CNS10-NPC-GDNF for the Treatment of ALS

This study will be the first to use a genetically modified progenitor cells to treat a neurodegenerative disease. This is a Phase 1/2a, single-center, blinded (as to side of injection), safety study of two escalating doses of human neural progenitor cells expressing GDNF (CNS10-NPC-GDNF) delivered unilaterally to the lumbar region in ALS subjects with moderate leg involvement. Subjects meeting all Eligibility Criteria and providing Informed Consent will be enrolled in one of two sequential dosing groups. Subjects will be treated sequentially with a minimum of one month interval between surgeries for the first three subjects in each dosing cohort. The remaining subjects in the cohort will be treated with a minimum interval of at least two weeks between surgeries. Specific aims: Safety, as evaluated by: * Adverse Events and Serious Adverse Events * Clinical laboratory assessments, as clinically indicated (hematology, chemistry, immunology)