A Study to Evaluate the Effectiveness and Safety of Tapentadol (CG5503) in the Treatment of Acute Pain From Bunionectomy Compared With Placebo

A Study to Evaluate the Effectiveness and Safety of Tapentadol (CG5503) in the Treatment of Acute Pain From Bunionectomy Compared With Placebo

A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Multicenter Study to Evaluate the Efficacy and Safety of Tapentadol Immediate-Release Formulation in the Treatment of Acute Pain From Bunionectomy

The purpose of this study is to evaluate the analgesic efficacy and safety of tapentadol immediate-release (IR [CG5503]) for use in the relief of moderate to severe acute pain, compared with placebo, in adult Taiwanese patients with acute pain following bunionectomy.

Patients undergoing bunionectomy (a surgical procedure to remove a bunion, an enlargement of the joint at the base of the big toe comprised of bone and soft tissue) often experience moderate to severe acute pain post-surgery. Normally such pain is controlled when patients receive repeated doses of opioid analgesics. Tapentadol (CG5503) is a newly synthesized opioid drug acting as a centrally acting analgesic like opioid analgesics but has a different mode of action. This study, a randomized (patients are assigned different treatments based on chance), double-blind (neither investigator nor patient knows which treatment the patient receives), placebo-controlled (placebo is an inactive substance that is compared with a drug to test whether the drug has a real effect in a clinical trial), parallel-group (each group of patients will be treated at the same time), multicenter study (the study is performed at more than one clinic) is designed to evaluate the effectiveness (level of pain control) and safety (side effects) of tapentadol immediate-release (IR) 50 mg or 75 mg versus placebo. The study will consist of a screening phase, during which the patients will be evaluated for study entry (Days -28 to -2) followed by the surgical period (Day -1) during which the bunionectomy will be performed and which will start with the first surgical incision and continues until termination of the popliteal sciatic block (PSB) infusion. During the qualification period (Day 1) which starts after termination of the post-operative continuous PSB infusion, patients will be evaluated for entry in the double blind treatment phase. Patients will be randomly assigned to one of three treatment groups to receive either 50 mg tapentadol IR, 75 mg tapentadol IR or a placebo if their PI is equal to or greater than 4 on a 0-10 numerical rating scale. The inpatient double-blind treatment period will be 72 hours in duration and will include a final end-of-double-blind evaluation (on Day 4, i.e., 72 hours after the administration of the first dose) for all patients. Any patient requiring analgesia for pain relief in addition to study drug during the double-blind treatment period will be discontinued from the study due to lack of efficacy. All patients who discontinue for lack of efficacy will complete pain assessments and the Patient Global Impression of Change (PGIC) before receiving rescue medication. Pain intensity and pain relief will be periodically assessed during the treatment period using rating scales. Safety evaluations include monitoring of adverse events, physical examinations, and clinical laboratory tests. The study length, including the screening period, will be up to a maximum duration of 32 days.

Tapentadol IR 50 mg will be administered as a single oral dose once every 4 to 6 hours, during the double blind treatment period.

Tapentadol IR 75 mg will be administered as a single oral dose once every 4 to 6 hours, during the double blind treatment period.

Placebo will be administered as a single oral dose once every 4 to 6 hours, during the double blind treatment period.

Pain Intensity (PI) was assessed on an 11-point numerical rating scale from 0=no pain to 10=pain as bad as you can imagine. PID was the difference between baseline PI (prior to the first dose) and current PI at assessment. SPID was calculated as the time-weighted Sum of PID scores over 48 hours. Total score ranges from -480 (worst) to 480 (best) for SPID48. A higher value of SPID indicates greater pain relief.

Rescue medication was defined as any analgesic medication used for participants discontinued due to lack of efficacy (including those started at time of discontinuation) or analgesic medication used during the double-blind period for completed participants.

Response rate was defined as the percentage of participants with a 30 percent or greater reduction in pain intensity from baseline to 12, 24, 48, and 72 hours. Pain intensity was assessed on a 11-point numerical rating scale from 0=no pain to 10=pain as bad as you can imagine. Participants with no assessment at the given time point, who used an analgesic medication prior to the time point, or who had worse pain intensity at the time point compared to baseline were assigned a percent reduction of 0 percent.

