Open-Label Extension to Evaluate the Long-Term Safety, Tolerability and Analgesic Efficacy

An Open-Label Extension Study to Evaluate the Long-Term Safety, Tolerability and Analgesic Efficacy of Numorphan® CR (Oxymorphone HCL Controlled Release) in Subjects With Cancer Pain or Chronic Lower Back Pain.

The purpose of this study is to evaluate the long-term safety and tolerability of oxymorphone ER as an analgesic in cancer and lower back pain subjects having chronic moderate to severe pain.

Inclusion Criteria:

• The subject enrolled in this study must have been previously randomized and dosed in the double-blind treatment period of study EN3202-016 or EN3202-019 and completed the exit visits for these studies.
• Males or females, age 18 and 75 years, inclusively.
• The subject continues to have chronic moderate to severe back or cancer pain that requires opioid medication. Women must continue to be of non-childbearing potential.

Exclusion Criteria:

• The subject experienced any serious drug related adverse events in studies EN3202-016 or EN3202-019.
• The subject withdrew from EN3202-016 or EN3202-019 for a reason other than lack of efficacy.
• Subjects with known allergies to opiate-class narcotic agents (morphine, codeine, hydrocodone, propoxyphene, meperidine, oxycodone, etc.) or naproxen, or subjects who have any medical condition in which opiates are medically contraindicated.