OBJECTIVES

The primary objective of this study was to assess the efficacy and tolerability of tapentadol immediate release (IR) in patients who were candidates for joint replacement surgery due to end-stage joint disease. A secondary objective was to compare tapentadol IR with oxycodone HCl IR with respect to efficacy and prespecified tolerability end points.

METHODS

This 10-day, Phase III, randomized, double-blind, active- and placebo-controlled study compared the efficacy and tolerability of tapentadol IR, oxycodone HCl IR, and placebo in patients with uncontrolled osteoarthritis pain who were candidates for primary replacement of the hip or knee as a result of end-stage degenerative joint disease. Patients received tapentadol IR 50 mg, tapentadol IR 75 mg, oxycodone HCl IR 10 mg, or placebo every 4 to 6 hours during waking hours. The primary end point was the sum of pain intensity difference (SPID) over 5 days. Secondary efficacy end points included 2- and 10-day SPID; 2-, 5-, and 10-day total pain relief (TOTPAR); and the sum of total pain relief and pain intensity difference (SPRID). Prespecified noninferiority comparisons with oxycodone HCl IR were performed with respect to efficacy (based on 5-day SPID) and tolerability (based on incidence of the reported adverse events (AEs) of nausea and/or vomiting and constipation).

RESULTS

Of 666 patients originally enrolled, 659 were included in the efficacy analysis (51% male; 91% white; mean age, 61.2 years; mean weight, 97 kg). Five-day SPID was significantly lower in those treated with tapentadol IR (tapentadol IR 50 mg: least squares mean difference [LSMD] = 101.2 [95% CI, 54.58- 147.89]; tapentadol IR 75 mg: LSMD = 97.5 [95% CI, 51.81-143.26]) or oxycodone HCl IR (LSMD = 111.9 [95% CI, 66.49-157.38]) (all, P < 0.001). Tapentadol IR 50 and 75 mg and oxycodone HCl IR 10 mg were associated with significant reductions in pain intensity compared with placebo, based on 2- and 10-day SPID and 2-, 5-, and 10-day TOTPAR and SPRID (all, P < 0.001). The efficacy of tapentadol IR 50 and 75 mg was noninferior to that of oxycodone HCl IR 10 mg; however, the incidence of selected gastrointestinal AEs (nausea, vomiting, and constipation) was significantly lower for both doses of tapentadol IR compared with oxycodone HCl IR 10 mg (nominal P < 0.001). The odds ratios for nausea and/or vomiting for tapentadol IR 50 and 75 mg relative to oxycodone HCl IR 10 mg were 0.21 (95% CI, 0.128-0.339) and 0.32 (95% CI, 0.204-0.501), respectively; for constipation, the corresponding odds ratios were 0.13 (95% CI, 0.057-0.302) and 0.20 (95% CI, 0.098-0.398). Rates of treatment discontinuation were 18% (28/157) in the tapentadol IR 50-mg group, 26% (43/168) in the tapentadol IR 75-mg group, 35% (60/172) in the oxycodone HCl IR 10-mg group, and 10% (17/169) in the placebo group. In a post hoc analysis, tapentadol IR 50 mg was associated with a significantly lower incidence of treatment discontinuation than was oxycodone HCl IR 10 mg (P < 0.001).

CONCLUSIONS

In these patients with uncontrolled osteoarthritis pain who were awaiting joint replacement surgery, tapentadol IR 50 and 75 mg were associated with analgesia that was noninferior to that provided by oxycodone HCl IR 10 mg. Tapentadol treatment was associated with improved gastrointestinal tolerability.