Emerging agents and regimens for multiple myeloma

Disruption of DNA-PKcs-mediated cGAS retention on damaged chromatin potentiates DNA damage-inducing agent-induced anti-multiple myeloma activity

BACKGROUND

Targeting DNA damage repair factors, such as DNA-dependent protein kinase catalytic subunit (DNA-PKcs), may offer an opportunity for effective treatment of multiple myeloma (MM). In combination with DNA damage-inducing agents, this strategy has been shown to improve chemotherapies partially via activation of cGAS-STING pathway by an elevated level of cytosolic DNA. However, as cGAS is primarily sequestered by chromatin in the nucleus, it remains unclear how cGAS is released from chromatin and translocated into the cytoplasm upon DNA damage, leading to cGAS-STING activation.

METHODS

We examined the role of DNA-PKcs inhibition on cGAS-STING-mediated MM chemosensitivity by performing mass spectrometry and mechanism study.

RESULTS

Here, we found DNA-PKcs inhibition potentiated DNA damage-inducing agent doxorubicin-induced anti-MM effect by activating cGAS-STING signaling. The cGAS-STING activation in MM cells caused cell death partly via IRF3-NOXA-BAK axis and induced M1 polarization of macrophages. Moreover, this activation was not caused by defective classical non-homologous end joining (c-NHEJ). Instead, upon DNA damage induced by doxorubicin, inhibition of DNA-PKcs promoted cGAS release from cytoplasmic chromatin fragments and increased the amount of cytosolic cGAS and DNA, activating cGAS-STING.

CONCLUSIONS

Inhibition of DNA-PKcs could improve the efficacy of doxorubicin in treatment of MM by de-sequestrating cGAS in damaged chromatin.

Effect of human bone marrow mesenchymal stem cell-derived microvesicles on the apoptosis of the multiple myeloma cell line U266

BACKGROUND

Microvesicles are membraned particles produced by different types of cells recently investigated for anticancer purposes. The current study aimed to investigate the effects of human bone marrow mesenchymal stem cell-derived microvesicles (BMSC-MVs) on the multiple myeloma cell line U266. BMSC-MVs were isolated from BMSCs via ultracentrifugation and characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). U266 cells were treated with 15, 30, 60, and 120 µg/mL BMSC-MVs for three and seven days and the effects of treatment in terms of viability, cytotoxicity, and DNA damage were investigated via the MTT assay, lactate dehydrogenase (LDH) assay, and 8‑hydroxy-2'-deoxyguanosine (8‑OHdG) measurement, respectively. Moreover, the apoptosis rate of the U266 cells treated with 60 µg/mL BMSC-MVs was also assessed seven days following treatment via flow cytometry. Ultimately, the expression level of BCL2, BAX, and CCND1 by the U266 cells was examined seven days following treatment with 60 µg/mL BMSC-MVs using qRT-PCR.

RESULTS

BMSC-MVs had an average size of ~ 410 nm. According to the MTT and LDH assays, BMSC-MV treatment reduced the U266 cell viability and mediated cytotoxic effects against them, respectively. Moreover, elevated 8‑OHdG levels following BMSC-MV treatment demonstrated a dose-dependent increase of DNA damage in the treated cells. BMSC-MV-treated U266 cells also exhibited an increased apoptosis rate after seven days of treatment. The expression level of BCL2 and CCND1 decreased in the treated cells whereas the BAX expression demonstrated an incremental pattern.

CONCLUSIONS

Our findings accentuate the therapeutic benefit of BMSC-MVs against the multiple myeloma cell line U266 and demonstrate how microvesicles could be of therapeutic advantage. Future in vivo studies could further corroborate these findings.

