Panobinostat plus bortezomib and dexamethasone versus placebo plus bortezomib and dexamethasone in patients with relapsed or relapsed and refractory multiple myeloma: a multicentre, randomised, double-blind phase 3 trial

Efficacy and Safety of triplet versus doublet regimens in patients with multiple myeloma: A systematic review and meta-analysis

BACKGROUND

The efficacy and safety of various therapies for multiple myeloma (MM) remain a subject of ongoing debate, with inconsistent findings. This meta-analysis aimed to compare the efficacy and safety of triplet versus doublet regimens in the management of MM. This study followed the guidelines delineated in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 statement, with our protocol duly registered in PROSPERO (CRD42024527903).

METHODS

An exhaustive literature search was performed across four databases, PubMed, EMBASE, Web of Science, and Cochrane Library, from their commencement to March 5, 2024. Data on overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), adverse events (AEs), and grade ≥ 3 AEs were synthesized using either random-effects or fixed-effects models.

RESULTS

This analysis considered 29 studies, which cover approximately 11,230 MM patients in total. Triplet regimens were found to yield better PFS and OS for MM patients as compared to the doublet regimens. Although the incidence of serious AEs was higher under the triplet regimens, with pooled RRs of grade ≥ 3 AEs reaching 1.13. Besides, subgroup analysis demonstrated that patients with relapsed/refractory multiple myeloma (RRMM) tended to have better PFS and OS under triple therapy, in contrast to newly diagnosed multiple myeloma (NDMM) and older adults, who experienced little to no significant impact.

CONCLUSIONS

Triplet regimens demonstrate superior PFS and OS compared to doublet regimens in MM patients, but also have a higher likelihood of causing AEs of grade 3 or 4.

HDAC inhibitors: Cardiotoxicity and paradoxical cardioprotective effect in ischemia-reperfusion myocardiocyte injury

Histone deacetylase inhibitors (HDACIs) are epigenetic drugs that regulate the acetylation status of histones and non-histone proteins, thereby leading to chromatin remodeling and transcriptional regulation of key apoptotic and cell cycle regulatory genes. There are currently five HDACIs clinically approved by the major regulatory authorities for treating hematological cancers, primarily as monotherapy. While HDACIs have been particularly effective in T-cell lymphomas, their clinical efficacies have not yet extended to solid tumors. The development of HDACIs continues, including for the treatment of a non-malignant conditions, with givinostat recently approved by the US FDA. However, the early development of HDACIs was limited by concerns about cardiotoxicity including QT interval prolongation. Yet, paradoxically, the latest research suggests some cardioprotective effect of HDACIs in ischemic heart disease or heart failure. This review presents the latest update about the cardiotoxicity of the clinically approved HDACIs. The mechanisms leading to HDACI-induced cardiotoxic adverse events and clinical strategies for their management are discussed. We will also deliberate the potential repurposing use of HDACIs and their HDAC isoform selectivity for treating ischemia-reperfusion cardiac muscle injury, cardiac hypertrophy, and fibrosis.

Ubiquitin proteasome system (UPS): a crucial determinant of the epigenetic landscape in cancer

The ubiquitin proteasome system (UPS), comprising of ubiquitinases, deubiquitinases and 26S proteasome plays a significant role in directly or indirectly regulating epigenetic players. DNA-templated processes like replication, repair and transcription require chromatin decondensation to allow access to specific DNA sequence. A thorough survey of literary articles in PubMed database revealed that the UPS functions as a key regulator, determining the precise state of open and closed chromatin by influencing histones and histone modifiers through proteolytic or non-proteolytic means. However, a comprehensive understanding of how specific UPS components affect particular epigenetic pathways in response to environmental cues remains underexplored. This axis holds substantial potential for deciphering mechanisms of tumorigenesis. Although our current knowledge is limited, it can still guide the development of novel therapeutic strategies that can potentially bridge the gap between cancer chemotherapeutics in bench and bedside.

Discovery of novel antimyeloma agents targeting TRIP13 by molecular modeling and bioassay

Thyroid hormone receptor-interacting protein-13 (TRIP13) is an AAA+ ATPase that regulates protein complex assembly and disassembly and is known to be a chromosomal instability gene with the ability to repair DNA double-strand breaks. TRIP13 overexpression has been linked to the proliferation and development of many human malignancies, including multiple myeloma (MM). Accordingly, TRIP13 is recognized as a potential drug target for anticancer drug development. Although some TRIP13 inhibitors have been reported, none are under clinical trial or approved for clinical use. This study aimed to identify novel small molecules as potential TRIP13 inhibitors structurally different from previously reported compounds through molecular modeling and bioassays. As a result, five compounds were successfully identified as novel TRIP13 inhibitors. F368-0183 showed the best antiproliferative activity with IC50 = 5.25 μM (NCI-H929 cell line), comparable with the positive control DCZ0415 (IC50 = 9.64 μM). Also, the cellular thermal shift assay confirmed that this compound could interact with the TRIP13 protein in MM cells. In addition, the AAA+ ATPase inhibitory bioassay demonstrated that the five compounds had better inhibitory activity than DCZ0415, having strong correlations with the calculated free energy perturbation (FEP). Further molecular dynamics simulation studies revealed that the novel compounds could significantly interact with 12 residues of TRIP13, especially R386, L139, R389, L135, S138, Y141, and G385. We also assessed the F368-0183 inhibition on a kinase panel, no other targets were found, but the potential binding to other target proteins of these compounds cannot be totally excluded. Therefore, the new molecular scaffolds of these compounds, their efficacy in suppressing MM cell line proliferation, and the displayed TRIP13 AAA+ ATPase inhibitory properties provide important clues for developing novel TRIP13-based multi-target anti-MM drugs.

Mechanisms of HDACs in cancer development

Histone deacetylases (HDACs) are a class of epigenetic regulators that play pivotal roles in key biological processes such as cell proliferation, differentiation, metabolism, and immune regulation. Based on this, HDAC inhibitors (HDACis), as novel epigenetic-targeted therapeutic agents, have demonstrated significant antitumor potential by inducing cell cycle arrest, activating apoptosis, and modulating the immune microenvironment. Current research is focused on developing highly selective HDAC isoform inhibitors and combination therapy strategies tailored to molecular subtypes, aiming to overcome off-target effects and resistance issues associated with traditional broad-spectrum inhibitors. This review systematically elaborates on the multidimensional regulatory networks of HDACs in tumor malignancy and assesses the clinical translation progress of next-generation HDACis and their prospects in precision medicine, providing a theoretical framework and strategic reference for the development of epigenetic-targeted antitumor drugs.

The BCL2 family: from apoptosis mechanisms to new advances in targeted therapy

The B cell lymphoma 2 (BCL2) protein family critically controls apoptosis by regulating the release of cytochrome c from mitochondria. In this cutting-edge review, we summarize the basic biology regulating the BCL2 family including canonical and non-canonical functions, and highlight milestones from basic research to clinical applications in cancer and other pathophysiological conditions. We review laboratory and clinical development of BH3-mimetics as well as more recent approaches including proteolysis targeting chimeras (PROTACs), antibody-drug conjugates (ADCs) and tools targeting the BH4 domain of BCL2. The first BCL2-selective BH3-mimetic, venetoclax, showed remarkable efficacy with manageable toxicities and has transformed the treatment of several hematologic malignancies. Following its success, several chemically similar BCL2 inhibitors such as sonrotoclax and lisaftoclax are currently under clinical evaluation, alone and in combination. Genetic analysis highlights the importance of BCL-XL and MCL1 across different cancer types and the possible utility of BH3-mimetics targeting these proteins. However, the development of BH3-mimetics targeting BCL-XL or MCL1 has been more challenging, with on-target toxicities including thrombocytopenia for BCL-XL and cardiac toxicities for MCL1 inhibitors precluding clinical development. Tumor-specific BCL-XL or MCL1 inhibition may be achieved by novel targeting approaches using PROTACs or selective drug delivery strategies and would be transformational in many subtypes of malignancy. Taken together, we envision that the targeting of BCL2 proteins, while already a success story of translational research, may in the foreseeable future have broader clinical applicability and improve the treatment of multiple diseases.

Cost-effectiveness analysis of combination therapies involving novel agents for first/second-relapse patients with multiple myeloma: a Markov model approach with calibration techniques

BACKGROUND

As the number of randomized clinical trials (RCTs) demonstrating the survival benefits of combination therapies in previously treated multiple myeloma (MM) patients increases, it is essential to determine the most cost-effective treatment through robust economic evaluation. This study aims to assess the cost-effectiveness of combination therapies for first/second-relapse MM patients from the perspective of the Chinese healthcare system.

METHODS

A Markov model was developed to evaluate three combination therapy groups based on primary drugs (bortezomib, lenalidomide, and carfilzomib). The economic evaluation was conducted within each group individually, rather than across different groups. Clinical inputs for the model were derived from RCT reports, while healthcare costs were sourced from the Zhejiang Province bidding database and a retrospective analysis. Utility values were obtained through an on-site survey using the Chinese version of the EuroQoL Five-dimensional Five-level Questionnaire. One-way and probabilistic sensitivity analyses were performed to assess the robustness of the base-case results.

