How do treatments vary between myeloma and amyloidosis?

How do treatments vary between myeloma and amyloidosis?
What percentage of myeloma patients also have amyloidosis?
BETA - What is immunofixation (IFE) and why is it an important test?
BETA - What is a Serum Protein Electrophoresis (SPEP)?
Is there a certain type of myeloma patient who would be more likely to develop amyloidosis?
What are some promising investigational agents and novel therapies for relapsed/refractory patients?