A randomized, double-blind, placebo-controlled study of fentanyl buccal tablets for breakthrough pain: efficacy and safety in Japanese cancer patients

Context Rapid-onset opioids for treating breakthrough pain (BTP) in patients with cancer are needed in the Japanese care setting. Objectives To examine the efficacy and safety of fentanyl buccal tablets (FBTs) for treating BTP in Japanese cancer patients. Methods This was a randomized, double-blinded, placebo-controlled study. In subjects receiving around-the-clock (ATC) opioids at doses of 30mg or more to less than 60mg or 60–1000mg of oral morphine equivalents (low and high ATC groups), dose titration was started from 50 to 100μg FBT, respectively. Subjects whose effective dose was identified were randomly allocated to a prearranged administration order of nine tablets (six FBTs and three placebos), one tablet each for nine episodes of BTP (double blinded). Efficacy and safety of FBT were assessed for patients overall, and also for the low and high ATC groups. Results A significant difference was observed between FBT and placebo for the primary endpoint of pain intensity difference at 30 minutes. The analgesic onset of FBT was observed from 15 minutes in several secondary variables (e.g., pain relief). Adverse events were somnolence and other events associated with opioids were mostly mild or moderate. Of the low and high ATC group subjects, an effective FBT dose was identified in 72.2% and 73.1%, respectively. Conclusion The safety of FBT and its analgesic effect on BTP were confirmed in Japanese cancer patients receiving opioids. Our findings suggest that analgesic onset may occur from 15 minutes after FBT, and that FBT can be administered to patients with low doses of ATC opioids.