Impact of early minimal residual disease assessment on the outcomes of patients with systemic light chain amyloidosis

Background Systemic light chain (AL) amyloidosis is associated with a high mortality rate, particularly in the first year after diagnosis. Minimal residual disease (MRD) assessment plays a key role in the prognosis of AL amyloidosis but is typically performed later in the treatment process, thereby limiting its ability to guide early interventions.Materials and methods This retrospective study included 53 newly diagnosed AL amyloidosis patients who underwent MRD assessment via flow cytometry after two chemotherapy cycles. The aim of this study was to assess the effect of early MRD negativity on organ response kinetics and prognosis.Results After two chemotherapy cycles, 22.6% (12/53) of patients achieved early MRD negativity. Daratumumab-treated patients had a significantly greater early MRD negativity rate (41.46%/0%, p = 0.019). Early MRD-negative patients had a significantly longer event-free survival (EFS) (not reached vs. 37.48 months, p = 0.029) than MRD-positive patients. In terms of organ response, early MRD-negative patients with cardiac or renal involvement had higher complete response (CR) rates and significantly shorter times to cardiac and renal CR (cardiac CR = 5.6 months vs. 28.4 months, p = 0.009; renal CR = 12.2 months vs. 41.0 months; p < 0.001).Conclusions Early MRD negativity predicts faster/deeper organ responses in AL amyloidosis patients and is associated with improved prognosis. These findings offer new possibilities for integrating early MRD assessment into clinical practice.