A Proof of Concept Study to Investigate the Effect of a New Treatment in Patient With Chronic Pain

Inclusion Criteria: * Are men or women of at least 18 years of age * Diagnosed with Peripheral Neuropathic Pain (PNP) or knee or hip pain attributed to Osteoarthritis (OA) since at least 6 months * Affiliated with national welfare * Reliable and willing to make themselves available for the duration of the study and are willing to follow study procedures * Have given written informed consent approved by the relevant Ethics Committee (EC) governing the study sites * Patients will be required to report pain with a score between 4 and 8 inclusive on the mean Average Pain Score (APS) during the baseline period preceding randomization and to have completed at least 10 days of pain assessments in their diary between Visit 1 and Visit 2. If more than 10 days were completed, the mean APS will be calculated on the last 10 ones. Inclusion Disease Criteria: * Diagnosis criterium for PNP: Patient with chronic PNP supported by a distinct neuroanatomical plausible distribution with sensory signs and symptoms, and consecutive to one of the following causes: a traumatic event, a surgical procedure (excluding limb amputation), radiculopathy, post- herpetic or post- zoster neuralgia, diabetic polyneuropathy or post chemotherapy. Diagnosis will have to be confirmed by the DN4 questionnaire at the screening visit (pain is considered as neuropathic if DN4 score ≥ 4) * Diagnosis criterium for OA: Patient with a unilateral or bilateral OA of the knee or hip diagnosed according to the American College of Rheumatology (ACR) criteria based on clinical and radiographic evidence (Altman et al. 1986). The clinical diagnosis of OA will be confirmed by the ACR clinical and radiographic criteria for classification of idiopathic OA of the knee or hip based upon the following criteria: 1. Knee or hip pain as an average at least half of the time for the last 3 months before screening visit 2. At least 1 of the following 3 conditions: Age \> 50 or morning stiffness \< 30 minutes or crepitus 3. Kellgren and Lawrence grade \> 1 as assessed if possible by an X-ray of the referred joint to confirm the diagnosis. If considered medically required by the Investigator based on patient needs and as part of regular patient management, a new anterior-posterior view X- ray should be obtained and reviewed by Investigator or his delegates to verify that the patient meets the disease diagnostic criteria Exclusion Criteria: * Patient changed his/her " regular analgesic therapy " for PNP or OA in the last 4 w…