RESULTS

In the bortezomib group, bortezomib-dexamethasone (Vd) yielded 2.42 quality-adjusted life years (QALYs) at a cost of ¥783,775. With a willingness-to-pay (WTP) threshold of three times the 2023 per capita GDP in China (¥258,074), pomalidomide-bortezomib-dexamethasone was the most cost-effective therapy (¥86,129/QALY) in this group. In the lenalidomide group, lenalidomide-dexamethasone (Rd) resulted in 3.06 QALYs at a cost of ¥840,509. Compared to Rd, the incremental cost-effectiveness ratios (ICERs) of elotuzumab-lenalidomide-dexamethasone (¥5,095,300/QALY), ixazomib-lenalidomide-dexamethasone (¥1,605,712/QALY), carfilzomib-lenalidomide-dexamethasone (¥955,255/QALY), and daratumumab-lenalidomide-dexamethasone (¥851,933/QALY) all exceeded the WTP threshold. In the carfilzomib group, carfilzomib-dexamethasone (Kd) resulted in 3.19 QALYs at a cost of ¥1,961,624. Compared to Kd, the ICERs of daratumumab-carfilzomib-dexamethasone (¥2,250,821/QALY) and isatuximab-carfilzomib-dexamethasone (¥4,977,964/QALY) also exceeded the WTP. Sensitivity analyses confirmed the robustness of the base-case results.

CONCLUSIONS

Although this study did not fully account for the heterogeneity of subsequent treatment regimens among first/second-relapse MM patients, it highlights that the substantial financial burden associated with combination therapies involving novel agents poses a significant challenge in justifying their economic value.

Synthesis of fluorinated tubastatin A derivatives with bi-, tri-, and tetracyclic cap groups: molecular docking with HDAC6 and evaluation of in vitro antitumor activity

Herein, we report the synthesis of 16 tubastatin A derivatives with fluorinated bi-, tri-, and tetracyclic cap groups. Most derivatives show strong in vitro antitumor activity, achieving micromolar or sub-micromolar efficacy. The most promising compound, 4-(6-bromo-3,3-difluoro-1,2,3,4-tetrahydro-9H-carbozol-9-yl)methyl)-N-hydroxybenzamide (14f), demonstrated potent anti-proliferative effects against human nasopharyngeal carcinoma cells (SUNE1) and human breast cancer cells (MDA-MB-231), with IC50 values of 0.51 μM and 0.52 μM, respectively. Notably, compound 4-((8-fluoroindeno[2,1-b]indol-5(6H)-yl)-N-hydroxybenzamide (13c) exhibited significant anti-proliferative activity against pancreatic cancer cells (SW1990), with an IC50 of 2.06 μM and low cytotoxicity to normal cells. Overall, variations in the cap group from bi- to tri-, then to tetracyclic, and the introduction of fluorinated groups enhance the antitumor activity of these derivatives. Among them, difluoromethyl-modified tricyclic derivatives show a broad spectrum in vitro antitumor effect. Molecular docking studies indicate that these derivatives bind to Histone Deacetylase 6 (HDAC6) at low binding energies, ranging from -6.54 to -9.84 kcal mol-1, through metal complexation, hydrogen bonding, π-π stacking, and π-cation interactions, which correlates with their good antitumor activity. Compound 4-((2-fluoro-5,6-dihydro-7H-benzo[c]carbazol-7-yl)methyl)-N-hydroxybenzamide (13a) with the lowest binding energy of -9.84 kcal mol-1 exhibited the best in vitro antitumor activity against MCF-7, with IC50 of 1.98 μM.

Heterochromatin fidelity is a therapeutic vulnerability in lymphoma and other human cancers

Genes involved in the regulation of chromatin structure are frequently disrupted in cancer, contributing to an aberrant transcriptome and phenotypic plasticity. Yet, therapeutics targeting mutant forms of chromatin-modifying enzymes have yielded only modest clinical utility, underscoring the difficulty of targeting the epigenomic underpinnings of aberrant gene regulatory networks. Here, we sought to identify novel epigenetic vulnerabilities in diffuse large B-cell lymphoma (DLBCL). Through phenotypic screens and biochemical analysis, we demonstrated that inhibition of the H3K9 demethylases KDM4A and KDM4C elicits potent, subtype-agnostic cytotoxicity by antagonizing transcriptional networks associated with B-cell identity and epigenetically rewiring heterochromatin. KDM4 demethylases associated with the KRAB zinc finger ZNF587, and their enzymatic inhibition led to DNA replication stress and DNA damage-einduced cGAS-STING activation. Broad surveys of transcriptional data from patients also revealed KDM4 family dysregulation in several other cancer types. To explore this potential therapeutic avenue, we performed high-throughput small molecule screens with H3K9me3 nucleosome substrates and identified novel KDM4 demethylase inhibitors. AI-guided protein-ligand binding predictions suggested diverse modes of action for various small molecule hits. Our findings underscore the relevance of targeting fundamental transcriptional and epigenetic mechanisms for anti-cancer therapy.

Synthetic approaches and clinical applications of representative HDAC inhibitors for cancer therapy: A review

Histone deacetylase (HDAC) inhibitors are a promising class of epigenetic modulators in cancer therapy. This review provides a comprehensive analysis of recent synthetic strategies and clinical applications of key HDAC inhibitors for oncology. HDACs play a critical role in modulating chromatin structure and gene expression by removing acetyl groups from histone proteins, leading to transcriptional repression of tumor suppressor genes. By inhibiting HDAC activity, HDAC inhibitors restore normal acetylation patterns, reactivating silenced tumor suppressor genes and inducing cell cycle arrest, apoptosis, and autophagy in cancer cells. The review explores synthetic approaches to developing representative HDAC inhibitors that have been approved or in various clinical trials. Through an integrated perspective on the synthesis, mechanism of action, and clinical advancements of HDAC inhibitors, this review aims to guide future research toward next-generation HDAC inhibitors that could enhance cancer treatment efficacy while minimizing toxicity, offering insights for chemists and clinicians in the field of oncology.

Getting the right combination to break the epigenetic code

Rapid advances in the field of epigenetics have facilitated the development of novel therapeutics targeting epigenetic mechanisms that are hijacked by cancer cells to support tumour growth and progression. Several epigenetic agents have been approved by the FDA for the treatment of cancer; however, the efficacy of these drugs is dependent on the underlying biology and drivers of the disease, with inherent differences between solid tumours and haematological malignancies. The efficacy of epigenetic drugs as single agents remains limited across most cancer types, which has spurred the clinical development of combination therapies, with the hope of attaining synergistic activity and/or overcoming treatment resistance. In this Review we discuss clinical advances that have been achieved with the use of epigenetic agents in combination with chemotherapies, immunotherapies or other targeted agents, including epigenetic-epigenetic combinations, as well as limitations and challenges associated with these combinatorial strategies. So far, the success of combination therapies targeting epigenetic mechanisms has generally been confined to haematological malignancies, with limited efficacy observed in patients with solid tumours. Nevertheless, this Review captures the field of epigenetic combination therapies across the spectra of haematology and oncology, highlighting opportunities for precision therapy to effectively harness the potential of epigenetic agents and produce meaningful improvements in clinical outcomes.

Epigenetics-targeted drugs: current paradigms and future challenges

Epigenetics governs a chromatin state regulatory system through five key mechanisms: DNA modification, histone modification, RNA modification, chromatin remodeling, and non-coding RNA regulation. These mechanisms and their associated enzymes convey genetic information independently of DNA base sequences, playing essential roles in organismal development and homeostasis. Conversely, disruptions in epigenetic landscapes critically influence the pathogenesis of various human diseases. This understanding has laid a robust theoretical groundwork for developing drugs that target epigenetics-modifying enzymes in pathological conditions. Over the past two decades, a growing array of small molecule drugs targeting epigenetic enzymes such as DNA methyltransferase, histone deacetylase, isocitrate dehydrogenase, and enhancer of zeste homolog 2, have been thoroughly investigated and implemented as therapeutic options, particularly in oncology. Additionally, numerous epigenetics-targeted drugs are undergoing clinical trials, offering promising prospects for clinical benefits. This review delineates the roles of epigenetics in physiological and pathological contexts and underscores pioneering studies on the discovery and clinical implementation of epigenetics-targeted drugs. These include inhibitors, agonists, degraders, and multitarget agents, aiming to identify practical challenges and promising avenues for future research. Ultimately, this review aims to deepen the understanding of epigenetics-oriented therapeutic strategies and their further application in clinical settings.

Challenges in the treatment of soft-tissue plasmacytoma: a retrospective analysis of 120 patients with extramedullary multiple myeloma

PURPOSE

Despite the development of novel drugs and the widespread use of hematopoietic cell transplantation, the prognosis of patients (pts) with multiple myeloma and extramedullary involvement (soft-tissue plasmacytoma, STP) is rather unfavorable.

