PURPOSE The primary objective of this randomized, double-blind, placebo-controlled, multicenter phase II study (Alliance A221805) was to screen two doses of duloxetine for preventing sensory oxaliplatin-induced peripheral neuropathy (OIPN). METHODS Participants were randomly assigned 1:1:1 to receive once daily 30 mg duloxetine, 60 mg duloxetine, or placebo. Eligible participants had stage II to III colorectal cancer and no baseline neuropathy, had Eastern Cooperative Oncology Group performance status 0-2, were age 25 years and older, and received oxaliplatin via one of the following doses and schedules: 85 mg/m 2 every 2 weeks (6 or 12 doses) or 130 mg/m 2 every 3 weeks (4 doses). Duloxetine/placebo was taken once daily beginning day 1 of cycle 1 and continued for 17 weeks. The primary end point, a composite response reflecting sensory OIPN symptom severity and onset, was measured in weeks 19-21 using a validated participant-reported outcome survey assessing extremity numbness, tingling, and pain. Response was defined as a participant-reported highest score of ≤2 (ie, 1 = not at all; 2 = a little) on survey items. To be evaluable for the response end point, eligible participants must have initiated oxaliplatin and submitted ≥1 postbaseline OIPN survey. RESULTS Of the 199 participants (n = 66, 30 mg duloxetine; n = 66, 60 mg duloxetine; n = 67, placebo), 46, 47, and 50 (N = 143, 71.8%), respectively, were evaluable for primary end point analysis based on modified intention-to-treat criteria. Participant mean age was 55.1 years (standard deviation = 10.4). Most were White (n = 113, 80.7%) and male (n = 82, 58.6%). The proportion of responders among those receiving placebo (68.0%) was similar to those receiving duloxetine 30 mg (65.2%) or 60 mg (66.0%). Duloxetine adherence rates, measured via pill counts—30 mg (54%), 60 mg (57%), and placebo (59%) groups—were low (<75%). CONCLUSION Duloxetine is not more promising than placebo for preventing sensory OIPN.
Smith et al. (2026) studied this question.