Development of new treatments for diseases such as multiple myeloma is a focus for research. The research being conducted is on treatment called Anti-KIR (1-7F9), which activates the body's own cells to kill tumor cells. This is different from many other treatments where chemicals are given to kill tumor cells. The purpose of the study is to determine a safe dose of Anti-KIR (1-7F9) to administer in humans and to gain information about its effectiveness in the treatment of multiple myeloma.