cancer. Completely resected low-grade dysplasia will be excluded. 7. Participants with a positive Clostridium difficile (C. difficile) test at screening may be enrolled only if they have: 1. Completed appropriate standard-of-care treatment for C. difficile infection; 2. Achieved clinical resolution of diarrheal symptoms; AND 3. A documented negative repeat stool test (toxin A/B assay or NAAT/PCR) conducted after completion of treatment and within 7-14 days prior to baseline/randomization. 8. Participants with evidence of other intestinal infections within 30 days of endoscopic screening, or other intestinal pathogen screening. 9. The participant has or previously had: 1. Clinically significant infection (e.g., requiring hospitalization or parenteral antimicrobial therapy or opportunistic infection) within 1 month before baseline. 2. History of herpes zoster occurring twice or more, or herpes zoster disseminated (occurring once). 3. Any other infection history that the investigator considers might be aggravated by participation in this study. 4. Presence of any infection requiring antimicrobial therapy within 2 weeks before screening (excluding local antimicrobial therapy). 2. Use of any of the following drugs or participation in clinical study (defined as signing the ICF and receiving at least one dose of drug or device therapy): 1. Received JAK inhibitors (upadacitinib, tofacitinib) within 4 weeks before baseline. 2. Received biological agents before baseline (for specific washout time, see Section 6.8.1): 1. Received anti-TNFα antibody therapy within 8 weeks before baseline; 2. Received anti-α4β7 antibody therapy within 12 weeks before baseline; 3. Received anti-interleukin (IL)-23 antibody therapy within 12 weeks before baseline. 3. Received treatment with azathioprine/6-mercaptopurine, methotrexate, or thalidomide within 2 weeks before baseline. 4. Treatment with ciclosporin, mycophenolate mofetil, or tacrolimus within 4 weeks before baseline. 5. Received intravenous corticosteroids, or corticosteroids by rectal use, or 5-ASA by rectal use within 2 weeks before baseline. 6. Participation in any clinical study of drugs (including investigational vaccine) or medical devices within 3 months before baseline or within 5 half-lives of the investigational drug(s) (whichever is longer). 3. Presence of the following important medical history or pre-existing diseases affecting safety: 1. The participant has a medical history of lymphoproliferative diseases, including lymphoma or symptoms and signs of potential lymphoproliferative disorders. 2. Participants with any active neoplasm malignant or history of neoplasm malignant within 5 years prior to the screening visit, except for recovered cutaneous squamous cell carcinoma or basal cell carcinoma or cervix carcinoma in situ. 3. Within 3 months prior to screening, participants with a medical history of moderate to severe cardiac failure congestive (New York Heart Association \[NYHA\] Grade 3 or above), occurrence of cardiovascular events or severe hemorrhage events, which the investigator considers unsuitable for the participant to participate in the clinical study. 4. Active tuberculosis (TB) or latent TB infection (defined as meeting at least one of the following criteria): 1. Presence of active TB or symptoms of active TB at screening. 2. A positive TB test (by QuantiFERON-TB Gold Test or other interferon-gamma release assay \[IGRA\]). If the IGRA result is indeterminate, a retest is allowed; participants within determinate results on both tests will be considered positive. For participants with a positive TB test but no clinical symptoms or imaging findings, prophylactic anti-TB treatment for at least 1 month is recommended before re-screening, and a positive result upon re-screening does not lead to exclusion criterion. For participants with a positive TB test but no clinical symptoms or imaging findings who have previously received prophylactic anti-TB treatment for at least 1 month, they should not be excluded based on this criterion; 3. Imaging examination within 3 months prior to screening indicating signs of active TB; 4. Participants with a medical history of active TB but with medical records proving completion of a full course of anti-TB treatment may confirm with the sponsor whether they could enter the study. 5. Hepatitis B Virus Surface Antigen (HBsAg), human immunodeficiency virus (HIV) antibody, syphilis antibody investigation, anti-Hepatitis C Virus (HCV) antibody test positive; if HBsAg-negative, but Hepatitis B core antibody (HBcAb)-positive and Hepatitis B Virus (HBV) DNA-positive or above the upper limit of normal (ULN). 6. Presence of severe, progressive, or uncontrolled diseases of the cardiovascular and cerebrovascular, hepatic, renal, pulmonary, gastrointestinal, hematopoietic, endocrine, nervous system (e.g., depression, suicidal tendency, and psychological disorders), or other conditions that the investigator considers inappropriate for the patient to participate in this trial. 4. Screening: 1. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥ 3 × ULN. 2. Total bilirubin ≥ 1.5 × ULN. 3. Serum creatinine \> 2.0 mg/dL (177 μmol/L). 4. Male participants with hemoglobin \< 85.0 g/L, female participants \< 80.0 g/L. 5. White blood cell count \< 3.0 × 10\^9/L. 6. Neutrophil count \< 1.5 × 10\^9/L. 7. Platelet count \< 100 × 10\^9/L. 8. 12-lead ECG investigation suggesting abnormalities with clinical significance that may affect the safety of the participant, including but not limited to acute myocardial ischemia myocardial infarction, severe arrhythmia or significant QTc prolongation. ECG exclusion criteria are detailed in Appendix 0. 5. General conditions: 1. Pregnant or breastfeeding women (pregnancy is defined as the state after conception to the termination of gestation), or with a positive human chorionic gonadotropin (hCG) test result. 2. Allergy to the study drug or any component of the study drug. 3. A history of alcoholism or illegal drug abuse within 1 year prior to screening. 4. Received a live attenuated vaccine within 12 weeks before the first drug administration, or intends to receive a live attenuated vaccine during the study period, or participated in a vaccine clinical trial within 12 weeks before the first drug administration. 5. Donated approximately 500 mL or more of blood within 8 weeks prior to the first dose and/or plans to donate blood during the study period. The investigator judges that there are circumstances affecting the evaluation of the safety and efficacy of the study drug.