This is a Phase 3 clinical trial of the investigational drug REXLEMESTROCEL-L combined with Hyaluronic Acid for the treatment of Lumbar Degenerative Disc Disease. REXLEMESTROCEL-L (Mesenchymal Precursor Cells) + 1% Hyaluronic Acid are administered by an injection into the spinal disc. Possible benefits include the reduction of pain-related disability associated with degenerative disc disease. This study involves a minimum of 7 visits to our site over the course of 24 months and includes a stipend for each follow-up visit.