Efficacy and Safety of SAR292833 Administration for 4 Weeks in Patients With Chronic Peripheral Neuropathic Pain

Primary Objective:

To assess the efficacy of SAR292833 versus placebo in reducing pain intensity associated with chronic peripheral neuropathic pain using 11-point numerical rating scale (NRS).

Secondary Objectives:

* To compare the effects of SAR292833 with placebo on the change of neuropathic pain symptoms versus baseline Neuropathic Pain Symptoms Inventory (NPSI);
* To evaluate the effects of SAR292833 in comparison to placebo on the change in pain intensity of mechanical allodynia;
* To investigate the safety and tolerability of SAR292833 in comparison to placebo;
* To investigate the pharmacokinetics (PK) and the relationships between main efficacy parameters or pharmacodynamic effect (PD) and pharmacokinetics (PK/PD) of SAR292833 in patients with chronic peripheral neuropathic pain.

Total study duration (from screening to last follow-up visit) is 9 weeks that includes a 3 week follow-up period.

Eligibility Criteria:
Inclusion criteria:

-The study will include adult patients of either gender, 18 - 85 of age, who have signed the informed consent form, and presenting with chronic peripheral neuropathic pain associated with: diabetic polyneuropathy, post-herpetic neuralgia.

* The neuropathic pain must have a distinct neuroanatomically plausible distribution with sensory signs and symptoms confirmed by DN4 (Douleur Neuropathique en 4 questions) score of ≥4 and being present for more than 3 months.
* SAR292833 should be taken in fed condition. Therefore, only patients who were judged to be reliable to fulfill this condition (used to having breakfast and dinner) will be included in the study.

Exclusion criteria:

* Patients with a baseline average daily pain intensity for their neuropathic pain \< 5 on the 11-point NRS over the last 7 days before randomization;
* Patients with a pain intensity of ≥ 9 on the 11-point NRS at Visit 1;
* Any pain other than the neuropathic pain of equal or greater severity;
* Sensory polyneuropathy post chemotherapy or in the context of cancer or AIDS;
* Patients with complex regional pain syndrome;
* Trigeminal neuralgia;
* Patients with clinically significant or uncontrolled hepatic, metabolic, gastrointestinal, cardiovascular, respiratory, neurological (other than neuropathy), psychiatric, hematological, renal, or dermatological disease, or any other medical condition that might interfere with the evaluation of study medication according to Investigator's medical judgment;
* Patients on statins metabolized by CYP3A4, (e.g. simvastatin, atorvastatin) and abnormal CPK level;
* Major depression;
* Serum creatinine \>150 μmol/L;
* ALT 3 x ULN;
* Total bilirubin \> 1.5 x ULN except known Gilbert syndrome;
* Presence of signs of clinically significant abnormalities on a standard electrocardiogram (ECG) recording at the screening visit according to Investigator's medical judgment;
* Pregnant or breastfeeding women;
* Women of childbearing potential (WOCBP), not protected by highly effective contraceptive method of birth control;
* Patients with diabetes mellitus and time between diagnosis of diabetes and enrolment \<6 months;
* Patients with diabetes mellitus and HbA1c \>10% or fasting plasma glucose \>250 mg/dL;
* Use of the following drugs within 7 days prior to start with the pain intensity assessment (Visit 2):
* Antidepressants (except for stable \[\>30 days\] regimens of Selective serotonin reuptake inhibitors (SSRIs) for treatment of anxiety or depression), anticonvulsants or mexiletine for the treatment of pain;
* Opioids or morphinomimetics;
* Fatty acid supplements, primrose oil, myoinositol, chromium picolinate that are known to be used in neuropathic pain;
* Acetyl salicylic acid (ASA) except up to 325 mg/d for myocardial infarction or transient ischemic attack prophylaxis;
* Benzodiazepines other than indicated at low doses for sleep disorders;
* Capsaicin patch;
* Lidocaine patch;
* Electroconvulsive therapy within 30 days of baseline evaluation;
* CYP3A4 potent and moderate inhibitors;
* CYP3A4 potent and moderate inducers;
* Substrates of CYP3A4 with narrow therapeutic window.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.