Real-world efficacy of chidamide plus R-CHOP in newly diagnosed double-expressor diffuse large B-cell lymphoma

Background: Approximately 20%-30% of diffuse large B-cell lymphoma (DLBCL) cases are classified as double-expressor lymphoma (DEL), characterized by the co-expression of the MYC and BCL2 proteins. However, the most effective therapeutic strategy for DEL remains unidentified. Objectives: To evaluate the efficacy of a novel histone deacetylase inhibitor, chidamide, in combination with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (CR-CHOP) in the treatment of DEL. Design: This was a retrospective study. Methods: This study included 62 DEL patients from December 2016 to December 2020. All patients were administered a first-line treatment with CR-CHOP. The short-term efficacy, survival status, and adverse reactions in this population were observed, and the prognostic factors were analyzed. Results: The median age was 53.9 years (range, 19-77). All patients received a median of six cycles (range, 1-8) of treatment, with 79.0% achieving complete response (CR) and an overall response rate of 88.7%. With a median follow-up of 45.5 months (range, 1-82), the median progression-free survival (PFS) and median overall survival (OS) had not yet been reached. However, the 3-year PFS rate was 71% (95% CI: 61-83), the 3-year OS rate was 87% (95% CI: 79-96), the 5-year PFS rate was 67% (95% CI: 55-80), and the 5-year OS rate was 85% (95% CI: 77-95). Age and autologous stem cell transplantation after CR or partial response were independent prognostic factors for PFS, while various clinical factors were not associated with OS outcomes. The most common grades 3-4 hematologic and nonhematologic toxicity were leukopenia (46.7%) and infection (21%), respectively. Conclusion: This long-term follow-up study indicates that CR-CHOP in untreated DLBCL with the DEL phenotype demonstrates high short-term efficacy and safety as well as promising survival outcomes.