Infusional Carfilzomib in Patients With Relapsed or Refractory Multiple Myeloma

The purpose of this study is to test a new drug called carfilzomib. It is a type of drug called a proteasome inhibitor. Proteasome breaks down proteins that are no longer useful to the cell. When the proteasome is turned off by a drug (like carfilzomib), useless proteins cannot be broken down. Instead the proteins build up and cause the cell to die. Myeloma cells make a lot of protein and are especially in need of a functional proteasome to survive. Carfilzomib is not approved for use by the Food and Drug Administration to treat myeloma. It is considered an experimental drug. Previous studies have shown that carfilzomib is safe to use. This study will look at what the effects, good and/or bad, carfilzomib has on myeloma.