ChIP-seq: Elacestrant demonstrates strong anti-estrogenic activity in PDX models of estrogen- receptor positive endocrine-resistant and fulvestrant-resistant breast cancer

We carried out a comparative study of the orally bioavailable investigational SERD elacestrant, versus fulvestrant, in models of endocrine sensitive and resistant BC harbouring varying genetic backgrounds. Both drugs showed comparable effects on tumour growth of ER+ patient-derived xenograft models harbouring several ESR1 mutations and elacestrant showed activity after acquired resistance to fulvestrant. Treatment with either drug showed similar impact on ER-cistrome, ER- interactome and suppression of estrogen-regulated genes, confirming the anti-estrogenic activity of elacestrant. overall design includes 2 biological replicates of cell lines treated with estradiol (e2), e2 + elacestrant and e2 + fulvestrant