This study is a single-arm, open, 2-stage (dose-escalation phase and dose-expansion phase), multi-center, phase I clinical trial to evaluate the safety and tolerance of SYS6020 injection in the participants with refractory systemic myasthenia gravis, and determine the recommended dose (RD) for subsequent studies of the product, and to preliminarily evaluate the clinical efficacy of the product, as well as to explore the pharmacokinetics and immunogenicity of the product in vivo.
The dose-escalation phase and dose-expansion phase include 7 periods, and they are respectively in sequence as follows: the screening period, apheresis period, pre-dosing assessment, SYS6020 injection infusion, DLT observation period, the primary follow-up period (6 months), and the long-term follow-up period (5 years). The DLT observation period is 28 days after receiving SYS6020 injection. The participants will not undergo lymphodepleting chemotherapy.
The efficacy and safety profile of the participants will be continuously assessed during the trial. Efficacy measurement includes the MG-ADL, QMG, MGC, MG-QoL 15R scale, MGFA clinical classification, and MGFA post-intervention state (MGFA PIS) grading scales, as well as self-antibodies, etc. Safety measurement includes vital signs, physical examination, laboratory tests, cytokines, and ECG, etc. The adverse events and concomitant therapy will be continuously collected during the trial. In addition, during the study period, blood samples will be collected from participants who have received SYS6020 treatment for PK/PD test, and immunogenicity test.
For the dose-escalation phase, 3 to 5 dose levels are proposed to be explored. The Safety Monitoring Committee (SMC) will discuss the safety data and make a decision if the next SYS6020 injection could be initiated or dose-escalation could be initiated. After the completion of the dose-escalation phase, the recommended doses would be determined for dose-expansion phase. For the dose-expansion phase, further safety and efficacy data will be collected among the participants who will receive the recommended dose of SYS6020 injection.