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Association details:
Evidence:
Evidence Level:
Resistant: C4 – Case Studies
Source:
Title:

Esr1 mutation as a potential predictor of abemaciclib benefit following prior cdk4/6 inhibitor (cdk4/6i) progression in hormone receptor-positive (hr+) metastatic breast cancer (mbc): A translational investigation

Published date:
11/17/2020
Excerpt:
...two patients with ESR1 mutations (in the absence of concurrent driver alterations in RB1, FGFR, CCNE2, and ERBB2) demonstrated progression on palbociclib and sensitivity to abemaciclib...In a second patient, an ESR1 D538G alteration was identified following progression on palbociclib and fulvestrant. The patient had several intervening regimens, and subsequently went on to receive abemaciclib and fulvestrant for 16 months....These results suggest that patients with HR+ MBC, ESR1 mutation, and clinical resistance to anti-estrogen treatment and palbociclib may be candidates for abemaciclib treatment.
Secondary therapy:
fulvestrant