Efficacy and Safety of GRT6005 in Patients With Chronic Low Back Pain.

Inclusion Criteria: * Chronic Low Back Pain of non-malignant origin and present for at least 3 months. * Signed informed consent. * Pain intensity score of 5 or greater on the 11-point numeric rating scale (where 0 indicates "no pain" and 10 indicates "as bad as you can imagine"). * On stable analgesic medications (non-opioid and/or opioid medications) for chronic low back pain with regular intake for at least 3 months and dissatisfied with current analgesic treatment. Exclusion Criteria: * Female subjects who are pregnant or are breastfeeding. * Presence of risk factors for Torsade de Pointes. * Any clinically significant disease or laboratory findings that may affect efficacy or safety assessments or may compromise the safety during trial participation, e.g., significant unstable cardiac, vascular, pulmonary, gastrointestinal, endocrine, metabolic, neurological, or psychiatric disorders. * History of acute hepatitis within the past 3 months or chronic hepatitis or a positive result on anti-hepatitis A antibody, hepatitis B surface antigen, or anti-hepatitis C antibody. History of human immunodeficiency virus (HIV) infection. * History of seizure disorder. * Chronic low back pain potentially associated with a specific spinal cause. * Surgery or painful procedure during or within 3 months of enrollment. * Conditions that contribute and confound the assessment of pain. * Subjects with impaired renal function. * Subjects with impaired hepatic functionality. * Neuromodulation. * Cancer. * Clinically relevant history of hypersensitivity, allergy or contraindications to any of the Investigational Medicinal Products' excipients, paracetamol/acetaminophen, tapentadol Hydrochloride, or opioid analgesics (or excipients).