Safety and Efficacy of EMA401 in Patients With Painful Diabetic Neuropathy (PDN)

Inclusion Criteria: * At the time of Screening, must have had documented diagnosis of Type I OR Type II diabetes mellitus (DM) with painful distal symmetrical sensorimotor neuropathy (ICD-10 code G63.2) of more than 6 months duration with any one or more of the following: * Neuropathic symptoms (e.g. numbness, non-painful paresthesias or tingling, non-painful sensory distortions or misinterpretations, etc.) * Decreased distal sensation (e.g. decreased vibration, pinprick sensation, light touch, etc.) * Been assessed as suffering from moderate to severe neuropathic pain across the Screening epoch (NRS ≥ 4). * A score of ≥4 on the Douleur Neuropathique en 4 Questions (DN4) questionnaire at Screening. Exclusion Criteria: * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they were using highly effective methods of contraception during dosing and for 3 days after stopping of study medication. Highly effective contraception methods included: * Total abstinence (when this was is in line with the preferred and usual lifestyle of the subject). Periodic abstinence (e.g., calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal were not acceptable methods of contraception. * Female sterilization (have had surgical bilateral oophorectomy with or without hysterectomy), total hysterectomy or tubal ligation at least six weeks before taking investigational drug. In case of oophorectomy alone, only when…