Abstract 226P
Background
Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) combined with endocrine therapy (ET) are standard first-line (1L) therapy for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC); however, patient (pt) and clinical factors may influence 1L treatment (tx) choice. We assessed 1L tx patterns, pt characteristics, and baseline comorbidities of adults with HR+/HER2- mBC.
Methods
Data were collected from Jul 2022 to present using the Adelphi Disease Specific Programme™ (DSP), a cross-sectional survey of oncologists in France, Germany, Italy, Spain, and the UK. We report results for abstracted medical records of pts with HR+/HER2- mBC receiving 1L tx. Pt demographics, disease characteristics, and comorbidities reported from a prespecified list at mBC diagnosis were analyzed descriptively.
Results
Among 962 pts included, 75% started 1L tx in 2022, 16% in 2021, and 10% in 2020 or before. The mean pt age at mBC diagnosis was 62 years. 51% had visceral metastases (mets) and 25% had bone-only disease. 73% received CDK4/6i + ET, while chemotherapy-containing regimens (CT) and ET monotherapy (EM) were used in 12% and 9%, respectively. Pts receiving EM were more likely to be older, have worse ECOG performance status (PS), and have bone only disease than pts receiving CDK4/6i + ET or CT. Conversely, pts on CT were more likely to be younger or have visceral mets. The most common comorbidity types were cardiovascular (36%), metabolic (11%), and gastrointestinal (5%) conditions. On average, pts on EM had more comorbidities than those on CT or CDK4/6i + ET. Table: 226P
Pt Demographics/Clinical characteristics by 1L therapy
| Total (n=962) | EM (n=86) | Any CT (n=120) | CDK4/6i + ET (n=700) | Othera (n=56) | |
| Age b | |||||
| Median (IQR) | 64 (16) | 76 (14) | 58 (16) | 64 (15) | 51 (21) |
| ≥70 y, n (%) | 245 (27) | 58 (70) | 14 (13) | 170 (25) | 3 (6) |
| Sites of mets, n (%) b | |||||
| Bone only | 240 (25) | 28 (33) | 12 (10) | 189 (27) | 11 (19) |
| Visceralc | 487 (51) | 33 (38) | 86 (72) | 335 (48) | 34 (59) |
| Non-viscerald | 67 (7) | 11 (13) | 8 (7) | 42 (6) | 7 (12) |
| ECOG, n (%) b | |||||
| 0-1 | 796 (83) | 49 (57) | 99 (82) | 595 (85) | 55 (95) |
| ≥2 | 165 (17) | 36 (42) | 21 (18) | 105 (15) | 3 (5) |
| Comorbidities | |||||
| Mean (SD) | 0.8 (1.2) | 1.3 (1.6) | 0.6 (1.0) | 0.7 (1.0) | 0.5 (0.9) |
aPARPi, CDK4/6i + Combo ET/Other, mTORi b<5% Unknown/MissingcLiver, lung, malignant effusion, adrenal, stomach, peritoneum dExcludes bone only
Conclusions
Across 5 European countries, most pts received CDK4/6i + ET, consistent with international guidelines. Age, PS, site of mets, and comorbidities may influence guideline deviations. The pt sample may not represent all pts with mBC. More research and statistical analyses are needed to understand tx choices in this setting.
Legal entity responsible for the study
Pfizer Inc.
Funding
Pfizer Inc.
Disclosure
R.L. Mahtani: Financial Interests, Personal, Advisory Board, RM has served as a consultant/advisor: Agendia, Amgen, AstraZeneca, Biotheranostics, Daiichi, Eisai, Genentech, Immunomedics, Lilly, Merck, Novartis, Pfizer, Puma, Sanofi, Seagen. K.A. Hanson, E. Broughton: Financial Interests, Personal, Stocks/Shares, employees and stockholders of Pfizer Inc.: Pfizer Inc. K. Lewis: Financial Interests, Personal, Full or part-time Employment, Katie Lewis is an employee of Adelphi Real World,: Adelphi Real World. G. Foley: Financial Interests, Personal, Stocks/Shares, employees and stockholders of Pfizer Inc.: Pfizer Inc. A. Lambert: Financial Interests, Personal, Full or part-time Employment, employee of Adelphi Real World,: Adelphi Real World. C. Chen: Financial Interests, Personal, Stocks/Shares, employees and stockholders of Pfizer Inc.: Pfizer Inc. C. Criscitiello: Financial Interests, Personal, Speaker’s Bureau, CC reports personal fees for consulting, advisory role and speakers’ bureau: Roche, Novartis, Pfizer, Lilly, MSD, AstraZeneca, Gilead, Seagen, and Daiichi Sankyo.