Comparison of VER-01 to Opioids in Patients With Chronic Non-specific Low Back Pain

Inclusion Criteria: 1. Male and female patients ≥18 years of age 2. Provision of informed consent form voluntarily signed and dated by the patient 3. For women of childbearing potential and men of reproductive potential: use of a reliable contraceptive method (Pearl index \< 1) at least 1 month before the start of the study and willingness to use it during the study participation and 3 months after the last intake of the test or comparative intervention 4. Patient understands the local language and is willing and able to comply with scheduled visits, treatment plan, patient diary and other study related procedures throughout study participation 5. Chronic (for at least 3 months) non-specific pain in the lower back (between the 12th thoracic vertebra and lower gluteal folds). Non-specific pain refers to pain without a clear specific treatable cause. 6. Patients with indicated drug treatment where previous optimized treatments with non-opioid analgesics (including combinations) have not led to sufficient pain relief or were unsuitable due to contraindications or intolerance. 7. Low back pain intensity on average at least 4 points on an 11-point Numeric Rating Scale in the last 4 weeks prior visit 1 8. Ongoing non-drug pain therapy (physical or behavioral therapy) must have been stable for at least 2 weeks prior visit 1 and must be continued during the run-in phase 9. Ongoing additional analgesic treatment prior visit 1 must be continued during the run-in phase 10. Bowel Function Index total score of 28.8 or less at visit 1. Exclusion Criteria: 1. Patients with a known history of alcohol/drug/medication abuse or dependency and previous or current use of methadone 2. Evidence of drugs of abuse or illegal drugs by urine drug test performed at visit 1 3. Known intolerance or hypersensitivity to ingredients of rescue medication, opioid therapy (assigned by the investigator) and/or VER-01 4. Participation in another clinical interventional study within the last 30 days prior screening visit (visit 1) 5. Occupational groups with primary activity of operating machinery and driving motor vehicles 6. Planned blood donation or planned donation or freezing of sperm or oocytes during study participation and 3 months after end of study participation 7. Pregnant or breastfeeding female patients 8. Patient is unable to provide written informed consent, in need for care, has a guardian/caretaker, is immobile, or is particularly vulnerable (e.g., imprisoned; institutionalised…