Primary analysis of the phase 3 trial BG01-1323L demonstrated that utidelone plus capecitabine significantly improved progression-free survival (PFS) and overall response rate (ORR) vs capecitabine alone in heavily pretreated patients with metastatic breast cancer (MBC). Here, we report the final overall survival (OS) analysis and updates of other endpoints.In total, 405 patients were randomised 2:1 to receive utidelone (30 mg/m2 IV daily, days 1-5, over 90 minutes) plus capecitabine (1000 mg/m2 orally bid, days 1-14) or capecitabine alone (1250 mg/m2 orally bid, days 1-14) every 21 days. The secondary endpoint, OS, was estimated using the Kaplan-Meier product-limit approach at a two-sided alpha level of 0.05 after the pre-specified 310 death events had been reached. Exploratory analyses of the primary endpoint, PFS, and the secondary endpoint, ORR, were also done. Safety was analysed in patients who had at least one dose of study drug.At the final OS analysis, the median duration of follow up was 19.6 months in the utidelone plus capecitabine group and 15.4 months in the capecitabine alone group. In the intention-to-treat population, 313 deaths had occurred at data cut-off, 203 of 270 patients in the combination group and 110 of 135 in the monotherapy group. Median OS in the combination group was 19.8 months compared with 16.0 months in the monotherapy group (hazard ratio [HR]=0.75, 95% CI 0.59-0.94, P=0.0142). The updated analysis of PFS and ORR showed that the combination therapy remained superior to monotherapy. Safety results were similar to those previously reported with respect to incidence, severity and specificity. No late-emerging toxicities or new safety concerns occurred.For heavily pretreated, anthracycline- and taxane-resistant MBC patients, utidelone plus capecitabine significantly improved OS vs capecitabine alone. These results support the use of utidelone plus capecitabine as a novel therapeutic regimen for patients with MBC.