The purpose of the study is to determine the effect of Egalet® Morphine once daily compared to MST Continus twice daily on pain intensity and use of rescue medication for break through pain after 2 weeks of treatment in patients with pain due to cancer.

Inclusion Criteria:

• The patient has stable strong opioid use equipotent to 30-240 mg oral morphine sulphate daily for a minimum of 2 weeks prior to entering the run-in phase.
• The patient has opioid-sensitive pain caused by active cancer.
• The patient is aged minimum 18 years.

Exclusion Criteria:

• The patient has a life expectancy less than 2 months.
• The patient has received chemotherapy or radiation therapy less than 4 weeks prior to entering run-in phase
• Patients with medical conditions contraindicating morphine treatment
• The patient has hepatic disease or impaired kidney function
• The patient is taking monoamine oxidase inhibitors (MAOIs) or has taken a MAOI within two weeks prior to entering baseline.
• The patient is taking other opioid agonists or antagonists, zidovudine or cimetidine.