Aberrant non-canonical NF-κB signalling reprograms the epigenome landscape to drive oncogenic transcriptomes in multiple myeloma

In multiple myeloma, abnormal plasma cells establish oncogenic niches within the bone marrow by engaging the NF-κB pathway to nurture their survival while they accumulate pro-proliferative mutations. Under these conditions, many cases eventually develop genetic abnormalities endowing them with constitutive NF-κB activation. Here, we find that sustained NF-κB/p52 levels resulting from such mutations favours the recruitment of enhancers beyond the normal B-cell repertoire. Furthermore, through targeted disruption of p52, we characterise how such enhancers are complicit in the formation of super-enhancers and the establishment of cis-regulatory interactions with myeloma dependencies during constitutive activation of p52. Finally, we functionally validate the pathological impact of these cis-regulatory modules on cell and tumour phenotypes using in vitro and in vivo models, confirming RGS1 as a p52-dependent myeloma driver. We conclude that the divergent epigenomic reprogramming enforced by aberrant non-canonical NF-κB signalling potentiates transcriptional programs beneficial for multiple myeloma progression.

Therapeutic Effect and Adverse Event Rate of Different Treatment Methods in Patients with Multiple Myeloma and Renal Insufficiency

INTRODUCTION

This study involves the collation and analysis of clinical characteristics and laboratory findings in patients with multiple myeloma (MM) combined with renal insufficiency. The objective was to assess the impact of various treatment methods on patient outcomes and the incidence of adverse events in individuals with MM and renal insufficiency.

METHODS

We analyzed the correlation between clinical characteristics, gene loci, fluorescence in situ hybridization, treatment methods, and prognosis in patients with MM and renal insufficiency. The differences in hematological and therapeutic efficacy indexes between two groups subjected to different treatments were evaluated. The assessment of treatment effectiveness was based on the total effective rate, calculated as the sum of stringent CR rate, complete remission rate, very good partial remission rate, and partial remission rate.

RESULTS

(1) The renal insufficiency group exhibited higher percentages of bone marrow abnormal plasma cells, lactate dehydrogenase (LDH), blood calcium, white blood cell count, percentage of neutrophils, and blood β2-microglobulin (β2-MG) levels compared to the normal renal function group. Conversely, hemoglobin levels and lymphocyte percentage were lower in the renal insufficiency group. Binary logistic regression analysis identified hemoglobin, blood calcium values, blood β2-MG, and LDH as independent risk factors for the development of renal insufficiency in patients with MM (p < 0.05). (2) Based on the Durie-Salmon staging criteria, the proportion of Stage III patients was the highest (up to 81.8%), indicating that patients with MM usually suffer from insidious disease, often with high tumor load and late-disease stage at the time of consultation. International Staging System (ISS) and Revised ISS staging also revealed a higher proportion of Stage III patients in the renal insufficiency group (p < 0.05), indicating a worse long-term prognosis in patients with MM and renal insufficiency. (3) Before treatment, there was no significant difference between the two groups in the analysis of various indices. Complications such as sepsis, herpes zoster, peripheral neuropathy, thrombosis, secondary pulmonary infection, and cardiac complications were significantly lower in the BCD group (Bortezomib + Cyclophosphamide + Dexamethasone) compared to the BD group (Bortezomib + Dexamethasone) (χ2 = 6.333, p < 0.05), suggesting fewer complications with the BCD regimen. (4) The clinical treatment effects analysis indicated that the BCD group demonstrated a more significant impact than the BD group in the treatment of MM.

CONCLUSION

The application of the BCD regimen in the treatment of MM has shown significant efficiency, effectively alleviating clinical symptoms with fewer adverse reactions and high safety.

Global, regional, and national burden and quality of care of multiple myeloma, 1990-2019

Background

Multiple myeloma (MM) is the second most common haematologic malignancy, presenting a great disease burden on the general population; however, the quality of care of MM is overlooked. We therefore assessed gains and disparity in quality of care worldwide from 1990 to 2019 based on a novel summary indicator - the quality of care index (QCI) - and examined its potential for improvement.

Methods

Using the Global Burden of Disease 2019 data set, we calculated the QCI of MM for 195 countries and territories. We used the principal component analysis to extract the first principal component of ratios with the combinations of mortality to incidence, prevalence to incidence, disability-adjusted life years to prevalence, and years of life lost to years lived with disability as QCI. We also conducted a series of descriptive and comparative analyses of QCI disparities with age, gender, period, geographies, and sociodemographic development, and compared the QCI among countries with similar socio-demographic index (SDI) through frontier analysis.