METHODS

A retrospective analysis of 120 pts with STP treated between 2007 and 2022 was performed. The effects of demographic and clinical characteristics on treatment response, progression-free survival (PFS), and overall survival (OS) were evaluated.

RESULTS

The rate of serological response to first-line STP treatment (at least partial remission) was 67%, and the rate of imaging response was 59%. With a median follow-up of 84.2 months, the median PFS was 10.5 months (primary STP: 20.2 months; secondary STP: 5.8 months), and the median OS was 24.5 months (primary STP: 34.5 months; secondary STP: 12.4 months). Based on the multivariate regression analysis, secondary STP (HRPFS 2.75; HROS 2.63) and organ involvement (HRPFS 1.45; HROS 1.68) were found to be negative prognostic factors of both PFS and OS. In a prognostic model, pts with at least one of these factors had a significantly worse PFS (HRPFS 3.31) and OS (HROS 3.45) than those with none risk factor.

CONCLUSION

In pts with STP, risk-adapted treatment strategies including immunotherapies and cell therapies are urgently required.

Hydrazide-Based Class I Selective HDAC Inhibitors Completely Reverse Chemoresistance Synergistically in Platinum-Resistant Solid Cancer Cells

In this work, we have synthesized a set of peptoid-based histone deacetylase inhibitors (HDACi) with a substituted hydrazide moiety as zinc-binding group. Subsequently, all compounds were evaluated in biochemical HDAC inhibition assays and for their antiproliferative activity against native and cisplatin-resistant cancer cell lines. The hydrazide derivatives with a propyl or butyl substituent (compounds 5 and 6) emerged as the most potent class I HDAC selective inhibitors (HDAC1-3). Further, compounds 5 and 6 outperformed entinostat in cytotoxicity assays and were able to reverse chemoresistance in cisplatin-resistant A2780 (ovarian) and Cal27 (head-neck) cancer cell lines. Moreover, the hydrazide derivatives 5 and 6 showed strong synergism with cisplatin (combination indices <0.2), again outperforming entinostat, and increased DNA damage, p21, and pro-apoptotic BIM expression, leading to caspase-mediated apoptosis and cell death. Thus, compounds 5 and 6 represent promising lead structures for developing new HDACi capable of reversing chemoresistance in cisplatin resistant cancer cells.

Changes in immune subsets during chemotherapy as prognosis biomarkers for multiple myeloma patients by longitudinal monitoring

Multiple myeloma (MM) is a malignancy of plasma cells accompanied by immune dysfunction. This study aimed to provide a comprehensive and dynamic characterization of the peripheral immune environment in MM patients and find its diagnostic and prognostic values for therapy. The peripheral immune profiles of MM inpatients and healthy controls were assessed by flow cytometry. A longitudinal study of immune subsets was observed during cycles of chemotherapy. The diagnostic and prognostic models were established based on immune subsets by the absolute shrinkage and selection operator (LASSO) and multivariate regression. MM patients possessed an impeded immune landscape, including reduced activation of B cells, increased effective T cells and regulatory T cells (Tregs), augmented CD16 expression on monocytes and dendritic cell percentages, decreased CD56dimCD16+ natural killer cells (NKs), and amplified CD56bright and HLA-DR+ natural killer T cells (NKTs). Chemotherapy has different dynamic effects on specific cells, of which 2 cycles is the key turning point. NKT, dendritic cells, naïve Tc and Th cells, HLA-DR+ Tc cells, CD56dim NKTs, CD16++ monocytes, and CD25+ B cells could have the diagnostic value, and a prognostic model including neutrophils, naïve Tc cells, CD56brightCD16dim NKs, and CD16+ dendritic cells was established with acceptable accuracy. Our data showed dynamic and abnormal peripheral immune profiles in MM patients, which had prognostic values and could provide the basis for clinical therapy.

Matching-adjusted indirect comparison of talquetamab vs selinexor-dexamethasone and vs belantamab mafodotin in patients with relapsed/refractory multiple myeloma

OBJECTIVE

Talquetamab is the first GPRC5D-targeting bispecific antibody approved for the treatment of triple-class exposed (TCE) relapsed/refractory multiple myeloma (RRMM). This matching-adjusted indirect comparison (MAIC) study was conducted to compare the effectiveness of talquetamab vs selinexor-dexamethasone (sel-dex) and vs belantamab mafodotin (belamaf) in patients with TCE RRMM.

METHODS

An unanchored MAIC was performed using individual patient-level data from patients treated with subcutaneous talquetamab 0.4 mg/kg weekly (QW) and 0.8 mg/kg every other week (Q2W) from MonumenTAL-1 (NCT03399799/NCT04636552) and published summary data for sel-dex from STORM (NCT02336815) and belamaf from DREAMM-2 (NCT0325678). Patients from MonumenTAL-1 who met key eligibility criteria for STORM and DREAMM-2 were included. Outcomes of interest were overall response rate (ORR), complete response or better (≥CR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

RESULTS

After adjustment for cross-trial differences, patients treated with both dosing schedules of talquetamab showed significantly better ORR, ≥CR, and DOR vs sel-dex and significantly higher ORR and ≥ CR vs belamaf; DOR was relatively similar to belamaf. PFS was significantly improved with talquetamab Q2W and numerically in favor of talquetamab QW vs sel-dex and significantly improved with both dosing schedules of talquetamab vs belamaf. OS was significantly improved with both dosing schedules of talquetamab vs sel-dex and was numerically in favor of both dosing schedules of talquetamab vs belamaf.

CONCLUSION

These analyses show superior effectiveness of both talquetamab dosing schedules vs sel-dex and vs belamaf for most outcomes and highlight talquetamab as an effective treatment option for patients with TCE RRMM.

Comprehensive analysis of microRNAs modulated by histone deacetylase inhibitors identifies microRNA-7-5p with anti-myeloma effect

Basic research to expand treatment options for multiple myeloma is greatly needed due to the refractory nature of the disease. Histone deacetylase (HDAC) inhibitors, which are epigenetic regulators, are attractive but have limited applications. MicroRNAs (miRNAs), which are also epigenetic regulators, are important molecules that may lead to future therapeutic breakthroughs. In this study, we comprehensively searched for miRNAs that are altered by HDAC inhibitors in myeloma cells. We identified miR-7-5p (miR-7) as a miRNA downregulated by HDAC inhibitors. Transfection of myeloma cell lines with miR-7 suppressed cell proliferation, induced apoptosis, and enhanced the effects of the HDAC inhibitor panobinostat. Expression of miR-7 was downregulated by c-Myc inhibition, but upregulated by bortezomib. Comprehensive examination of miR-7 targets revealed four candidates: SLC6A9, LRRC59, EXOSC2, and PSME3. Among these, we focused on PSME3, an oncogene involved in proteasome capacity in myeloma cells. PSME3 knockdown increases myeloma cell death and panobinostat sensitivity. In conclusion, miR-7, which is downregulated by HDAC inhibitors, is a tumor suppressor that targets PSME3. This miR-7 downregulation may be involved in HDAC inhibitor resistance. In addition, combinations of anti-myeloma drugs that complement changes in miRNA expression should be considered.

Different Strategies to Overcome Resistance to Proteasome Inhibitors-A Summary 20 Years after Their Introduction

Proteasome inhibitors (PIs), bortezomib, carfilzomib, and ixazomib, are the first-line treatment for multiple myeloma (MM). They inhibit cytosolic protein degradation in cells, which leads to the accumulation of misfolded and malfunctioned proteins in the cytosol and endoplasmic reticulum, resulting in cell death. Despite being a breakthrough in MM therapy, malignant cells develop resistance to PIs via different mechanisms. Understanding these mechanisms drives research toward new anticancer agents to overcome PI resistance. In this review, we summarize the mechanism of action of PIs and how MM cells adapt to these drugs to develop resistance. Finally, we explore these mechanisms to present strategies to interfere with PI resistance. The strategies include new inhibitors of the ubiquitin-proteasome system, drug efflux inhibitors, autophagy disruption, targeting stress response mechanisms, affecting survival and cell cycle regulators, bone marrow microenvironment modulation, and immunotherapy. We list potential pharmacological targets examined in in vitro, in vivo, and clinical studies. Some of these strategies have already provided clinicians with new anti-MM medications, such as panobinostat and selinexor. We hope that further exploration of the subject will broaden the range of therapeutic options and improve patient outcomes.

Anti-tumour activity of Panobinostat in oesophageal adenocarcinoma and squamous cell carcinoma cell lines

BACKGROUND

Oesophageal cancer remains a challenging disease with high mortality rates and few therapeutic options. In view of these difficulties, epigenetic drugs have emerged as potential alternatives for patient care. The goal of this study was to evaluate the effect and biological consequences of Panobinostat treatment, an HDAC (histone deacetylase) inhibitor already approved for treatment of patients with multiple myeloma, in oesophageal cell lines of normal and malignant origin, with the latter being representative of the two main histological subtypes: adenocarcinoma and squamous cell carcinoma.

