A Randomized Withdrawal, Active- and Placebo-controlled, Double-blind, Multi-center Phase III Trial Assessing Safety and Efficacy of Oral CG5503 PR* in Subjects With Moderate to Severe Chronic Malignant Tumor-related Pain
Normally chronic tumor related pain is controlled when subjects receive repeated doses of
opioid analgesics. However, opioid therapy is commonly associated with side effects such as
nausea, vomiting, sedation, constipation, addiction, tolerance, and respiratory depression.
CG5503, a newly synthesized drug with an prolonged release (PR) formulation, also acts as a
centrally acting pain reliever but has a dual mode of action. The aim of this trial is to
investigate the effectiveness (level of pain control) and safety (side effects) of CG5503 PR
compared with no drug (placebo) and corresponding dose of morphine (an opioid commonly used
to treat tumor related pain). This trial is a randomized, double-blind (neither
investigator nor patient will know which treatment was received), active- and
placebo-controlled, parallel-group, multicenter trial.
The trial includes a 2 week titration phase starting with either 40 mg morphine (PR) bid or
100 mg CG5503 PR bid. Based on effectiveness and side effects subjects can up-titrate in
steps of 50 mg CG5503 PR (20 mg morphine PR) to a maximal dose of 250 mg CG5503 PR bid or
100 mg morphine PR bid. If subjects meet the stabilisation criteria at the end of the
titration phase they will be re-randomized to either placebo or active treatment and will
continue 4 weeks at the last dose level in the maintenance phase.
Assessments of pain relief include the pain intensity numeric rating scale (NRS), patient
global impression of change scale (PGIC). Safety evaluations include monitoring of adverse
events, physical examinations, and clinical laboratory tests. Venous blood samples will be
collected for the determination of serum concentrations of CG5503
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment
Proportion of subjects classified as responders. Responders are subjects who meet all of the following criteria: • Complete 28 days of the Maintenance phase • Have a mean pain intensity < 5.0 point on an 11-poi
End of trial
Hans Georg Kress, Dr.
Clinic of Anaesthesiology and Pain Management, AKH Vienna
Bulgaria: Bulgarian Drug Agency