Results

The age-standardised rates of MM were 1.92 (95% uncertainty interval (UI) = 1.68, 2.12) in incidence and 1.42 (95% UI = 1.24, 1.52) in deaths per 100 000 population in 2019, and were predicted to increase in the future. The global age-standardised QCI increased from 51.31 in 1990 to 64.28 in 2019. In 2019, New Zealand had the highest QCI at 99.29 and the Central African Republic had the lowest QCI at 10.74. The gender disparity of QCI was reduced over the years, with the largest being observed in the sub-Saharan region. Regarding age, QCI maintained a decreasing trend in patients aged >60 in SDI quintiles. Generally, QCI improved with the SDI increase. Results of frontier analysis suggested that there is a potential to improve the quality of care across all levels of development spectrum.

Conclusions

Quality of care of MM improved during the past three decades, yet disparities in MM care remain across different countries, age groups, and genders. It is crucial to establish local objectives aimed at enhancing MM care and closing the gap in health care inequality.

Overall Survival in Patients With Multiple Myeloma in the U.S.: A Systematic Literature Review of Racial Disparities

Multiple myeloma (MM) accounts for 10% of hematologic cancers in the U.S.; however, incidence and mortality occur disproportionately between racial groups in real-world settings. Our study's objective was to systematically characterize the disparities in overall survival (OS) among Black and White patients with MM in the US using real-world evidence studies. A systematic literature review was undertaken by searching Embase and MEDLINE for observational studies conducted in the US, published between January 1, 2015 and October 25, 2021, and reporting OS for Black and White patients with MM. Records were reviewed by 2 independent researchers. OS data were extracted as hazard ratios (HR), median survival, or %, with methods of adjustment, as reported. Evidence quality was assessed by data source, population, and variables for which HRs for risk of death were adjusted. We included 33 US studies comprising 410,086 patients (21.5% Black; 78.5% White) with MM. Receipt of treatment varied; however, most studies reported that patients either underwent stem cell transplant and/or received systemic therapy. HRs from 9 studies were considered "high quality" by comparing nationally representative, generalizable cohorts and adjusting for key prognostic, treatment, and/or socioeconomic factors. After adjustment, these data suggested that Black patients exhibit similar or superior survival outcomes compared with their White counterparts. When data are adjusted for important confounders, Black patients exhibit better or equal survival to White patients, indicating that similarities in patient populations and equal access to treatment can bridge the disparity in patient outcomes between races.

Optimal timing and drug combination of selinexor in multiple myeloma: a systematic review and meta-analysis

OBJECTIVES

Multiple myeloma (MM) remains an incurable disease despite advances in treatment options. Recently, selinexor has shown promising efficacy for relapsed/refractory multiple myeloma (RRMM), whereas its optimal timing and drug combination remain unclear. In order to assess the various regimens that incorporate selinexor, a systematic review and meta-analysis was conducted.

METHODS

Clinical trials and real-world studies involving MM patients treated with selinexor were included. Pooled risk ratio (RR) was calculated to compare the rates, along with a 95% confidence interval (CI) and concurrent p-value assessment. A random-effects model was employed to provide a more conservative evaluation.

RESULTS

A total of 16 studies enrolling 817 patients were reviewed. The usage of selinexor as the fifth-line or prior therapy achieved a higher objective response rate (ORR) (65.9% versus 23.4%, p < 0.01) and longer pooled progression-free survival (PFS) (median: 12.5 months versus 2.9 months, p < 0.01) than those after the fifth-line usage. In addition, early usage also resulted in a consistent trend of pooled overall survival (median: 22.7 months versus 8.9 months, p = 0.26), compared with post-fifth-line usage. Selinexor and dexamethasone (Xd) plus either protease inhibitors (PIs) or immunomodulatory drugs (IMiDs) achieved better ORRs than the Xd-only regimen for RRMM, with ORRs of 56.1%, 52.5% and 24.6%, respectively (p < 0.01).

CONCLUSION

In conclusion, using selinexor as the fifth-line or prior therapy had a beneficial impact on RRMM. The regimen of Xd plus PIs or IMiDs was recommended.

