TROPiCS-02: Overall survival benefit of sacituzumab govitecan in HR+/HER2- metastatic breast cancer

Antibody-drug conjugates (ADCs) are an emerging class of anticancer drugs consisting of a monoclonal antibody linked to a cytotoxic chemotherapy payload, enabling a targeted therapeutic response. Sacituzumab govitecan, an ADC consisting of an anti-Trop-2 antibody and the topoisomerase I inhibitor SN-38, was approved by the FDA for patients with metastatic triple-negative breast cancer in April 2021.1

The Phase III TROPiCS-02 study (NCT03901339) assessed sacituzumab govitecan in patients with hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) metastatic breast cancer who have previously been treated with at least one prior taxane, CDK4/6 inhibitor, and endocrine therapy. Patients were randomized to receive sacituzumab govitecan or single-agent chemotherapy; primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS) respectively. Initial results presented at the American Society of Clinical Oncology (ASCO) 2022 Annual Meeting determined sacituzumab govitecan to have a significant PFS benefit of 5.4 months [95% CI, HR = 0.66].2

A second interim analysis was presented at the European Society for Medical Oncology (ESMO) 2022 Annual Meeting in Paris, France.3 After a median follow-up of 12.5 months, patients receiving sacituzumab govitecan had a superior median OS of 14.4 months versus 11.2 months in chemotherapy arm [95% CI, HR = 0.79]. An overall response rate (ORR) and medial duration of response (DOR) of 21% and 8.1 months respectively were additionally reported in the sacituzumab govitecan arm, compared to 14% and 5.6 months in patients receiving chemotherapy [95% CI, HR = 0.75]. The investigational ADC also resulted in a longer time to deterioration in fatigue, pain and global health status quality of life, with no further safety signals reported.

Elisa Agostinetto, MD, of the Institut Jules Bordet, Brussels, Belgium, comments that:

“It is interesting to see that sacituzumab govitecan, an agent that is changing the treatment landscape for triple-negative breast cancer in the second line, is still also showing some promising results in other breast cancer subtypes like patients with HR+/HER2- breast cancer”

Sacituzumab govitecan has demonstrated further benefit in terms of OS in a second interim analysis of the TROPiCS-02 trial, a study which previously showed PFS benefit in patients. The most recent data support the use of sacituzumab govitecan in patients with HR+/HER2- metastatic breast cancer, providing much needed treatment options for this subset of patients.


References:

  1. FDA grants regular approval to sacituzumab govitecan for TNBC [Internet]. U.S. Food and Drug Administration. 2022 [cited 7 October 2022]. Available from: https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-regular-approval-sacituzumab-govitecan-triple-negative-breast-cancer
  2. Rugo HS, Bardia A, Marmé F, et al. Primary results from TROPiCS-02: A randomized phase 3 study of sacituzumab govitecan (SG) versus treatment of physician’s choice (TPC) in patients (Pts) with hormone receptor–positive/HER2-negative (HR+/HER2-) advanced breast cancer. Journal of Clinical Oncology. 2022;40(17_suppl):LBA1001-LBA1001.
  3. Rugo HS, Bardia A, Marmé F et al. Overall survival (OS) results from the phase III TROPiCS-02 study of sacituzumab govitecan (SG) vs treatment of physician’s choice (TPC) in patients (pts) with HR+/HER2- metastatic breast cancer (mBC). Annals of Oncology. 2022;33 (suppl_7): S808-S869

Written by Simon Ng