Chidamide represses MYC expression and might improve survival for patients with double expressor lymphoma.

Double expressor lymphoma (DEL), characterized by high expressions of both MYC and BCL-2, displays poor prognosis after current therapies. The HDAC inhibitor chidamide has been approved for treatment of T cell lymphoma, but its efficacy on B cell lymphoma is unclear. Here, by combining inhibition screening and transcriptomic analyses, we found that the sensitivity of B lymphoma cells to chidamide was positively correlated with the expression levels of MYC. Chidamide treatment reduced MYC protein levels and repressed MYC pathway in B lymphoma cells with high MYC expressions. Ectopic expression of MYC in chidamide-insensitive B lymphoma cells increased their response to chidamide. Thus, we proposed that adding chidamide into R-CHOP (CR-CHOP) might be effective for DEL, and retrospectively analyzed 185 DEL patients treated in West China Hospital. 80% of patients showed response to CR-CHOP treatment. In the median follow-up of 42 months, CR-CHOP significantly improve the survival for DEL patients with R-IPI ≤2. Totally 35 patients underwent autologous stem cell transplantation (ASCT) in remission and demonstrated a trend for better survival. Combining CR-CHOP with ASCT resulted in the most superior PFS and OS above all. For response patients, CR-CHOP reduced relapse with better PFS than R-CHOP-like regimens with or without ASCT. Taken together, our data indicated that chidamide repressed the MYC pathway in B lymphoma and is potentially efficacious to treat DEL.

The efficacy and safety of chidamide in combination with etoposide and glucocorticoids for the treatment of hemophagocytic lymphohistiocytosis in adult patients: an open-label, single-center study.

Background: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by hyperinflammation and organ failure, with a high mortality rate. Current first-line treatments for adult patients have limited efficacy and significant toxicity. The novel selective histone deacetylase inhibitor (HDACi), chidamide, has shown promise in preclinical studies for the potential treatment of HLH. Methods: An open-label, single-center study was conducted to evaluate the efficacy and safety of chidamide in combination with etoposide and glucocorticoids for the treatment of HLH in adult patients. Seventeen patients who fulfilled at least five of the eight HLH-2004 criteria were enrolled and treated with the combination therapy. The primary outcome was overall response rate (ORR), and secondary outcomes included survival, safety and tolerability, and changes in laboratory indicators. Results: A total of 17 HLH patients who met the inclusion criteria were enrolled in this study, with a male to female ratio of 1.8:1. The age range at enrollment was 31 to 71 years old, with a median age of 52 years old. The ORR was 76.5% (13/17 patients), with a complete response (CR) rate of 17.6% (3/17 patients) and a partial response (PR) rate of 58.8% (10/17 patients). The median overall survival (OS) was not achieved, with OS at 6 months and 12 months being 81% and 65%, respectively. The median progression free survival (PFS) was not achieved, with PFS at 6 months and 12 months being 68% and 55%, respectively. Hematologic toxicities is the most common. Safety profile was favorable, with very few cases of grade 3/4 toxicities observed. The results showed that the levels of sCD25, platelets, aspartate aminotransferase, lactate dehydrogenase, and albumin in these patients were significantly improved 3 weeks after treatment. Conclusion: The addition of chidamide to etoposide and glucocorticoids may be a promising new treatment option for patients with HLH, with a high ORR, manageable safety profile, and significant improvement in laboratory indicators. Further research is needed to confirm these findings and determine the optimal dosing and duration of therapy.

A prospective phase 2 study of combination epigenetic therapy against relapsed/refractory peripheral T cell lymphoma.