Immune checkpoint inhibitors for multiple myeloma immunotherapy

Multiple myeloma (MM) is related to immune disorders, recent studys have revealed that immunotherapy can greatly benefit MM patients. Immune checkpoints can negatively modulate the immune system and are closely associated with immune escape. Immune checkpoint-related therapy has attracted much attention and research in MM. However, the efficacy of those therapies need further improvements. There need more thoughts about the immune checkpoint to translate their use in clinical work. In our review, we aggregated the currently known immune checkpoints and their corresponding ligands, further more we propose various ways of potential translation applying treatment based on immune checkpoints for MM patients.

Advances in the management of myeloma: an update

Myeloma is an aggressive B-cell malignancy resulting from an uncontrolled production of plasma cells in the bone marrow. A multitude of drugs and combinations of drugs are now approved for use to treat this complex disease and nurses require knowledge and skills in recognising and managing new side effects associated with these treatments. This article presents an overview of some of the newer and recently approved drugs and the important side effects that have been associated with them. Clinical nurse specialists and advanced nurse practitioners are at the forefront of patients' treatment journeys and play a central role in supporting patients and families to manage side effects. Through this support, patients can continue the treatments for as long as possible with the aim of maintaining a good quality of life.

The present roles and future perspectives of Interleukin-6 in biliary tract cancer

Biliary tract cancer (BTC) is a highly malignant tumor that originates from bile duct epithelium and is categorized into intrahepatic cholangiocarcinoma (iCCA), perihilar cholangiocarcinoma (pCCA), distal cholangiocarcinoma (dCCA) and gallbladder cancer (GBC) according to the anatomic location. Inflammatory cytokines generated by chronic infection led to an inflammatory microenvironment which influences the carcinogenesis of BTC. Interleukin-6 (IL-6), a multifunctional cytokine secreted by kupffer cells, tumor-associated macrophages, cancer-associated fibroblasts (CAFs) and cancer cells, plays a central role in tumorigenesis, angiogenesis, proliferation, and metastasis in BTC. Besides, IL-6 serves as a clinical biomarker for diagnosis, prognosis, and monitoring for BTC. Moreover, preclinical evidence indicates that IL-6 antibodies could sensitize tumor immune checkpoint inhibitors (ICIs) by altering the number of infiltrating immune cells and regulating the expression of immune checkpoints in the tumor microenvironment (TME). Recently, IL-6 has been shown to induce programmed death ligand 1 (PD-L1) expression through the mTOR pathway in iCCA. However, the evidence is insufficient to conclude that IL-6 antibodies could boost the immune responses and potentially overcome the resistance to ICIs for BTC. Here, we systematically review the central role of IL-6 in BTC and summarize the potential mechanisms underlying the improved efficacy of treatments combining IL-6 antibodies with ICIs in tumors. Given this, a future direction is proposed for BTC to increase ICIs sensitivity by blocking IL-6 pathways.

Overcoming proteasome inhibitor resistance in the immunotherapy era

Proteasome inhibitors (PIs) are a fascinating class of small molecules that disrupt protein homeostasis and are highly efficacious in the blood cancer multiple myeloma. However, PIs are not curative, and overcoming PI resistance to extend patient survival remains a major unmet need. Recent strategies to overcome PI resistance, including inhibiting alternative protein homeostasis pathways and targeting the mitochondrion as a nexus of metabolic adaptation to PIs, are gaining momentum. However, these focused approaches may be surpassed or even obviated by quickly emerging immunotherapy strategies that do not selectively target PI resistance mechanisms but are highly efficacious in PI-resistant disease, nonetheless. Informed by insights from these promising areas of research moving in parallel, we propose that pharmacological strategies to enforce immunotherapeutic vulnerabilities in resistant disease may provide a unified outlook to overcome PI resistance in a 'new era' of myeloma treatment.

