Abstract 258P
Background
Endocrine therapy (ET) combined with CDK4/6 inhibitors (CDK4/6i) is the standard of care for HR+/HER2- mBC pts. However, efficacy is limited due to acquired ET resistance, after which treatment options are limited to CT and, more recently, antibody-drug conjugates. This rw study describes patient characteristics, treatment patterns and survival outcomes in HR+/HER2- mBC pts initiating at least first (1st)CT in France and Germany.
Methods
This is an interim analysis of adults with HR+/HER2- mBC initiating CT (Jan 2016 - Feb 2023) for mBC at the Institut de Cancérologie de l'Ouest in France. Germany data will be assessed in the final analyses. Demographics, clinical characteristics, and treatments were described using descriptive statistics. Kaplan-Meier method was used to describe rw overall survival (OS) for 1st to 4th CT line, separately, from each line start.
Results
339 pts were analysed: 99% were female, 28% had de novo mBC, with median age of 62 years at 1st CT. Prior to 1st CT start, 43% received CDK4/6i and 52% ET for mBC. 61%, 39% and 24% had records of subsequent second, 3rd and 4th CT line, respectively. Most pts received CT as monotherapy: paclitaxel and capecitabine were the most used agents followed by eribulin and cyclophosphamide. Median rwOS was 19.9, 12.3, 8.1 and 7.2 months (mo) from 1st, 2nd, 3rd and 4th CT line, respectively (Table). Table: 258P
rwOS by CT line
| 1st CT | 2nd CT | 3rd CT | 4th CT | ||
| N Pts | 339 | 207 | 132 | 83 | |
| N Deaths | 241 | 151 | 102 | 59 | |
| Median rwOS in moInterquartile range | 19.9 (8.0-38.7) | 12.3 (5.7-24.1) | 8.1 (4.3-18.5) | 7.2 (2.9-15.1) | |
| 6 mo | N | 268 | 144 | 81 | 39 |
| Survival[95% Confidence interval (CI)] | 80% [75-84] | 73% [67-79] | 66% [58-74] | 55% [45-68] | |
| 12 mo | N | 206 | 92 | 37 | 19 |
| Survival[95% CI] | 63% [58-68] | 50% [44-58] | 35% [27-45] | 34% [24-47] | |
| 18 mo | N | 164 | 49 | 23 | - |
| Survival[95% CI] | 54% [49-60] | 33% [27-41] | 26% [19-35] | ||
| 24 mo | N | 112 | 33 | - | - |
| Survival[95% CI] | 42% [36-47] | 25% [19-33] | |||
| 32 mo | N | 53 | 11 | - | - |
| Survival[95% CI] | 26% [22-32] | 15% [10-23] |
Conclusions
HR+/HER2- mBC pts initiating CT in France showed poor survival, decreasing with each subsequent CT line. There is still a high unmet need for improved treatment options in this population.
Legal entity responsible for the study
Gilead Sciences, Inc
Funding
Gilead Sciences, Inc
Disclosure
M. Campone: Financial Interests, Institutional, Advisory Board: AstraZeneca, Novartis, Sanofi, Menarini, Gilead, Seagen; Financial Interests, Personal, Invited Speaker: Novartis, Lilly; Financial Interests, Personal, Advisory Board: Daiichi Sankyo, Lilly. J. Frenel: Financial Interests, Personal, Advisory Board: Pfizer, Novocure, Pierre Fabre, Eisai, Seagen, Gilead; Financial Interests, Personal, Invited Speaker: GSK, Amgen, Eisai; Financial Interests, Institutional, Advisory Board: Exact Science, Lilly, Daiichi Sankyo, AstraZeneca, Clovis Oncology; Financial Interests, Institutional, Invited Speaker: Novartis, MSD; Financial Interests, Invited Speaker: AstraZeneca, Seagen, MSD, Daiichi Sankyo; Non-Financial Interests, Principal Investigator: Novartis, Lilly, AstraZeneca, Pfizer, Daiichi Sankyo, MSD. A.G. Kerscher: Financial Interests, Institutional, Other, IT-Infrastructure: Janssen; Other, Consulting: IQVIA. M. Krebs: Financial Interests, Personal, Advisory Board: Janssen, GSK Oncology; Financial Interests, Personal, Expert Testimony: IQVIA; Financial Interests, Personal, Stocks/Shares: General Electric. C.S. Leal: Financial Interests, Personal, Full or part-time Employment, Epidemiologist: IQVIA. V.M. Saglimbene: Financial Interests, Personal, Full or part-time Employment: IQVIA Solutions. M.K. Rehnquist: Financial Interests, Institutional, Full or part-time Employment: Gilead Sciences; Financial Interests, Institutional, Stocks/Shares: Gilead Sciences. N. Sadetsky: Financial Interests, Personal, Full or part-time Employment: Gilead; Financial Interests, Personal, Stocks/Shares: Gilead, Roche/Genentech. N. Sjekloca: Financial Interests, Personal, Stocks/Shares: Gilead Sciences. O. Libert: Financial Interests, Personal, Full or part-time Employment, Medical Affairs: Gilead Sciences; Financial Interests, Personal, Stocks/Shares: Gilead Sciences. A. Kaushik: Financial Interests, Institutional, Full or part-time Employment: Gilead Sciences; Financial Interests, Institutional, Stocks/Shares: Gilead Sciences. All other authors have declared no conflicts of interest.