RJK-002

The goal of the study aims to evaluate the safety and tolerability of a single intrathecal injection of RJK002 in subjects with amyotrophic lateral sclerosis (ALS), and to determine the recommended Phase II dose (RP2D).

The goal of this clinical trial is to evaluate the safety and efficacy of a single intrathecal injection of RJK002 in patients with Amyotrophic Lateral Sclerosis (ALS). The main questions it aims to answer are:
* The safety, tolerability, and preliminary efficacy of a single intrathecal injection of RJK002 in subjects with amyotrophic lateral sclerosis (ALS)
* The adeno-associated virus (AAV) viral load, changes of biomarkers in serum and cerebrospinal fluid (CSF), and electromyography (EMG) motor unit counts in subjects with ALS treated with a single intrathecal injection of RJK002.
Participants will receive a single intrathecal administration of investigational product and a systemic immunomodulatory regimen. There will be 3 cohorts: 6E13 vg/person (6 mL), 1.2E14 vg/person (12 mL), and 2.4E14 vg/person (24 mL). 3 subjects will be enrolled in each dose cohort. The dose level will be escalated sequentially from low to high.