A Reliable and Effective UPLC-MS/MS Method for the Determination of Oprozomib in Rat Plasma

Oprozomib, as a second-generation orally bioavailable protease inhibitor (PI), is undergoing clinical evaluation for the treatment of haematological malignancies. In relapsed refractory multiple myeloma (RRMM) patients, oprozomib has shown good efficacy as a single agent or combination therapy. In this experiment, our purpose was to validate a sensitive and rapid method for the determination of oprozomib concentration in rat plasma by ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The samples were treated with acetonitrile as the precipitant and separated by gradient elution using a Waters Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm). Using the selective reaction monitoring (SRM) method, the measurement was finished with the ion transitions of m/z 533.18 ⟶ 199.01 for oprozomib and m/z 493.03 ⟶ 112.03 for tepotinib (internal standard, IS), respectively. Meanwhile, acetonitrile and 0.1% formic acid aqueous solution were used as the mobile phase, and the flow rate was 0.3 mL/min. The lower limit of quantification (LLOQ) of the method was 1.0 ng/mL, and the linear relationship was good in the range of 1.0-100 ng/mL. In addition, the precision of four concentration levels was determined with the values of 3.1-7.3% and the accuracy was from -14.9% to 12.9%. Moreover, the recovery was determined to be from 85.1% to 96.1%, and the values of matrix effect were no more than 110.4%. The optimized UPLC-MS/MS method was also suitable for the pharmacokinetic study of rats after a single oral administration of 21 mg/kg oprozomib.

Therapeutic strategies to enhance immune response induced by multiple myeloma cells

Multiple myeloma (MM)as a haematological malignancy is still incurable. In addition to the presence of somatic genetic mutations in myeloma patients, the presence of immunosuppressive microenvironment greatly affects the outcome of treatment. Although the discovery of immunotherapy makes it possible to break the risk of high toxicity and side effects of traditional chemotherapeutic drugs, there are still obstacles of ineffective treatment or disease recurrence. In this review, we discuss therapeutic strategies to further enhance the specific anti-tumor immune response by activating the immunogenicity of MM cells themselves. New ideas for future myeloma therapeutic approaches are provided.

Real-world effectiveness and safety of multiple myeloma treatments based on thalidomide and bortezomib: A retrospective cohort study from 2009 to 2020 in a Brazilian metropolis

BACKGROUND

Multiple myeloma (MM) is an incurable cancer of plasma cells; the survival of which has improved over the years with the emergence of new treatments. In Brazil, the availability of treatment-regimens is different from developed countries. Real-world evidence with Brazilian patients is lacking.

OBJECTIVES

Our aim was to evaluate the effectiveness and the safety of MM treatments in a Brazilian metropolis.

METHODS

This was a retrospective cohort study with MM patients, beginning MM treatment from 2009 to 2020 (i.e., before bortezomib became available in public health services). Patients' medical records were revised to obtain clinical variables. The primary outcomes were Overall Survival (OS) and Progression Free Survival (PFS, measured as time to next treatment), and the secondary outcomes were Adverse Events (AE). Kaplan-Meier curves were obtained and the Cox proportional hazards model was performed for univariate and multivariate analyses. The incidence of AE was estimated and the chi-squared test was performed to evaluate the association between AE and MM regimens.

RESULTS

In total, 278 patients participated in the study with median age of 64 years; 50.4 % were females, 55.8 % attended a private clinic, 34.9 % received autologous stem cell transplantation (ASCT) and 32.4 % were on polypharmacy. Most patients from public services used thalidomide-based regimens (40.3 %) and at private clinics used bortezomib-based regimens (38.1 %) as first-line treatment. Patients had a median OS of 99 months. Patients had median PFS of 28 months in first-line treatment, which was significantly different for age (p = 0.0055), polypharmacy (p = 0.0094) and ASCT (p < 0.0001). PFS was independently associated to polypharmacy and ASCT. The incidence of peripheral neuropathy (39.6 %) was high. In contrast, the incidence of severe AE was low. We found significant difference between first-line T + B-based regimens and leukopenia (p = 0.012).

CONCLUSION

Our study showed that patients on polypharmacy and who did not receive ASCT had worse PFS. Similar to other Latin countries, most patients used thalidomide- and bortezomib-based regimens as first-line treatments having similar OS and PFS. Treatments were considered relatively safe, especially regarding serious AE.

