The Phase 3 study is a randomized-withdrawal placebo-controlled trial included three phases: an open-label phase, during which the optimized 100-250mg two times per day dose of tapentadol ER was determined for each patient, a 12-week double-blind maintenance phase, during which patients with a one-point or greater reduction in pain intensity were randomized either to continue taking tapentadol ER or to receive placebo, and a follow-up period after discontinuation of drug.
In the trial, the primary efficacy endpoint was the mean change in average pain intensity from baseline to the last week of the 12-week double-blind maintenance phase, as determined by an 11-point pain rating scale or numerical rating scale (NRS).
The study data showed that patients undergoing three weeks of treatment with tapentadol ER and those who continued on an optimized dose of tapentadol ER for an additional 12 weeks experienced better pain control compared to those who switched to placebo.
Janssen Research & Development Integrated Operations vice president and head Christine Auschwitz said the Phase 3 data showed that tapentadol ER was effective at providing pain management for patients with chronic, moderate to severe pain associated with DPN.