Efficacy & Safety Study of Nonracemic Methadone for the Relief of Chronic Peripheral Neuropathic Pain

Diabetic Peripheral Neuropathic Pain Clinical Trial

Official title: Pilot Study to Evaluate Efficacy, Tolerability and Safety Nonracemic Methadone HCl in Patients With Chronic Peripheral Neuropathic Pain: Double-Blind, Placebo-Controlled, Crossover Study Followed by Open-Label, Single-Arm Extension

Status Completed

Clinical Trial Summary

There is a growing evidence that the d-isomer of methadone is effective in treating neuropathic pain while the l-isomer of methadone is the only effective isomer of methadone for treating somatic pain. This study will examine a combination of different amounts of the d- and l-isomers of methadone specifically tailored to the chronic peripheral neuropathic pain. Non-racemic mixture of methadone isomers will be tested in this pilot efficacy and safety study.

This study will evaluate effect of the three doses of the non-racemic mixture of methadone hydrochloride patients with chronic peripheral neuropathic pain compared with a placebo. The study will also examine the minimally effective and maximally tolerated doses of the non-racemic mixture of methadone. Finally, the safety and tolerability of the non-racemic methadone therapy will be evaluated.

Clinical Trial Description

Objectives:

• To evaluate effect of the three doses of the non-racemic methadone HCl on the metrics of pain intensity in comparison to placebo.

• To determine minimally effective and maximally tolerated doses of non-racemic methadone HCl for the treatment of diabetic peripheral neuropathic pain.

• To evaluate safety and tolerability of non-racemic methadone HCl therapy.

Study Design:

This is a pilot efficacy and safety study comprised of two parts.

Part I is a double-blind, placebo-controlled, crossover study of three daily doses (15 mg, 30 mg and 40 mg) of non-racemic methadone compared with placebo. Two lower doses (15 mg and 30 mg) will be administered for 1 week. The final dose (40 mg) will be administered for 2 weeks. After receiving three consecutive doses of the assigned drug the subjects will be switched to another regimen. Two 28-day treatment periods will be separated by a 14-day washout (drug-free) interval.

Subjects will be randomly assigned to one of the two treatment sequences:

Sequence 1: non-racemic methadone HCl (Period 1) followed by Placebo (Period 2); Sequence 2:

Placebo (Period 1) followed by non-racemic methadone HCl (Period 2).

Subjects completing Part I will be enrolled into the open-label, single-arm extension. Subjects discontinuing the study while on placebo may also be eligible for the enrollment. During the 6-week extension phase (Part II of the study) subjects will be treated with non-racemic methadone HCl with continuous dose titration driven by the clinical response (degree of pain relief) and reported adverse events. The Parts I and II will be separated by a 14-day washout (study drug-free) interval.

Number of Patients:

Up to fifty (50) subjects diagnosed with neuropathic pain associated with diabetic peripheral neuropathy will be enrolled in the study; approximately 30 subjects are expected to complete Study Part I. Enrollment will be terminated when this completion target is achieved.

Study Duration:

The duration of Study Part I is approximately 12 weeks, the duration of Study Part II is approximately 6 weeks. A total study duration (including screening and final evaluations) is expected to be approximately 20 weeks. ;

Related Conditions & MeSH terms

• Diabetic Neuropathies
• Diabetic Peripheral Neuropathic Pain
• Neuralgia

• NCT number: NCT01429181
• Study type: Interventional
• Source: MetaPharm, Inc.
• Status: Completed
• Phase: Phase 2
• Start date: January 2012
• Completion date: December 2014