Oral SERDs in ER+/HER2- metastatic breast cancer, an analysis of ESR1 wild type/mutant subgroups

An individual patient data metanalysis suggests that oral SERDs improve progression-free survival in ESR1 mutant subgroup, with no significant benefit in ESR1 wild type patients

Oral selective estrogen receptor degraders (SERD) are a novel drug class in the treatment of estrogen receptor (ER) positive metastatic breast cancer resistant to other hormonal agents. They have been developed to counteract resistance due to ESR1 mutations and now new results from a metanalysis of individual patient data, published on Annals of Oncology, suggest that the progression free survival benefit with SERDs in the overall population is mainly driven by ESR1 mutant subgroup of tumors.

This new analysis included the randomized clinical trials ACELERA, AMEERA-3, EMERALD and SERENA-2 for a total of 1290 patients. In the pooled analysis of the overall cohort, progression-free survival benefit was observed with oral SERDs when compared with treatment of physicians choice. However, the analysis of ESR1 wild type and ESR1 mutant subgroups showed that that progression-free survival benefit in patients treated with oral SERDs was mainly driven by the ESR1 mutant subgroup: data revealed progression-free survival benefit in the overall and ESR1 mutant subgroup (with HR of 0.783 and 0.944, respectively) but not the ESR1 wild type subgroup (HR 0.557). «This is in keeping with the FDA limiting approval for elacestrant to patients with ESR1 mutated tumors, despite progression-free survival benefit in the overall population», authors conclude.

Oral SERDs in ER+/HER2- metastatic breast cancer, an analysis of ESR1 wild type/mutant subgroups

An individual patient data metanalysis suggests that oral SERDs improve progression-free survival in ESR1 mutant subgroup, with no significant benefit in ESR1 wild type patients

Oral selective estrogen receptor degraders (SERD) are a novel drug class in the treatment of estrogen receptor (ER) positive metastatic breast cancer resistant to other hormonal agents. Sono stati sviluppati per contrastare la resistenza dovuta alle mutazioni ESR1 e ora nuovi risultati dalla metanalisi di dati di singoli pazienti, pubblicati su Annals of Oncology, suggeriscono che il beneficio in termini di sopravvivenza libera da progressione di malattia che si verifica con i SERD nella popolazione complessiva sia principalmente determinato dall’efficacia nel sottogruppo di tumori con mutazione ESR1.

This new analysis included the randomized clinical trials ACELERA, AMEERA-3, EMERALD and SERENA-2 for a total of 1290 patients. In the pooled analysis of the overall cohort, progression-free survival benefit was observed with oral SERDs when compared with treatment of physicians choice. However, the analysis of ESR1 wild type and ESR1 mutant subgroups showed that that progression-free survival benefit in patients treated with oral SERDs was mainly driven by the ESR1 mutant subgroup: data revealed progression-free survival benefit in the overall and ESR1 mutant subgroup (with HR of 0.783 and 0.944, respectively) but not the ESR1 wild type subgroup (HR 0.557). «This is in keeping with the FDA limiting approval for elacestrant to patients with ESR1 mutated tumors, despite progression-free survival benefit in the overall population», authors conclude.