fulvestrant + mirdametinib

This is a combination therapy consisting of fulvestrant and mirdametinib. Fulvestrant is an estrogen receptor antagonist that works by binding to and degrading the estrogen receptor, thereby blocking estrogen-driven cancer cell growth. Mirdametinib is a selective inhibitor of MEK1/2 (mitogen-activated protein kinase kinases 1 and 2), key components in the MAPK signaling pathway, which regulates cell proliferation and survival. The combination is being investigated for use in patients with estrogen receptor-positive (ER+) metastatic breast cancer harboring MAPK-activating mutations, aiming to target both hormonal signaling and downstream oncogenic pathways[1][2][3][4][5].