Efficacy and Safety of Sublingual Fentanyl Tablets in Treatment of Breakthrough Pain in Cancer Patients.

Inclusion Criteria: Males or females 17 years of age or older Stable cancer-related pain. Are receiving a stable, fixed-schedule oral opioid regimen equivalent to 60 to 1000 mg of oral morphine per day or transdermal fentanyl therapy equivalent to 50 to 300 µg/h, and are on a stable dose of opioid medication for relief of breakthrough pain for at least 14 days prior to screening. Experiencing 1-4 episodes of breakthrough pain per day. Meet the criteria defined in the Eastern Cooperative Oncology Group (ECOG) Performance Status for Grade 0, 1, or 2. Exclusion Criteria: Are pregnant or lactating. Have uncontrolled or rapidly escalating pain. Have moderate to severe ulcerative mucositis. Have a cardiopulmonary disease that would increase the risk of administering potent opioids. Have neurologic or psychologic disease that would compromise data collection Have any clinically significant condition that would, in the investigator's opinion, preclude study participation. Are currently taking monoamine oxidase inhibitors (MAOIs), or have taken MAOIs within 14 days prior to enrolling in the study. Have received strontium 89 therapy within 60 days prior to entering the study. Have received anti-neoplastic therapy within 2 weeks of study entry that, in the investigator's opinion, will influence assessment of breakthrough pain Have received any investigational drug (non-approved) within 30 days prior to the first dose of study medication, or are scheduled to receive an investigational drug other than EN3267 during the course of the study. Have hypersensitivities, allergies, or contraindications to fentanyl. Have a significant prior history of substance abuse or alcohol abuse. May have difficulty complying with the protocol, as assessed by the investigator.