RESULTS

Panobinostat treatment inhibited growth and hindered proliferation, colony formation and invasion of oesophageal cancer cells. Considering HDAC tissue expression, HDAC1 was significantly upregulated in normal oesophageal epithelium in comparison with tumour tissue, whereas HDAC3 was overexpressed in oesophageal cancer compared to non-malignant mucosa. No differences between normal and tumour tissue were observed for HDAC2 and HDAC8 expression.

CONCLUSIONS

Panobinostat exposure effectively impaired malignant features of oesophageal cancer cells. Because HDAC3 was shown to be overexpressed in oesophageal tumour samples, this epigenetic drug may represent an alternative therapeutic option for oesophageal cancer patients.

Inhibition of lysine acetyltransferase KAT6 in ER+HER2- metastatic breast cancer: a phase 1 trial

Inhibition of histone lysine acetyltransferases (KATs) KAT6A and KAT6B has shown antitumor activity in estrogen receptor-positive (ER+) breast cancer preclinical models. PF-07248144 is a selective catalytic inhibitor of KAT6A and KAT6B. In the present study, we report the safety, pharmacokinetics (PK), pharmacodynamics, efficacy and biomarker results from the first-in-human, phase 1 dose escalation and dose expansion study (n = 107) of PF-07248144 monotherapy and fulvestrant combination in heavily pretreated ER+ human epidermal growth factor receptor-negative (HER2-) metastatic breast cancer (mBC). The primary objectives of assessing the safety and tolerability and determining the recommended dose for expansion of PF-07248144, as monotherapy and in combination with fulvestrant, were met. Secondary endpoints included characterization of PK and evaluation of antitumor activity, including objective response rate (ORR) and progression-free survival (PFS). Common treatment-related adverse events (any grade; grades 3-4) included dysgeusia (83.2%, 0%), neutropenia (59.8%, 35.5%) and anemia (48.6%, 13.1%). Exposure was approximately dose proportional. Antitumor activity was observed as monotherapy. For the PF-07248144-fulvestrant combination (n = 43), the ORR (95% confidence interval (CI)) was 30.2% (95% CI = 17.2-46.1%) and the median PFS was 10.7 (5.3-not evaluable) months. PF-07248144 demonstrated a tolerable safety profile and durable antitumor activity in heavily pretreated ER+HER2- mBC. These findings establish KAT6A and KAT6B as druggable cancer targets, provide clinical proof of concept and reveal a potential avenue to treat mBC. clinicaltrial.gov registration: NCT04606446 .

A real-world pharmacovigilance study investigating the toxicities of histone deacetylase inhibitors

Histone deacetylase (HDAC) inhibitors are emerging as promising treatments for hematological malignancies, with potential applications extending to solid tumors in the future. Given their wide-ranging biological effects, there is a pressing need for a thorough understanding of the toxicities linked to HDAC inhibition. In this study, a pharmacovigilance analysis was conducted using the FDA Adverse Event Reporting System database. Suspected adverse events linked to HDAC inhibitors were detected through various statistical methodologies, including reporting odds ratio, proportional reporting ratio, information component, and Empirical Bayes Geometric Mean. Our study findings have illuminated that, among the total reported cases examined, gastrointestinal disorders accounted for 13% patients of the cohort, while lymphatic system disorders comprised 8% cases of the cohort, all of which manifested as adverse events induced by HDAC inhibitors. Importantly, the usage of HDAC inhibitors was found to be associated with incidents of atrial fibrillation, heart failure, respiratory failure, hepatic dysfunction, and acute kidney injury. Romidepsin and belinostat demonstrated more pronounced signals of adverse events compared to panobinostat and vorinostat, emphasizing the need for vigilant monitoring of adverse events in this particular population. Furthermore, atrial fibrillation (clinical priority score of 7 points) emerged as the paramount medical event warranting utmost clinical attention. Eventually, multiple adverse events were observe to emerge within the initial and second months following the initiation of treatment. Vigilant monitoring and supportive care strategies are critical in addressing the toxicities associated with HDAC inhibitors, particularly those concerning cardiotoxicity, respiratory toxicity, renal toxicity, and hepatotoxicity.

Rediscovering hemostasis abnormalities in multiple myeloma: The new era

Multiple myeloma (MM) is a malignancy arisen from the abnormal proliferation of clonal plasma cells. It has a high risk of developing bleeding and thrombotic complications, which are related to poor prognosis and decreased survival. Multiple factors are involved in the breaking of the hemostasis balance, including disease specific factors, patient-specific factors, and drug factors that change pro-and anticoagulant and fibrinolysis. Recently, with the introduction of new treatments such as monoclonal antibodies, chimeric antigen receptor modified T-cell therapy, antibody-drug conjugates directed against BCMA, programmed death-1 inhibitor, export protein 1 inhibitors, histone deacetylase inhibitors, immunomodulatory drugs, proteasome inhibitors and Bcl-2 inhibitors, the therapy of MM patients has entered into a new era. Furthermore, it arouses a question whether these new treatments would alter the hemostasis balance in MM patients, which highlights the importance of the underlying pathophysiology of hemostasis abnormalities in MM, and on prophylaxis approaches. In this review, we updated the mechanisms of hemostasis abnormalities in MM, the impact of the new drugs on hemostasis balance and reliable therapeutic strategies.

Descriptive Analysis of Adverse Events Reported for New Multiple Myeloma Medications Using FDA Adverse Event Reporting System (FAERS) Databases from 2015 to 2022

BACKGROUND

New multiple myeloma (MM) medications have revolutionized the treatment landscape, but they are also associated with a range of adverse events (AEs). This study aims to provide a comprehensive overview of AEs reported for four new MM medications: daratumumab, ixazomib, elotuzumab, and panobinostat.

METHODS

This study uses a descriptive retrospective approach to analyze the FDA Adverse Event Reporting System (FAERS) from 2015 to 2022. It includes variables like medication names, report details, patient demographics, adverse events, and reporter types. The initial dataset consists of over 3700 adverse events, which are categorized into 21 groups for clarity and comparison.

RESULTS

The FAERS database revealed 367,756 adverse events (AEs) associated with novel multiple myeloma drugs from 2015-2022. Ixazomib had the highest number of reported AEs with 206,243 reports, followed by daratumumab with 98,872 reports, then elotuzumab with 26,193 AEs. Ixazomib's AE reports increased dramatically over the study period, rising approximately 51-fold from 1183 in 2015 to 60,835 in 2022. Of the medications studied, ixazomib also recorded the highest number of deaths (24,206), followed by daratumumab (11,624), panobinostat (7227), and elotuzumab (3349). The majority of AEs occurred in patients aged 55-64 and 65-74 years.

CONCLUSIONS

Ixazomib, a new MM medication, had the highest number of AEs reported. Also, it has the highest rate of reported deaths compared to other new MM medications. Clinicians should be aware of the potential AEs associated with this medication and further research is needed to understand the reasons for the high number of AEs and to develop mitigation strategies. More attention should also be paid to the safety of new multiple myeloma medications in younger patients.

The impact of current therapeutic options on the health-related quality of life of patients with relapse/refractory multiple myeloma: a systematic review of clinical studies

PURPOSE

Patients with relapse and/or refractory multiple myeloma (RRMM) have a high disease burden with poor health-related quality of life (HRQoL) which worsens with each additional relapse. We aimed to review the impact of triplet, doublet, monotherapies, and salvage autologous stem cell transplantation on the HRQoL of RRMM patients.

METHODS

We performed a comprehensive literature search of Medline/PubMed, Wiley Cochrane Library, EMBASE, Scopus, CINAHL, and Clinicaltrials.gov to identify clinical studies in RRMM patients with HRQoL as an outcome measure. The ISOQoL and CONSORT-PRO extension guidelines were used to assess the quality of HRQoL reporting. We synthesized the result using a qualitative analysis.

RESULTS

A total of 10,245 RRMM patients enrolled in 28 eligible studies received either a triplet, doublet regimen, monotherapy, or salvage autologous stem cell transplantation. The EORTC QLQ-C30 was the most used questionnaire, and compliance with HRQoL reporting standards is generally poor among studies without an additional HRQoL publication. Most of the current therapeutic options are at best able to maintain HRQoL at baseline but not improve it. The methodological and reporting heterogeneity among the studies complicates generalizations.

CONCLUSIONS

Many of the current treatment regimens for RRMM have demonstrated clinical effectiveness in trials. Unlike newly diagnosed MM, these regimens are less likely to result in significant improvement in HRQoL in RRMM. This should be communicated to patients before initiating therapies.

IMPLICATIONS FOR CANCER SURVIVORS

Individualized therapeutic approach for RRMM should be chosen based on a shared decision-making process that aligns clinical efficacy with patients' treatment priorities and HRQoL.

