419P - Aspire to ASCENT: Real-world outcomes from patients with metastatic triple-negative breast cancer (mTNBC) treated with Sacituzumab govitecan (Saci) in a single academic institution

Background

Saci is FDA approved for mTNBC and metastatic HR-positive BC based on ASCENT (Bardia et al., NEJM 2022) and TROPiCS-02 (Rugo et al., JCO 2022). In ASCENT, patients with heavily pre-treated mTNBC, including CNS metastases, had improved PFS and OS with Saci. It remains to be seen whether clincial trial results are uniformly applicable to real-world patients. The objectives of this study are to examine patients treated with Saci for mTNBC at our institution and to determine if clinical trial results can be replicated in the real-world setting.

Methods

We retrospectively identified all patients treated with Saci at our institution. Patient demographics, tumor characteristics, response and outcomes were assessed. Statistics are reported descriptively.

Results

From July 2018-June 2022, 188 patients with MBC were treated with Saci at our institution. Of those, 126 patients with mTNBC received at least one dose of Saci. Patients received a median of 2 lines (0-8) of therapy for metastatic disease prior to Saci. At commencement of Saci, 69.8% of patients had visceral metastases and 23% had CNS metastases. The median PFS with Saci was 3 months (0-13). The clinical benefit rate (CR/PR/SD) with Saci was 59.5% and 15% of patients remained on Saci at the time of reporting. The median OS was 21 months (2-50) and the median survival from Saci to death was 6 months (0-33). Table: 419P

Patient and tumor characteristics (n=126)

Conclusions

In this real-world series, we report on a patient population similar to that studied in the ASCENT trial. The median PFS was numerically shorter in this series compared to the ASCENT study (3.0 vs 4.8 months) despite our patients being less heavily pre-treated (median 2 vs 4 prior lines). The median OS was numerically longer in this series (21 vs 11.8 months). Further work is ongoing to evaluate real-world outcomes of patients treated with Saci for HR-positive disease and translational work seeks to establish biomarkers of resistance to Saci and other ADCs.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

E. M. Walsh.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.