Methadone to treat chemotherapy-induced peripheral neuropathy (METACIN): study protocol

Area of Science:

• Oncology
• Neurology
• Pharmacology

Background:

• Chronic chemotherapy-induced peripheral neuropathy (CIPN) affects 70% of cancer patients, leading to neuropathic pain.
• Duloxetine is the standard treatment, but methadone, effective for refractory neuropathic cancer pain, is under-studied for CIPN.
• Limited treatment options exist for this common and debilitating condition.

Purpose of the Study:

• To determine if methadone is a viable treatment for CIPN.
• To compare the efficacy of methadone versus duloxetine in reducing pain intensity in CIPN patients.

Main Methods:

• A triple-blind, double-dummy randomized controlled trial.
• Adult cancer patients with >grade 1 CIPN lasting ≥3 months were randomized to methadone or duloxetine.
• Weekly follow-up over 5 weeks with dose titration; 24-week follow-up for adverse events and dose escalation.

Main Results:

• Primary outcome: Efficacy of methadone vs. duloxetine in reducing average pain intensity from baseline to study end.
• Secondary outcomes: Improvements in functional interference and quality of life.
• Exploratory outcomes: Pain reduction thresholds (≥30% or ≥50%), patient-reported global impression of change, adverse events, and methadone dose escalation.

Conclusions:

• This study will provide crucial data on methadone's efficacy and safety as a treatment for CIPN.
• Findings could expand treatment options for cancer patients suffering from CIPN.
• Results will inform clinical practice and guidelines for managing CIPN.