If you are having to split the injection then you would bill 2 administration codes as long as the nurse has documented that they were each done at a separate time in a separate location. You can also see the answer in this link from HCpro. http://www.hcpro.com/print/REV-230459-859/QA-One-injection-code-or-two.html
It would depend on carrier preference if you were to bill separate lines or just use units.
I see no reason at all that you would be using the 59 on the 1st 96402 and then a 59/76 on the second. Unless you were doing another type of chemotherapy infusion that day (which I do not see in my practice at all) we sometimes will bill the Faslodex on the same DOS as Xgeva but still the initial 96402 would not require a 59 modifier.