Response rate was defined as the percentage of participants with a 50 percent or greater reduction in pain intensity from baseline to 12, 24, 48, and 72 hours. Pain intensity was assessed on a 11-point numerical rating scale from 0=no pain to 10=pain as bad as you can imagine. Participants with no assessment at the given time point, who used an analgesic medication prior to the time point, or who had worse pain intensity at the time point compared to baseline were assigned a percent reduction of 0 percent.

Pain Intensity (PI) was assessed on an 11-point numerical rating scale from 0=no pain to 10=pain as bad as you can imagine. PID was the difference between baseline PI (prior to the first dose) and current PI at assessment. SPID was calculated as the time-weighted Sum of PID scores over 12, 24, and 72 hours. Total score ranges from -120 (worst) to 120 (best) for SPID12, -240 (worst) to 240 (best) for SPID24, -720 (worst) to 720 (best) for SPID72. A higher value of SPID indicates greater pain relief.

Participants rated pain relief on 5-point categorical scale of 0-4 (0=none, 1=A little, 2=Some, 3=A lot, 4=Complete). Total Pain Relief (TOTPAR) was calculated as the time-weighted sum of pain relief scores up to Hour 12, 24, 48, and 72. Total score ranges from 0 (worst) to 48 (best) for TOTPAR12, 0 (worst) to 96 (best) for TOTPAR24, 0 (worst) to 192 (best) for TOTPAR48, and 0 (worst) to 288 (best) for TOTPAR72. A higher value of TOTPAR indicated greater pain relief.

Participants rated pain relief on 5-point categorical scale of 0-4 (0=none, 1=A little, 2=Some, 3=A lot, 4=Complete). Pain Intensity (PI) was assessed on an 11-point numerical rating scale from 0=no pain to 10=pain as bad as you can imagine. PID was the difference between baseline PI (prior to the first dose) and current PI at assessment. PRID is the sum of pain relief and PID at the same assessment time. SPRID was calculated as the time-weighted Sum of PRID scores over 12, 24, 48, and 72 hours. Total score ranges from -120 (worst) to 168 (best) for SPRID12, -240 (worst) to 336 (best) for SPRID24, -480 (worst) to 672 (best) for SPRID48, and -720 (worst) to 1008 (best) for SPRID72. A higher value of SPRID indicates greater pain relief.

The PGI-C is a 7-point scale that requires the participants to assess how much their illness has improved or worsened relative to a baseline state at the beginning of the intervention. The response options are: 1=very much improved; 2=much improved; 3=minimally improved; 4=no change; 5=minimally worse; 6=much worse; and 7=very much worse. Higher scores indicate worsening.

Inclusion Criteria: Patients must be undergoing primary unilateral first metatarsal bunionectomy that includes a distal Chevron osteotomy only, with or without the Akin procedure Patients must be healthy or medically stable on the basis of clinical laboratory tests performed at screening Women must be postmenopausal, surgically sterile, abstinent, or practicing or agree to practice an effective method of birth control and have a negative serum pregnancy test at screening and a negative urine pregnancy test before surgery If a male, must use an approved method of birth control and does not donate sperm from the day of study drug administration until 3 months afterwards Qualifying baseline Pain Intensity must be rated as greater than or equal to 4 on an 11-point (0 to 10) PI NRS, recorded within 30 minutes before randomization, no earlier than 10 hours after the first surgical incision and within 9 hours after termination of the continuous Popliteal Sciatic Block (PSB) infusion Exclusion Criteria: - History of seizure disorder or epilepsy, severe traumatic brain injury, episode(s) of unconsciousness of more than 24 hours duration, malignancy in the past 2 years with the exception of successfully treated basal cell carcinoma Mild or moderate traumatic brain injury, stroke, transient ischemic attack, or brain neoplasm within 1 year of screening Renal insufficiency, impaired hepatic function Use of anticonvulsants, monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs), neuroleptics, serotonin norepinephrine reuptake inhibitors (SNRIs), selective serotonin reuptake inhibitors (SSRIs) or triptans

Chen YJ, Chiang CC, Huang PJ, Huang J, Karcher K, Li H. Tapentadol immediate-release for acute postbunionectomy pain: a phase 3, randomized, double-blind, placebo-controlled, parallel-group study in Taiwan. Curr Med Res Opin. 2015 Nov;31(11):2001-9. doi: 10.1185/03007995.2015.1082992. Epub 2015 Sep 21.