A Study of GKL-006Allo Injection in Patients With Ankylosing Spondylitis

Inclusion Criteria:

1. Participants must be able to understand the informed consent form and voluntarily agree to participate, with a signed and dated informed consent form.
2. Age 18 to 65 years (inclusive), both sexes.
3. Diagnosis of ankylosing spondylitis (AS) according to the 1984 modified New York criteria, and classification as axial spondyloarthritis (axSpA) according to the 2025 ASAS-SPARTAN axSpA classification criteria. Participants must have active disease, meeting both of the following criteria: (a) Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score >= 4; and (b) spinal pain score >= 4 as measured by BASDAI question 2.
4. Prior treatment with at least 2 nonsteroidal anti-inflammatory drugs (NSAIDs) at full dose on a regular schedule for at least 4 weeks, with no significant improvement in symptoms as assessed by the investigator; or intolerance to NSAIDs (discontinuation of NSAID treatment due to treatment-related adverse events, such as allergic reactions or gastrointestinal signs or symptoms; the 4-week treatment duration requirement does not apply in this case); or contraindication to NSAID treatment.
5. Participants who have received no more than 1 prior biologic agent or JAK inhibitor (agents with the same generic name count as 1): treatment must have been administered at the recommended dose for at least 12 weeks with inadequate response, intolerance (adverse events leading to discontinuation), or inability to continue for other reasons. Washout periods before the first dose: etanercept, 4 weeks; infliximab, 8 weeks; adalimumab, certolizumab pegol, or golimumab, 10 weeks; IL-17 inhibitors, 12 weeks; JAK inhibitors, 4 weeks; biologic classes not listed, 5 drug half-lives.
6. If participants are receiving methotrexate (MTX), sulfasalazine (SSZ), or hydroxychloroquine (HCQ), the treatment duration before enrollment must be at least 3 months, and the dose must have been stable for at least 4 weeks.
7. Participants of childbearing potential must use at least 1 medically accepted contraceptive method during the study treatment period and for 6 months after the end of study treatment. Serum human chorionic gonadotropin (HCG) must be negative within 7 days before the first dose for women of childbearing potential; participants must be non-lactating and non-pregnant.
8. Able to communicate well with the investigator and comply with the requirements of the study.

Exclusion Criteria:

1. Allergy to immunotherapy or to the excipients of the investigational drug.
2. Known or suspected history of complete spinal ankylosis, or complete spinal ankylosis confirmed clinically and radiographically.
3. Complete ankylosis of the sacroiliac joints.
4. Spinal or joint surgery within 2 months before dosing, or planned spinal or joint surgery during the study period.
5. Other untreated malignancy within the past 5 years or concomitant malignancy, except adequately treated skin basal cell carcinoma, carcinoma in situ, and breast cancer with no recurrence for more than 3 years after curative surgery.
6. Any active, known, or suspected autoimmune disease other than the indication under study (including but not limited to myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, vasculitis, glomerulonephritis, uveitis, hypophysitis, and hyperthyroidism). Exceptions: type 1 diabetes mellitus on stable-dose insulin therapy for at least 3 months before enrollment; hypothyroidism requiring only hormone replacement therapy; and skin conditions (such as eczema, vitiligo, or psoriasis) requiring no systemic treatment and without acute exacerbation within 1 year before screening.
7. Severe trauma or major surgery (such as transabdominal or transthoracic surgery) within 6 months before screening, or planned major surgery during the study.
8. History of idiopathic pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radiation pneumonitis (may be enrolled if only detected on imaging and no corticosteroid treatment is required), or drug-induced pneumonitis.
9. Poorly controlled cardiac signs, symptoms, or diseases: (a) congestive heart failure of NYHA class II or above; Poorly controlled cardiac signs, symptoms, or diseases: (a) heart failure of New York Heart Association (NYHA) class II or above;b) unstable angina within 6 months; (c) acute myocardial infarction within 1 year; (d) clinically significant supraventricular or ventricular arrhythmias requiring treatment or intervention (such as QTc > 450 msec in males or > 470 msec in females).
10. Hypertension not well controlled by antihypertensive medication (systolic blood pressure >= 140 mmHg or diastolic blood pressure >= 90 mmHg within 7 days before enrollment).
11. Cerebrovascular or cardiovascular events within 3 months before dosing (myocardial infarction, ischemic or hemorrhagic stroke excluding lacunar infarction, deep vein thrombosis, etc.).
12. Any of the following at screening or baseline: (a) aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 2.5 x ULN; (b) serum creatinine > 1.5 x ULN or glomerular filtration rate < 60 mL/min/1.73 m2; (c) activated partial thromboplastin time (APTT) > 1.5 x ULN or prothrombin time (PT) > 2.5 x ULN (without anticoagulant therapy); (d) left ventricular ejection fraction <= 50%; (e) urine protein > 2+ on urinalysis within 7 days before enrollment, confirmed by 24-hour urine protein quantification > 1.0 g; (f) white blood cell count < 3 x 10^9/L, hemoglobin < 90 g/L, absolute neutrophil count < 1.5 x 10^9/L, or platelet count < 90 x 10^9/L.
13. Any of the following bleeding conditions: bleeding events of CTCAE v6.0 grade 2 or above within 4 weeks before enrollment; gastrointestinal bleeding history or definite gastrointestinal bleeding within 6 months before enrollment, or bleeding from esophageal and/or gastric varices without endoscopic or transjugular intrahepatic portosystemic shunt prophylaxis; known hereditary or acquired bleeding or thrombotic tendency (such as hemophilia or coagulation disorders).
14. Systemic active infection requiring treatment within 2 weeks before enrollment, or unexplained fever with temperature >= 38.5 degrees C within 7 days before enrollment.
15. Congenital or acquired immunodeficiency (such as HIV infection); active syphilis infection; positive tuberculosis test.
16. HBV or HCV infection at screening with viral load above the lower limit of detection (HBV DNA >= 10 IU/mL or HCV RNA >= 10 IU/mL).
17. Prior receipt of genetically modified cell therapy, or receipt of non-genetically modified cell therapy within 6 months before screening.
18. Prior use of oral glucocorticoids, or receipt of glucocorticoids by any intra-articular, intramuscular, or intravenous injection.
19. Receipt of disease-modifying antirheumatic drugs (DMARDs) other than sulfasalazine and hydroxychloroquine within 1 month before dosing; leflunomide discontinued for less than 8 weeks; or discontinuation for less than 5 drug half-lives according to the actual drug class (i.e., the DMARD washout period should exceed 5 half-lives of the corresponding drug), whichever is longer.
20. Current use of strong opioid analgesics (such as methadone, hydromorphone, or morphine).
21. Vaccination with live or attenuated vaccines within 4 weeks before screening.
22. Enrollment in another clinical study of a drug or device within 4 weeks before screening.
23. Other factors judged by the investigator that may lead to premature study termination, such as other serious concomitant diseases (including severe diabetes, thyroid disease, spinal cord compression, superior vena cava syndrome, or psychiatric illness), severe laboratory abnormalities, or family or social factors that may affect participant safety or the collection of data and samples.
24. Intolerance to venipuncture, or history of needle or blood phobia.
25. History of alcoholism, drug abuse, or use of any illicit drugs.
26. Other factors considered by the investigator to be unsuitable for enrollment or likely to affect participant participation or completion of the study.