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).

Main Inclusion Criteria:

1. Female or male subjects who are ≥ 18 years of age at screening;
2. Patients with a diagnosis consistent with clinically or laboratory-supported possible, probable, or definite sporadic or familial ALSALS in accordance with Revised EI Escorial diagnostic criteria published by the World Federation of Neurology (WFN);
3. The duration of the disease from the first symptom (any ALS symptom) prior to the screening visit must be less than 2 years (inclusive);
4. The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) score ≥30 during the screening period, and the three respiratory scores (dyspnea, upright respiration, and respiratory insufficiency) must be ≥3;
5. The forced vital capacity (FVC) of predicted during the screening period is ≥70% at screening;
6. Body mass index (BMI) greater than 18 kg/m2 at screening;

Main Exclusion Criteria:

1. Subjects with other neurological diseases similar to ALS that affect the evaluation of drug efficacy, such as cervical spondylotic myelopathy, syringomyelia, spinal cord and brain stem tumors, hirayama disease, multifocal motor neuropathy, multiple sclerosis, Guillain-Barre syndrome, Parkinson's disease and dementia;
2. Patients with a diagnosis consistent with clinically or laboratory-supported possible, probable, or definite sporadic or familial ALSALS in accordance with Revised EI Escorial diagnostic criteria published by the World Federation of Neurology (WFN);
3. Subjects who refuse to take food and medication by nasal feeding tube during the study period due to swallowing dysfunction;

Part of the data are planed to share on Oct 2025, Oct 2026, and Sep 2032.