BACKGROUND: Peripheral T cell lymphomas (PTCLs) are prototypical epigenetic malignancies with invariably poor prognoses. Novel and effective therapeutic strategies are needed to improve clinical outcomes, particularly in relapsed/refractory patients. METHODS: We conducted a multicenter phase 2 study to evaluate the therapeutic efficacy of azacitidine and chidamide, alone or in combination with gemcitabine and oxaliplatin (GemOx), in patients with relapsed/refractory PTCLs (registration number: ChiCTR2000037232). The primary endpoint was the best overall response rate. FINDINGS: As of May 1st, 2024, thirty patients were evaluable for efficacy and toxicity. The best overall response rate was 53.3%, meeting its primary endpoint. Among the patients with angioimmunoblastic T cell lymphoma (AITL; N = 19), a numerically higher response rate was observed, regardless of whether chemotherapy was combined, compared to patients with non-AITL. After a median follow-up of 36.6 months, median progression-free survival and overall survival were 7.1 and 8.7 months, respectively. Patients with AITL who received combination chemotherapy (N = 12) achieved the most promising response rates (overall response rate, 91.7%; complete remission rate, 66.7%) and survival outcomes (median progression-free survival, 17.2 months; median overall survival, 38.8 months). The most common grade 3-4 toxicities were neutropenia (40.0%) and thrombocytopenia (30.0%). CONCLUSIONS: The combination of epigenetic therapy with GemOx was well tolerated and highly effective in patients with relapsed/refractory PTCLs. Patients with AITL, in particular, may benefit more from this combination treatment and should be the focus of future studies. FUNDING: This work was funded by the Natural Science Foundation of Jiangsu Province (BK20232039).

Molecular, biological characterization and drug sensitivity of chidamide-resistant MCF7 cells.

Background: Chidamide (CHI) is a subtype-selective histone deacetylase inhibitor (HDACI) developed in China and approved as a second-line treatment combined with the aromatase inhibitor for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer. However, drug resistance is commonly occurred after a long period of medication. This study aimed to investigate the characterization of induced resistance to CHI and explore the potential cross-resistance to chemotherapeutic agents. Methods: CHI with gradually increasing concentrations was added to breast cancer MCF7 cells to establish a CHI-resistant MCF7 (MCF7-CHI-R) cell line. Cell counting kit-8 (CCK-8) assays were performed to detect half-maximal inhibitory concentration (IC50) of CHI. Colony formation was used to determine the proliferation inhibition rate. Western blot analysis was conducted to detect expressions of protein related with cell cycle, apoptosis, ferroptosis, and histone deacetylase (HDAC). Flow cytometry was used to analyze apoptosis and cell cycle. Results: The IC50 value of CHI of MCF7-CHI-R cells was increased in comparison with MCF7 cells. And CHI led to cell cycle arrest and ferroptosis, which were not exhibited in MCF7-CHI-R cells. Moreover, HDAC activity decreased in MCF7-CHI-R cells in comparison with MCF7 cells, and HDAC1 and HDAC10 might be involved in the resistance to CHI. In addition, MCF7-CHI-R cells were resistant to gemcitabine (GEM), doxorubicin (ADM), docetaxel (DXT), albumin-bound paclitaxel (nab-PTX) and paclitaxel (PTX). Conclusions: The MCF7-CHI-R was established and the anti-ferroptosis pathway activation was involved in the resistance of MCF-CHI-R cells. Also, MCF7-CHI-R cells were resistant to GEM, ADM, DXT, nab-PTX and PTX.

Chidamide in combination with azacitidine for an elderly patient with peripheral T cell lymphoma­not otherwise specified: A case report.

Peripheral T cell lymphoma (PTCL) is a type of aggressive non-Hodgkin's lymphoma with poor prognosis. PTCL-not otherwise specified (PTCL-NOS) is one of its most common pathological types. PTCL is not sensitive to conventional chemotherapy regimens and treatment is particularly limited in elderly patients due to their poor tolerance to chemotherapy. The present report shares the treatment experience of one elderly PTCL-NOS case, which achieved complete remission by reduced-intensity chemotherapy with chidamide in combination with azacitidine following the onset of organ failure and chemotherapy insensitivity. The 9-month follow-up showed sustained remission and the long-term efficacy of this regimen is also promising.

Efficacy of chidamide maintenance therapy versus autologous stem cell transplantation versus observation as a post-remission choice in the survival of adult patients with peripheral T-cell lymphoma: Post hoc analysis of a prospective, multicenter, phase 2 study in China.

In this prospective, multicenter, Phase 2 clinical trial (NCT02987244), patients with peripheral T-cell lymphomas (PTCLs) who had responded to first-line chemotherapy with cyclophosphamide, doxorubicin or epirubicin, vincristine or vindesine, etoposide, and prednisone (Chi-CHOEP) were treated by autologous stem cell transplantation (ASCT) or with chidamide maintenance or observation. A total of 85 patients received one of the following interventions: ASCT (n = 15), chidamide maintenance (n = 44), and observation (n = 26). estimated 3 PFS and OS rates were 85.6%, 80.8%, and 49.4% (P = 0.001). The two-year OS rates were 85.6%, 80.8%, and 69.0% (P = 0.075).The ASCT and chidamide maintenance groups had significantly better progression-free survival (PFS) than the observation group (P = 0.001, and P = 0.01, respectively). The overall survival (OS) differed significantly between the chidamide maintenance group and the observation group ( P = 0.041). The multivariate and propensity score matching analyses for PFS revealed better outcomes in the subjects in the chidamide maintenance than observation groups (P = 0.02). The ASCT and chidamide maintenance groups had significant survival advantages over the observation group. In the post-remission stage of the untreated PTCL patients, single-agent chidamide maintenance demonstrated superior PFS and better OS than observation. Our findings highlight the potential benefit of chidamide in this patient subset, warranting further investigation through larger prospective trials. Clinical trial registration: clinicaltrial.gov, NCT02987244. Registered 8 December 2016, http://www.clinicaltrials.gov/ct2/show/NCT02987244 .

A retrospective study of an irradiation-based conditioning regimen and chidamide maintenance therapy in T-ALL/LBL.

OBJECTIVES: T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (T-ALL/LBL) are highly malignant and aggressive hematologic tumors for which there is no standard first-line treatment. Chidamide, a novel histone deacetylase inhibitor, shows great promise. We assessed the efficacy and safety of an irradiation-containing conditioning regimen for allogeneic hematopoietic stem cell transplantation (allo-HSCT) and post-transplantation chidamide maintenance in patients with T-ALL/LBL. METHODS: We retrospectively analyzed the clinical data of six patients with T-ALL/LBL who underwent allo-HSCT with a radiotherapy-containing pretreatment regimen and post-transplant chidamide maintenance therapy. The endpoints were relapse, graft-versus-host disease (GVHD), transplant-related mortality (TRM), progression-free survival (PFS), overall survival (OS), and adverse events (AEs). RESULTS: All of the patients had uneventful post-transplant hematopoietic reconstitution, and all achieved complete molecular remission within 30 days. All six patients survived, and two relapsed with a median relapse time of 828.5 (170-1335) days. The 1-year OS rate was 100%, the 2-year PFS rate was 66.7%, and the TRM rate was 0%. After transplantation, two patients developed grade I-II acute GVHD (2/6); grade III-IV acute and chronic GVHD were not observed. The most common AEs following chidamide administration were hematological AEs, which occurred to varying degrees in all patients; liver function abnormalities occurred in two patients (grade 2), and symptoms of malaise occurred in one patient (grade 1). CONCLUSION: Chidamide maintenance therapy after T-ALL/LBL transplantation is safe, but the efficacy needs to be further investigated.

Targeting epigenetic and post-translational modifications regulating pyroptosis for the treatment of inflammatory diseases.

Inflammatory diseases, including infectious diseases, diabetes-related diseases, arthritis-related diseases, neurological diseases, digestive diseases, and tumor, continue to threaten human health and impose a significant financial burden despite advancements in clinical treatment. Pyroptosis, a pro-inflammatory programmed cell death pathway, plays an important role in the regulation of inflammation. Moderate pyroptosis contributes to the activation of native immunity, whereas excessive pyroptosis is associated with the occurrence and progression of inflammation. Pyroptosis is complicated and tightly controlled by various factors. Accumulating evidence has confirmed that epigenetic modifications and post-translational modifications (PTMs) play vital roles in the regulation of pyroptosis. Epigenetic modifications, which include DNA methylation and histone modifications (such as methylation and acetylation), and post-translational modifications (such as ubiquitination, phosphorylation, and acetylation) precisely manipulate gene expression and protein functions at the transcriptional and post-translational levels, respectively. In this review, we summarize the major pathways of pyroptosis and focus on the regulatory roles and mechanisms of epigenetic and post-translational modifications of pyroptotic components. We also illustrate these within pyroptosis-associated inflammatory diseases. In addition, we discuss the effects of novel therapeutic strategies targeting epigenetic and post-translational modifications on pyroptosis, and provide prospective insight into the regulation of pyroptosis for the treatment of inflammatory diseases.

Comparison of chemotherapy and chidamide combined with chemotherapy in patients with untreated angioimmunoblastic T-cell lymphoma.

Background: Angioimmunoblastic T-cell lymphoma (AITL) is characterized by high recurrence rates and poor prognosis, and effective first-line treatment is lacking. Recently, histone deacetylase inhibitors (HDACi), such as chidamide, have been found to induce durable remissions in AITL patients. Methods: Patients with untreated AITL from March 2015 to March 2023 were retrospectively collected and divided into chemotherapy (ChT) group and chidamide combined with chemotherapy (C-ChT) group based on the first-line treatment received. The comparison of efficacy and safety between the two groups was conducted. Results: 86 patients with newly diagnosed AITL were enrolled, in which 35 patients were in the ChT group and 51 in the C-ChT group. The objective response rate (ORR) of C-ChT group was significantly higher than that of ChT group (84.3% vs. 60%, P= 0.011), and had superior progression-free survival (PFS) (27 months vs. 12 months, P= 0.025). However, no significant difference in overall survival (OS) was observed between the two groups (P= 0.225). In addition, the responding patients who received autologous stem cell transplantation (ASCT) had superior PFS compared to those who did not (P= 0.015). Conclusions: Compared with ChT regimen, C-ChT regimen was well tolerated and had superior ORR and PFS in patients with untreated AITL. ASCT may contribute to longer PFS in remission patients.

[Chidamide Promotes Osteogenic Differentiation of Bone Marrow Mesenchymal Stromal Cells from Patients with Myelodysplastic Syndromes].

OBJECTIVE: To explore the effects and mechanisms of chidamide on the osteogenic differentiation of bone marrow mesenchymal stromal cells (MSC) from myelodysplastic syndromes (MDS). METHODS: MSC were isolated and cultured from bone marrow of MDS patients and healthy donors. CCK-8 assay was used to detect the effects of chidamide on the proliferation of MSC. The effects of chidamide on the activity of histone deacetylase (HDAC) in MSC was measured by a fluorescence assay kit and Western blot. Alkaline phosphatase (ALP) activity was detected on day 3 and calcium nodule formation was observed by Alizarin Red staining on day 21 after osteogenic differentiation. The expression of early and late osteogenic genes was detected on day 7 and day 21, respectively. RT-PCR and Western blot were used to detect the effects of chidamide on mRNA and protein expression of RUNX2 which is the key transcription factor during osteogenesis. RESULTS: As the concentration of chidamide increased, the proliferation of MSC was inhibited. However, at a low concentration (1 µmol/L), chidamide had no significant inhibitory effect on MSC proliferation but significantly inhibited HDAC activity. In MSC from both MDS patients and healthy donors, chidamide (1 µmol/L) significantly increased ALP activity, calcium nodule formation, thereby mRNA expression of osteogenic genes, and restored the reduced osteogenic differentiation ability of MDS-MSC compared to normal MSC. Mechanistic studies showed that the osteogenic-promoting effect of chidamide may be related to the upregulation of RUNX2 . CONCLUSION: Chidamide can inhibit HDAC activity in MSC, upregulate the expression of the osteogenic transcription factor RUNX2, and promote the osteogenic differentiation of MDS-MSC.

Combination of chidamide and PD-1 blockade in Refractory/Relapsed aggressive large B-cell lymphomas with high risk of failing CAR-T therapy.

BACKGROUND: Refractoriness and relapse after chimeric antigen receptor T-cell therapy have emerged as major challenges for immunotherapy of aggressive large B-cell lymphoma. Thus far, there is no consensus on how to address treatment failure and whether to administer maintenance therapy following CAR-T cell therapy. METHODS: From August 2017 through November 2022, 52 patients with refractory/relapsed aggressive LBCL who had a high risk of resistance to CAR-T cell therapy were given chidamide in combination with a PD-1 inhibitor as maintenance therapy following either CAR19/22 T-cell cocktail therapy or CAR19/22 T-cell cocktail therapy plus autologous stem cell transplantation (ASCT). Another 52 aggressive LBCL patients who had comparable baseline characteristics and received similar therapeutic regimens but did not receive any interventions following CAR-T cell therapy or CAR-T cell therapy plus ASCT were regarded as the control group to evaluate the efficacy and safety of the combination of chidamide and a PD-1 inhibitor. RESULTS: Among the 52 patients who received chidamide and a PD-1 inhibitor as maintenance therapy, with a median follow-up of 26.5 months (range: 1.1-53.8), neither the median progression-free survival (PFS) nor overall survival (OS) was reached, and the expected 2-year OS and PFS rates were 89 % and 77 %, respectively, which were superior to those of the control group (p < 0.001). Long-term chidamide administration and a specific genetic subtype of EZB were strongly associated with a better response after chidamide plus PD-1 blockade therapy. Additionally, long-term chidamide administration was significantly associated with prolonged persistence and reactivation of CD19-directed CAR-T cells in the peripheral blood. Adverse effects (AEs) were moderate and reversible, and no treatment-related deaths occurred. CONCLUSION: Our results indicate that the combination of chidamide and PD-1 blockade as maintenance therapy could improve the outcomes of aggressive LBCL patients at high risk of failing CAR-T cell therapy.

Integration of caveolin-mediated cytosolic delivery and enzyme-responsive releasing of squalenoyl nanoparticles enhance the anti-cancer efficacy of chidamide in pancreatic cancer.

We explored the potential of overcoming the dense interstitial barrier in pancreatic cancer treatment by enhancing the uptake of hydrophilic chemotherapeutic drugs. In this study, we synthesized the squalenoyl-chidamide prodrug (SQ-CHI), linking lipophilic squalene (SQ) with the hydrophilic antitumor drug chidamide (CHI) through a trypsin-responsive bond. Self-assembled nanoparticles with sigma receptor-bound aminoethyl anisamide (AEAA) modification, forming AEAA-PEG-SQ-CHI NPs (A-C NPs, size 116.6 ± 0.4 nm), and reference nanoparticles without AEAA modification, forming mPEG-SQ-CHI NPs (M-C NPs, size 88.3 ± 0.3 nm), were prepared. A-C NPs exhibited significantly higher in vitro CHI release (74.7 %) in 0.5 % trypsin medium compared to release (20.2 %) in medium without trypsin. In vitro cell uptake assays revealed 3.6 and 2.3times higher permeation of A-C NPs into tumorspheres of PSN-1/HPSC or CFPAC-1/HPSC, respectively, compared to M-C NPs. Following intraperitoneal administration to subcutaneous tumor-bearing nude mice, the A-C NPs group demonstrated significant anti-pancreatic cancer efficacy, inducing cancer cell apoptosis and inhibiting proliferation in vivo. Mechanistic studies revealed that AEAA surface modification on nanoparticles promoted intracellular uptake through caveolin-mediated endocytosis. This nanoparticle system presents a novel therapeutic approach for pancreatic cancer treatment, offering a delivery strategy to enhance efficacy through improved tumor permeation, trypsin-responsive drug release, and specific cell surface receptor-mediated intracellular uptake.

Matrine Enhances the Antitumor Efficacy of Chidamide in CTCL by Promoting Apoptosis.

BACKGROUND: Cutaneous T-cell Lymphoma (CTCL) is a rare group of non-Hodgkin lymphoma originating from the skin, which is characterized by T-cell lymphoproliferative disorders. Chidamide, a Chinese original antineoplastic agent with independent intellectual property rights, and matrine, an extract of Chinese herbal medicine, both have been reported to exert effects on the treatment of tumors individually. However, chidamide combined with matrine has not been tested for the treatment of CTCL. METHODS: Both HH and Hut78 CTCL cell lines were treated with chidamide (0.4 µmol/L), matrine (0.6 g/L), or chidamide combined with matrine for 24, 48, and 72 h. Cell viability was estimated by MTS assay at each time point. Flow cytometry was then conducted to detect cell apoptosis. The exact mechanism of chidamide combined with matrine on CTCL cells was detected by Western blotting and further validated in xenograft models of NOD/SCID mice. RESULTS AND DISCUSSION: Compared to the single drug, chidamide combined with matrine showed a more significant effect on proliferation inhibition and apoptosis induction on CTCL cells both in vitro and in vivo. The results from the in vitro and in vivo studies suggested that matrine could enhance the anti-tumor effect of chidamide by increasing the protein expression of cleaved caspase- 3 and decreasing the expression of E-cadherin, NF-κB, p-Bad, and Bcl-2 to activate apoptosis. CONCLUSION: Our data have demonstrated chidamide combined with matrine to exhibit elevated antitumor activity in both CTCL cells and xenograft models of NOD/SCID mice, which may be a potential treatment option for CTCL.

Chidamide plus envafolimab as subsequent treatment in advanced non-small cell lung cancer patients resistant to anti-PD-1 therapy: A multicohort, open-label, phase II trial with biomarker analysis.

BACKGROUND: Combination of chidamide and anti-PD-L1 inhibitor produce synergistic anti-tumor effect in advanced NSCLC patients resistant to anti-PD-1 treatment. However, the effect of chidamide plus envafolimab has not been reported. AIMS: This study aimed to evaluate the efficacy of chidamide plus envafolimab in advanced NSCLC patients resistant toanti-PD-1 treatment. MATERIALS AND METHODS: Eligible advanced NSCLC patients after resistant to anti-PD-1 therapy received chidamide and envafolimab. The primary endpoint was objective response rate (ORR). The secondary end points included disease control rate (DCR), progression-free survival (PFS), and safety. The expression of histone deacetylase 2 (HDAC2), PD-L1, and blood TMB (bTMB) was also analyzed. RESULTS: After a median follow-up of 8.1 (range: 7.6-9.2) months, only two patients achieved partial response. The ORR was 6.7% (2/30), DCR was 50% (15/30), and median PFS (mPFS) was 3.5 (95% confidence interval: 1.9-5.5) months. Biomarker analysis revealed that patients with high-level HDAC2 expression had numerically superior ORR (4.3% vs. 0), DCR (52.2% vs. 0) and mPFS (3.7 vs. 1.4m). Patients with negative PD-L1 had numerically superior DCR (52.2% vs. 33.3%) and mPFS (3.7m vs. 1.8m), so were those with low-level bTMB (DCR: 59.1% vs. 16.7%, mPFS: 3.8 vs.1.9m). Overall safety was controllable. DISCUSSION: High HDAC2patients showed better ORR, DCR, and PFS. In addition, patient with negative PD-L1 and low-level bTMB had better DCR and PFS. This may be related to the epigenetic function of chidamide. However, the sample size was not big enough, so it is necessary to increase sample size to confirm the conclusion. CONCLUSION: Combination of chidamide and envafolimab showed efficacy signals in certain NSCLC patients. But further identification of beneficial population is necessary for precision treatment.

Treatment patterns and clinical outcomes of chidamide combined with endocrine therapy in hormone receptor-positive, HER2-negative metastatic breast cancer: A real-world multicenter study.

BACKGROUND: Chidamide is a selective histone deacetylase inhibitor approved for patients with hormone receptor (HoR)-positive and HER2-negative metastatic breast cancer (MBC). We aimed to investigate the efficacy, safety, and treatment patterns of chidamide and identify clinicopathological factors that predict the efficacy of chidamide in real-world scenarios. METHODS: Consecutive MBC patients treated with chidamide from January 2020 to August 2021 across 11 institutions were enrolled in this multicenter, retrospective study. Eligible patients were pre- and postmenopausal women who had clinically or histologically confirmed ER-positive, HER2-negative MBC, and Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. Patients with multiple primary malignancies or missing baseline characteristics were excluded. Patients received 30 mg chidamide orally twice a week, combined with aromatase inhibitors (AIs) or non-AIs. Efficacy analyses included progression-free survival (PFS), objective response rate (ORR), and clinical benefit rate (CBR). Univariate and multivariate Cox regression analyses were performed to identify the potential efficacy predictors. RESULTS: A total of 157 patients were finally included for analysis. The median number of lines prior to chidamide was four. In the whole cohort, the median PFS was 4.2 months (95% confidence interval [CI] 3.8-4.5). The ORR was 7.5% and the CBR was 31.3%. The efficacy of chidamide was consistent in patients pretreated with CDK4/6 inhibitors and patients treated with different endocrine combinations. Multivariate analysis indicated that patients who had liver metastases (adjusted HR = 1.66, 95% CI 1.14-2.43, adjusted p = 0.008) or ≥3 prior lines of treatment (adjusted HR = 1.80, 95% CI 1.17-2.77, adjusted p = 0.008) had significantly worse PFS. The most common AEs with chidamide were thrombocytopenia, leucopenia, neutropenia, and anemia. CONCLUSION: This study provided real-world data for the use of chidamide in patients with HoR-positive and HER2-negative MBC. Our data endorsed the use of chidamide in patients pretreated with CDK4/6 inhibitors and patients treated with different endocrine combinations.

Chidamide and orelabrutinib synergistically induce cell cycle arrest and apoptosis in diffuse large B-cell lymphoma by regulating the PI3K/AKT/mTOR pathway.

OBJECTIVE: The initial therapeutic approach for diffuse large B-cell lymphoma (DLBCL) entails a rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen. However, 40% of patients exhibit suboptimal responses, with some experiencing relapse and refractory conditions. This study aimed to explore novel therapeutic strategies and elucidate their underlying mechanisms in DLBCL. METHODS: Bioinformatics techniques were employed to scrutinize correlations between the HDAC1, HDAC2, HDAC3, HDAC10, BTK, MYC, TP53, and BCL2 genes in DLBCL. In vitro experiments were conducted using DB and SU-DHL-4 cells treated with chidamide, orelabrutinib, and a combination of both. Cell viability was assessed by cell counting kit-8. Cell apoptosis and the cell cycle were determined using flow cytometry. Reactive oxygen species (ROS) production and mitochondrial function were assessed through ROS and JC-1 staining. RNA sequencing and western blot analyses were conducted to elucidate the molecular mechanisms underlying the combined action of chidamide and orelabrutinib in DLBCL cells. RESULTS: This investigation revealed markedly enhanced antiproliferative effects when chidamide was combined with orelabrutinib. Compusyn software analysis indicated a synergistic effect of chidamide and orelabrutinib in inhibiting DLBCL cell proliferation, with a combination index (CI) < 1. This synergy further manifested as augmented cell cycle arrest, apoptosis induction, the downregulation of cell cycle-associated and antiapoptotic proteins, and the upregulation of proapoptotic proteins. Furthermore, the western blot and RNA-Seq findings suggested that combining chidamide and orelabrutinib modulated the PI3K/AKT/mTOR signaling pathway, thereby promoting DLBCL cell cycle arrest and apoptosis. CONCLUSION: The findings of this study provide a compelling justification for the clinical utilization of chidamide and orelabrutinib to treat relapsed/refractory DLBCL.

Chidamide improves gefitinib treatment outcomes in NSCLC by attenuating recruitment and immunosuppressive function of myeloid-derived suppressor cells.

Clinical resistance to EGFR tyrosine kinase inhibitors in non-small-cell lung cancer (NSCLC) remains a significant challenge. Recent studies have indicated that the number of myeloid-derived suppressor cells (MDSCs) increases following gefitinib treatment, correlating with a poor patient response in NSCLC. Our study revealed that gefitinib treatment stimulates the production of CCL2, which subsequently enhances monocyte (M)-MDSC migration to tumor sites. Chidamide, a selective inhibitor of the histone deacetylase subtype, counteracted the gefitinib-induced increase in CCL2 levels in tumor cells. Additionally, chidamide down-regulated the expression of CCR2 in M-MDSCs, inhibiting their migration. Furthermore, chidamide attenuated the immunosuppressive function of M-MDSCs both alone and in combination with gefitinib. Chidamide also alleviated tumor immunosuppression by reducing the number of M-MDSCs in LLC-bearing mice, thereby enhancing the antitumor efficacy of gefitinib. In conclusion, our findings suggest that chidamide can improve gefitinib treatment outcomes, indicating that MDSCs are promising targets in NSCLC.

Metformin and chidamide synergistically suppress multiple myeloma progression and enhance lenalidomide/bortezomib sensitivity.

Multiple myeloma (MM) is a common hematological malignancy, and patients with MM are recommended to take immunomodulatory drugs such as lenalidomide along with proteasome inhibitors such as bortezomib to extend survival. However, drug resistance influences the efficacy of treatment for MM. In our study, we found that metformin and chidamide both suppressed MM cell growth in a concentration- and time-dependent way (p < .001). Moreover, combined therapy with metformin and chidamide exhibited enhanced inhibition of the growth of MM cells compared with monotherapy (p < .05). Additionally, the triple-drug combination of metformin and chidamide with lenalidomide or bortezomib was used to stimulate the MM cells, and the results revealed that metformin and chidamide treatment sensitized MM cells to lenalidomide and bortezomib. As a result, the apoptosis (p < .001) together with cell cycle arrest at G0/G1 phase (p < .05) was stimulated by lenalidomide and bortezomib, and showed significant elevation in the triple-drug combination group compared with the lenalidomide or bortezomib treatment alone group (p < .05). Furthermore, the impacts of different drugs on glycolysis in MM cells were examined. We found that metformin and chidamide combined treatment significantly promoted glucose uptake and reduced energy production in MM cells treated with lenalidomide and bortezomib (p < .001), suggesting that metformin and chidamide affected glycolysis in MM cells and enhanced the sensitivity of lenalidomide and bortezomib in MM by regulating glucose metabolism. In conclusion, metformin and chidamide synergistically hindered MM cell growth and sensitized cells to lenalidomide/bortezomib. The findings of this study might provide novel clues to improve MM therapy.

The combination of brentuximab vedotin and chidamide synergistically suppresses the proliferation of T-cell lymphoma cells through the enhancement of apoptosis.

PURPOSE: Peripheral T-cell lymphoma (PTCL) is an aggressive disease with a poor prognosis. Brentuximab vedotin (BV), an anti-CD30 monoclonal antibody linked to a microtubule-disrupting agent, has been approved for the treatment of PTCL. We evaluated a new effective combination partner of BV using non-clinical approaches that could potentially identify agents capable of improving survival times for patients with PTCL. METHODS: A high-throughput screening test was used to select the most synergistic partner of BV from 14 candidate drugs that were under development or available in clinical practice for PTCL. HH cells, originating from an aggressive cutaneous T-cell lymphoma, were used as an experimental model of PTCL. Apoptotic effects of the synergistic partner of BV were further investigated in vitro and in vivo using HH-cell xenograft mice. RESULTS: Chidamide (tucidinostat), a novel histone deacetylase inhibitor, was found to have the greatest synergistic effect with BV on HH cells. The combined effects of chidamide and BV were demonstrated in a study of HH-cell xenograft mice; mean tumor size following combined treatment was 22% of that observed in the control group, compared with 71% and 58% following chidamide and BV monotherapy, respectively. Further investigations in vitro and in vivo revealed that the levels of an anti-apoptotic protein, Bcl-2, and a rate-limiting factor of DNA replication, CDC45, were reduced in HH cells treated with chidamide combined with BV compared with the control group. CONCLUSION: The use of chidamide in conjunction with BV may positively affect and enhance T-cellular apoptotic pathways without offsetting each other.

Effects of chidamide combined with PD-1 inhibitor on anti-tumor function of CD8+ T cells in mouse model of colorectal cancer / 解放军医学杂志

Objective To investigate the efficacy of histone deacetylase(HDAC)inhibitor chidamide combined with the PD-1 inhibitor on CD8+ T cells anti-cancer function in OVA-expressing MC38(MC38-OVA)colorectal-bearing mice.Methods Animal experiments:C57BL/6 tumor models were constructed by subcutaneously injecting MC38-OVA colorectal cancer cells into the back of mice.We randomized mice into control group,chidamide group,anti-PD-1 group and chidamide+anti-PD-1 group(20 each group).We monitored the tumor growth and animal survival rate of each group;we employed a flow-based method to detect the number and ratio of tumor-infiltrating CD8+ T cells,CD8+IFN-γ+ T cells,OVA antigen-specific CD8+ T cells,and the expression changes of regulatory T cells(Treg),myeloid-derived suppressor cells(MDSC),and tumor-associated macrophages(TAM).Cell experiments:We used a flow-based method to detect the apoptosis of CD8+ T cells and MC38-OVA tumor cells after 0,10,25,50,100,or 200 nmol/L chidamide treatment.The proliferation of CD8+ T cells and MC38-OVA tumor cells treated with 0 and 100 nmol/L chidamide was detected by Ki-67 antibody labeling and cell counting.To evaluate CD8+ T cell killing ability,we treated CD8+ T cells with various conditions(control group,chidamide group,anti-PD-1 group and chidamide+anti-PD-1 group)followed by co-culture with MC38-OVA tumor cells,using the flow-based method.In the condition that CD8+ T cells treated with 0 and 100 nmol/L chidamide co-cultured with the same number of MC38-OVA tumor cells,the expression of CD107a was detected by flow cytometry.Results Compared with control group,the tumor growth was inhibited(P<0.05)while the survival rate was improved(P<0.01)in chidamide+anti-PD-1 group.The number of tumor-infiltrating CD8+ T cells was significantly higher in chidamide group,anti-PD-1 group and chidamide+anti-PD-1 group than that in control group(P<0.05).Nonetheless,the ratio and levels of CD8+IFN-γ+ and OVA antigen-specific CD8+ T cells were significantly higher in chidamide+anti-PD-1 group than those in other groups(P<0.05).The in vitro experiment results showed that chidamide could enhance the killing ability of CD8+ T cells and the expression of CD107a.Conclusion Chidamide combined with PD-1 inhibitor significantly enhanced the number and function of tumor-infiltrating CD8+ T cells and increased antigen-specific CD8+ T cells,which will provide a theoretical and experimental basis for the combination of chidamide in clinical solid tumor immunotherapy.