Next-Generation Therapies for Multiple Myeloma

Recent therapeutic advances have significantly improved the outcome for patients with multiple myeloma (MM). The backbone of successful standard therapy is the combination of Ikaros degraders, glucocorticoids, and proteasome inhibitors that interfere with the integrity of myeloma-specific superenhancers by directly or indirectly targeting enhancer-bound transcription factors and coactivators that control expression of MM dependency genes. T cell engagers and chimeric antigen receptor T cells redirect patients' own T cells onto defined tumor antigens to kill MM cells. They have induced complete remissions even in end-stage patients. Unfortunately, responses to both conventional therapy and immunotherapy are not durable, and tumor heterogeneity, antigen loss, and lack of T cell fitness lead to therapy resistance and relapse. Novel approaches are under development to target myeloma-specific vulnerabilities, as is the design of multimodality immunological approaches, including and beyond T cells, that simultaneously recognize multiple epitopes to prevent antigen escape and tumor relapse.

Oncology's trial and error: Analysis of the FDA withdrawn accelerated approvals

Launched in 1992, the FDA accelerated approval program grants drugs indicated in rare/life threatening diseases the ability to be marketed at a faster pace than through the traditional track. Each manufacturing company presents its drug to the FDA, and within 60 days it will determine if the drug is eligible for this path. Many drugs that were initially approved through this route, subsequently did not demonstrate their clinical benefits. With cancer being a leading cause of death, a vast majority of drugs that have been approved/withdrawn from this pathway are indicated within oncology. There are a wide variety of cancer subtypes and therapeutic target sites that these drugs have been evaluated for. Herein, is an overview of the 17 oncology drugs, spanning 22 cancer-related indications, that had been approved within the accelerated route and subsequently withdrawn.

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

Immunotherapy represented by anti-PD-(L)1 and anti-CTLA-4 inhibitors has revolutionized cancer treatment, but challenges related to resistance and toxicity still remain. Due to the advancement of immuno-oncology, an increasing number of novel immunoregulatory targets and mechanisms are being revealed, with relevant therapies promising to improve clinical immunotherapy in the foreseeable future. Therefore, comprehending the larger picture is important. In this review, we analyze and summarize the current landscape of preclinical and translational mechanistic research, drug development, and clinical trials that brought about next-generation pharmacological immunoregulatory anti-cancer agents and drug candidates beyond classical immune checkpoint inhibitors. Along with further clarification of cancer immunobiology and advances in antibody engineering, agents targeting additional inhibitory immune checkpoints, including LAG-3, TIM-3, TIGIT, CD47, and B7 family members are becoming an important part of cancer immunotherapy research and discovery, as are structurally and functionally optimized novel anti-PD-(L)1 and anti-CTLA-4 agents and agonists of co-stimulatory molecules of T cells. Exemplified by bispecific T cell engagers, newly emerging bi-specific and multi-specific antibodies targeting immunoregulatory molecules can provide considerable clinical benefits. Next-generation agents also include immune epigenetic drugs and cytokine-based therapeutics. Cell therapies, cancer vaccines, and oncolytic viruses are not covered in this review. This comprehensive review might aid in further development and the fastest possible clinical adoption of effective immuno-oncology modalities for the benefit of patients.

Targeting HIF-1α in sickle cell disease and cancer: unraveling therapeutic opportunities and risks

INTRODUCTION

HIF-1α, a key player in medical science, holds immense significance in therapeutic approaches. This review delves into its complex dynamics, emphasizing the delicate balance required for its modulation. HIF-1α stands as a cornerstone in medical research, its role extending to therapeutic strategies. This review explores the intricate interplay surrounding HIF-1α, highlighting its critical involvement and the necessity for cautious modulation.

AREAS COVERED

In sickle cell disease (SCD), HIF-1α's potential to augment fetal hemoglobin (HbF) production and mitigate symptoms is underscored. Furthermore, its role in cancer is examined, particularly its influence on survival in hypoxic tumor microenvironments, angiogenesis, and metastasis. The discussion extends to the intricate relationship between HIF-1α modulation and cancer risks in SCD patients, emphasizing the importance of balancing therapeutic benefits and potential hazards.

EXPERT OPINION

Managing HIF-1α modulation in SCD patients requires a nuanced approach, considering therapeutic potential alongside associated risks, especially in exacerbating cancer risks. An evolutionary perspective adds depth, highlighting adaptations in populations adapted to low-oxygen environments and aligning cancer cell metabolism with primitive cells. The role of HIF-1α as a therapeutic target is discussed within the context of complex cancer biology and metabolism, acknowledging varied responses across diverse cancers influenced by intricate evolutionary adaptations.

The pharmacoepigenetic paradigm in cancer treatment

Epigenetic modifications, characterized by changes in gene expression without altering the DNA sequence, play a crucial role in the development and progression of cancer by significantly influencing gene activity and cellular function. This insight has led to the development of a novel class of therapeutic agents, known as epigenetic drugs. These drugs, including histone deacetylase inhibitors, histone acetyltransferase inhibitors, histone methyltransferase inhibitors, and DNA methyltransferase inhibitors, aim to modulate gene expression to curb cancer growth by uniquely altering the epigenetic landscape of cancer cells. Ongoing research and clinical trials are rigorously evaluating the efficacy of these drugs, particularly their ability to improve therapeutic outcomes when used in combination with other treatments. Such combination therapies may more effectively target cancer and potentially overcome the challenge of drug resistance, a significant hurdle in cancer therapy. Additionally, the importance of nutrition, inflammation control, and circadian rhythm regulation in modulating drug responses has been increasingly recognized, highlighting their role as critical modifiers of the epigenetic landscape and thereby influencing the effectiveness of pharmacological interventions and patient outcomes. Epigenetic drugs represent a paradigm shift in cancer treatment, offering targeted therapies that promise a more precise approach to treating a wide spectrum of tumors, potentially with fewer side effects compared to traditional chemotherapy. This progress marks a step towards more personalized and precise interventions, leveraging the unique epigenetic profiles of individual tumors to optimize treatment strategies.

Exploring the role of histone deacetylase and histone deacetylase inhibitors in the context of multiple myeloma: mechanisms, therapeutic implications, and future perspectives

Histone deacetylase inhibitors (HDACis) are a significant category of pharmaceuticals that have developed in the past two decades to treat multiple myeloma. Four drugs in this category have received approval from the U.S. Food and Drug Administration (FDA) for use: Panobinonstat (though canceled by the FDA in 2022), Vorinostat, Belinostat and Romidepsin. The efficacy of this group of drugs is attributed to the disruption of many processes involved in tumor growth through the inhibition of histone deacetylase, and this mode of action leads to significant anti-multiple myeloma (MM) activity. In MM, inhibition of histone deacetylase has many downstream consequences, including suppression of NF-κB signaling and HSP90, upregulation of cell cycle regulators (p21, p53), and downregulation of antiapoptotic proteins including Bcl-2. Furthermore, HDACis have a variety of direct and indirect oxidative effects on cellular DNA. HDAC inhibitors enhance normal immune function, thereby decreasing the proliferation of malignant plasma cells and promoting autophagy. The various biological effects of inhibiting histone deacetylase have a combined or additional impact when used alongside other chemotherapeutic and targeted drugs for multiple myeloma. This helps to decrease resistance to treatment. Combination treatment regimens that include HDACis have become an essential part of the therapy for multiple myeloma. These regimens incorporate drugs from other important classes of anti-myeloma agents, such as immunomodulatory drugs (IMiDs), conventional chemotherapy, monoclonal antibodies, and proteasome inhibitors. This review provides a comprehensive evaluation of the clinical efficacy and safety data pertaining to the currently approved histone deacetylase inhibitors, as well as an explanation of the crucial function of histone deacetylase in multiple myeloma and the characteristics of the different histone deacetylase inhibitors. Moreover, it provides a concise overview of the most recent developments in the use of histone deacetylase inhibitors for treating multiple myeloma, as well as potential future uses in treatment.

Histone deacetylase (HDAC) inhibitor specificity determinants are preserved in a class of dual HDAC/non-covalent proteasome inhibitors

Many disease states require multiple drugs to inhibit multiple targets for their effective treatment/management, i.e. a drug cocktail regimen, or "polypharmacy". Polypharmacology, in contrast, is the development of single agents that can inhibit multiple targets. Each strategy is associated with advantages and disadvantages. Motivated by promising clinical trial data for the treatment of multiple myeloma with the combination of the HDAC6 inhibitor ricolinostat and the proteasome inhibitor bortezomib, we herein describe a focused family of dual HDAC/non-covalent proteasome inhibitors, and explore the impact of linker and zinc-binding group identities on HDAC1/6 isozyme selectivity. In general, previously reported specificity determinants of monovalent HDAC1/6 inhibitors were preserved in our dual HDAC/proteasome inhibitors.

