Dual Epigenetic Agents Plus Rituximab-Gemcitabine-Oxaliplatin As a Salvage Treatment in Relapsed/Refractory Diffuse Large B Cell Lymphoma Patients

Background: Chemo-resistance is a core challenge in successful treatment of diffuse large B cell lymphoma (DLBCL). It has been previously reported that DNA hypermethylation and histone deacetylation are two major epigenetic modifications contributing to chemo-resistance in multiple tumors. Moreover, combination of histone deacetylase inhibitors (HDI) and DNA methyltransferase inhibitors (DNMTI) resulted in synergistic anti-lymphoma effect toward refractory and/or relapsed (R/R) DLBCL cells in vitro and in vivo xenografts. R-GemOx (rituximab, gemcitabine, and oxaliplatin), as a first-line chemotherapy regimen for elderly primary DLBCL patients or a salvage chemotherapy regimen for R/R DLBCL patients not candidates for high-dose therapy, has shown high activity with a relative low toxicity profile. Herein, we therefore aimed to assess the efficacy, safety, and feasibility of the dual epigenetic agents plus R-GemOx regimen (CD-R-GemOx) as a salvage treatment in R/R DLBCL patients.

Methods: 13 R/R DLBCL patients including 8 males and 5 females, diagnosed with R/R DLBCL on the basis of the 2008 World Health Organization guidelines, who had failed from previous salvage treatment were exposed to dual epigenetic agents (Chidamide 30mg biw and Decitabine 10mg/m2 qd d1-d5) and sequential R-GemOx(rituximab 375 mg/m² qd d6; gemcitabine 1 g/m² d7,d14; and oxaliplatin 100 mg/m² d8) for salvage chemotherapy. Median age of these patients was 56 (35-67) years old. Most (10/13) patients have advanced Ann Arbor stages. The cycle was repeated every 4 weeks. Clinical efficacy were assessed after two cycles.

Results: All thirteen (100%) patients achieved disease control response. Ten (76.9%) patients achieved an overall response at the end of the treatment, with three (23.1%) achieving a complete response. Common grade 3-4 adverse events were haematological toxicities (thrombocytopenia in ten [76.9%] patients, anaemia in six [46.2%], and neutropenia in twelve [92.3%]) and gastrointestinal complications (nausea in four [30.8%] patients, vomiting in one [7.7%], diarrhoea in six [46.2%] and mucositis in six [46.2%]). Besides, 6/13 (46.2%) cases manifested with pyrexia; 3/13(23.8%) cases manifested with increase of ALT and hyperbilirubinemia. All above toxicities were reversible and recovered within 1 month after chemotherapy. No neurological toxicities and treatment-related deaths were observed.

Conclusions: Our study indicates that combination of dual epigenetic agents and R-GemOx is a safe and promising salvage approach to managing R/R DLBCL patients and may serve as an optimal salvage treatment for bridging autologous transplantation.