EMERALD
The first oral oestrogen-receptor degrader to beat standard hormone therapy, with the benefit concentrated in tumours carrying ESR1 mutations.
PFS 2.8 vs 1.9 months overall (HR 0.70); in ESR1-mutant tumours 3.8 vs 1.9 months (HR 0.55). Benefit grew with longer prior CDK4/6 exposure (≥12 months: 8.6 vs 1.9 months in ESR1-mutant). Approved January 2023 for ESR1-mutant disease with a ctDNA companion diagnostic.
Setting
ER+/HER2- advanced breast cancer after 1-2 endocrine lines including a CDK4/6 inhibitor: elacestrant vs standard endocrine therapy
Phase
Phase 3
Sponsor
Radius / Menarini
Registry
Headline result
PFS HR 0.55 in ESR1-mutant.
Reported
2021
Enrolled
478
Replication
The ESR1-mutant-restricted benefit was replicated by imlunestrant (EMBER-3) and vepdegestrant (VERITAC-2).
In plain words
What these results mean for people, not percentages
Progression-free survival (ESR1-mutant)primarysurrogate endpoint
- Median 3.8 vs 1.9 months with Elacestrant compared with Standard endocrine therapy; about 1.9 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 45 percent lower chance of the event at any given time (hazard ratio 0.55, likely range 0.39 to 0.77).
Progression-free survival (all patients)primarysurrogate endpoint
- Median 2.8 vs 1.9 months with Elacestrant compared with Standard endocrine therapy; about 0.9 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 30 percent lower chance of the event at any given time (hazard ratio 0.7, likely range 0.55 to 0.88).
Be careful
- This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
- These results apply to the people the trial enrolled: ER+/HER2- advanced breast cancer after 1-2 endocrine lines including a CDK4/6 inhibitor: elacestrant vs standard endocrine therapy. People in a different situation may not see the same effect.
- The trial selected people by a biomarker (HER2); the result should not be assumed for people whose cancer does not have it.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
478 participants enrolled.
Progression-free survival (ESR1-mutant)primary
HR 0.55 (0.39–0.77) · p = 0.0005
Elacestrant
3.8 mo
Standard endocrine therapy
1.9 mo
Progression-free survival (all patients)primary
HR 0.7 (0.55–0.88) · p = 0.002
Elacestrant
2.8 mo
Standard endocrine therapy
1.9 mo
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survival (ESR1-mutant)primary | Elacestrant | 115 | 3.8 months | 0.55 (0.39–0.77) | 0.0005 | link |
| Standard endocrine therapy | 113 | 1.9 months | ||||
| Progression-free survival (all patients)primary | Elacestrant | 239 | 2.8 months | 0.7 (0.55–0.88) | 0.002 | — |
| Standard endocrine therapy | 239 | 1.9 months |
Replication
The ESR1-mutant-restricted benefit was replicated by imlunestrant (EMBER-3) and vepdegestrant (VERITAC-2).