Background

Treatment options for pre-treated patients with metastatic triple-negative breast cancer (mTNBC) remain limited. The TROP-2-targeting antibody drug-conjugate sacituzumab govitecan (SG) recently demonstrated superior efficacy over single agent chemotherapy in mTNBC patients with at least 2 lines of prior chemotherapy. The aim of this study was to assess the real-world safety and efficacy of sacituzumab govitecan in the UK.

Methods

Data were retrospectively collected from 16 major UK cancer centres. This study included all mTNBC patients who received at least one dose of sacituzumab govitecan as part of the UK compassionate use programme. Patients were required to have had at least 2 prior lines of chemotherapy. Key endpoints include progression-free survival (PFS), overall survival (OS) and safety. Kaplan-Meier survival analysis was calculated using Prism.

Results

A total of 132 patients were included. The median age was 56 years (range 28-91 years); all patients were performance status (PS) 0-3 (39 pts PS0, 76 pts PS1, 16 pts PS2, 1 pt PS3); 75% (99/132) had visceral metastases including 24 patients with central nervous system (CNS) disease. SG treatment was 2^nd line in 28% and 3^rd line in 31% of pts in the metastatic setting. 41% of pts had received 3 or more prior lines of chemotherapy. Median PFS was 5.2 months and median OS was 8.7 months (n= 126, 6 pts excluded due to incomplete data). Subgroup analysis of pts with CNS disease showed a PFS of 5.1 months; OS was not reached. 11/24 pts with CNS disease were treated with radiotherapy (RT) to the CNS prior to or during treatment with SG. Pts with CNS disease who did not receive RT at any point had a PFS of 1.6 months and OS of 2.6 months. SG dose reduction was required in 54% of pts due to adverse events (AEs). Most common AEs were fatigue (all grade, 82%; G1, 44%; G2, 22%; G3, 14%; G4, 1%), neutropenia (all grade, 55%; G1, 9%; G2, 16%; G3, 15%; G4, 14%), diarrhoea (all grade, 58%; G1, 25%; G2, 18%; G3, 11%; G4, 4%), and nausea (all grade, 38%; G1, 24%; G2, 10%; G3, 3%).

Conclusions

This study provides the first real-world experience of sacituzumab govitecan in the UK, confirming substantial anti-tumour activity in pre-treated mTNBC. The safety profile is consistent with clinical trial experience.

Dr. Michael John Devlin (Medical Oncology, Barts NHS Trust, London, UK) has equally contributed to the study.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.