Safety and Tolerance of Umbilical Cord Mesenchymal Stem Cells (UC-MSC) in Patients With Ankylosing Spondylitis

"The trial was conducted sequentially from the low dose group to the high dose group, with 3-6 subjects enrolled in each dose group. The trial was conducted on a case-by-case basis in the high dose group, with each subject in the high dose group being enrolled in subsequent subjects only after completion of at least 7 days of post-dose safety observation. Each subject received only one corresponding dose. All subjects received experimental drugs and conventional treatment during the study period.~All subjects in each test dose group will complete a 4-week (28-day) dose-limiting toxicity (DLT) After the observational evaluation period, a decision will be made by the investigator and sponsor based on a discussion of relevant safety data whether to start the next dose group."