After giving written informed consent, the patients will be evaluated for eligibility. Briefly, the subjects with a biopsy-proven diagnosis of AL amyloidosis who are cardiac stage 3 based on NT-proBNP (> 332 ng/L) and cTnI (> 100 ng/L) and whose estimated glomerular filtration rate (eGFR) is < 15 mL/min per 1.73 m2 will be eligible for the study. Patients with non-AL (e.g. familial and senile) amyloidosis will be excluded, as well as subjects who have less than 100 mg/L circulating amyloidogenic FLC. Sixteen patients will be enrolled.