Exparel as a nerve block? It very well may still happen, but the manufacturer of Exparel has hit a snag in its effort to have the surgical-pain drug approved by the FDA as a nerve block.

Pacira Pharmaceuticals this week said Exparel (bupivacaine liposome injectable suspension) had failed in a late-stage clinical trial to determine its efficacy in blocking intercostal nerves. A Phase 3 study of 180 patients in 5 countries produced mixed results. Patients in some countries responded favorably, but those in others had a very high placebo response. Pacira said it is further analyzing the data to better understand why results differed.

In May, Pacira reported positive results from a Phase 2 portion of a clinical trial to determine efficacy as a femoral nerve block for knee arthroplasty.

Pacira said it has 2 more Phase 3 studies in the works and that the FDA has indicated that a single positive pivotal trial will be sufficient to spur approval of the drug as a nerve block. It said it still expects to file for marketing approval for that indication early in 2014.

Exparel, which is opioid-free and uses a time-release delivery system to treat post-surgical pain with bupivacaine for up to 3 days, is currently indicated for single-dose administration into the surgical site to produce postsurgical analgesia.

Jim Burger