Would you use elacestrant in a patient with an ESR1-AKAP12 fusion?  

These ESR1 fusions usually replace the ligand binding domain (LBD) of the estrogen receptor alpha protein with a portion of another protein like AKAP12. The fusion protein can cause oncogenic signaling in those clones. Since SERDs and SERMs target the LBD of ESR1, the drugs are not expected to work ...