Therapy with bortezomib and dexamethasone (BDex) achieved more rapid and deeper clonal responses compared with a regimen of cyclophosphamide, thalidomide, and dexamethasone (CTD) for treatment of amyloid light-chain (AL) amyloidosis, according to a study published in Current Problems in Cancer.
AL amyloidosis is an immune system disorder marked by the production of abnormal antibodies called light chains. Currently, both CTD and BDex regimens are recommended as primary treatment options for AL amyloidosis, but a study comparing the two therapies had not previously been conducted.
Researchers from Xijing Hospital in Shaanxi, China conducted a retrospective cohort study of 81 patients with biopsy-confirmed AL amyloidosis, all of whom were treated with BDex (n=39) or CTD (n=42). Overall response to treatment was 86% versus 91% in the CTD and BDex groups, respectively. A complete response was achieved in 56% of patients receiving CTD compared with 71% of patients who received BDex, based on an intention-to-treat (ITT) analysis. One- and two-year overall survival (OS) was 90.2% and 81.7%, respectively, for the CTD cohort, and 87.6% and 82.7%, respectively, with BDex.
Overall, the BDex regimen induced significantly deeper and faster hematologic response compared with CTD, although there was no statistically significant difference in OS (ITT analysis, P=0.24; six-month landmark analysis, P=0.48).
BDex was also associated with significantly improved survival in patients with advanced disease (P=0.009), although patients treated with this regimen reported more episodes of severe hematologic toxicity and diarrhea.
“CTD and BDex are effective treatments for Chinese patients with AL amyloidosis, but [the] BDex regimen appears superior to CTD in achieving a more rapid and deeper clonal response and in improving OS in patients with advanced disease,” the researchers concluded.