Methodological issues in conducting pilot trials in chronic pain as randomized, double-blind, placebo-controlled studies

Primary tabs

SCIENCE
Abstracts
Methodological issues in conducting pilot trials in chronic pain as randomized, double-blind, placebo-controlled studies
Key Take-Away: 

Peripheral neuropathy causes loss of sensation, numbness, and sometimes pain in the feet, legs, or hands due to nerve impairment caused by chronically high blood sugar and diabetes. In this study, methodological issues were investigated with respect to tapentadol extended release (ER) for managing chronic pain. 

The efficacy of tapentadol extended release (ER) for managing chronic pain has been demonstrated in large-scale, randomized, controlled, phase 3 studies (N=318–1,030) in patients with chronic osteoarthritis (OA) pain, low back pain (LBP), and pain related to diabetic peripheral neuropathy (DPN), which led to registration in many regions, including the United States and Europe. 

ABSTRACT: 
Background: 

The efficacy of tapentadol extended release (ER) for managing chronic pain has been demonstrated in large-scale, randomized, controlled, phase 3 studies (N=318–1,030) in patients with chronic osteoarthritis (OA) pain, low back pain (LBP), and pain related to

diabetic peripheral neuropathy (DPN), which led to registration in many regions, including the United States and Europe. 2 pilot 12-week, randomized, double-blind, placebo-controlled phase 2 studies of tapentadol ER for chronic pain (OA knee pain or LBP, n=91; DPN or peripheral herpetic neuralgia [PHN] pain; n=91) were conducted in Japan. These small exploratory studies were substantially underpowered compared with the registration trials.

Expand section
Methods: 

Patients in both studies were randomized (2:1) to tapentadol ER (25–250 mg) or placebo for 12 weeks (≤6-week titration plus maintenance periods).

Expand section
Results: 

For the primary efficacy endpoint (change in pain intensity from baseline to last week of treatment; last observation carried forward), both studies failed to differentiate between tapentadol ER and placebo; least-squares mean differences (95% confidence intervals)

for tapentadol ER vs. placebo were −0.1 (−1.04, 0.80) in the OA/LBP study and −0.1 (−1.10, 0.99) in the DPN/PHN study. More than 80% of patients took concomitant analgesics during these studies. Tapentadol was well tolerated.

Expand section
Conclusion: 

Both studies were associated with methodological issues, including populations with different disease entities, small sample sizes,

use of concomitant analgesics, and possible placebo effect that may have led to the failure to differentiate between tapentadol ER and placebo.

Expand section
Drug Res (Stuttg) 2016; 66(07): 363-370
Exploratory, Tapentadol, Chronic pain, Opioid, Randomized controlled Trial, Efficacy
Log in or register to post comments