Efficacy and Tolerability of AP707 in Patients With Chronic Back Pain

Inclusion Criteria: 1. Signed and dated informed consent form 2. Patients with chronic back pain since at least 3 months 3. Female and male patients (\> 18 years) 4. Patients with more than 1 year life expectancy 5. Patients with optimized sCPT on study entry as defined in section 3.1.1 and section 3.1.3 of the study protocol 6. Willingness of study patients of both sexes to use reliable contraception during study participation and for three months after taking the last study medication 7. Good command of German language, in order to understand questionnaires in German 8. Current moderate to severe pain with pain intensity \> 5 on Numeric Rating Scale (NRS, 0 - 10) and thus an existing need for further pain therapy 9. Completed QUISS (Quantification Inventory for Somatoform Syndromes) questionnaire with 45 or less score points 10. Completed painDETECT questionnaire with 20 or more score points Exclusion Criteria: 1. Medical history of hypersensitivity or intolerance to the investigational product or its ingredients or to ingredients of similar chemical structure 2. Known intolerance to cannabinoids or cannabis products. 3. Participation in another clinical trial within the last four weeks prior to inclusion. 4. Pregnant or nursing women (as excluded by pregnancy testing at visit 1). 5. Other medical conditions that do not allow the trial subject to appraise the nature, scope, and potential consequences of the clinical trial 6. Indications that the trial subject is unlikely to comply with the study protocol (e.g., unwillingness to cooperate) 7. Known use of medicinal cannabis products within the last 8 weeks 8. Active malignant tumor disease, tumor pain, or other dominant severe pain other than that of the study indication 9. Known history of severe liver or kidney diseases 10. Known history of severe cardiovascular disease 11. Known history of or acute mental illness such as severe depression, psychosis, bipolar disorder, mania, anxiety, or obsessive-compulsive disorder 12. Known history of addictive disease (e.g., alcohol, medication, drug addiction) 13. Answered during Screening less than 12 times of 18 the pain intensity (NRS) inquiry 14. Laboratory liver values: Alanine aminotransferase (ALT, GPT) \> 3 x ULN (Upper Limit of Normal range), Aspartate aminotransferase (AST, GOT) \> 3 x ULN, Alkaline phosphatase (AP) \> 2.5 x ULN, and for bilirubin \> 1.5 x ULN 15. Laboratory renal value: Serum creatinine \> 1.5 ULN