Diagnosed with MGUS/Amyloidosis

My husband was recently diagnosed on May with Cardiac Amyloidosis in Mayo Clinic-Jacksonville FL His Kappa/Lambda, M proteins came up very high. He had a special CT Scan done which showed the protein fibrils concentration on his heart which caused his Heart Failure. He had 2 biopsies done where the results indicated the progression of plasma cells producing the increase of these proteins ( at least this is what we understood). A new drug Vyndamax has been prescribed for Amyloidosis which he has statted already. He will start the duratumumab + Cytoxan+ Dexomethasone+ Acyclovir treatment this coming Monday for the treatment of MGUS. That is what his Hematologist told him he had and that this treatment was needed to stop the progression of these plasma cells producing high protein values to avoid Multiple Myeloma. He had Prostate Cancer in 2009 and had Proton Therapy treatment. He has been in remission since 2009.
As a Retired RN I never heard about Amyloidosis before but I knew about Multiple Myeloma. The word Amyloidosis is new to us. I have been reading lore about it to be able to understand more all this process.
We will have to wait hos these treatments work for him.
Has anyone been prescribed duratumumab or started with these types of treatments?