SYHX2011 is a novel albumin-bound paclitaxel formulation designed to simplify drug preparation and reduce skin rash by replacing most non-particulate human serum albumin with mannitol and sucrose. This exploratory analysis evaluated updated survival outcomes after extended follow-up of a multicenter, randomized, doubleblind, phase III trial comparing SYHX2011 with approved albumin-bound paclitaxel (PAB; Keaili (R)) in patients with unresectable locally advanced or metastatic breast cancer. Overall, 459 patients were randomized 1:1 to receive SYHX2011 or PAB. At the December 29, 2025 data cutoff, median follow-up was 25.2 and 25.0 months, respectively. Median progression-free survival (PFS) was 7.6 months with SYHX2011 and 5.6 months with PAB (p=0.028; hazard ratio [HR]=0.79, 95% confidence interval [CI]: 0.63-1.01). Median overall survival (OS) was not reached with SYHX2011 and was 24.3 months with PAB (p=0.11; HR=0.84, 95% CI: 0.64-1.11). Descriptive trends toward longer PFS and OS with SYHX2011 were observed across hormone receptor-positive, triple-negative, first-line, and later-line subgroups. Although OS data remain immature and subgroup findings require cautious interpretation, the updated results support continued clinical evaluation of SYHX2011 as an albumin-bound paclitaxel option for advanced breast cancer.