Conditions: Diabetic Peripheral Neuropathy
Keywords: Diabetic Peripheral Neuropathy Painful Polyneuropathy Peripheral neuropathy
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 460
Healthy volunteers: no

Brief summary:
The purpose of this study is to evaluate the efficacy, safety, and tolerability of orally administered tapentadol extended release (ER) at dosages of 100 to 250 mg twice daily compared with placebo in patients with moderate to severe pain due to chronic, painful diabetic peripheral neuropathy (DPN) who tolerated tapentadol (ER) and have an initial treatment effect (pain improvement) after a 3-week, open-label titration period.

Detailed description:
This is a randomized-withdrawal (only patients that have an initial response to tapentadol are assigned to either tapentadol or placebo), placebo-controlled, multicenter study evaluating the efficacy, safety, and tolerability of orally administered tapentadol, using the extended release tamper-resistant formulation (TRF), at dosages of 100 to 250 mg twice daily in patients with moderate to severe pain due to chronic, painful DPN. The study consists of 1) an open-label (all people involved know the identity of the intervention) phase, including a 13-day screening period, a 5-day washout period (where patients are to stop taking their pain medication), a 3-day pre-titration pain-intensity evaluation period (where patients will record their pain intensity twice daily in the morning and evening), and a 3-week, open-label titration period (all patients receive tapentadol study drug), 2) a 12-week, double-blind (neither physician nor patient knows the name of the assigned drug) maintenance phase, and 3) a posttreatment phase of approximately 10 to 14 days. The study will evaluate the effectiveness of orally administered tapentadol ER versus placebo in reducing patients' pain intensity. The pain intensity will be assessed by comparing the baseline pain level to the level at week 12 of the maintenance phase. The total duration of study drug treatment for each patient will be approximately 15 weeks. Safety and tolerability will be evaluated by vital signs, physical examinations, clinical laboratory tests, 12-lead electrocardiograms (ECGs), standardized neurologic examinations, and monitoring of adverse events. Patients will be titrated on tapentadol ER from a starting dose of 50 mg twice daily to the patient's optimal dose ranging between 100 mg and 250 mg twice a day, or placebo. All doses of study medication will be taken orally with approximately 120 ml of water with or without food for a maximum timeframe of 15 weeks.

Arms:
arm 1: None arm 2: None

Interventions: intervention 1: Tapentadol extended release (ER) intervention 2: Placebo
Intervention descriptions: intervention 1: Type= range, unit= mg, number= 100 to 250, form= tablet, route= oral use. Tapentadol ER optimal dose ranging between 100 mg and 250 mg twice daily for 15 weeks. intervention 2: Form= tablet, route= oral use. Matching placebo twice daily.

Protocol document: