216P Sacituzumab govitecan in metastatic triple-negative breast cancer: Efficacy -with a focus on brain metastases- and toxicity in a real-world cohort

ASCENT demonstrated the efficacy of Sacituzumab govitecan (SG) in patients (pts) with metastatic triple-negative breast cancer (mTNBC), and led to EMA approval in November 2021. We set up an ambispective bicentric cohort study to assess the real-world effectiveness and safety of SG in pts with mTNBC. This study included pts treated through the French Early Access Program from May 2021 to January 2023. Pts provided written consent for their clinical data to be reported. The cohort included 103 pts with a median age of 55 years [26-89]; 7/74 pts (9%) had BRCA1/BRCA2 germline mutation, 15 pts (15%) de novo metastatic disease and 32 pts (31%) brain metastases. Pts had previously received a median of 2 lines [1-10] of treatment in advanced setting, 29 pts (28%) and 6 pts (6%) had previously received anti-PD-1/PD-L1 and PARP inhibitors respectively. After a median follow-up of 9.6 months, median progression-free survival (PFS) and overall survival (OS) were 4.0 months (95%CI[3.4-5.3]) and 9.2 months (95%CI[7.2-NR]) respectively. The objective response rate (ORR) was 30% (2 pts achieved a complete response). Among pts with brain metastases, median PFS was 3.7 months (95%CI[2.6-6.2]) and OS 6.7 months (95%CI[6.3-NR]). Of 103 treated pts, 78 pts (76%) discontinued SG due to progressive disease (73 pts, 94%), toxicity (1 pt, 1%), physical deterioration (3 pts, 4%) or the patient’s request (1 pt, 1%). Twenty-five pts (24%) were on treatment at data cut-off. The median duration of treatment was 3 months, corresponding to 6 cycles of SG. Dose reductions were required in 19 pts (18%) within a median of 2 cycles [2-11], due to gastrointestinal toxicity (6 pts), hematological toxicity (8 pts), liver enzyme elevation (1 pt), febrile neutropenia (3 pts), and physical deterioration (1 pt). There was no related death to SG. Our real-world data in mTNBC pts are consistent with results of the ASCENT trial in terms of ORR and safety, but observed PFS and OS are numerically shorter, including pts with brain metastases.