A Study of Tapentadol Immediate-Release in the Treatment of Patients With Acute Pain From Bunionectomy

The purpose of this study is to demonstrate the efficacy of at least 1 dose of tapentadol IR 50 mg and/or 75 mg versus placebo using the sum of pain intensity difference at 48 hours (SPID48) to measure analgesic effect in Korean patients with acute pain following bunionectomy.

This is a randomized (study drug assigned by chance like flipping a coin), double-blind (neither physician nor patient knows the name of the assigned drug), placebo-controlled, parallel-group, multicenter study to evaluate the efficacy and safety of tapentadol immediate-release (IR) 50 mg and 75 mg in patients who are undergoing bunionectomy (a surgical procedure to remove a bunion). This study was designed to be a similar study to the pivotal global study of PAI-3003/KF32 in order to bridge the results from the global studies and to show similarity in effect of tapentadol between Korean and Caucasian population which will allow extrapolation of the foreign clinical data of tapentadol into Korea. The study will be divided into screening period, surgical period, qualification period, and a double-blind treatment period. The study length, including the screening period, will be up to a maximum duration of 32 days. Eligible patients will be randomly assigned to 1 of 3 treatment groups (tapentadol IR 50 mg, tapentadol IR 75 mg or placebo) in a 1:1:1 ratio. Efficacy and safety assessments will be performed during the study.

Eligibility Criteria:
Inclusion Criteria:

* Patients who are undergoing primary unilateral first metatarsal bunionectomy that includes a distal Chevron osteotomy only with or without the Akin procedure
* Healthy or medically stable on the basis of clinical laboratory tests performed at screening. If results are outside the normal reference ranges, the patient may be included only if the investigator judges the abnormalities or deviations from normal to be not clinically significant or to be appropriate and reasonable for the population under study
* Women must be postmenopausal, surgically sterile, abstinent, or practicing or agree to practice an effective method of birth control if they are sexually active before entry and throughout the study. Women of childbearing potential must have a negative serum β human chorionic gonadotropin pregnancy test at screening and a negative urine pregnancy test before surgery
* If a male and sexually active, agrees to use an approved method of birth control to prevent pregnancy in his female partner and not to donate sperm from the day of first study drug intake until 3 months after the day of last study drug intake. To qualify for entry into the double-blind treatment period, the following criteria must be met:
* Qualifying baseline pain intensity (PI) must be rated as greater than or equal to 4 on an 11-point (0 to10) PI numerical rating scale (NRS), recorded within 30 minutes before randomization
* Qualifying PI must occur no earlier than 10 hours after the first surgical incision
* Qualifying baseline PI must occur within 9 hours after termination of the systemic analgesia during the postoperative surgical period

Exclusion Criteria:

* History of seizure disorder or epilepsy suggested by the presence of mild or moderate traumatic brain injury, stroke, transient ischemic attack, or brain neoplasm within 1 year of screening, and/or severe traumatic brain injury, episode(s) of unconsciousness of more than 24 hours duration, or posttraumatic amnesia of more than 24 hours duration within 15 years of screening
* History of malignancy within the past 2 years before the start of the study
* Evidence of active infections that may spread to other areas of the body or a history of human immunodeficiency virus 1 or 2
* Clinical laboratory values reflecting severe renal insufficiency
* Moderately or severely impaired hepatic function, or patients with abnormal alanine aminotransaminase or aspartate aminotransferase
* Clinical laboratory values outside acceptable limits for surgery in the opinion of the investigator
* A clinically significant disease that in the investigator's opinion may affect efficacy or safety assessments
* Treated with anticonvulsants, monoamine oxidase inhibitors, tricyclic antidepressants, neuroleptics, or serotonin norepinephrine reuptake inhibitor within 2 weeks before randomization
* Systemic steroid therapy, excluding inhalers or topical steroids, within the 4 weeks before screening
* Women who plan to become pregnant during the study, or who are breast feeding