SI-6603 (Condoliase) Study for Lumbar Disc Herniation (Discovery 6603 Study)

Inclusion Criteria: * Subjects with single-level LDH (L4-L5 or L5-S1 (or L5-L6)) with clear, demonstrable nerve root impingement as assessed by magnetic resonance imaging (MRI) and clinical symptoms corresponding to position of the impaired nerve root. * Subjects with radiculopathy/radicular leg pain in the unilateral leg for 6 weeks or more but 1 year or less. * Subjects with positive result of Straight Leg Raise (SLR) test (≤70°) only on the ipsilateral leg having chief complaint of radiculopathy * Subjects with inadequate improvement in pain caused by LDH despite 6 weeks or more of conservative treatment. Exclusion Criteria: * Subjects who have 2 or more lumbar disc herniations as assessed by MRI. * Subjects who have undergone a lumbar operation, lumbar percutaneous nucleotomy, or lumbar intradiscal therapies at the affected level of lumbar spine. * Subjects who have received block procedure (e.g., spinal injection, epidural injection or nerve block) for treatment of LDH, oral or injectable corticosteroids within 28 days prior to randomization. * Subjects who have received opioids or cannabis by any route of administration, local anesthesia to the back, buttock, or posterior/lateral aspects of the affected leg within 7 days prior to randomization. * Subjects with a body mass index (BMI) ≥40. * Subjects who are receiving compensation according to the Workers' Compensation Act or are involved in personal injury litigation due to a lumbar-related injury.