Cost effectiveness analysis of CAR-T cell therapy for patients with relapsed/refractory multiple myeloma in China

BACKGROUND

The landscape of treatment strategies for relapsed/refractory multiple myeloma (RRMM) has dramatically changed due to the emergence of chimeric antigen receptor T (CAR-T) cell therapy. The aim of this study was to evaluate the cost-effectiveness of two CAR-T cell treatments for RRMM patients from the perspective of the Chinese healthcare system.

METHODS

Markov model was used to compare currently available salvage chemotherapy with Idecabtagene vicleucel (Ide-cel) and Ciltacabtagene autoleucel (Cilta-cel) for treatment of patients with RRMM. The model was developed based on data from three studies: CARTITUDE-1, KarMMa and MAMMOTH. The healthcare cost and utility of RRMM patients were collected from a provincial clinical center in China.

RESULTS

In the base case analysis, 3.4% and 30.6% of RRMM patients were expected to be long-term survivors after 5 years of Ide-cel and Cilta-cel treatment, respectively. Compared to salvage chemotherapy, Ide-cel and Cilta-cel were associated with incremental QALYs of 1.19 and 3.31, and incremental costs of US $140,693 and $119,806, leading to ICERs of $118,229 and $36,195 per QALY, respectively. At an ICER threshold of $37,653/QALY gained, the probability that Ide-cel and Cilta-cel are cost-effective were estimated to be 0% and 72%, respectively. With younger target people entering the model, and partitioned survival model in scenario analysis, the ICERs of Cilta-cel and Ide-cel changed rather mildly and their cost-effectiveness results were same to base analysis.

CONCLUSIONS

Base on the willingness-to-pay of 3 times China's per capita GDP in 2021, Cilta-cel was considered to be a more cost-effective option compared to salvage chemotherapy for RRMM in China, while Ide-cel was not.

Calcium silicate/bortezomib combinatory therapy for multiple myeloma

Multiple myeloma (MM) is the second most common hematologic malignancy. Bortezomib (BOR), a first-generation proteasome inhibitor, is the basic agent for the treatment of MM and has greatly improved the survival of patients with MM. However, the side effects of BOR (e.g. peripheral neuropathy) occur frequently and almost all MM patients eventually develop resistance to BOR and go on to develop refractory relapsed multiple myeloma (RRMM). Therefore, it is of great significance to find a method to increase the sensitivity of MM to BOR to reduce toxicity and drug resistance. Herein, we found that calcium silicate (CS), a silicate bioceramic that releases Si ions (SIs), enhanced the BOR anti-myeloma effect in vitro in human myeloma cell lines (HMCLs), including BOR-resistant cell lines (U266/BOR). The enhanced anti-myeloma effect of these two agents was demonstrated in primary MM cells regardless of disease status and in MM xenograft mice. Mechanistically, SI enhanced G2/M cell cycle arrest and the inhibition of the NF-κB pathway induced by BOR. These results imply that the combination of SI and BOR (SI/BOR) is a promising way to overcome BOR resistance in MM and RRMM. The future use of nanotechnology to prepare CS nanomaterials as BOR carriers for the treatment of MM and RRMM is a very promising clinical application.

BDNF/TrkB confers bortezomib resistance in multiple myeloma by inducing BRINP3

BACKGROUND

The proteasome inhibitor bortezomib (BTZ) has significantly improved the survival of multiple myeloma (MM) patients. However, most MM patients still relapse and have drug resistance after BTZ treatment.

METHODS

siRNA transfection was performed to knock down BDNF and TrkB expression. ELISA, western blot, quantitative polymerase chain reaction, CCK-8 assay, and flow cytometry analysis were performed to analyze the functions of BDNF/TrkB signaling in MM cells.

RESULTS

We identified a cell-autonomous mechanism that promotes BTZ resistance in MM, prolongs their RPMI 8226/BTZ resistant cell survival and optimizes their proliferating function. Specifically, RPMI 8226/BTZ cells produced the brain derived neurotrophic factor (BDNF) and its receptor TrkB, which served as a survival factor in the RPMI 8226/BTZ resistant environment. BDNF/TrkB induced phosphorylation of STAT3 that upregulated the bone morphogenetic protein/retinoic acid inducible neural-specific 3 (BRINP3).

