Fentanyl Buccal Tablets Versus Immediate Release Oxycodone for Breakthrough Pain in Patients With Chronic Pain

Key Inclusion Criteria: * The patient has chronic pain of at least 3 months duration associated with any of the following conditions: diabetic peripheral neuropathy, postherpetic neuralgia, traumatic injury, complex regional pain syndrome, back pain, neck pain, fibromyalgia, chronic pancreatitis, osteoarthritis, rheumatoid arthritis, or cancer. Other chronic painful conditions may be evaluated for possible inclusion. * The patient is currently using at least one of the following: at least 60 mg of oral morphine/day, or at least 25 mcg of transdermal fentanyl/hour, or at least 30 mg of oxycodone/day, or at least 8 mg of hydromorphone/day, or an equianalgesic dose of another opioid/day as ATC therapy for at least 7 days before administration of the first dose of study drug. * The patient is willing to provide written informed consent, including a written opioid agreement form, to participate in this study. * Women must be surgically sterile, 2 years postmenopausal, or, if of childbearing potential, using a medically accepted method of birth control and agree to continued use of this method for the duration of the study. * Any patient with cancer should have a life expectancy of at least 3 months. * The patient reports an average PI score, over the 24 hours prior to screening, of 6 or less (0=no pain through 10=pain as bad as you can imagine) for their chronic pain. * The patient experiences, on average, at least 1 and less than 5 BTP episodes per day while taking ATC opioid therapy, and on average, the duration of each BTP episode is less than 4 hours during the screening period. * The patient currently uses opioid therapy for alleviation of BTP episodes, occurring at the location of the chronic pain, and achieves at least partial relief. * The patient must be willing and able to successfully self administer the study drug, comply with study restrictions, complete the electronic diary, and return to the clinic for scheduled study visits as specified in this protocol. Key Exclusion Criteria: * The patient has uncontrolled or rapidly escalating pain as determined by the investigator or has pain uncontrolled by therapy that could adversely impact the safety of the patient or that could be compromised by treatment with study drug. * The patient has a recent history (within 5 years) or current evidence of alcohol or other substance abuse. * The patient has known or suspected hypersensitivities, allergies, or other contraindications to any ingredient in either stu…