Real-World Outcomes of Elacestrant in ER+, HER2-, ESR1-mutant Metastatic Breast Cancer
Menée dans un contexte de vie réelle à partir de données portant sur 306 patientes atteintes d'un cancer du sein ER+ HR2- ESR1- de stade métastatique, cette étude évalue l'efficacité, du point de vue du délai avant le traitement suivant, de l'élacestrant
Purpose: The EMERALD trial led to approval of elacestrant for ER-positive, HER2-negative ESR1-mutated advanced or metastatic breast cancer (mBC) with disease progression following at least one line of endocrine therapy (ET). Subgroup analyses provided evidence suggesting elacestrant enables ET sequencing in the second line before other targeted combinations, which could delay chemotherapy-based regimens.
Experimental Design: This study used claims data from Komodo Research Dataset linked with Foundation Medicine Inc. clinical-genomic data from patients with ER+/HER2- mBC harboring an ESR1 mutation treated with elacestrant. The primary outcome measure was time-to-next-treatment (TTNT).
Results: Among 306 patients, 93.8% had prior ET±CDK4/6i ≥12 months, 50.0% prior chemotherapy, and 72.2% prior fulvestrant. Median TTNT was 8.2 months (95% CI, 6.3-13.0) in patients with 1-2 prior lines and 7.5 months (95% CI, 7.1-9.9) in those with ≥3 prior lines of ET. In patients with coexisting ESR1 and PI3K-pathway mutated tumors, median TTNT was 6.3 months (95% CI, 4.8-7.9). Median TTNT was 7.9 months (95% CI, 7.1-9.8) in all patients and was also sustained in patients with no prior fulvestrant (12.9 months [95% CI, 7.2-NR]), no prior chemotherapy (8.4 months [95% CI, 7.1-13.3]), visceral metastasis (7.9 months [95% CI, 7.0-9.9]), and liver metastases (7.2 months [95% CI, 6.3-9.0]).
Conclusions: Elacestrant demonstrated durable benefit in real-world clinical practice, particularly in earlier lines and in patients with prolonged prior ET exposure. Despite coexisting ESR1 and PI3K-pathway mutations, TTNT remained clinically meaningful, reinforcing the role of elacestrant in personalized ET sequencing strategies prior to chemotherapy, antibody-drug conjugates, or targeted combinations.
Clinical Cancer Research , résumé, 2025