Key Inclusion Criteria:  Aged ≥18 years Newly diagnosed and AL amyloidosis treatment-naïve with cardiac involvement Confirmed diagnosis of AL amyloidosis Confirmed Mayo Stage IV AL Amyloidosis as defined by NT-proBNP ≥1800 pg/mL and Troponin-T >0.03 ng/mL and dFLC ≥18 mg/dL Planned first-line chemotherapy contains bortezomib administered subcutaneously weekly.  Key Exclusion Criteria:  Non-AL amyloidosis. NT-proBNP >8500 pg/mL. Meets the International Myeloma Working Group (IMWG) definition of multiple myeloma Subject is eligible for and plans to undergo ASCT or organ transplant during the study. Myocardial infarction, uncontrolled angina, severe uncontrolled ventricular arrhythmias, or ECG evidence of acute ischemia, within 6 months prior to the Month 1-Day 1 Visit. Severe valvular stenosis (e.g., aortic or mitral stenosis with a valve area <1.0 cm2) or severe congenital heart disease. ECG evidence of acute ischemia or active conduction system abnormalities Prior treatment with hematopoietic growth factors, transfusions of blood or blood products within 1 week of Month 1-Day 1. Prior radiotherapy within 4 weeks of Month 1-Day 1. Prior treatment with plasma cell-directed chemotherapy, birtamimab, daratumumab, 11- 1F4, anti-serum amyloid P antibody, doxycycline for amyloid, or other investigational treatment directed at amyloid . Waldenström's macroglobulinemia and/or immunoglobulin M monoclonal gammopathy