Table 2.
PFS in subgroups of patients with ESR1-mutated tumors and prior ET+CDK4/6i ≥12 months.
| Patient subgroup | n (%) | mPFS, months | HR (95% CI) | |
|---|---|---|---|---|
| Elacestrant | SOC | |||
| All patients with ESR1-mutated tumors | 159 (100) | 8.6 | 1.9 | 0.41 (0.26–0.63) |
| ESR1-mutated tumors and bone metastasesa | 136 (86) | 9.1 | 1.9 | 0.38 (0.23–0.62) |
| ESR1-mutated tumors and liver and/or lungb metastases | 113 (71) | 7.3 | 1.9 | 0.35 (0.21–0.59) |
| ESR1-mutated tumors and <3 metastatic sitesc | 82 (52) | 9.0 | 1.9 | 0.41 (0.23–0.75) |
| ESR1-mutated tumors and ≥3 metastatic sitesc | 53 (33) | 10.8 | 1.8 | 0.31 (0.12–0.79) |
| ESR1- and PIK3CA-mutated tumorsd | 62 (39) | 5.5 | 1.9 | 0.42 (0.18–0.94) |
| ESR1- and TP53-mutated tumors | 61 (38) | 8.6 | 1.9 | 0.30 (0.13–0.64) |
| ESR1-mutated tumors and HER2-low expressione | 77 (48) | 9.0 | 1.9 | 0.30 (0.14–0.60) |
| ESR1 D538G -mutated tumors | 97 (61) | 9.0 | 1.9 | 0.38 (0.21–0.67) |
| ESR1 Y537S/N -mutated tumors | 92 (58) | 9.0 | 1.9 | 0.25 (0.13–0.47) |
a
Eighty-five percent of patients had bone and other sites of metastases (30% of these patients had no liver or lung involvement).
b
Fifty-five percent of patients had liver and other sites of metastases (10% of these patients had no lung or bone involvement); 25% of patients had lung and other sites of metastases (2% of these patients had no liver or bone involvement).
c
The number of metastatic sites was available for 135 of 159 patients with ESR1-mutated tumors and prior ET+CDK4/6i ≥12 months.
d
Includes E545K, H1047R, E542K, and others.
e
Locally assessed HER2 IHC score of 1+ and 2+ with no ISH amplification. Data not available for all patients.