CONCLUSIONS

BDNF/TrkB enhanced downstream pathway expression of phosphorylation STAT3 and BRINP3 molecules, promoting RPMI 8226/BTZ cell proliferation and survival.

GENERAL SIGNIFICANCE

These data place BDNF/TrkB at the top of a pSTAT3-BRINP3 survival pathway and link adaptability to BTZ resistant conditions in MM disease.

Interleukin-32γ promotes macrophage-mediated chemoresistance by inducing CSF1-dependent M2 macrophage polarization in multiple myeloma

Macrophages (MΦs) are an abundant component in the multiple myeloma (MM) environment and contribute to MM drug resistance. We previously showed that interleukin-32 (IL-32) is highly expressed in MM patients and induces the immunosuppressive function of MΦs. The present study was designed to explore the role of IL-32 in MΦ-mediated MM drug resistance and the underlying mechanism. Our analysis revealed that IL-32 expression was upregulated in relapsed MM patients and associated with CD206⁺ M2 MΦ infiltration. Subsequently, we found that the most active isoform, IL-32γ, promoted MΦs to protect MM cells from drug-induced apoptosis both in vitro and in vivo. Furthermore, by evaluating many parameters, including surface markers, cytokines, metabolic enzymes and characteristic molecules, IL-32γ was verified to induce the polarization of M2 MΦs, a function that was partly dependent on increasing the expression of colony-stimulating factor 1 (CSF1). Taken together, the results of our study indicate that IL-32γ promotes MΦ-mediated MM drug resistance and modifies MΦs toward the M2 phenotype, providing a crucial theoretical basis for targeted MΦ immunotherapy.

Cytokine profiles are associated with prolonged hematologic toxicities after B-cell maturation antigen targeted chimeric antigen receptor-T-cell therapy

BACKGROUND AIMS

The considerable efficacy of B-cell maturation antigen-targeted chimeric antigen receptor (CAR)-T-cell therapy has been extensively demonstrated in the treatment of relapsed or refractory multiple myeloma. Nevertheless, in clinical practice, prolonged hematologic toxicity (PHT) extends hospital stay and impairs long-term survival.

METHODS

This retrospective study reviewed 99 patients with relapsed or refractory multiple myeloma who underwent B-cell maturation antigen CAR-T-cell therapy at our institution between April 2018 and September 2021 (ChiCTR1800017404).

RESULTS

Among 93 evaluable patients, the incidence of prolonged hematologic toxicities was high after CAR-T-cell infusion, including 38.71% (36/93) of patients with prolonged neutropenia, 22.58% (21/93) with prolonged anemia and 59.14% (55/93) with prolonged thrombocytopenia. In addition, 9.68% (9/93) of patients experienced prolonged pancytopenia. Our multivariate analyses identified that cytokine profiles were independent risk factors for PHTs, whereas a sufficient baseline hematopoietic function and high CD4/CD8 ratio of CAR-T cells were protective factors for PHTs after CAR-T-cell infusion. Subgroup analyses found that the kinetics of post-CAR-T hematologic parameters were primarily determined by the collective effects of cytokine release syndrome and baseline hematopoietic functions, and showed influential weights for the three lineages.

CONCLUSIONS

Our findings improve the understanding of the impact of cytokines on hematopoietic functions, which could contribute to the mechanism investigation and exploration of potential intervention strategies.

Vitamin D deficiency linked to abnormal bone and lipid metabolism predicts high-risk multiple myeloma with poorer prognosis

Purpose

Vitamin D deficiency is frequent in patients with multiple myeloma (MM), however, its prognostic relevance in MM was rather inconclusive. We first investigated the association of vitamin D deficiency with abnormal bone and lipid metabolism in newly diagnosed multiple myeloma (NDMM), and next assessed the impact of serum ratio of vitamin D to carboxy-terminal telopeptide of type I collagen (β-CTX) on progression-free survival (PFS) and overall free survival (OS) in patients with NDMM.

