Sustained-release noninferior to immediate-release pregabalin formulation

The novel once-daily sustained-release (SR) pregabalin formulation is safe and as good as the twice-daily immediate-release (IR) formulation at reducing peripheral neuropathic pain, according to the results of a phase III trial.

A total of 371 patients with diabetic peripheral neuropathy (DPN) or postherpetic neuralgia (PHN) in South Korea were randomized to receive once-daily SR pregabalin or twice-daily IR pregabalin (150–600 mg/d) for 12 weeks. The randomization used a double-dummy blinding and done using a stratified permuted block method.

The primary outcome was the daily pain rating scale (DPRS) score at the end of treatment, averaged from the last seven available scores.

Of the patients, 319 (86.0 percent) completed the 12-week treatment (SR pregabalin: n=154; IR pregabalin: n=165; per protocol set: n=296). At week 12, there was no significant difference in the DPRS score between the two groups (least square mean difference, 0.06, 95 percent confidence interval [CI], −0.31 to 0.42), with the lower limit of the CI above the prespecified margin (−0.78; p_{noninferiority}<0.0001).

In terms of safety, the incidence of drug-related treatment-emergent adverse events (TEAEs) was slightly higher in the SR group than in the IR group, although the difference was not significant (2.7 percent vs 1.1 percent). None of the patients developed serious drug-related TEAEs or died.