ESMO 2025 First-line sacituzumab govitecan improves progression-free survival in metastatic triple-negative breast cancer

MedNet.nl: In patients with locally advanced, unresectable, or metastatic triple-negative breast cancer (TNBC) who are not eligible for immunotherapy, first-line treatment with sacituzumab govitecan leads to better outcomes than standard chemotherapy. This is evident from the phase 3 ASCENT-03 study.

The ASCENT-03 study included 558 patients with metastatic TNBC who were PD-L1-negative (CPS <10) or PD-L1-positive (CPS ≥10) but were not eligible for immune checkpoint inhibitors due to comorbidities or prior treatment in a curative setting. If patients had been treated previously, a minimum treatment interval of 6 months was required. They were randomized between sacituzumab govitecan (n=279) and chemotherapy of the investigator's choice (paclitaxel, nab-paclitaxel, gemcitabine, or carboplatin; n=279). Patients in the chemotherapy group could switch to sacituzumab govitecan upon progression, and 82% of patients who received treatment after progression on chemotherapy received sacituzumab govitecan.

After a median follow-up of 13.2 months, median progression-free survival was significantly better in the sacituzumab govitecan group, at 9.7 versus 6.9 months (HR=0.62). After 12 months, 41% versus 24% were progression-free. The duration of response was also longer (median  12.2 vs 7.2 months). By contrast, the percentage of patients with a response was relatively similar: 48.4% versus 45.5%. Overall survival could not yet be analyzed.

Sacituzumab govitecan led to grade ≥3 adverse events in 66% of patients, compared with 62% in the chemotherapy group. The main adverse events were neutropenia (43%) and diarrhea (9%). A total of 4% and 12% of patients discontinued treatment, respectively. However, there were six treatment-related deaths in the sacituzumab govitecan group versus one in the chemotherapy group.

Sacituzumab govitecan has the potential to become a new standard treatment in this setting, according to the researchers.

Cortés JC, et al. Primary results from ASCENT-03: a randomized phase III study of sacituzumab govitecan (SG) vs chemotherapy (chemo) in patients (pts) with previously untreated advanced triple-negative breast cancer (TNBC) who are unable to receive PD-(L)1 inhibitors (PD-[L]1i). ESMO 2025, abstract LBA20.

This article was originally published in Dutch on MedNet.nl