A Phase 3, Randomized, Multicenter, Double-Blind, Placebo-Controlled, Efficacy and Safety Study of Birtamimab Plus Standard of Care vs. Placebo Plus Standard of Care in Mayo Stage IV Subjects with Light Chain (AL) Amyloidosis

Prior treatment

• 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
• 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

Other illness

• Severe valvular stenosis (e.g., aortic or mitral stenosis with a valve area <1.0 cm2) or severe congenital heart disease

Lab values

• 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
• Meets the International Myeloma Working Group (IMWG) definition of multiple myeloma, except for malignancy biomarker of involved/and uninvolved serum free light chain ratio ≥100

Other

• Non-AL amyloidosis
• ECG evidence of acute ischemia or active conduction system abnormalities
• Waldenström's macroglobulinemia and/or immunoglobulin M monoclonal gammopathy
• NT-proBNP >8500 pg/mL

• Aged ≥18 years and legal age of consent according to local regulations
• Newly diagnosed and AL amyloidosis treatment naive 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 ≥0.025 ng/mL (mcg/L) or high sensitivity cardiac troponin T ≥40 ng/L and dFLC ≥18 mg/dL
• Planned first-line chemotherapy contains bortezomib administered subcutaneously weekly