Effectiveness, Safety, and Tolerability Study of Oxymorphone Immediate Release (IR) Oral Liquid in Opioid Tolerant Pediatric Subjects

Inclusion Criteria: 1. Males or females 2 to ≤6 years of age, inclusive 2. Chronic cancer or non-cancer pain, currently requiring treatment of pain with a strong opioid for at least 5 days (3 of 5 days at a dose \>1 mg/kg qd oral morphine equivalent) 3. Expected to continue to require a strong opioid for pain relief for at least 4 months 4. Able to swallow the oxymorphone HCl immediate-release oral liquid 5. Have been informed of the nature of the study and informed consent and assent by minor (if IRB required) has been obtained from the legally responsible parent/legal guardian in accordance with IRB requirements Exclusion Criteria: 1. Known allergy to, or a significant reaction to, oxymorphone or another opioid 2. Life expectancy \<4 months 3. Any clinical condition in the investigator's opinion that would preclude participation 4. Plan to undergo a surgical procedure within 1 month of study entry or anytime during study 5. Currently prescribed a long-acting opioid (eg., Kadian® morphine sulfate extended release) as part of their analgesic regimen 6. Received any investigational medication within 30 days prior to the first dose of study medication, or are scheduled to receive an investigational drug other than oxymorphone during the course of the study 7. An ileostomy 8. Received a monoamine oxidase inhibitor (MAOI) within 14 days prior to the start of study medication 9. Investigator anticipates that the subject would be unable to comply with the protocol 10. Parent/legal guardian is unable to complete the subject's daily study medication diary 11. Parent/legal guardian is unable to effectively communicate the subject's status to the investigator