Abstract 313P
Background
Pts with BRCA1/2mut represent ∼5% of all HER2− ABC. Historically, treatment options were limited to chemotherapy (CTX) and endocrine monotherapy (ET mono). Other treatments (mTOR, CDK 4/6, and PIK3CA inhibitors) have since become available. Recently, poly (ADP-ribose) polymerase inhibitors (PARPi) have become available as targeted treatments for germline BRCA1/2mut HER2− ABC in the US and some European countries. This study assessed treatment trends among pts with HER2− ABC and BRCA1/2mut (somatic and/or germline) in the US, and France, Germany, Italy, and Spain (EU4).
Methods
Oncologists abstracted data from medical charts for the next 8-10 consecutive pts with HER2− ABC over three waves of data collection (Feb-May 2015, Mar-Jul 2017, Sept 2019-Apr 2020). In the 2019/2020 sample, pts with BRCA1/2 mutations were oversampled. Known 1st line treatments were stratified by region and hormone receptor (HR) status; HR+/HER2−, triple-negative breast cancer (TNBC) and were compared by year of data collection.
Results
755 adult pts with HER2− BRCA1/2mut ABC were included (471 [62%] HR+/HER2−; 284 [38%] TNBC). Mean age was 55.2 years. Among HR+/HER2− pts in the US and EU4, CTX +/- immunotherapy (IT) declined across all years. ET mono declined between 2017 and 2019/2020, and endocrine-based therapy (EBT: ET + mTOR or CDK4/6 or PIK3CA inhibitors) increased (Table). Among pts with TNBC in the EU4, CTX +/- IT declined between 2017 and 2019/2020. In 2019/2020, PARPi monotherapy (PARPi mono) was used in the US and EU4.
Conclusions
Decreased use of CTX +/- IT in HR+/HER2− pts was observed in the US and EU4 coinciding with availability of more EBT. PARPi mono utilization was observed in 2019/2020 coinciding with availability of this treatment in the US and some European countries. Table: 313P
| n (%) | US | |||||
| HR+/HER2− | TNBC | |||||
| 2015 n=15 | 2017 n=38 | 2019/2020 n=66 | 2015 n=14 | 2017 n=17 | 2019/2020 n=43 | |
| CTX +/- ITa | 9 (60) | 9 (24) | 12 (18) | 10 (71) | 10 (59) | 35 (81) |
| EBT | 0 (0) | 1 (3) | 16 (24) | 0 (0) | 2 (12) | 2 (5) |
| ET mono | 5 (33) | 13 (34) | 20 (30) | 2 (14) | 2 (12) | 0 (0) |
| PARPi mono | 0 (0) | 0 (0) | 7 (11) | 0 (0) | 0 (0) | 3 (7) |
| Other | 1 (7) | 15 (39) | 11 (17) | 2 (14) | 3 (18) | 3 (7) |
| EU4 | ||||||
| HR+/HER2− | TNBC | |||||
| n (%) | 2015 n=12 | 2017 n=28 | 2019/2020 n=312 | 2015 n=13 | 2017 n=37 | 2019/2020 n=160 |
| CTX +/- ITa | 9 (75) | 11 (39) | 66 (21) | 5 (38) | 27 (73) | 101 (63) |
| EBT | 0 (0) | 0 (0) | 133 (43) | 0 (0) | 0 (0) | 5 (3) |
| ET mono | 3 (25) | 10 (36) | 54 (17) | 0 (0) | 0 (0) | 3 (2) |
| PARPi mono | 0 (0) | 0 (0) | 8 (3) | 0 (0) | 0 (0) | 18 (11) |
| Other | 0 (0) | 7 (25) | 51 (16) | 8 (62) | 10 (27) | 33 (21) |
aIT in combination with CTX only in 2019/2020 dataset: 1 HR+/HER2– US pt; 9 TNBC US pts; 5 TNBC EU4 pts
Clinical trial identification
Editorial acknowledgement
Medical writing support was provided by Ann Gordon, of CMC AFFINITY, McCann Health Medical Communications, and was funded by Pfizer.
Legal entity responsible for the study
Pfizer.
Funding
Pfizer.
Disclosure
R. Mahtani: Advisory/Consultancy, Research grant/Funding (self): Genentech; Advisory/Consultancy: Pfizer; Advisory/Consultancy: Eli Lilly; Advisory/Consultancy: Novartis; Advisory/Consultancy: Daiichi Sankyo; Advisory/Consultancy: Seattle Genetics; Advisory/Consultancy: Eisai; Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Puma; Advisory/Consultancy: Amgen. A. Niyazov: Shareholder/Stockholder/Stock options, Full/Part-time employment: Pfizer Inc. K. Lewis: Full/Part-time employment: Adelphi Real World. L. Massey: Full/Part-time employment: Adelphi Real World. A. Rider: Full/Part-time employment: Adelphi Real World. B. Arondekar: Shareholder/Stockholder/Stock options, Full/Part-time employment: Pfizer Inc. M.P. Lux: Honoraria (self), Advisory/Consultancy, fees for non-CME services : Eli Lilly; Honoraria (self), Advisory/Consultancy, fees for non-CME services : AstraZeneca; Honoraria (self), Advisory/Consultancy, fees for non-CME services : MSD; Honoraria (self), Advisory/Consultancy, fees for non-CME services : Novartis; Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses, fees for non-CME services : Pfizer; Honoraria (self), Advisory/Consultancy, fees for non-CME services : Eisai; Honoraria (self), Advisory/Consultancy, fees for non-CME services: Genomic Health; Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses, fees for non-CME services : Roche; Honoraria (self), Advisory/Consultancy: Hexal; Honoraria (self), Advisory/Consultancy, Officer/Board of Directors: Medac.