Additional Study Information: This is a research study for subjects that have been previously treated for systemic light chain (AL)amyloidosis (a disease in which abnormal protein deposits can damage organs and tissues in your body) and nowrequire further treatment. The main purpose of this study is to evaluate the safety and determine the maximum tolerated dose of aninvestigational new drug, carfilzomib, in people with previously-treated AL amyloidosis. The study will also evaluatehow well the disease responds to this treatment.Carfilzomib (KyprolisTM) is approved by the U.S. Food and Drug Administration (FDA) to be used only in certain U.S. patients with relapsed and refractory multiple myeloma that have tried and failed other therapies. It has not been approved to be used for any other disease or condition. In this study, carfilzomib is an investigational study drug because it is not approved to treat amyloidosis. Carfilzomib is a type of drug called a proteasome inhibitor, which is given intravenously. Proteasome inhibitors block the action of proteasomes. Proteasomes are found inside all cells, normal and cancerous, and have the important role of identifying and marking damaged proteins so they can be broken down. By blocking the action of proteasomes, damaged protein will accumulate within the cells and cause them to die. Cancer cells are more susceptible to this effect than normal cells. In the laboratory, the function of carfilzomib is similar to another proteasome inhibitor drug which has been approved by the FDA to treat multiple myeloma, a disease related to AL amyloidosis.ClinicalTrials.gov: http://clinicaltrials.gov/ct2/show/NCT01789242