Research Hypothesis:

There will be a greater proportion of VAS responders defined as those who achieve ≥ 50% reduction from baseline in VAS for low back pain at week 12 following intradiscal injection of YH14618 compared to placebo. Patients have been diagnosed as one or two symptomatic lumbar degenerative disc disease defined as Pfirrmann grade 2 to 4 using MRI. Patients have suffered from persistent low back pain with at least 3 months of conservative therapy and must have low back pain measured by VAS≥4 cm and modified Oswestry disability index (mODI) ≥30% at the baseline.

Inclusion Criteria:

• Patients diagnosed as one or two symptomatic early lumbar (L1/L2 ~ L5/S1) degenerative disc disease defined as Pfirrmann grade 2 to 4 using MRI performed within 4 weeks prior to randomization.
• Patients have suffered from persistent low back pain with at least 3-month conservative therapy.
• Patients have low back pain measured by VAS≥4cm and mODI≥30% at screening and randomization visit (Day 0).

Exclusion Criteria:

• Clinically significant spine compression fracture, spinal stenosis, or spinal instability.
• Clinically significant sacroiliac joint dysfunction, facet joint pain, or those who are suspected.
• Modic change type III assessed by X-ray and MRI
• History of spine surgery
• Neurologic disorders.
• Any other systemic disease which can influence spine such as rheumatoid arthritis, ankylosing spondylitis, or autoimmune disease.
• Participation in other clinical trials with intradiscal injection (eg, Phase 1/2a YH14618-201 trial, or Cell therapy, etc.)