Duloxetine in Symptomatic Chemotherapy-Induced Peripheral Neuropathy: Single-Center Experience Beyond the Clinical Trial.

e20713 Background: Duloxetine, a serotonin-norepinephrine reuptake inhibitor, is the only agent demonstrated effective in treating pain related with chemotherapy induced peripheral neuropathy (CIPN). The phase III randomized, double-blind, placebo-controlled trial published in 2013 showed a moderate effect on CIPN pain relief, becoming the first choice. Methods: Single-institution consecutive cancer patients with CIPN treated with duloxetine during the year 2014 were prospectively collected. Aim of the study was to evaluate the drug's efficacy, rate of compliance and adverse-effects profile. Only patients with chronic symptomatic CIPN, non-progressive disease and two follow-up visits were included. CIPN was graded employing the Total Neuropathy Score and NCI.CTC v4. Response to duloxetine was assessed with patient global impression of change (PIGC) scale (1: no benefit; 7: excellent response). Results: 73 patients were analyzed. 39 (53%) were women. Median age was 61 (29-81). 51 and 20 patients received platinum and taxane-based regimen, respectively, for colorectal (n = 40), breast (n = 17), germinal (n = 5), gynecological (n = 3), lung (n = 1), gastric (n = 2), and other (n = 5) cancer. Median TNS was 9 (1-17). Severity of CIPN was grade 1 (12%), grade 2 (49%) and grade 3 (12%). 45 (61.6%) patients discontinued duloxetine treatment due to side-effects (38%) or ineffectiveness (23%). No differences on rates of stopping treatment due to side-effects were observed between gender. Discontinuation due to perception of ineffectiveness was more frequently reported by men (37.1% vs 10.5%, p = 0.005). Women presented higher punctuations on PIGC scale compared with men (3.8 ±2.1 vs 1.94 ±1.8, p = 0.005) and were more probable that continue treatment (20% vs 34.2%, p = 0.022). No significant differences according CIPN severity neither type of chemotherapy were observed in drop-out and retention rates. Conclusions: More than one-third of all patients stop duloxetine early due to intolerable side-effects, a rate three times higher than reported. Among treated, women population seems to experiment more benefit. Low tolerability and male gender may limit duloxetine usefulness in symptomatic CIPN.