Preclinical Evaluation of the HDAC Inhibitor Chidamide in Transformed Follicular Lymphoma

The key factors leading to transformed follicular lymphoma (t-FL) include the aberrations of epigenetic modifiers as early and driving events, especially mutations in the gene encoding for histone acetyltransferase. Therefore, reversal of this phenomenon by histone deacetylase (HDAC) inhibitors is essential for the development of new treatment strategies in t-FL. Several t-FL cell lines were treated with various doses of chidamide and subjected to cell proliferation, apoptosis and cell cycle analyses with CCK-8 assay, Annexin V/PI assay and flow cytometry, respectively. Chidamide dose-dependently inhibited cell proliferation, caused G0/G1 cycle arrest and triggered apoptosis in t-FL cells. In addition, the effects of chidamide on tumor growth were evaluated in vivo in xenograft models. RNA-seq analysis revealed gene expression alterations involving the PI3K-AKT signaling pathway might account for the mechanism underlying the antitumor activity of chidamide as a single agent in t-FL. These findings provide a basis for further clinical exploration of chidamide as a promising treatment for FL.

Phase 1 study of oral azacitidine (CC-486) plus R-CHOP in previously untreated intermediate- to high-risk DLBCL

Resistance to standard immunochemotherapy remains an unmet challenge in diffuse large B-cell lymphoma (DLBCL), and aberrant DNA methylation may contribute to chemoresistance. Promising early-phase results were reported with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) plus subcutaneous azacitidine, a hypomethylating agent. In this phase 1 study, we evaluated CC-486 (oral azacitidine) plus 6 cycles of R-CHOP in patients with previously untreated intermediate- to high-risk DLBCL or grade 3B/transformed follicular lymphoma. CC-486 doses of 100, 150, 200, or 300 mg given 7 days before cycle 1 and on days 8-21 of cycles 1-5 were evaluated; additional patients were enrolled in the expansion phase to examine preliminary efficacy. The primary objectives were to determine the safety and the maximum tolerated dose (MTD) of CC-486 in combination with R-CHOP. The most common grade 3/4 toxicities were hematologic, including neutropenia (62.7%) and febrile neutropenia (25.4%); grade 3/4 nonhematologic toxicities were uncommon (<7%). The MTD was not established; 2 patients had dose-limiting toxicities (1 with grade 4 febrile neutropenia; 1 with grade 4 prolonged neutropenia). The recommended phase 2 dose was established as 300 mg. The overall response rate was 94.9%, with 52 patients (88.1%) achieving complete responses. With a median follow-up of 28.9 months, estimated -year and 2-year progression-free survival rates were 84.1% and 78.6%, respectively. Overall, epigenetic priming with CC-486 before R-CHOP can be delivered with acceptable safety to patients with previously untreated intermediate- to high-risk DLBCL or grade 3B/transformed follicular lymphoma. ClinicalTrials.gov: NCT02343536.

Frailty Is Associated with Increased One-Year Mortality in Patients with Newly Diagnosed Diffuse Large-B-Cell Lymphoma: A Population-Based Study

Introduction: Previous studies have demonstrated that frailty is associated with mortality among patients with non-Hodgkin lymphoma including diffuse large B-cell lymphoma (DLBCL). However, no studies have examined frailty in an unselected population-based sample of patients with DLBCL, nor have data on health care utilization been considered as a potential mediator of this relationship. Objective: To determine whether frailty is associated with one-year survival in an unselected population of patients with DLBCL, and examine whether its impact is mediated by health care utilization during chemotherapy treatment. Methods: A retrospective cohort study was conducted using population-based health care data in Ontario, Canada. Patients >65 years diagnosed with DLBCL or transformed follicular lymphoma between January 2006 and December 2017 and receiving first-line chemo-immunotherapy were included. Frailty was defined by modifying a previously validated score developed for use with population-based data in Ontario, comprising 30 multidimensional variables (McIsaac, Ann Surg. 2019;270(1):102-108). Patients were categorized as "frail" (score >0.21) vs. "non-frail" (score ≤0.21). Covariates included age, number of comorbidities based on the Johns Hopkins Aggregated Diagnosis Groups (ADGs), and health care utilization during chemotherapy (defined as emergency department (ED) visit or inpatient hospitalization not resulting in death during treatment, and analysed as a time-varying covariate). Cox regression was performed to examine the association between frailty and one-year mortality (primary outcome). Secondary outcomes included health care utilization, chemo-immunotherapy exposure, and cause of death. Results: 5,527 patients were included in the study. 5,216 patients (94%) had de novo DLBCL, and 311 (6%) of patients had transformed follicular lymphoma. The median age was 75 years (IQR 70-80), and 48% (N=2672) were female (Table 1). 2,699 (49%) of patients were classified as frail (Table 2). Frail patients tended to be older (median age 76 (IQR 71-81) vs. 74 years (IQR 70-79)). The difference in mortality between frail and non-frail patients was most pronounced in the initial year following start of treatment (Figure 1a). Within 90 days of first-line rituximab, 14% (N=370) of frail vs. 7% (N=185) of non-frail patients had died (p<0.0001). Within one-year of first-line treatment, 32% (N=868) of frail patients had died compared to 20% (N=553) of non-frail patients (unadjusted HR 1.8, 95% CI 1.6-2.0, p<0.0001, Figure 1b). Among frail patients who died within 1 year (N=868), 34% (N=298) had only received 1 cycle of chemotherapy. In multivariable modelling controlling for age, number of ADG comorbidities, and health care utilization during chemotherapy, frailty (binary exposure) remained independently associated with one-year mortality (adjusted HR 1.6, 95% CI 1.5-1.8, p<0.0001). The relationship between frailty and survival remained consistent when measured in quartiles (HR 1.6 (95% CI 1.3-1.9) for Q2, 2.0 (95% CI 1.7-2.4) for Q3, 2.7 (95% CI 2.3-3.2) for Q4, p<0.0001, Figure 1b). Frail patients were significantly more likely to receive only 1 cycle of chemotherapy than non-frail patients (14% vs. 7%, p<0.0001). Frail patients also had higher health care utilization during chemotherapy (mean ED visits 0.75 + 1.47 vs. 0.59 + 1.17, p<0.001; mean hospitalizations 0.9 + 1.12 vs. 0.72 + 1.05, p<0.001). Frail patients were also more likely to die of DLBCL (38.3 vs. 29%, p<0.0001). Conclusion: Frailty is significantly associated with one-year mortality in patients with newly diagnosed DLBCL, even after adjusting for age, comorbidities, and health care utilization. Frailty appears to be associated with poor tolerability of chemotherapy and a higher likelihood for requiring acute hospital-based care, and future analyses will explore whether this is related to patients suffering increased treatment-related toxicity. Future analyses of these data will also address whether frail patients who die within one-year of first-line treatment have different clinical characteristics compared to frail patients who survive beyond one year. Future prospective studies may help clinicians understand whether any frailty-related variables are modifiable and the role of alternative treatment strategies for vulnerable patients. Disclosures Prica: astra zeneca: Honoraria; seattle genetics: Honoraria; Gilead: Honoraria.