A Safety and Efficacy Study of Sufentanil Transdermal System in Patients With Chronic Pain Due to Cancer

Inclusion Criteria: 1. Male or female patients aged 18 to 75 with a diagnosis of cancer; 2. If female, is non-pregnant (negative pregnancy test at Visit 1) and non-lactating; 3. If female, is not of childbearing potential 4. Documented history of moderate to severe chronic cancer pain requiring around-the-clock therapy and are likely to benefit from WHO step III opioid analgesics for the duration of the study; 5. Has been informed of the nature of the study and has provided written informed consent; 6. Is willing, able, and competent to complete the entire study and comply with study instructions Exclusion Criteria: 1. Patient is a pregnant or lactating female (serum pregnancy test conducted at the Screening Visit); 2. Any ongoing serious adverse events (SAEs) at screening and at baseline; 3. Has scheduled elective surgery or other invasive procedures during the period of study participation; 4. Patients with a known intolerance to opioid analgesics or any excipient of the Investigational Product; 5. Patients with respiratory depression with hypoxia and/or hypercapnia, sever chronic obstructive pulmonary disease, cor pulmonale, severe bronchial asthma, paralytic ileus, (obstructive) sleep apnea syndrome; 6. Evidence of clinically significant cardiovascular, renal, hepatic or psychiatric disease, as determined by medical history, clinical laboratory tests, ECG results, and physical examination, that would place the patient at risk upon exposure to the study medication or that may confound the analysis and/or interpretation of the results; 7. Abnormal aspartate aminotransferase (AST; SGOT), alanine aminotransferase (ALT; SGPT), or alkaline phosphatase levels (\> 3 times the upper level of normal) or an abnormal total bilirubin level (\> 1.5 times the upper level of normal) or creatinine clearance \< 50 ml/min (calculated using the Cockcroft-Gault formula); 8. Patients with uncontrolled seizures; 9. Patients with increased intracranial pressure; 10. Patients who are receiving hypnotics or other central nervous system (CNS) depressants that, in the opinion of the investigator, may pose a risk of additional CNS depression with opioid medication; 11. Patients with myxoedema, inadequately controlled hypothyroidism or Addisons disease; 12. History of alcohol and/or drug abuse (or a positive urine drug screen at Visit 1) within one year preceding the Screening Visit; 13. Active skin disease; 14. Patients suffering from diarrhea and/or opioid withdrawal; 15. Known positive Hepatitis B or C or HIV status; 16. Has participated in another clinical study of drugs or devices parallel to or \< 1 month before study entry, or previous participation in this study; 17. Is an employee of the investigator or study site with direct involvement in the proposed study or other studies under the direction of that investigator or study site, or is a family member of the employees or the investigator.