Capsaicin 179 mg Patch Versus Oral Duloxetine in Patients With Chemotherapy-induced Peripheral Neuropathy

Chemotherapy induced peripheral neuropathy (CIPN) is a frequent and disabling complication of systemic chemotherapy, particularly with oxaliplatin or taxanes. The incidence of CIPN is variable but approximately 30-40% of patients treated with neurotoxic chemotherapy agents develop CIPN after long-term use of taxanes or oxaliplatin.

This CIPN is essentially a sensory peripheral neuropathy with pain manifested by unpleasant symptoms such as numbness, tingling, and less frequently shooting/burning pain. These symptoms spread proximally to affect both lower and upper extremities in a characteristic "stocking and glove" distribution.

Many symptoms of CIPN may resolve completely for some patients. However, CIPN is only partly reversible for most. In the worst instances, it does not appear to be reversible at all and can even increase over time.

CIPN is difficult to manage. Only duloxetine is recommended, based on the positive result of a randomized phase III double-blind placebo-controlled crossover trial. The use of duloxetine resulted in a greater reduction in pain and was effective in decreasing numbness and tingling in the feet. But, systemic antidepressants are often associated with toxicities and patients often refuse or abandon the treatment.

Capsaicin inhibits neural transmission in sensory axons and has been proven as effective on the intensity of pain for post-herpetic neuralgia and human immunodeficiency virus-associated neuropathy. Efficacy appears at one month and persists for at least 2 months.

Only a few studies focused on the efficacy of capsaicin 179 mg patch on the intensity of CIPN-induced pain. These non-randomized studies show that more than 50% of patients have a reduction in pain intensity of more than 30%.

Until now, no clinical trial has compared the efficacy of the capsaicin 179 mg patch with duloxetine.

Accordingly, this open-label phase 3, randomized, multicenter trial, will compare efficacy and safety of capsaicin patch with oral duloxetine on painful CIPN persisting more than 3 months after the end of the responsible chemotherapy.