Efficacy and tolerability of fentanyl buccal tablet (FBT) in opioid-tolerant cancer patients with neuropathic pain

Abstract

19549 Background: Fentanyl buccal tablet (FBT), a new formulation recently approved by the FDA for opioid-tolerant patients with cancer-related breakthrough pain (BTP), provides rapid-onset analgesia. Neuropathic pain is the primary pain pathophysiology in a significant proportion of patients with chronic cancer pain; therefore, the efficacy and safety of FBT was studied in this subpopulation. Methods: The efficacy and safety of FBT in the treatment of BTP in opioid-tolerant cancer patients with neuropathic pain were evaluated as a sub-analysis of two randomized, double-blind, placebo-controlled studies. Of the 45 patients in the sub-analysis (50% male, 86% white, mean age 56 years), 30 identified an effective FBT dose during open-label titration and were randomly assigned to double-blind crossover dose sequences of 10 tablets (7 FBT, 3 placebo). Pain intensity (PI) and pain relief (PR) were recorded at intervals after dosing. The primary efficacy measures were the sum of pain intensity differences (PIDs) for the first 30 (SPID30) and 60 minutes (SPID60); secondary efficacy measures included PIDs, PR, and total pain relief (TOTPAR). Use of supplemental BTP medication and adverse events (AEs) were recorded. Results: Combined data (all values mean ±SD) favored FBT vs placebo for SPID30 (3.35±3.11 vs 1.88±2.58) and were significant for SPID60 (9.90±7.19 vs 5.51±6.06; 95% CI, 2.99, 5.81). There was a greater reduction in PI following FBT vs placebo at 10 minutes (PID, 0.55±0.89 vs 0.24±0.48), which continued through observation periods of up to 2 hours (3.43±2.44 vs 1.95±1.99). Higher PR scores were noted following FBT vs placebo at 10 minutes (0.43±0.39 vs 0.21±0.28), which continued for up to 2 hours (1.99±0.72 vs 1.36±0.60). TOTPAR was better following FBT vs placebo at 15 (0.88±0.89 vs 0.48±0.73), 30 (2.42±1.85 vs 1.40±1.65), 45 (4.29±2.90 vs 2.61±2.68), and 60 minutes (6.34±4.02 vs 3.94±3.81). Patients were more than twice as likely to require supplemental opioids for BTP episodes following placebo vs FBT. AEs were typical for opioids; e.g., headache (23%), nausea (18%), dizziness (18%), vomiting (14%), and fatigue (11%). Conclusions: FBT was effective and well tolerated in a subgroup of cancer patients with BTP in association with chronic neuropathic pain. No significant financial relationships to disclose.