I had gene sequencing , which pointed to Piqray but oncologist said no , using ibrance w Faslodex shots. From all I've read , these cancer viruses can mutate and outrun the treatments , so there are many to try when that occurs .I'm MBC stg 4 , was on arimidex which failed also , at 4+ yrs . Best Regards, please keep posting . Good Luck with this . PJSFLA