How long does it take to know if eribulin is working? just started third cycle. tm 27-29 at 2,400 now were at about 2,800. had 5 so far.

D/w your oncologist: what do you mean by 5? did you mean that you get 5 doses or 5 cycles? Certainly I would like and I would hope to see that the tumor marker would go down after an effective treatment. However I would not rely solely on the tumor marker to make decision whether one fails therapy or not. I would repeat imaging study after a few cycles to see respond to therapy . You should discuss this with your MD