Abstract 222P
Background
Sacituzumab govitecan was approved by the FDA and EMA in 2021 for pts with unresectable mTNBC who received 2+ prior systemic therapies, with ≥1 therapy in advanced disease. To understand the effect of time to relapse (TTR)/disease-free interval from early to advanced disease on survival after second line (2L), this study evaluated overall survival (OS) in pts with 2 lines of treatment for mTNBC.
Methods
A retrospective medical record review identified adult females in the UK and GER who were initially diagnosed with early-stage disease that recurred to mTNBC and had 2L treatment for mTNBC between January 2015 and December 2019. TTR was calculated from the end of last systemic early-stage breast cancer treatment to recurrence to mTNBC. Real-world progression-free survival and OS were estimated by the Kaplan-Meier method. Cox regression model assessed the association of TTR on 2L OS, adjusting for demographics and clinical characteristics.
Results
Data were abstracted for 420 pts (205 UK, 215 GER) at mean age 56.4±10.2 years. Most pts had visceral metastases (72%) and were treated with chemotherapy-only regimens in first-line (1L; 82%) and 2L (85%). Immunotherapy- and target-based regimens comprised 17% of 1L and 14% of 2L treatments. TTR was ≤12 mo for 48% and >12 mo for 52% of pts. Median OS (95% CI, mo) from 2L was 14.3 (13.0-15.8) overall; 14.4 (11.8-16.7) for TTR ≤12 mo; 14.1 (12.7-16.6) for TTR >12 mo. Multivariate Cox regression showed 2L OS was not associated with TTR (HR=0.88 [95% CI, 0.70-1.11]) but associated with 2L regimen type, country, stage at advanced diagnosis, and distant metastases sites (Table).
Conclusions
This evaluation of real-world clinical outcomes showed similar 2L OS between patients with TTR >12mo and TTR ≤12mo.
Table: 222P
Patient characteristics and 2L OS regression analysis
| 2L | HR (95% CI) | |
| 420 | ||
| TTR, n (%) | ||
| ≤12 mo | 202 (48.1) | |
| >12 mo | 218 (51.9) | 0.88 (0.70-1.11) |
| Country, n (%) | ||
| UK | 205 (48.8) | |
| GER | 215 (51.2) | 0.56 (0.44-0.72) |
| Stage at advanced diagnosis, n (%) | ||
| Unresectable IIIB, IIIC | 173 (41.2) | |
| IV | 247 (58.8) | 1.33 (1.04-1.69) |
| Distant metastases at start of 2L treatment, n (%) | ||
| Visceral ± Bone | 304 (72.4) | |
| Brain ± Visceral ± Bone | 64 (15.2) | 2.77 (2.07-3.71) |
| Bone | 13 (3.1) | 0.52 (0.21-1.27) |
| Other1 | 39 (9.3) | 0.57 (0.36-0.89) |
| 2L regimen, n (%) | ||
| Chemotherapy only | 358 (85.2) | |
| IO-/target-based | 59 (14.0) | 0.57 (0.39-0.85) |
| Other | 3 (0.7) | 0.48 (0.07-3.47) |
1Includes distant lymph nodes, adrenal gland, chest wall, skin, pericardium.
Legal entity responsible for the study
Gilead Sciences, Inc.
Funding
Gilead Sciences, Inc.
Disclosure
P.S. Hall: Financial Interests, Institutional, Funding: Gilead Sciences, Inc., Lilly, Eisai, Novartis, Merk, Gilead, Sanofi, Roche, Seagen, Medical Research Council and the National Institute for Health Research, UK. L. Chang, M. Summerhayes, I. Ntalla, M. Gharaibeh: Financial Interests, Personal, Full or part-time Employment: Gilead Sciences, Inc.; Financial Interests, Personal, Stocks/Shares: Gilead Sciences, Inc. R. Parikh: Financial Interests, Personal, Full or part-time Employment: RTI Health Solutions; A. Hitchens: Financial Interests, Personal, Full or part-time Employment: RTI Health Solutions. K. Davis: Financial Interests, Institutional, Funding: Gilead Sciences, Pfizer, Eisai. N. Sjekloca: Financial Interests, Personal, Stocks/Shares: Gilead Sciences. V. Derrien Ansquer: Financial Interests, Personal, Full or part-time Employment: RTI Health Solutions. E. Bergamaco: Financial Interests, Personal, Full or part-time Employment: Gilead Sciences, Inc.; Financial Interests, Personal, Stocks/Shares: Gilead Sciences, Inc.; Financial Interests, Personal, Funding: Gilead Sciences, Inc.; Financial Interests, Personal, Advisory Board: Gilead Sciences, Inc. P.A. Fasching: Financial Interests, Personal, Advisory Board: Roche, Novartis, Pfizer, Daiichi Sankyo, Eisai, Merck, Sharp & Dohme, AstraZeneca, Hexal, Lilly, Pierre Fabre, Seagen, Agendia, Sanofi Aventis; Financial Interests, Personal, Invited Speaker: Novartis, Daiichi Sankyo, Eisai, Merck, Sharp & Dohme, AstraZeneca, Lilly, Seagen, Gilead; Financial Interests, Personal, Other, Medical Writing Support: Roche; Financial Interests, Institutional, Invited Speaker: BionTech, Cepheid; Non-Financial Interests, Member: ASCO, Arbeitsgemeinschaft für Gynäkologische Onkologie e.V., Translational Research in Oncology, Deutsche Gesellschaft für Senologie e.v.