Long-term Safety Study of Sublingual Fentanyl Tablets 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. 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: Have previously been exposed to EN3267. Are pregnant or lactating. Have uncontrolled or rapidly escalating pain. Have any clinically significant condition that would, in the investigator's opinion, preclude participation in the study or compromise data collection. These conditions may include cardiopulmonary disease, and/or neurologic/psychologic conditions. Are scheduled to take MAOIs (monoamine oxidase inhibitors) during the study. Are scheduled to receive anti-neoplastic therapy that, in the investigator's opinion, will influence assessment of breakthrough pain. Are scheduled to receive an investigational drug other than EN3267 during the course of the study. Have hypersensitivity, allergy or contraindication to fentanyl. Have significant prior history of substance abuse or alcohol abuse. Would have difficulty complying with the protocol, as assessed by the investigator. Are unable to read, write, or comprehend the English language in order to complete diaries.