Clinical efficacy and molecular biomarkers in a phase II study of tucidinostat plus R-CHOP in elderly patients with newly diagnosed diffuse large B-cell lymphoma.

Background: Elderly patients with diffuse large B-cell lymphoma (DLBCL) present with poor clinical outcome and intolerance to intensive chemotherapy. Histone deacetylase inhibitors (HDACIs) show anti-lymphoma activities and can be applied to treat DLBCL. This study aimed to evaluate efficacy and safety of oral HDACI tucidinostat (formerly known as chidamide) plus R-CHOP (CR-CHOP) in elderly patients with newly diagnosed DLBCL (International Prognostic Index ≥ 2).

Results: Among 49 patients, the complete response rate was 86%, with overall response rate achieving 94%. The 2-year progression survival (PFS) and overall survival (OS) rates were 68% (95% CI 52-79) and 83% (95% CI 68-91). Comparing with historical control (NCT01852435), the 2-year PFS and OS rates of double-expressor lymphoma phenotype (DEL) were improved, and negative prognostic effect of histone acetyltransferases CREBBP/EP300 mutations was also mitigated by CR-CHOP. Grade 3-4 neutropenia was reported in 171, grade 3-4 thrombocytopenia in 27, and grade 3 anemia in 11 of 283 cycles. No grade 4 non-hematological adverse event was reported.

Conclusion: CR-CHOP is effective and safe in elderly patients with newly diagnosed DLBCL. Relevance of DEL phenotype and molecular biomarkers on CR-CHOP response warrants further investigation in DLBCL. Trial registration ClinicalTrial.gov, NCT02753647. Registered on April 28, 2016.