Efficacy and safety of utidelone in pretreated patients with metastatic breast cancer in China: a multicenter, real-world study

Abstract

Background: Utidelone (UTD1), a genetically engineered epothilone derivative, has been approved in China for use in combination with capecitabine in treating metastatic breast cancer (MBC) patients previously treated with anthracyclines or taxanes. Objectives: To evaluate the real-world efficacy and safety of UTD1 in Chinese patients with MBC and to explore potential predictors of therapeutic effectiveness. Design: A multicenter, retrospective, real-world study. Methods: MBC patients who received UTD1 between March 2021 and August 2023 were identified using an electronic database. Outcome variables included progression-free survival (PFS), overall survival (OS), time to treatment failure (TTF), objective response rate (ORR), clinical benefit rate (CBR), and adverse events (AEs). Results: A total of 270 MBC patients were included, with 81.1% presenting with visceral metastasis and 23.7% with brain metastasis. The median number of treatment lines for UTD1 was 3. UTD1 showed a median PFS of 3.97 months (95% confidence interval (CI) 3.33–4.61) and a median OS of 20.63 months (95% CI 16.72–24.54). Among the patients, 17.4% received UTD1 monotherapy, and 82.6% received UTD1-based combination therapy. The median TTF was 2.80 months (95% CI 2.31–3.29). The ORR was 8.4%, and the CBR was 33.5%. The most common AE was peripheral neuropathy (PN, 55.2%). Patients with unresolved PN from previous therapy or receiving UTD1 through intravenous infusion on days 1–5 were more likely to develop ⩾grade 3 PN. Conclusion: UTD1 is a new option for patients who have previously received taxanes and anthracyclines, with its clinical toxicity controllable.