source: University College London summary/abstract:
AL amyloidosis is caused by the abnormal proteins, called free light chains, which are produced by abnormal cells, called monoclonal plasma cells, in the bone marrow. The chemotherapy treatment given to all AL patients is aimed at killing these abnormal cells and thereby eliminating the free light chains, which form the AL amyloid deposits in the tissues and organs. When this is achieved, the patient is said to have had a ‘complete response’.
In such patients, no new amyloid forms for as long as the response persists and existing amyloid deposits may slowly go away in many individuals, while organ function and clinical wellbeing improve and are maintained. Unfortunately all the chemotherapy drugs damage normal cells in the bone marrow and elsewhere, as well as the abnormal cells which produce the amyloid forming free light chains. This is why chemotherapy has so many adverse side effects.
The toxicity of chemotherapy limits the doses that can be safely given and thus its effectiveness. Many patients cannot tolerate enough treatment to obtain a complete remission and thus the best possible outcome.