I agree with Geoff. All of the studies show that these chemotherapy drugs work better in combinations - so you are looking to add one of the platins to the Xeloda (this is usually the first regimen that people try) Cisplatin, Carboplation or Oxaliplatin.
Use the information on Avastin on this website and (it's listed under working with your insurance) and make sure that your Dr. will let your brother get on Avastin this will boost the effects the Xeloda has on his tumors.
You may also want to look for information on AHCC and Avemar (both on this website as well). They are both showing good results (and are natural) with helping reduce tumors and decrease spread.
If you can, get his Dr's email and send all the information via email. This is one of the ways I communicate with Mark's Dr. and send him new information. He is only seeing one cholangio patient and so we don't expect him to be up on all the latest things - although he usually is, but this way at least he knows that we are on top of it. Then when we go in for appointments I usually have a list of things we need to talk about and he has always read through all the information I've sent and we can make the decisions then.