To assess clinical outcomes in patients with ERBB2-negative metastatic breast cancer treated with indoximod plus a taxane….A taxane (paclitaxel [80 mg/m2] weekly 3 weeks on, 1 week off, or docetaxel [75 mg/m2] every 3 weeks) plus placebo or indoximod (1200 mg) orally twice daily as first-line treatment....This randomized clinical trial found that, among patients with ERBB2-negative metastatic breast cancer, addition of indoximod to a taxane did not improve PFS compared with a taxane alone.