Inclusion Criteria:

• Males and females ages 18 to 60 years old, inclusive, at the Screening Visit.
• ALS diagnosed as possible, laboratory-supported probable, probable, or definite as defined by revised El Escorial criteria.
• Having onset of ALS disease symptoms, including limb weakness within 24 months at the Screening Visit.
• ALSFRS-R ≥ 25 at the screening Visit.
• Upright slow vital capacity (SVC) measure ≥ 65% of predicted for gender, height, and age at the screening Visit.
• Decline in ALSFRS-R total score of 3 or more points in the three months before randomization.
• Taking a stable dose of riluzole, or no riluzole at all (riluzole-naïve participants are permitted in the study), for at least 30 days prior to the Screening Visit and be willing to maintain the riluzole dose for the duration of the study.

Exclusion Criteria:

• Prior stem cell therapy of any kind.
• Active participation in any other ALS interventional study.
• Inability to lie flat for the duration of intrathecal cell transplantation and/or bone marrow biopsy, or inability to tolerate study procedures for any other reason.
• History of autoimmune disease that may confound study results myelodysplastic or myeloproliferative disorder, leukemia or lymphoma, whole body irradiation, hip fracture, or severe scoliosis.
• Any unstable clinically significant medical condition other than ALS (e.g., within six months of baseline, had myocardial infarction, angina pectoris, and/or congestive heart failure), treatment with anticoagulants that, in the opinion of the investigator, would compromise the safety of participants.