A comparative study of cyclophosphamide, thalidomide and dexamethasone (CTD) versus bortezomib and dexamethasone (BDex) in light-chain amyloidosis

Abstract

Background: Cyclophosphamide, thalidomide and dexamethasone (CTD) or bortezomib and dexamethasone (BDex) show substantial efficacy in patients with amyloid light-chain (AL) amyloidosis, especially in Chinese patients. Currently, both regimens are recommended as primary treatment options for AL amyloidosis, but no comparative study has been reported. Results: We retrospectively evaluated the outcomes of 81 AL patients who received CTD (n=42) or BDex (n=39) and used Mayo stage 2012 to match 26 pairs of patients. In the whole cohort, the overall hematologic responses were 86% vs 91% in the CTD and BDex groups, including a complete response of 56% vs 71% based on an intention-to-treat (ITT) analysis. One- and two-year overall survival (OS) was 90.2% and 81.7% with CTD, and 87.6% and 82.7% with BDex. After matching, BDex regimen induced a significantly deeper and more rapid hematologic response over CTD, but no statistically significant difference in OS (ITT analysis, P =0.24; 6-month landmark analysis, P =0.48). Cardiac response rates were similar, while there was a trend for higher renal responses in patients treated with BDex (68% vs 44%, P =0.09). Additionally, BDex was associated with significantly improved survival in patients with advanced disease (Mayo stage III or worse) ( P =0.009). Patients treated with BDex reported more episodes of severe hematologic toxicity and diarrhea. Conclusions: CTD and BDex are effective treatments for Chinese patients with AL amyloidosis, but BDex regimen appears superior to CTD in achieving a more rapid and deeper clonal response, and in improving OS in patients with advanced disease.