A Study to Assess the Efficacy and Safety of Oxycodone/Naloxone in Korean Patients With Chemotherapy-Induced Peripheral Neuropathy (CIPN)

Inclusion Criteria: * Male or female ≥ 20 and \<80 years of age * Patients who has diagnosed as Chemotherapy-Induced Peripheral Neuropathy by investigator's judgment * Patient who are receiving pregabalin for the treatment of Chemotherapy- Induced Peripheral Neuropathy * Patients who have moderate to severe pain intensity which is not controlled with 300mg of pregabalin per day for at least 1 week: NRS ≥ 4 * Patients who need opioid combination treatment with existing pregabalin treatment * Naïve patients for strong opioid (Naïve patient defined as who did not treated for 90 days) * Patients who signed a written informed consent form Exclusion Criteria: * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant. UNLESS they are: * women whose partners have been sterilized by vasectomy or other means * two birth control methods. The two methods can be a double barrier method or a barrier method plus a hormonal method. Adequate barrier methods of contraception include: diaphragm, condom (by the partner), intrauterine device (copper or hormonal), sponge or spermicidal. Hormonal contraceptives include any marketed contraceptive agent that includes an estrogen and/or (Progest - progesterone) progestational agent. * Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive urine pregnancy test * Patients with known hypersensitivity to Oxycodone or Naloxone or to any of the excipients * Patients with severe respiratory depression with hypoxia and/or hypercapnia * Patients with severe chronic obstructive pulmonary disease * Patients with cor pulmonale * Patients with severe bronchial asthma * Patients with non-opioid induced paralytic ileus * Patients with moderate to severe hepatic impairment * Targin product contains lactose. Patients with rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption should not take * Abnormal aspartate aminotransferase (AST; SGOT), alanine aminotransferase (ALT; SGPT), or alkaline phosphatase levels (\>2.5 times the upper limit of normal, it is allowed \>5 times the upper limit of normal in case of transition in liver) or an abnormal total bilirubin and/or creatinine level(s) (greater than 1.5 times the upper limit of normal), gamma glutamyl transpeptidase (GGT or GGTP) ≥ 3 times the upper limit of normal * Patients with uncontrolled seizures * Requiring interventional treatment for pain such as neural blockade procedure or regional infusion * Patients with increased intracranial pressure * In the investigator's opinion, subjects who are receiving hypnotics or other central nervous system (CNS) depressants that may pose a risk of additional CNS depression with opioid study medication * Patients with myxoedema, not adequately treated hypothyroidism or Addison's disease * Patients receiving opioid substitution therapy for opioid addiction (e.g. methadone or buprenorphine) * Clinically significant impairment of cardiovascular, respiratory and renal function * Major surgery within 1 month prior to screening or planned surgery * Chemotherapy or radiotherapy within 2 weeks prior to the screening visit, or planned chemotherapy or radiotherapy during the study period. * Mainly pain originated other than Chemotherapy-Induced Peripheral Neuropathy * Patients with diabetic neuropathy * With a disability that may prevent the patient from completing all study requirements and in particular, interfere with 24hrs pain intensity score * Patients known to have, or suspected of having a history of drug abuse * Patients with history of opioid or drug dependence * Any situation where opioids are contraindicated * Having used other investigational drugs at the time of enrollment, or within 30 days of enrollment