393P - Real-world (RW) use patterns, effectiveness, and tolerability of sacituzumab govitecan (SG) for second-line (2L) and later treatment of metastatic triple-negative breast cancer (mTNBC)

Background

SG is a Trop-2-directed antibody-drug conjugate approved in multiple countries for patients (pts) with mTNBC after ≥ 2 prior systemic therapies (≥ 1 for metastatic disease). In the ASCENT study (NCT02574455) in pts with mTNBC, SG had superior efficacy vs single-agent chemotherapy and a manageable safety profile (Bardia et al. NEJM 2021 ). This study describes RW SG dosing and clinical outcomes in pts with mTNBC treated with SG in 2L and later in the US.

Methods

This retrospective cohort study used de-identified US electronic health records in the ConcertAI database of pts (≥ 18 y) with mTNBC treated with SG in 2L and later from April 2020 to May 2022 to allow for a 3-month minimum data accrual. Clinical outcomes (RW overall survival [rwOS], time to next treatment or death [TTNTD], and RW progression-free survival [rwPFS]) from start of SG (index date) were estimated by Kaplan-Meier methods.

Results

230 female pts (median age 60 y, 26% Black, 17% ECOG performance status ≥ 2, 66% treated in community settings) were included in the analysis. Median follow-up was 7.2 months (IQR 3.9-11.1). SG RW outcomes for all pts and by SG line (2L and 3L+) are in the Table. Clinical outcomes were similar for all pts and stratified analyses (by race, concomitant G-CSF use, treatment-free interval duration). Of 134 pts (58%) who had G-CSF during SG treatment, 99 (74%) previously received G-CSF. Median time from SG start to G-CSF use was 8.5 days (IQR 8-29). SG was discontinued due to toxicity in 17 pts (7%). Table: 393P

IQR, interquartile range; NE, not estimable. *Kalinsky et al. ASCO 2023 abstr e18879. ^†Measured from index date.

Conclusions

This RW analysis included patients with mTNBC treated with SG in 2L and later line settings since approval of SG in the US. SG showed survival benefit in this broad patient population. Follow-up duration was short for some pts in this analysis. As data will continue to mature over time, they will provide more insight into RW effectiveness of SG.

Clinical trial identification

Editorial acknowledgement

Editorial support was provided by Yvonne E Yarker, PhD, ISMPP CMPP, of Parexel and funded by Gilead Sciences, Inc.

Legal entity responsible for the study

Gilead Sciences, Inc.

Funding

Gilead Sciences, Inc.

Disclosure

K. Kalinsky: Financial Interests, Personal, Advisory Board: Daiichi Sankyo, Eli-Lilly, Pfizer, Novartis, Eisai, AstraZeneca, Immunomedics, Merck, Seattle Genetics, Cyclacel, Oncosec, 4D Pharma, Puma; Financial Interests, Personal, Stocks/Shares, Employment + Stock = spouse: Grail; Financial Interests, Personal and Institutional, Local PI, Consultant: Novartis, Eli-Lilly, AstraZeneca, Daiichi Sankyo; Financial Interests, Personal and Institutional, Local PI, consultant: Genentech; Financial Interests, Institutional, Local PI, consultant: Pfizer; Financial Interests, Institutional, Local PI: Seattle Genetics, Ascentantage; Financial Interests, Personal, Other, Consultant: Myovant, Takeda, Menarini; Financial Interests, Personal, Other, consultant: Menarini; Other, Support for attending meetings and/or travel: Eli-Lilly, AstraZeneca, Pfizer; Other, Steering Committee: Immunomedics, AstraZeneca, Ambryx, Genentech. L. Spring: Financial Interests, Personal, Advisory Board: Novartis, Puma, G1 therapeutics, Daiichi Pharma, AstraZeneca; Financial Interests, Institutional, Research Grant: Phillips, Merck, Genentech, Gilead, Eli Lilly . C. Yam: Financial Interests, Institutional, Advisory Board, reimbursement for travel: Gilead; Financial Interests, Institutional, Local PI: Gilead, Amgen, Merck, Pfizer, Astellas, Genentech, Novartis; Financial Interests, Institutional, Research Grant: GSK; Financial Interests, Institutional, Steering Committee Member: Gilead. I. Ntalla, B. Stwalley, C. Lai: Financial Interests, Personal, Full or part-time Employment: Gilead Sciences; Financial Interests, Personal, Stocks/Shares: Gilead Sciences. N. Sjekloca: Financial Interests, Personal, Stocks/Shares: Gilead. A. Kaushiva: Financial Interests, Institutional, Full or part-time Employment: ConcertAI. A.J. Taylor: Financial Interests, Personal, Full or part-time Employment, I work full time for Gilead.: Gilead Sciences Europe Lts; Financial Interests, Personal, Stocks/Shares, I own shares in Gilead.: Gilead Sciences Europe Ltd. R. Nanda: Financial Interests, Personal, Advisory Board: AstraZeneca , BeyondSpring, Daiichi Sankyo , Fujifilm, GE, Gilead, Infinity , iTeos, Macrogenics, Merck, Novartis, OBI, Oncosed, Pfizer, Sanofi, Seagen, Stemline; Financial Interests, Institutional, Research Funding: Arvinas, AstraZeneca, Celgene, Corcept Therapeutics, Genentech/Roche, Gilead/Immunomedics, Merck, Novartis, OBI Pharma, Pfizer, Relay, Seattle Genetics, Sun Pharma, Taiho.