Updates in the Treatment of Chemotherapy-Induced Peripheral Neuropathy

There are no known effective treatments for painful chemotherapy-induced peripheral neuropathy. To determine the effect of duloxetine, 60 mg daily, on average pain severity. Randomized, double-blind, placebo-controlled crossover trial at 8 National Cancer Institute (NCI)-funded cooperative research networks that enrolled 231 patients who were 25 years or older being treated at community and academic settings between April 2008 and March 2011. Study follow-up was completed July 2012. Stratified by chemotherapeutic drug and comorbid pain risk, patients were randomized to receive either duloxetine followed by placebo or placebo followed by duloxetine. Eligibility required that patients have grade 1 or higher sensory neuropathy according to the NCI Common Terminology Criteria for Adverse Events and at least 4 on a scale of 0 to 10, representing average chemotherapy-induced pain, after paclitaxel, other taxane, or oxaliplatin treatment. The initial treatment consisted of taking 1 capsule daily of either 30 mg of duloxetine or placebo for the first week and 2 capsules of either 30 mg of duloxetine or placebo daily for 4 additional weeks. The primary hypothesis was that duloxetine would be more effective than placebo in decreasing chemotherapy-induced peripheral neuropathic pain. Pain severity was assessed using the Brief Pain Inventory-Short Form "average pain" item with 0 representing no pain and 10 representing as bad as can be imagined. Individuals receiving duloxetine as their initial 5-week treatment reported a mean decrease in average pain of 1.06 (95% CI, 0.72-1.40) vs 0.34 (95% CI, 0.01-0.66) among those who received placebo (P = .003; effect size, 0.513). The observed mean difference in the average pain score between duloxetine and placebo was 0.73 (95% CI, 0.26-1.20). Fifty-nine percent of those initially receiving duloxetine vs 38% of those initially receiving placebo reported decreased pain of any amount. Among patients with painful chemotherapy-induced peripheral neuropathy, the use of duloxetine compared with placebo for 5 weeks resulted in a greater reduction in pain. clinicaltrials.gov Identifier: NCT00489411.

To update the ASCO guideline on the recommended prevention and treatment approaches in the management of chemotherapy-induced peripheral neuropathy (CIPN) in adult cancer survivors. An Expert Panel conducted targeted systematic literature reviews to identify new studies. The search strategy identified 257 new references, which led to a full-text review of 87 manuscripts. A total of 3 systematic reviews, 2 with meta-analyses, and 28 primary trials for prevention of CIPN in addition to 14 primary trials related to treatment of established CIPN, are included in this update. The identified data reconfirmed that no agents are recommended for the prevention of CIPN. The use of acetyl-l-carnitine for the prevention of CIPN in patients with cancer should be discouraged. Furthermore, clinicians should assess the appropriateness of dose delaying, dose reduction, substitutions, or stopping chemotherapy in patients who develop intolerable neuropathy and/or functional impairment. Duloxetine is the only agent that has appropriate evidence to support its use for patients with established painful CIPN. Nonetheless, the amount of benefit from duloxetine is limited. Additional information is available at www.asco.org/survivorship-guidelines .

Axon degeneration is an intrinsic self-destruction program that underlies axon loss during injury and disease. Sterile alpha and TIR motif-containing 1 (SARM1) protein is an essential mediator of axon degeneration. We report that SARM1 initiates a local destruction program involving rapid breakdown of nicotinamide adenine dinucleotide (NAD(+)) after injury. We used an engineered protease-sensitized SARM1 to demonstrate that SARM1 activity is required after axon injury to induce axon degeneration. Dimerization of the Toll-interleukin receptor (TIR) domain of SARM1 alone was sufficient to induce locally mediated axon degeneration. Formation of the SARM1 TIR dimer triggered rapid breakdown of NAD(+), whereas SARM1-induced axon destruction could be counteracted by increased NAD(+) synthesis. SARM1-induced depletion of NAD(+) may explain the potent axon protection in Wallerian degeneration slow (Wld(s)) mutant mice.