The oral antidepressant duloxetine (Cymbalta) at 60 mg/d improved chemotherapy-induced painful neuropathy in a randomized, double-blind, placebo-controlled, phase III trial.1 Overall, 59% of patients treated with duloxetine experienced some pain relief, 33% reported at least a 30% decrease in pain, and 21% reported at least a 50% decrease in pain.
“The pain relief in this trial was clinically meaningful,” said Ellen Lavoie Smith, PhD, Assistant Professor in University of Michigan’s School of Nursing, Ann Arbor. Duloxetine is the first drug shown to be effective for this disorder in a large randomized controlled trial.
Painful chemotherapy-induced neuropathy interferes with activities of daily living and can manifest as numbness, tingling, or shock-like feelings, mainly in the feet and hands. Some patients have this chronic painful adverse event for months or years, and it can be disabling.
The study included 231 patients treated with oxaliplatin or paclitaxel randomly assigned to duloxetine followed by placebo vs placebo followed by duloxetine. Although mean pain scores decreased in both treatment arms, the decrease was greater in the duloxetine arm. Also, when compared to placebo-treated patients, patients taking duloxetine reported less pain-related interference with activity, mood, walking, work, enjoyment of life, and social relationships.
About one-third of patients in the duloxetine arm had pain scores that were unchanged, and 11% had an increase in pain. “Unfortunately, no medication is completely effective,” she said.
Side effects reported in less than 10% of patients included fatigue, insomnia, nausea, somnolence, and dizziness.
Dr. Smith said that all patients were started on duloxetine at 30 mg/d for 1 week and then escalated to 60 mg/d for 4 additional weeks of treatment. The gradual dosing was used to reduce the side effects of duloxetine.
‘A Step Forward’
Nicholas Vogelzang, MD, US Oncology in Las Vegas, said, “This is a step forward. Duloxetine won’t work for every patient, but a significant proportion gain pain control. This gives a glimmer of hope for patients who are so debilitated by chemotherapy.” Dr. Vogelzang was moderator of an ASCO press conference where this paper was discussed.
Duloxetine is currently approved for the treatment of depression and painful diabetic neuropathy. ■
Disclosure: Drs. Smith and Vogelzang reported no potential conflicts of interest.
1. Smith EML, Pang H, Cirrincione C, et al: CALGB 170601: A phase III double-blind trial of duloxetine to treat painful chemotherapy-induced peripheral neuropathy (CIPN). 2012 ASCO Annual Meeting. Abstract CRA9013. Presented June 5, 2012.