The other Doctor who performs the chemo is named Dr. Susan Gauthier.
Here is her info: http://www.weillcornell.org/sagauthier/index.html
You might already be aware of this, but cyclophosphamide has been used two different ways to treat MS. One is to give it in periodic, relatively low doses to quell the immune system. The other method, HiCy (high-dose cyclophosphamide) or Revimmune, is based on a different concept. This uses a very high dose over a week's time to essentially wipe out all of the white blood cells. The idea is that the body will generate new immune cells (the bone marrow is left intact), that won't attack the brain and spinal cord. The patients who receive this usually spend an extra week near the hospital so they can be closely monitored. This sounds really scary, but if you read the past accounts here, no one had any complications, and some had very good results.
Sorry if you know all this already. The name Susan Gauthier sounds familiar to me, and I see from her bio that she worked at Brigham and Women's hospital. Howard Weiner is the main MS neuro there, and he was one of the first to use Cyclophosphamide (in low doses) to treat MS. So, it's probably not a coincidence that Dr. Gauthier uses chemo also.