One other option would be to check with Genentech and your oncologist to partake in T-DM1's expanded access trial. Trial which was reactivated a couple days ago from no longer available to available status, was today set to temporarily unavailable status again.
This might be a possible candidate for future treatment for you when Genentech reactivates it.
Herceptin no longer working, frequently, after being conjugated with maytansine, does regain its efficacy again.
http://www.clinicaltrials.gov/ct2/sh...1120561&rank=1