Evaluation of fentanyl buccal soluble film (FBSF) in opioid tolerant cancer patients with neuropathic breakthrough cancer pain (BTP)

Abstract

Neuropathic pain, in particular neuropathic breakthrough cancer pain (BTP), is poorly understood and difficult to effectively control. Pain clinicians generally use agents that are not ordinarily used as analgesics, such as anticonvulsants and antidepressants, alpha-2 adrenergic agonists and NMDA receptor antagonists in combination with opioids as treatments. In 2009, a fentanyl buccal soluble film (FBSF) was approved for the management of BTP in opioid-tolerant cancer patients ≥18 years of age. The safety and efficacy of FBSF was studied in a multicenter, randomized, double-blind, placebo-controlled, multiple-crossover study in adult cancer patients on stable opioid therapy who reported ≤4 BTP episodes per day. A subgroup of patients from that trial was analyzed to evaluate the efficacy and safety of FBSF in patients with neuropathic BTP pain. The primary variable evaluated was the sum of pain intensity differences (SPID) at 30 minutes with higher scores correlating with greater pain relief. Adverse events were recorded and summarized. Fourteen females and nine males (mean age ∼51 years) were included in the subgroup analysis and breast cancer (n=6) was the most prevalent type of cancer among these patients. Pain reduction after treatment with FBSF was greater than after treatment with placebo. SPID values in patients with neuropathic BTP were significantly higher for FBSF-treated episodes than for those episodes treated with placebo beginning 15 minutes after dosing. FBSF was as effective in this subgroup as in the entire population. The most commonly reported adverse events included somnolence, nausea, and dizziness. The results of this subgroup analysis indicate that FBSF may aid in the management of breakthrough cancer pain in patients experiencing neuropathic pain. This subgroup analysis was supported by a grant from Meda Pharmaceuticals, Inc.