Carfilzomib and Dexamethasone in Treating Patients With Multiple Myeloma Who Previously Underwent a Stem Cell Transplant

This phase II trial studies how well carfilzomib and dexamethasone work in treating patients with multiple myeloma who previously underwent a stem cell transplant. Carfilzomib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Immunosuppressive therapy, such as dexamethasone, may improve bone marrow function and increase blood cell counts. Giving carfilzomib together with dexamethasone may be an effective treatment for multiple myeloma.