Synergistic integration of histone deacetylase inhibitors apparently enhances the cytokine-induced killer cell efficiency in multiple myeloma via the NKG2D pathway

Objectives

The rapid recognition of epigenetic manipulation's potential in restricting cancer cell capabilities spurred translational initiatives, including histone deacetylase inhibitors (HDACis). Clinical trials on multiple myeloma (MM) demonstrated substantial benefits of HDACis, coupled with promising outcomes from cytokine-induced killer cell (CIK) immunotherapy. Intriguingly, the unexplored synergy of HDACis and CIK cell immunotherapy in MM prompted our study.

Methods

We examined clinically relevant HDACis (panobinostat/LBH589 and romidepsin) alongside CIK cells derived from peripheral blood mononuclear cells across diverse MM cell lines (U266, RPMI8226, OPM-2 and NCI-H929). Utilising various in vitro methodologies, we investigated how HDACis enhance CIK cell lysis of myeloma cells through NKG2D/NKG2D ligand interactions.

Results

The results of our analysis indicated several key findings. (1) Enhanced cytotoxicity of CIK cells in MM cells when combined with HDACis. (2) Significant increase in apoptosis, suggesting HDACis and CIK may together enhance apoptotic effects in specific MM cell lines. (3) Elevated IFN-γ secretion and alterations in granzyme B secretion because of the independent activity of HDACis. (4) Notably, HDACis increased the expression of MICA/B and ULBP2, crucial for inducing antitumor cytotoxicity of NKT cells. Validation through NKG2D receptor blocking in CIK cells with a purified mouse antihuman NKG2D antibody further supported our findings.

Conclusions

Our analyses provide sufficient evidence to consider this clinically forgotten instance (HDACis-CIK cell combination) as a therapeutic priority for MM treatment. Furthermore, we suggest that NKG2D/NKG2D-ligand interactions activating NK/NKT cells may contribute to enhanced myeloma cell lysis in response to HDACis treatment by CIK cells.

Therapeutic Targeting of Hypoxia-Inducible Factors in Cancer

In the realm of cancer therapeutics, targeting the hypoxia-inducible factor (HIF) pathway has emerged as a promising strategy. This study delves into the intricate web of HIF-associated mechanisms, exploring avenues for future anticancer therapies. Framing the investigation within the broader context of cancer progression and hypoxia response, this article aims to decipher the pivotal role played by HIF in regulating genes influencing angiogenesis, cell proliferation, and glucose metabolism. Employing diverse approaches such as HIF inhibitors, anti-angiogenic therapies, and hypoxia-activated prodrugs, the research methodologically intervenes at different nodes of the HIF pathway. Findings showcase the efficacy of agents like EZN-2968, Minnelide, and Acriflavine in modulating HIF-1α protein synthesis and destabilizing HIF-1, providing preliminary proof of HIF-1α mRNA modulation and antitumor activity. However, challenges, including toxicity, necessitate continued exploration and development, as exemplified by ongoing clinical trials. This article concludes by emphasizing the potential of targeted HIF therapies in disrupting cancer-related signaling pathways.

Groebke Blackburn Bienaymé-mediated multi-component synthesis of selective HDAC6 inhibitors with anti-inflammatory properties

Histone deacetylases (HDACs) are a class of enzymes that cleave acyl groups from lysine residues of histone and non-histone proteins. There are 18 human HDAC isoforms with different cellular targets and functions. Among them, HDAC6 was found to be overexpressed in different types of cancer. However, when used in monotherapy, HDAC6 inhibition by selective inhibitors fails to show pronounced anti-cancer effects. The HDAC6 enzyme also addresses non-histone proteins like α-tubulin and cortactin, making it important for cell migration and angiogenesis. Recently, the NLRP3 inflammasome was identified as an important regulator of inflammation and immune responses and, importantly, HDAC6 is critically involved the activation of the inflammasome. We herein report the design, synthesis and biological evaluation of a library of selective HDAC6 inhibitors. Starting from the previously published crystal structure of MAIP-032 in complex with CD2 of zHDAC6, we performed docking studies to evaluate additional possible interactions of the cap group with the L1-loop pocket. Based on the results we synthesized 13 novel HDAC6 inhibitors via the Groebke-Blackburn-Bienaymé three component reaction as the key step. Compounds 8k (HDAC1 IC50: 5.87 μM; HDAC6 IC50: 0.024 μM; selectivity factor (SF1/6): 245) and 8m (HDAC1 IC50: 3.07 μM; HDAC6 IC50: 0.026 μM; SF1/6: 118) emerged as the most potent and selective inhibitors of HDAC6 and outperformed the lead structure MAIP-032 (HDAC1 IC50: 2.20 μM; HDAC6 IC50: 0.058 μM; SF1/6: 38) both in terms of inhibitory potency and selectivity. Subsequent immunoblot analysis confirmed the high selectivity of 8k and 8m for HDAC6 in a cellular environment. While neither 8k and 8m nor the selectivity HDAC6 inhibitor tubastatin A showed antiproliferative effects in the U-87 MG glioblastoma cell line, compound 8m attenuated cell migration significantly in wound healing assays in U-87 MG cells. Moreover, in macrophages compounds 8k and 8m demonstrated significant inhibition of LPS-induced IL1B mRNA expression and TNF release. These findings suggest that our imidazo[1,2-a]pyridine-capped HDAC6 inhibitors may serve as promising candidates for the development of drugs to effectively treat NLRP3 inflammasome-driven inflammatory diseases.

Cancer epigenetics: from laboratory studies and clinical trials to precision medicine

Epigenetic dysregulation is a common feature of a myriad of human diseases, particularly cancer. Defining the epigenetic defects associated with malignant tumors has become a focus of cancer research resulting in the gradual elucidation of cancer cell epigenetic regulation. In fact, most stages of tumor progression, including tumorigenesis, promotion, progression, and recurrence are accompanied by epigenetic alterations, some of which can be reversed by epigenetic drugs. The main objective of epigenetic therapy in the era of personalized precision medicine is to detect cancer biomarkers to improve risk assessment, diagnosis, and targeted treatment interventions. Rapid technological advancements streamlining the characterization of molecular epigenetic changes associated with cancers have propelled epigenetic drug research and development. This review summarizes the main mechanisms of epigenetic dysregulation and discusses past and present examples of epigenetic inhibitors in cancer diagnosis and treatment, with an emphasis on the development of epigenetic enzyme inhibitors or drugs. In the final part, the prospect of precise diagnosis and treatment is considered based on a better understanding of epigenetic abnormalities in cancer.

Autophagy-related mechanisms for treatment of multiple myeloma

Multiple myeloma (MM) is a type of hematological cancer that occurs when B cells become malignant. Various drugs such as proteasome inhibitors, immunomodulators, and compounds that cause DNA damage can be used in the treatment of MM. Autophagy, a type 2 cell death mechanism, plays a crucial role in determining the fate of B cells, either promoting their survival or inducing cell death. Therefore, autophagy can either facilitate the progression or hinder the treatment of MM disease. In this review, autophagy mechanisms that may be effective in MM cells were covered and evaluated within the contexts of unfolded protein response (UPR), bone marrow microenvironment (BMME), drug resistance, hypoxia, DNA repair and transcriptional regulation, and apoptosis. The genes that are effective in each mechanism and research efforts on this subject were discussed in detail. Signaling pathways targeted by new drugs to benefit from autophagy in MM disease were covered. The efficacy of drugs that regulate autophagy in MM was examined, and clinical trials on this subject were included. Consequently, among the autophagy mechanisms that are effective in MM, the most suitable ones to be used in the treatment were expressed. The importance of 3D models and microfluidic systems for the discovery of new drugs for autophagy and personalized treatment was emphasized. Ultimately, this review aims to provide a comprehensive overview of MM disease, encompassing autophagy mechanisms, drugs, clinical studies, and further studies.

Epigenetic Alterations as Vital Aspects of Bortezomib Molecular Action

Bortezomib (BTZ) is widely implemented in the treatment of multiple myeloma (MM). Its main mechanism of action is very well established. BTZ selectively and reversibly inhibits the 26S proteasome. More precisely, it interacts with the chymotryptic site of the 20S proteasome and therefore inhibits the degradation of proteins. This results in the intracellular accumulation of misfolded or otherwise defective proteins leading to growth inhibition and apoptosis. As well as interfering with the ubiquitin-proteasome complex, BTZ elicits various epigenetic alterations which contribute to its cytotoxic effects as well as to the development of BTZ resistance. In this review, we summarized the epigenetic alterations elicited by BTZ. We focused on modifications contributing to the mechanism of action, those mediating drug-resistance development, and epigenetic changes promoting the occurrence of peripheral neuropathy. In addition, there are therapeutic strategies which are specifically designed to target epigenetic changes. Herein, we also reviewed epigenetic agents which might enhance BTZ-related cytotoxicity or restore the sensitivity to BTZ of resistant clones. Finally, we highlighted putative future perspectives regarding the role of targeting epigenetic changes in patients exposed to BTZ.

