Real-world effectiveness and safety of Sacituzumab Govitecan in metastatic triple-negative breast cancer: results from the multicenter retrospective observational SACISUR cohort in Southern Spain

Background: Sacituzumab govitecan (SG) has demonstrated efficacy in metastatic triple-negative breast cancer (mTNBC) in clinical trials, but real-world data from routine clinical practice remains limited. This study aimed to evaluate the effectiveness and safety of SG in mTNBC patients in Southern Spain. Methods: This observational, multicenter, retrospective study included 159 mTNBC patients who received at least one cycle of SG between January 2022 and December 2023. Primary endpoints included real-world progression-free survival (rwPFS), overall survival (rwOS), and safety. Secondary endpoints explored treatment tolerability and management of adverse events. A pre-specified subset analysis focused on patients with central nervous system (CNS) metastases. Results: The median age of patients at diagnosis was 50 years (46.5% premenopausal). Median rwPFS was 4.6 months (95% CI 3.7-6.3) and rwOS was 10.9 months (95% CI 7.6-14.2). The objective response rate was 31.2%, with a disease control rate of 68.9%. Patients with CNS metastases (13.8%) had a median rwPFS of 2.3 months (95% CI 1.3-3.2). The most common adverse events were neutropenia (59.4%, grade 3-4: 30.4%) and diarrhea (49%, grade 3-4: 8.2%). Granulocyte colony-stimulating factor was administered as primary prophylaxis in 29.6% of patients and as secondary prophylaxis in 17.6%. Treatment discontinuation due to adverse events occurred in 5.7% of patients, while 43.4% required at least one dose reduction. Conclusion: SG demonstrated effectiveness and tolerability in mTNBC patients treated in routine practice, including those with CNS metastases, consistent with ASCENT trial results. These findings support the use of SG in clinical practice for mTNBC patients and suggest clinically meaningful activity and a manageable safety profile in patients with CNS involvement, despite the clinical challenges presented by this subgroup.