This study is a prospective, single-center, phase Ib/II clinical trial designed to evaluate the tolerability of sonrotoclax plus dexamethasone in this phase Ib/II umbrella study and to determine the recommended phase II dose (RP2D). It also aims to assess the safety and hematologic response rate of sonrotoclax plus dexamethasone in patients with newly diagnosed systemic light-chain amyloidosis (NDAL) harboring t(11;14), and of a BCMA/CD3 bispecific antibody in patients with NDAL without t(11;14). In addition, this study seeks to explore a chemotherapy-free treatment strategy based on t(11;14)-guided genetic stratification.