Comparative efficacy of novel-drugs combined therapeutic regimens on relapsed/refractory multiple myeloma: a network meta-analysis

BACKGROUND

Although multiple myeloma is still incurable, an abundance of novel treatments have become available for relapsed and or refractory multiple myeloma (RRMM). Direct head-to-head comparisons between the novel treatments are lacking. We performed a network meta-analysis to evaluate immediate effects such as response quality of current novel-drugs combined therapeutic regimens, with the aim to identify treatments that could be more effective than others in RRMM.

METHODS

We searched Cochrane Library, PubMed, Embase, and Web of Science for randomized controlled clinical trials receiving novel-drugs combined treatments as means of interventions. The primary endpoint was objective response rates (ORRs). We used the surface under the cumulative ranking curve (SUCRA) to sequence treatments. Totally, 22 randomized controlled trials were identified for final evaluation. With the aim to include all regimens within one network analysis, we divided the treatment schemes into 13 categories according to the use of novel drugs.

RESULTS

Carfilzomib-, daratumumab-, and isatuximab-based treatments had better ORRs than bortezomib combined dexamethasone and lenalidomide combined dexamethasone. Daratumumab- and isatuximab-based treatments had better ORRs than pomalidomide combined dexamethasone. According to the SUCRA, daratumumab- and isatuximab-based triple-drug regimens had higher probabilities of achieving better ORRs, followed by carfilzomib, elotuzumab, venetoclax, selinexor, ixazomib, vorinostat, pomalidomide, panobinostat, lenalidomide.

CONCLUSIONS

Our network meta-analysis performed a complete review of the ORRs of all current available novel-drugs based regimens for RRMM. By using the clinical data all from randomized controlled studies, daratumumab- and isatuximab-based treatments were identified to be the best treatments receiving better response quality.

Progression-Free Survival Efficacy in Refractory/Relapsed Multiple Myeloma among Elderly Patients: A Systematic Review

BACKGROUND

Over the last decade, many studies have assessed the efficacy of treatments for refractory/relapsed multiple myeloma (R/R MM). While combination therapies show greater efficacy than traditional methods, limited research has targeted elderly patients who might be less resilient to treatments. Our study aimed to evaluate treatment efficacy for these elderly patients.

METHODS

We carried out a comprehensive review of the literature using a systematic approach. Initially, 4966 citations were retrieved and subsequently narrowed down to 13 eligible randomized controlled trials (RCTs) through our systematic review process from databases like Embase, PubMed, and Cochrane Library from 1 January 2000 to 31 December 2022. Evidence was collated through a frequentist network meta-analysis, using the hazard ratio (HR) for evaluation.

RESULTS

Combined therapy of daratumumab, lenalidomide, and dexamethasone (DaraLenDex) was the preferred treatment for R/R MM elderly patients. Its strengths included an HR for progression-free survival (0.15; 95% CI: 0.09-0.25) and a 96% P-score.

CONCLUSIONS

Our analysis suggests that, pending more comprehensive RCTs, DaraLenDex is the treatment with the highest efficacy for R/R MM in elderly patients.

Histone deacetylase-based dual targeted inhibition in multiple myeloma

Despite enormous advances in terms of therapeutic strategies, multiple myeloma (MM) still remains an incurable disease with MM patients often becoming resistant to standard treatments. To date, multiple combined and targeted therapies have proven to be more beneficial compared to monotherapy approaches, leading to a decrease in drug resistance and an improvement in median overall survival in patients. Moreover, recent breakthroughs highlighted the relevant role of histone deacetylases (HDACs) in cancer treatment, including MM. Thus, the simultaneous use of HDAC inhibitors with other conventional regimens, such as proteasome inhibitors, is of interest in the field. In this review, we provide a general overview of HDAC-based combination treatments in MM, through a critical presentation of publications from the past few decades related to in vitro and in vivo studies, as well as clinical trials. Furthermore, we discuss the recent introduction of dual-inhibitor entities that could have the same beneficial effects as drug combinations with the advantage of having two or more pharmacophores in one molecular structure. These findings could represent a starting-point for both reducing therapeutic doses and lowering the risk of developing drug resistance.

Effect modification in network meta-analyses for relapsed/refractory multiple myeloma: systematic review and meta-analysis

OBJECTIVES

To systematically review and meta-analyse the evidence for effect modification by refractory status and number of treatment lines in relapsed/refractory multiple myeloma (RRMM); and to assess whether effect modification is likely to invalidate network meta-analyses (NMA) that assume negligible modification.

DESIGN

Systematic review, meta-analysis and simulation.

DATA SOURCES

We systematically searched the literature (e.g., OVID Medline) to identify eligible publications in February 2020 and regularly updated the search until January 2022. We also contacted project stakeholders (including industry) ELIGIBILITY CRITERIA: Phase 2 and 3 randomised controlled trials reporting stratified estimates for comparisons with at least one of a prespecified set of treatments relevant for use in Norwegian RRMM patients.

OUTCOMES

We used meta-analysis to estimate relative HRs (RHRs) for overall survival (OS) and progression-free survival (PFS) with respect to refractory status and number of treatment lines. We used the estimated RHRs in simulations to estimate the percentage of NMA results expected to differ significantly in the presence versus absence of effect modification.

RESULTS

Among the 42 included publications, stratified estimates were published by and extracted from up to 18 (43%) publications and on as many as 8364 patients. Within-study evidence for effect modification is very weak (p>0.05 for 47 of 49 sets of stratified estimates). The largest RHR estimated was 1.32 (95% CI 1.18 to 1.49) for the modifying effect of refractory status on HR for PFS. Simulations suggest that, in the worst case, this would result in only 4.48% (95% CI 4.42% to 4.54%) of NMA estimates differing statistically significantly in the presence versus absence of effect modification.

CONCLUSIONS

Based on the available evidence, effect modification appears to be sufficiently small that it can be neglected in adequately performed NMAs. NMAs can probably be relied on to provide estimates of HRs for OS and PFS in RRMM, subject to caveats discussed herein.

Breaking through Multiple Myeloma: A Paradigm for a Comprehensive Tumor Ecosystem Targeting

Multiple myeloma (MM) is a cancerous condition characterized by the proliferation of plasma cells within the hematopoietic marrow, resulting in multiple osteolytic lesions. MM patients typically experience bone pain, kidney damage, fatigue due to anemia, and infections. Historically, MM was an incurable disease with a life expectancy of around three years after diagnosis. However, over the past two decades, the development of novel therapeutics has significantly improved patient outcomes, including response to treatment, remission duration, quality of life, and overall survival. These advancements include thalidomide and its derivatives, lenalidomide and pomalidomide, which exhibit diverse mechanisms of action against the plasma cell clone. Additionally, proteasome inhibitors such as bortezomib, ixazomib, and carfilzomib disrupt protein degradation, proving specifically toxic to cancerous plasma cells. Recent advancements also involve monoclonal antibodies targeting surface antigens, such as elotuzumab (anti-CS1) and daratumumab (anti-CD38), bispecific t-cell engagers such as teclistamab (anti-BCMA/CD3) and Chimeric antigen receptor T (CAR-T)-based strategies, with a growing focus on drugs that exhibit increasingly targeted action against neoplastic plasma cells and relevant effects on the tumor microenvironment.

Randomised controlled trials evaluating anticancer therapies in haematological cancers: an overview of global research activity

Background

Design, results, and interpretation of oncology randomised controlled trials (RCTs) have changed substantially over the past decade. In this study, we describe all RCTs evaluating anticancer therapies in haematological cancers published globally during 2014-2017 with comparisons with solid tumours RCTs.

Methods

A PubMed literature search identified all phase 3 RCTs of anticancer therapy for haematological cancers and solid tumours published globally during 2014-2017. Descriptive statistics, chi-square tests and the Kruskal-Wallis test were used to compare RCT design results, and output between haematological cancers and solid tumours as well as for different haematological cancer subtypes.

Results

694 RCTs were identified; 124 in haematological cancers and 570 in solid tumours. Overall survival (OS) was the primary endpoint in only 12% (15/124) of haematological cancer trials compared to 35% (200/570) in solid tumours (p < 0.001). Haematological cancer RCTs evaluated the systemic novel therapy more often than the solid tumour RCT (98% versus 84%, p = 0.002). Use of surrogate endpoints like progression-free survival (PFS) and time to treatment failure (TTF) were more common in haematological cancers than solid tumours (47% versus 31%, p < 0.001). Within haematological cancers, the use of PFS and TTF was more prevalent in chronic lymphocytic leukaemia and multiple myeloma as compared to others (80%-81% versus 0%-41%, p < 0.001). Seventy-eight percent of haematologic trials were funded by industry as compared to 70% of solid tumour trials. Only 4% (5/124) of haematologicalcancer trials were led by investigators in upper-middle and lower-middle-income countries as compared to the 9% of solid tumour trials.

Conclusion

The fact that only 12% of haematological cancer RCTs are designed to show improvements in OS is of grave concern for the field and the care of future patients. This is further compounded by the highly prevalent use of alternative primary endpoints that are rarely valid surrogates for OS in haematological cancers.

