5PSQ-022 Follow-up the effectiveness and safety of sacituzumab-govitecan in a cohort of patients with triple-negative metastatic breast cancer: a multicentre study

<h3>Background and Importance</h3> Sacituzumab-govitecan (SG) is an antibody-drug conjugate approved for unresectable/metastatic triple-negative breast cancer (TNBC), available in the Spanish public health system since late 2022. Real-life data remains scarce. <h3>Aim and Objectives</h3> This update, based on more mature data after a longer follow-up period, aims to analyse the effectiveness and safety of SG in TNBC patients from the three main university hospitals in the city. <h3>Material and Methods</h3> Retrospective, observational, and multicentre study was conducted, including all patients treated with SG until November 2023, with a median follow-up of 10.3 months. Data were obtained from medical records and analysed with SPSS Statistics v.21. Variables collected: sex, age, body mass index (BMI), hormone receptor (HR), human epidermal growth receptor-2 (HER2) status, primary granulocyte-colony-stimulating factor(G-CSF) prophylaxis, location of metastases, breast-cancer-gene (BRCA) mutational status, Eastern Cooperative Oncology Group (ECOG) score, treatment duration, objective response rate (ORR) according to RECIST-v1.1 criteria, progression-free survival (PFS), overall survival (OS), treatment discontinuation, cycles received, previous chemotherapy (CT) lines, and adverse effects (AEs) according to Common Terminology Criteria for Adverse Events-v5 (CTCAE). <h3>Results</h3> Forty-six patients were included (100% female); median age 52 (Interquartile range (IQR)=45–61). Mean BMI 26 (standard deviation (SD) =4.4). 100% HR-negative and 100% HER2-negative. 32.6% received primary prophylaxis with G-CSF. Lung metastases were the most frequent (56.5%), followed by bone (43.5%), hepatic (25.5%) and ganglionic (21.3%). 56.5% BRCA-negative, 6.5% BRCA2 and 34.8% not available. Most of the patients had a baseline ECOG 0–1 (72%). Median duration of treatment was 3.1 months (IQR=1.5–7.0). To date, two patients were still on treatment. Median follow-up: 10.3 months (IQR=3.5–15.5). ORR 32.6% (30.4% RP and 2.2% RC), stable disease in 21.7% and progression in the rest. Median PFS was 3.8 months (IC 95%: 2.5–5.1) and OS 10.1 months (IC 95%: 5.9–14.3). 81.8% of patients discontinued treatment due to disease progression and 15.9% exitus. Median total of cycles received was five (IQR=2.5–8.0) and a median of two (IQR=1–3) previous CT-lines in metastatic-stage. 97.8% of the patients had some AE during treatment. Most frequents: asthenia (80% (G3–4:6.7%)), anaemia (66.7% (G3–4:8.9%)), neutropenia (51% (G3–4:17.7%)), diarrhoea (46.7% (G3–4:6.7%)), alopecia (42.2% (G3–4:4.4%)). 69.6% had any reduction or delay of dose because of toxicity and no patient discontinued treatment due to AEs. <h3>Conclusion and Relevance</h3> Median PFS and OS were lower than in the pivotal ASCENT trial. While most patients experienced AEs, none led to treatment discontinuation. Further studies with a larger sample size are needed to confirm these results. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest