Durect has released results from a phase II clinical trial in chronic low back pain for Eladur (Transdurr-Bupivacaine), Durect's investigational transdermal bupivacaine pain patch. This study was conducted by Durect's collaborator, King Pharmaceuticals, which is now owned by Pfizer. In this study of 263 patients suffering from chronic low back pain, the primary efficacy endpoint of demonstrating a positive treatment difference for the mean change in pain intensity scores from baseline to the mean of weeks 11 and 12 between Eladur as compared to placebo was not met.  Complete data analysis is ongoing.

Eladur is an investigational transdermal drug patch intended to deliver bupivacaine for up to three days from a single application.  Bupivacaine, the active agent in Eladur, is a potent, FDA-approved long-acting local anesthetic used in regional anesthesia for local tissue infiltration, nerve block, and epidural and intrathecal anesthesia.  Eladur demonstrated a positive efficacy trend in a phase IIa study for post-herpetic neuralgia (PHN).

"Demonstrating efficacy against placebo in a chronic low back pain trial is challenging for any topical locally-acting product," stated James E. Brown, DVM, president and CEO of Durect.  "We and Pfizer are continuing to analyze this most recent study and will work together to determine next steps."