An Update of Epigenetic Drugs for the Treatment of Cancers and Brain Diseases: A Comprehensive Review

Epigenetics has long been recognized as a significant field in biology and is defined as the investigation of any alteration in gene expression patterns that is not attributed to changes in the DNA sequences. Epigenetic marks, including histone modifications, non-coding RNAs, and DNA methylation, play crucial roles in gene regulation. Numerous studies in humans have been carried out on single-nucleotide resolution of DNA methylation, the CpG island, new histone modifications, and genome-wide nucleosome positioning. These studies indicate that epigenetic mutations and aberrant placement of these epigenetic marks play a critical role in causing the disease. Consequently, significant development has occurred in biomedical research in identifying epigenetic mechanisms, their interactions, and changes in health and disease conditions. The purpose of this review article is to provide comprehensive information about the different types of diseases caused by alterations in epigenetic factors such as DNA methylation and histone acetylation or methylation. Recent studies reported that epigenetics could influence the evolution of human cancer via aberrant methylation of gene promoter regions, which is associated with reduced gene function. Furthermore, DNA methyltransferases (DNMTs) in the DNA methylation process as well as histone acetyltransferases (HATs)/histone deacetylases (HDACs) and histone methyltransferases (HMTs)/demethylases (HDMs) in histone modifications play important roles both in the catalysis and inhibition of target gene transcription and in many other DNA processes such as repair, replication, and recombination. Dysfunction in these enzymes leads to epigenetic disorders and, as a result, various diseases such as cancers and brain diseases. Consequently, the knowledge of how to modify aberrant DNA methylation as well as aberrant histone acetylation or methylation via inhibitors by using epigenetic drugs can be a suitable therapeutic approach for a number of diseases. Using the synergistic effects of DNA methylation and histone modification inhibitors, it is hoped that many epigenetic defects will be treated in the future. Numerous studies have demonstrated a link between epigenetic marks and their effects on brain and cancer diseases. Designing appropriate drugs could provide novel strategies for the management of these diseases in the near future.

Current status of drug development for patients with multiple myeloma: a review of comparison in China and the rest of world

Multiple myeloma (MM) is a highly heterogeneous malignancy. The treatment of MM has been significantly advanced in recent years. B cell maturation antigen (BCMA)-targeted immunotherapy and chimeric antigen receptor T (CAR-T) cell therapy have been approved for the treatment of relapsed and refractory MM (RRMM), which will be launched in China shortly. The CD38 (cluster of differentiation 38) antibody, daratumumab, improves the clinical outcomes both RRMM and newly diagnosed MM patients. The combination of daratumumab, bortezomib and dexamethasone achieved favorable outcomes as the first-line therapy in China. However, high-risk patients have limited benefits from these advanced therapeutics, and usually relapse early, progressing into aggressive end-stage MM. Therefore, novel therapies are sought to improve the cancer prognosis in these patients. This review furnishes an overview of the recent clinical developments of these novel drugs and compares the drug candidates under development in China to the rest of the world.

Autophagy: A Potential Therapeutic Target to Tackle Drug Resistance in Multiple Myeloma

Multiple myeloma (MM) is the second most prevalent hematologic malignancy. In the past few years, the survival of MM patients has increased due to the emergence of novel drugs and combination therapies. Nevertheless, one of the significant obstacles in treating most MM patients is drug resistance, especially for individuals who have experienced relapses or developed resistance to such cutting-edge treatments. One of the critical processes in developing drug resistance in MM is autophagic activity, an intracellular self-digestive process. Several possible strategies of autophagy involvement in the induction of MM-drug resistance have been demonstrated thus far. In multiple myeloma, it has been shown that High mobility group box protein 1 (HMGB1)-dependent autophagy can contribute to drug resistance. Moreover, activation of autophagy via proteasome suppression induces drug resistance. Additionally, the effectiveness of clarithromycin as a supplemental drug in treating MM has been reported recently, in which autophagy blockage is proposed as one of the potential action mechanisms of CAM. Thus, a promising therapeutic approach that targets autophagy to trigger the death of MM cells and improve drug susceptibility could be considered. In this review, autophagy has been addressed as a survival strategy crucial for drug resistance in MM.

Daratumumab Monotherapy for Heavily Pre-treated and Refractory Myeloma: Results from a UK Multicentre Real World Cohort

Daratumumab is the first anti-CD38 targeting monoclonal antibody approved as monotherapy in multiply relapsed myeloma patients who progressed following prior treatment with proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs). We present real world data on the efficacy of single agent daratumumab in a cohort of 55 multiply relapsed patients treated in the UK.The median age was 72 years, the majority (96%) received ≥ 3 previous lines of treatment; 54.5% were PI-refractory, 76.4% were IMiD-refractory and 47.2% were double refractory; 20% of patients had high-risk (HR) disease.The overall response rate was 49%. After a median follow up of 9.2 months, the median progression-free survival (PFS) for the total cohort was 5.1 months. Patients who achieved a partial response or better (≥PR) demonstrated a significantly longer PFS compared to those with <PR; 9.8 versus 2.7 months, p < 0.001. Double-refractory patients had an inferior PFS compared to single-refractory patients; 2.7 versus 7.4 months, p = 0.084. High-risk disease was associated with significantly shorter PFS compared to standard-risk (SR); 2.3 versus 6.7 months, p = 0.001. The median overall survival (OS) was 15.9 months. Despite a relatively short PFS seen in the double-refractory and high-risk patients; a favourable median overall survival of 12.9 months was achieved in these groups. Patients who achieved ≥PR, those with a previous objective response to PIs or IMiDs and those with SR disease, all benefited from a significantly longer OS which was not reached. A clear benefit in survival is encouraging in this setting of unmet clinical need and limited treatment options.

Outcomes with panobinostat in heavily pretreated multiple myeloma patients

Panobinostat is an oral pan histone-deacetylase inhibitor used in the treatment of relapsed and refractory multiple myeloma. Previously published studies of panobinostat demonstrated synergy with bortezomib but included few patients exposed to newer agent combinations (ie, panobinostat plus daratumumab or carfilzomib). Here, we report outcomes of panobinostat-based combinations at an academic medical center among patients whose disease had been heavily pretreated with modern agents. We retrospectively analyzed 105 patients with myeloma treated with panobinostat at The Mount Sinai Hospital in New York City between October 2012 and October 2021. These patients had a median age of 65 (range 37-87) and had received a median of 6 prior lines of therapy while in 53% the disease was classified as triple class refractory and in 54% the disease had high-risk cytogenetics. Panobinostat was most commonly utilized at 20 mg (64.8%) as part of a triplet (61.0%) or quadruplet (30.5%). Aside from steroids, panobinostat was most commonly administered in combination with lenalidomide, pomalidomide, carfilzomib, and daratumumab in descending order of frequency. Among the 101 response-evaluable patients, the overall response rate was 24.8%, clinical benefit rate (≥minimal response) was 36.6%, and median progression-free survival was 3.4 months. Median overall survival was 19.1 months. The most common toxicities ≥grade 3 were hematologic, primarily neutropenia (34.3%), thrombocytopenia (27.6%), and anemia (19.1%). Panobinostat-based combinations produced modest response rates in patients with heavily pretreated multiple myeloma, over half of whom had triple-class refractory disease. Panobinostat warrants continued investigation as a tolerable oral option for recapturing responses in patients whose disease has progressed after receipt of standard-of-care therapies.

Photocaged Histone Deacetylase Inhibitors as Prodrugs in Targeted Cancer Therapy

Histone deacetylases (HDACs) play a key role in the control of transcription, cell proliferation, and migration. FDA-approved histone deacetylase inhibitors (HDACi) demonstrate clinical efficacy in the treatment of different T-cell lymphomas and multiple myeloma. However, due to unselective inhibition, they display a wide range of adverse effects. One approach to avoiding off-target effects is the use of prodrugs enabling a controlled release of the inhibitor in the target tissue. Herein, we describe the synthesis and biological evaluation of HDACi prodrugs with photo-cleavable protecting groups masking the zinc-binding group of the established HDACi DDK137 (I) and VK1 (II). Initial decaging experiments confirmed that the photocaged HDACi pc-I could be deprotected to its parent inhibitor I. In HDAC inhibition assays, pc-I displayed only low inhibitory activity against HDAC1 and HDAC6. After irradiation with light, the inhibitory activity of pc-I strongly increased. Subsequent MTT viability assays, whole-cell HDAC inhibition assays, and immunoblot analysis confirmed the inactivity of pc-I at the cellular level. Upon irradiation, pc-I demonstrated pronounced HDAC inhibitory and antiproliferative activities which were comparable to the parent inhibitor I. Additionally, only phototreated pc-I was able to induce apoptosis in Annexin V/PI and caspase-Glo 3/7 assays, making pc-I a valuable tool for the development of light-activatable HDACi.