A single-center, randomized, double-blind, active, and placebo-controlled study of KAI-1678, a novel PKC-epsilon inhibitor, in the treatment of acute postoperative orthopedic pain.

Objective: KAI-1678, a novel inhibitor of the interaction of the epsilon isoform of protein kinase C (εPKC) with its intracellular receptor, has demonstrated activity in countering hyperalgesia in several models of pain. In this controlled randomized trial, KAI-1678 was tested for analgesic activity in an orthopedic acute postoperative pain setting.

Methods: Following hip or knee replacement surgery, subjects were treated with KAI-1678, ketorolac, or saline. Subjects recorded their pain intensity on a visual analog scale and rated their quality of analgesia. The pain intensity differences between baseline and the evaluations were summed over the first 4 hours.

Results: The analysis revealed that, while ketorolac displayed good analgesic activity, KAI-1678 was not significantly different than placebo. Analgesia quality ratings similarly did not show a difference between KAI-1678 and placebo in this pain model. A small excess of infusion site erythema was seen with KAI-1678, but otherwise the drug was safe and well tolerated.

Conclusions: We investigated the safety and efficacy of a novel inhibitor of εPKC and provide clinical evidence that inhibition of εPKC with KAI-1678 is not effective in the treatment of acute postoperative orthopedic pain.