Table 1.
Baseline Characteristics
| Totala (n = 96) | PIK3CA WT (n = 59) | PIK3CA Altered (n = 30) | ESR1 WT (n = 59) | ESR1 Altered (n = 30) | |
|---|---|---|---|---|---|
| Median age (range), years | 58 (32–83) | 59 (33–83) | 59 (32–83) | 59 (33–83) | 56 (32–70) |
|
| |||||
| Sex, n (%) | |||||
|
| |||||
| Female | 96 (100) | 59 (100) | 30 (100) | 59 (100) | 30 (100) |
|
| |||||
| Race, n (%) | |||||
|
| |||||
| White | 78 (81.3) | 51 (86.4) | 26 (86.7) | 51 (86.4) | 25 (83.3) |
|
| |||||
| Asian | 2 (2.1) | 1 (1.7) | 0 | 1 (1.7) | 0 |
|
| |||||
| Black | 4 (4.2) | 2 (3.4) | 1 (3.3) | 2 (3.4) | 2 (6.7) |
|
| |||||
| Other or unknown | 12 (12.5) | 5 (8.5) | 3 (10.0) | 5 (8.5) | 3 (10.0) |
|
| |||||
| ECOG PS, n (%) | |||||
|
| |||||
| 0 | 55 (57.3) | 37 (62.7) | 16 (53.3) | 37 (62.7) | 17 (56.7) |
|
| |||||
| 1 | 41 (42.7) | 22 (37.3) | 14 (46.7) | 22 (37.3) | 13 (43.3) |
|
| |||||
| Sites of metastases, n (%) b | |||||
|
| |||||
| Bone | 74 (77.1) | 48 (81.4) | 22 (73.3) | 45 (76.3) | 26 (86.7) |
|
| |||||
| Liver | 63 (65.6) | 40 (67.8) | 18 (60.0) | 37 (62.7) | 20 (66.7) |
|
| |||||
| Lung | 33 (34.4) | 19 (32.2) | 11 (36.7) | 20 (33.9) | 9 (30.0) |
|
| |||||
| Lymph nodes | 28 (29.2) | 19 (32.2) | 9 (30.0) | 18 (30.5) | 10 (33.3) |
|
| |||||
| Previous treatment c | |||||
|
| |||||
| Lines of treatment overall, median (range) | 1 (1–8) | 1 (1–8) | 1 (1–5) | 1 (1–5) | 1 (1–8) |
|
| |||||
| CDK4/6i, n (%) | 96 (100) | 59 (100) | 30 (100) | 59 (100) | 30 (100) |
|
| |||||
| Lines of treatment, median (range) | 1 (1–2) | 1 (1–2) | 1 (1–2) | 1 (1–2) | 1 (1–2) |
| 1 prior line | 92 (95.8) | 56 (94.9) | 29 (96.7) | 57 (96.6) | 28 (93.3) |
| 2 prior lines | 4 (4.2) | 13 (5.1) | 1 (3.3) | 2 (3.4) | 2 (6.7) |
|
| |||||
| Median duration of CDK4/6i (range), mo | 18.0 (6.0–141.0) | 14.0 (4.0–29.4) | 10.0 (3.5–34.0) | 11.5 (3.5–34.0) | 14.0 (4.6–26.7) |
|
| |||||
| Prior CDK4/6i, nd | |||||
|
| |||||
| Ribociclib | 12 | 6 | 4 | 9 | 1 |
|
| |||||
| Palbociclib | 96 | 61 | 31 | 58 | 34 |
|
| |||||
| ET, n (%) | 96 (100) | 59 (100) | 30 (100) | 59 (100) | 30 (100) |
|
| |||||
| Lines of treatment, median (range) | 1 (1–4) | 1 (1–4) | 1 (1–3) | 1 (1–4) | 1 (1–3) |
| 1 prior line | 75 (78.1) | 46 (78.0) | 24 (80.0) | 48 (81.4) | 22 (73.3) |
| 2 prior lines | 17 (17.7) | 11 (18.6) | 4 (13.3) | 8 (13.6) | 7 (23.3) |
| ≥ 3 prior lines | 4 (4.1) | 2 (3.4) | 2 (6.7) | 3 (5.1) | 1 (3.3) |
|
| |||||
| Prior ET, n (%)d | |||||
|
| |||||
| Anastrozole | 17 (17.7) | 9 (15.3) | 7 (23.3) | 10 (16.9) | 5 (16.7) |
|
| |||||
| Letrozole | 69 (71.9) | 41 (69.5) | 23 (76.7) | 41 (69.5) | 23 (76.7) |
|
| |||||
| Exemestane | 3 (3.1) | 1 (1.7) | 2 (6.7) | 1 (1.7) | 2 (6.7) |
|
| |||||
| Fulvestrant | 37 (38.5) | 25 (42.4) | 8 (26.7) | 23 (39.0) | 10 (33.3) |
|
| |||||
| Chemotherapy, n (%) | 12 (12.5) | 6 (10.2) | 2 (6.7) | 6 (10.2) | 1 (3.3) |
|
| |||||
| 1 prior line | 12 (12.5) | 6 (10.2) | 2 (6.7) | 6 (10.2) | 1 (3.3) |
CDK4/6i, cyclin-dependent kinase 4/6 inhibitor; ECOG PS, Eastern Cooperative Oncology Group performance status; ESR1, estrogen receptor 1; ET, endocrine therapy; PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; WT, wild type.
a
Intent-to-treat population.
b
Select sites of metastases.
c
In advanced/metastatic setting.
d
Patients can be counted in multiple rows.