This study is for patients diagnosed with degenerative disc disease. The spine is made of several vertebras from the neck to the lumbar region, each of them separated by a cartilage (an intervertebral disc) which allows full motion of the spine. Over time, the discs may be damaged, leading to disc degeneration with loss of motion and pain. This process is called degenerative disc disease. The patient's doctor believes that their disease is at a state that requires surgery to prevent the damaged disc from moving and thus decrease the associated pain. The way to achieve this is to remove the damaged disc and fuse the vertebras together by inserting a device (called a cage) with a bone graft to help stabilize your spine during the healing process, a procedure called spinal fusion. The main purpose of this study is to learn how well the investigational drug works, which dose will provide the best efficacy results, and how safe the investigational drug is compared to a standard surgical treatment. The standard treatment does not contain any investigational drug. In this study, researchers will compare two different doses of the investigational drug treatment with the standard surgical treatment. The investigational drug is KUR-113 Bone Graft. This is a combination product of a modified form of parathyroid hormone (PTH), a hormone naturally present in your body which increases bone formation and fracture healing and fibrin, a component of your blood naturally present during blood clotting and known to facilitate bone healing.