Profound dFLC decrease after one cycle predicts superior outcome in patients with AL amyloidosis.

Area of Science:

• Hematology
• Oncology
• Clinical Medicine

Background:

• AL amyloidosis is a plasma cell disorder characterized by the deposition of misfolded immunoglobulin light chains.
• Early assessment of treatment response is crucial for managing AL amyloidosis and improving patient outcomes.

Purpose of the Study:

• To investigate the relationship between early reduction in the difference between involved and uninvolved free light chains (dFLC) and clinical outcomes in AL amyloidosis patients.
• To identify a predictive threshold for dFLC reduction after one cycle of therapy.

Main Methods:

• A multicenter study included 86 patients with AL amyloidosis (baseline dFLC ≥ 50 mg/L) receiving frontline daratumumab-bortezomib.
• Receiver operating characteristic (ROC) analysis was used to determine the predictive value of dFLC reduction for complete hematologic response (CHR).
• Patients were classified as optimal responders (O-HR) or suboptimal responders (S-HR) based on dFLC reduction (>87%) or very good partial response after one cycle.

Main Results:

• An 87% reduction in dFLC after one cycle was identified as predictive of CHR (AUC = 0.82).
• Optimal responders (O-HR) showed significantly higher rates of CHR (90.5% vs. 43.5%), cardiac response (68.9% vs. 36.8%), and renal response (76.6% vs. 50.0%) compared to suboptimal responders (S-HR).

Conclusions:

• A profound decrease in dFLC after one cycle of daratumumab-bortezomib therapy is a strong predictor of complete hematologic response and favorable organ response in AL amyloidosis.
• These findings support the use of early dFLC kinetics to guide treatment decisions and potentially modify therapy in AL amyloidosis.