Utidelone plus bevacizumab shows promise in ERBB2-negative MBC

Combination treatment with utidelone plus bevacizumab has demonstrated therapeutic potential in patients with ERBB2-negative metastatic breast cancer (MBC) and active brain metastases in a single-arm, phase II study conducted in China.

The study included 47 women (median age 53 years) with ERBB2-negative MBC, of which 35 had untreated brain metastases and 12 had brain metastases that progressed after local radiotherapy. These patients received treatment with bevacizumab (15 mg/kg on day 1) and utidelone (30 mg/m² on days 1–5) every 3 weeks until disease progression or unacceptable toxicity.

The primary endpoint of central nervous system (CNS) objective response rate (ORR) based on RECIST 1.1 was 42.6 percent (95 percent confidence interval [CI], 28.3–57.8). This was similar to the CNS ORR according to the Response Assessment in Neuro-Oncology Brain Metastases criteria (40.4 percent, 95 percent CI, 26.4–55.7).

Over a median follow-up of 11.0 months, the median progression-free survival (PFS) was 7.7 months (95 percent CI, 5.6–9.7), while the median CNS-PFS was 10.6 months (95 percent CI, 8.4 months to not reached). The median overall survival was 15.1 months (95 percent CI, 12.0 months to not reached).

As for safety, the most common grade ≥3 treatment-emergent adverse events were decreased lymphocyte count (10.6 percent) and decreased white blood cell count (6.4 percent). None of the patients experienced serious or fatal adverse events.