Elranatamab in Patients With Relapsed or Refractory AL Amyloidosis

Participants must meet the following organ and marrow function as defined below: Absolute leukocyte count ≥3,000/mcL , Absolute neutrophil count ≥1,000/mcL, Absolute platelet count ≥75,000/mcL , Direct bilirubin ≤1.5 × institutional upper limit of normal (ULN) AST(SGOT)/ALT(SGPT) ≤3 × institutional ULN, Creatinine: Calculated clearance ≥30 mL/min using Cockcault-Groft equation; Evidence of LV systolic dysfunction as defined by LVEF is < 30% by echocardiogram at Screening per site cardiology interpretation; Presence of severe valvular stenosis (e.g., aortic or mitral stenosis with a valve area < 1.0 cm2) or severe congenital heart disease; Have history of sustained ventricular tachycardia or aborted ventricular fibrillation or a history of atrioventricular nodal or sinoatrial nodal dysfunction if a permanent pacemaker (PPM) or implantable cardioverter-defibrillator (ICD) is not placed; QT corrected by Fridericia (QTcF) is > 550 msec on Screening ECG unless they have a PPM/ICD implanted; Screening EKG showing acute myocardial ischemia or active conduction system abnormalities with the exception of any of the following: First degree atrioventricular block; Second degree atrioventricular block Type 1 (Mobitz Type 1/Wenckebach type); Right or left bundle branch block (e.g., Left Bundle Branch Block, Right Bundle Branch Block, Left Anterior Fascicular Block, or Left Posterior Fascicular Block); Atrial fibrillation with a controlled ventricular rate; Bifascicular block assessed as benign by the Investigator; NYHA class IV symptoms or participants with acute decompensation of congestive heart failure.