Sacituzumab Govitecan initial dose reduction in polish patients with metastatic triple-negative breast cancer: impact on efficacy and safety

Sep 23, 2026

Uploaded by Ben

Sacituzumab govitecan (SG) is used for metastatic triple-negative breast cancer in patients receiving at least two prior lines, typically at 10 mg/kg IV on Days 1 and 8. In Poland, early precautionary dose reductions occur in practice due to fixed 200 mg vials and drug waste without formal guidance. This retrospective study assesses how initial SG dose reduction affects real-world outcomes, tolerability, survival, and safety, using Kaplan–Meier, chi-square comparisons, and a multivariate Cox model to estimate independent effects on overall and progression-free survival.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Abstract

Background

Methods

Results

Conclusions

Introduction

Triple-negative breast cancer and treatment context

Mechanism of action of sacituzumab govitecan (SG)

Cancer Chemotherapy and Pharmacology (2025) 95:97 [https://doi.org/10.1007/s00280-025-04823-3](https://doi.org/10.1007/s00280-025-04823-3) ORIGINAL ARTICLE Sacituzumab Govitecan initial dose reduction in polish patients with metastatic triple-negative breast cancer: impact on efficacy and safety Małgorzata Pieniążek1,2 · Marcin Kubeczko3 · Manuela Las-Jankowska4,5 · Anna Polakiewicz-Gilowska3 · Aleksandra Łacko1,2 · Michał Jarząb3 · Zuzana Bielčiková6 · Renata Pacholczak-Madej7,8 · Miroslawa Püsküllüoğlu9 Received: 17 July 2025 / Accepted: 19 September 2025 © The Author(s) 2025 Abstract Background Sacituzumab govitecan (SG) is approved for metastatic triple-negative breast cancer in ≥ 2 line setting at 10 mg/ kg IV on Days 1 and 8 (21-day cycle) . Trials confirmed its superiority over 8 mg/kg with manageable safety. In practice, precautionary dose reductions are used despite no formal guidance. In Poland, fixed 200 mg vials and unreimbursed drug waste lead to early dose adjustments. Methods This retrospective study evaluated the impact of initial SG dose reduction on treatment outcomes and tolerability in Polish patients. Medical records provided data on baseline features, treatment, survival, and safety. Kaplan-Meier and chi-square tests were used for survival and group comparisons. A multivariate Cox model assessed the independent effect of dose reduction on overall survival (OS) and progression-free survival (PFS) . Significance was set atp< 0.05. Results Among 83 patients (median age 55, range 30–86), initial dose reductions ≥ 10% were observed in 16 patients (19.3%), including 9 (10.8%) with dose reduced ≥ 20%. Administrative adjustments (reductions> 10% to flat doses of 200 mg multiplications) accounted for 18.1% of the entire cohort. Grade ≥ 2 and ≥ 3 adverse events occurred in 83.1% and 56.6%, respectively. In a multivariate analysis, a ≥ 20% initial dose reduction remained an independent predictor of shorter PFS (HR: 2.6; 95% CI: 1.1–6.6; p = 0.04) and OS (HR: 6; 95% CI: 2–17.5; p = 0.001). Initial dose reduction did not affect toxicity. Conclusions In this preliminary report initial dose reduction of SG negatively impacted PFS and OS without reducing toxicity, highlighting the need for further studies and dosing policy adjustments. Keywords Sacituzumab govitecan · Triple negative breast cancer · Metastases · Dose reduction · Real world data 􀀍 Małgorzata Pieniążek [pieniadzgosia@interia.pl](pieniadzgosia@interia.pl) 􀀍 Marcin Kubeczko [marcin.kubeczko@gliwice.nio.gov.pl](marcin.kubeczko@gliwice.nio.gov.pl) 1 Department of Oncology, Wrocław Medical University, Plac Hirszfelda 12, Wrocław 53-413, Poland 2 Lower Silesian Comprehensive Cancer Center, Plac Hirszfelda 12, Wrocław 53-413, Poland 3 Breast Cancer Unit, Gliwice Branch, Maria SkłodowskaCurie National Research Institute of Oncology, Gliwice 44-102, Poland 4 Surgical Oncology, Oncology Centre, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Bydgoszcz 85-067, Poland 5 Department of Clinical Oncology, Oncology Center-Prof Franciszek Lukaszczyk Memorial Hospital, Bydgoszcz 85-796, Poland 6 Department of Oncology, First Faculty of Medicine, Charles University, General University Hospital, Prague, Czech Republic 7 Department of Gynecological Oncology, Maria SklodowskaCurie National Research Institute of Oncology, Garncarska Street 11, 31-115 Krakow, Branch, Poland 8 Department of Anatomy, Jagiellonian University Medical College, ŚwiętejAnny 12, Krakow 31-008, Poland 9 Department of Clinical Oncology, Kraków Branch, Maria Sklodowska-Curie National Research Institute of Oncology, Kraków, Poland 1 3 Introduction Triple-negative breast cancer (TNBC) represents a biologically aggressive breast cancer subtype characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression [1, 2] . Due to the lack of actio

FAQs

Why were initial dose reductions of SG used in Polish patients despite no formal guidance?

The study reports that, in Poland, fixed 200 mg vials and unreimbursed drug waste lead clinicians to adjust doses early in practice even without formal guidance.

How did an initial ≥20% dose reduction affect efficacy outcomes?

In multivariate analysis, an initial ≥20% dose reduction independently predicted shorter progression-free survival (HR 2.6) and overall survival (HR 6), indicating worse efficacy.

Did initial SG dose reduction change toxicity rates?

Initial dose reduction did not affect toxicity; the paper states that reduced dosing did not reduce adverse event-related outcomes.

Sep 23, 2026

Uploaded by Ben