Study Shows Drug Is Effective for Cancer Patients with Peripheral Neuropathy
Results of a phase III trial (CALGB-170601) show that duloxetine (Cymbalta®) effectively treats painful peripheral neuropathy caused by certain types of chemotherapy. The results, from the first randomized clinical trial to show an effective treatment for chemotherapy-induced peripheral neuropathy (CIPN), were published April 3, 2013, in JAMA.
CIPN causes chronic pain, tingling, and numbness—mainly in the hands and feet—that can interfere with a patient’s ability to perform everyday activities and to receive needed doses of chemotherapy. CIPN affects 20 to 30 percent of cancer patients treated with taxane and platinum-based chemotherapy drugs, which can damage nerve cells. CIPN may continue for months or even years after treatment is stopped and may worsen over time.
Ellen Lavoie Smith, PhD, of the University of Michigan, and her colleagues studied 231 people aged 25 or older who had previously reported high levels of pain from peripheral neuropathy. Patients in the trial had been treated with paclitaxel (Taxol®), oxaliplatin (Eloxatin®), docetaxel (Taxotere®), or cisplatin (Platinol®).
The researchers found that 59 percent of the patients who took daily duloxetine for 5 weeks reported a decrease in pain of any amount, compared with 38 percent of the patients who took a placebo. The average pain score of patients in the duloxetine group fell about 10 percent, which the researchers noted is "considered to represent a minimally clinically important change," while the average scores of those in the placebo group fell about 3 percent. The difference is similar to that seen in other studies of duloxetine for chronic pain.
The most commonly reported side effect was fatigue, which was higher in patients taking duloxetine than in patients taking the placebo.
The researchers acknowledged some potential limitations to the study. For example, they did not document the use of other pain medications during the study period and did not study duloxetine treatment beyond 5 weeks. In addition, the dropout rate due to adverse side effects was higher among participants who received duloxetine.
“This study is the first to demonstrate statistically significant improvements in established neuropathic pain compared to placebo,” said Joanna Brell, MD, of NCI’s Division of Cancer Prevention. “While duloxetine is approved by the Food and Drug Administration for painful neuropathy caused by diabetes, there are no [approved] treatments for CIPN.” Duloxetine is also approved to treat depression.