An Efficacy and Safety Study for Tapentadol Extended Release (JNS024ER) in Chronic Pain Participants

The purpose of this study is to evaluate the efficacy, safety and to explore the pharmacokinetics (how drugs are absorbed in the body, how they are distributed within the body and how they are removed from the body over time) of tapentadol hydrochloride extended release (ER) tablets in Japanese participants with moderate to severe chronic pain due to osteoarthritis (disorder in which the joints become painful and stiff) of knee or low back pain.

This is a randomized (study drug assigned by chance), multi-center (when more than one hospital or medical school team works on a medical research study), double-blind (neither physician nor participant knows the name of the assigned drug), placebo-control (participants are randomly assigned to a test treatment or to an identical-appearing treatment that does not contain the test drug), parallel-group (each group of participants will be treated at the same time) comparison study in participants with chronic pain due to osteoarthritis of knee or low back pain. The study duration will be of 14 weeks, which consists of a screening period of 1 week during which the participants will be evaluated for study eligibility, a treatment period of 12 weeks and a follow-up period of 1 week. The treatment period will consist of titration period (from the initiation of the study treatment to determination of the individual's maintenance dose) and maintenance period (from completion of the titration period to the completion of the treatment period). An optimal dose (maintenance dose) will be determined for each participant during the titration period and the treatment will be continued at the maintenance dose to assess the efficacy and safety. Tapentadol hydrochloride ER tablets 25 to 250 milligram or placebo will be administered orally twice daily. Efficacy and safety of the participants will primarily be evaluated by change from baseline in average pain intensity score based on 11-point Numerical Rating Scale (NRS) and Clinical Opiate Withdrawal Scale (COWS), respectively. Participants' safety will be monitored throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Participants with chronic pain due to osteoarthritis of knee or low back pain continuing for at least 12 weeks before informed consent
* Participants who did not achieve adequate analgesia (pain control) with routine treatment with an oral non-opioid analgesic (drug used to control pain) at its usual upper-limit dose or at an adequate fixed dose for at least 14 consecutive days during the 12 weeks before informed consent
* Participants who have not experienced treatment with conventional opioids, except for short term use of opioid analgesics for treatment of post-operative acute pain more than 30 days before consent or temporary use of codeine phosphate or dihydrocodeine phosphate for purposes other than pain relief (e.g. for antitussive) more than 2 days before informed consent
* Participants with average pain intensity score of greater than or equal to 5 on an 11-point Numerical Rating Scale (NRS) during 48 hours before informed consent and are considered requiring opioid treatment by the Investigator
* Participants who are able to visit the medical institutions throughout the study period

Exclusion Criteria:

* Participants who are taking a monoamine oxidase inhibitor within 14 days before informed consent
* Participants with current or a history of epilepsy or seizure disorders
* Participants suspected with intracranial hypertension (e.g. traumatic encephalopathy)
* Participants with uncontrolled or clinically significant arrhythmia (irregular heart rate)
* Participants with moderate to severe liver dysfunction or severe renal dysfunction