Abstract 213P
Background
Palbociclib (PB), a cyclin-dependent kinase 4/6 inhibitor, has become a standard of care in HR+/HER2- advanced/metastatic breast cancer (ABC) in Europe since EMA approval in 2016. This study examines clinical characteristics and outcomes in ABC patients treated with PB and an aromatase inhibitor (AI) in routine clinical practice in Europe.
Methods
A multicenter retrospective medical record review collected data on adult patients with HR+/HER2- ABC in Europe who received first-line PB+AI between September 2016 and July 2020. Sites screened all patients who received PB+AI during the study time frame and abstracted data for patients who met all eligibility criteria. We report here results from Germany, Spain and the UK; data from 4 additional European countries will be reported when data collection is complete. Study measures were descriptively analyzed, with the Kaplan-Meier method used to estimate real-world progression-free survival (rwPFS).
Results
Data were abstracted and analyzed for 668 patients from 47 sites. Median age at ABC diagnosis was 64.4 years (33.8% ≥70 yo), 99.6% were female, 82.9% were white, and median follow-up was 32.7 months. Of females (665), 14.1% were premenopausal at first-line PB+AI initiation. 38.5% of patients had de novo disease. At ABC diagnosis, 24.9% had bone only disease and 46.7% had visceral disease (Table). Objective response and clinical benefit rate were 35.8% and 80.7%, respectively. The median rwPFS (95% CI) was estimated to be 31.8 (27.7-35.4) months (Table).
Table: 213P
| N | % | |
| Total number of patients | 668 | 100.0 |
| Age (years) at ABC diagnosis | ||
| <50 | 101 | 15.1 |
| 50-69 | 341 | 51.1 |
| ≥70 | 226 | 33.8 |
| Clinical stage at initial BC diagnosis | ||
| Stage I–III (resectable) | 380 | 56.9 |
| Stage III–unresectable | 18 | 2.7 |
| Stage IV | 239 | 35.8 |
| Unknown | 31 | 4.6 |
| Disease-free interval | ||
| De novo | 257 | 38.5 |
| ≤12 months | 152 | 22.8 |
| >12 months | 221 | 33.1 |
| Unknown | 38 | 5.7 |
| Performance status at first-line | ||
| 0 | 161 | 24.1 |
| 1 | 176 | 26.3 |
| ≥2 | 58 | 8.7 |
| Not recorded | 273 | 40.9 |
| Objective response rate | 239 | 35.8 |
| rwPFS, Kaplan–Meier estimate | Months (95% CI) | |
| Median | 31.8 (27.7-35.4) | |
| rwPFS rate | % (95% CI) | |
| 12 months | 77.2 | (73.8-80.3) |
| 24 months | 59.5 | (55.5-63.2) |
| 36 months | 45.2 | (41.0-49.4) |
Conclusions
This real-world study affirms the favorable clinical outcomes demonstrated for first-line PB+AI in the previous clinical trials and supports its utilization as frontline treatment for this patient population. This study presents pooled analysis of 3 European countries and variability in practice patterns and disease management may exist among countries.
Editorial acknowledgement
Editorial support was provided by Oxford PharmaGenesis, Inc., Newtown, PA, with funding provided by Pfizer Inc.
Legal entity responsible for the study
Pfizer Inc., USA.
Funding
Pfizer Inc., USA.
Disclosure
O. Oikonomidou: Financial Interests, Personal, Advisory Board: Pfizer Inc., AstraZeneca, Novartis, Exact Sciences, Eisai, Daiichi Sankyo, Roche, Gilead, Lilly, Merck, Tesaro; Financial Interests, Personal, Other, Travel grant: Eisai, Roche, Pfizer Inc., Amgen, AstraZeneca, Novartis, Lilly; Financial Interests, Institutional, Research Grant: Pfizer Inc., Med Diagnostics, Novartis, M2C, Roche, BCI, Genomic Health. E. Galve-Calvo: Financial Interests, Personal, Advisory Board: AstraZeneca, Daiichi Sankyo, Gilead, Pfizer Inc.; Financial Interests, Personal, Expert Testimony: Pierre Fabre, Eisai, Novartis, Roche. A. Wöckel: Financial Interests, Personal, Advisory Board: Amgen, AstraZeneca, Celgene, Eisai, Lilly, Novartis, Pfizer, Roche, Tesaro, Sirtex, MSD, Pierre Fabre, Clovis, Organon, Seagen, Exact Sciences, Gilead, Daiichi Sankyo. R. Parikh, A. Hitchens, V. Derrien Ansquer, G. Frugier, M. Jimenez, K. Davis: Financial Interests, Personal, Full or part-time Employment: RTI Health Solutions. C. Chen, E. Gauthier, B. Li, E. Broughton: Financial Interests, Personal, Full or part-time Employment: Pfizer Inc.; Financial Interests, Personal, Stocks/Shares: Pfizer Inc.