Methods

The data of 431 consecutive patients with NDMM at Beijing Jishuitan Hospital from September 2013 to December 2022 were collected and retrospectively reviewed through our electronic medical record system. The measurement of 25-hydroxyvitamin D in the blood is an indicator of an individual's overall vitamin D status.

Results

The serum levels of vitamin D were negatively correlated with β-CTX in NDMM patients. Of note, positive correlation between vitamin D and cholesterol levels in the serum was found in this study. The cohort (n = 431) was divided into two groups based on the serum ratio of vitamin D to β-CTX. Compared to the group with a higher vitamin D to β-CTX ratio, the group with a lower vitamin D to β-CTX ratio (n = 257, 60%) exhibited hypocholesterolemia, inferior PFS and OS, along with increased cases of ISS stage-III and R-ISS stage-III, a higher number of plasma cells in the bone marrow, and elevated serum calcium levels. Consistent with this, multivariate analysis confirmed that the vitamin D to β-CTX ratio was an independent unfavorable indicator for survival in NDMM patients.

Conclusion

Our data demonstrated the ratio of vitamin D to β-CTX in the serum is a unique biomarker for NDMM patients to identify the high-risk cases with poor prognosis, which is superior to vitamin D itself for predicting PFS and OS in NDMM. Also, it is worth mentioning that our data on the connection between vitamin D deficiency and hypocholesterolemia might help clarify novel mechanistic aspects of myeloma development.

TGF-β: A novel predictor and target for anti-PD-1/PD-L1 therapy

Transforming growth factor-β (TGF-β) signaling regulates multiple physiological processes, such as cell proliferation, differentiation, immune homeostasis, and wound healing. Besides, TGF-β plays a vital role in diseases, including cancer. Accumulating evidence indicates that TGF-β controls the composition and behavior of immune components in the tumor microenvironment (TME). Advanced cancers leverage TGF-β to reshape the TME and escape immune surveillance. TGF-β-mediated immune evasion is an unfavorable factor for cancer immunotherapy, especially immune checkpoint inhibitors (ICI). Numerous preclinical and clinical studies have demonstrated that hyperactive TGF-β signaling is closely associated with ICI resistance. It has been validated that TGF-β blockade synergizes with ICI and overcomes treatment resistance. TGF-β-targeted therapies, including trap and bispecific antibodies, have shown immense potential for cancer immunotherapy. In this review, we summarized the predictive value of TGF-β signaling and the prospects of TGF-β-targeted therapies for cancer immunotherapy.

Current Status of Novel Agents for the Treatment of B Cell Malignancies: What's Coming Next?

Resistance to death is one of the hallmarks of human B cell malignancies and often contributes to the lack of a lasting response to today's commonly used treatments. Drug discovery approaches designed to activate the death machinery have generated a large number of inhibitors of anti-apoptotic proteins from the B-cell lymphoma/leukemia 2 family and the B-cell receptor (BCR) signaling pathway. Orally administered small-molecule inhibitors of Bcl-2 protein and BCR partners (e.g., Bruton's tyrosine kinase and phosphatidylinositol-3 kinase) have already been included (as monotherapies or combination therapies) in the standard of care for selected B cell malignancies. Agonistic monoclonal antibodies and their derivatives (antibody-drug conjugates, antibody-radioisotope conjugates, bispecific T cell engagers, and chimeric antigen receptor-modified T cells) targeting tumor-associated antigens (TAAs, such as CD19, CD20, CD22, and CD38) are indicated for treatment (as monotherapies or combination therapies) of patients with B cell tumors. However, given that some patients are either refractory to current therapies or relapse after treatment, novel therapeutic strategies are needed. Here, we review current strategies for managing B cell malignancies, with a focus on the ongoing clinical development of more effective, selective drugs targeting these molecules, as well as other TAAs and signaling proteins. The observed impact of metabolic reprogramming on B cell pathophysiology highlights the promise of targeting metabolic checkpoints in the treatment of these disorders.

Immunotherapy approaches for hematological cancers

Hematological cancers such as leukemia, lymphoma, and multiple myeloma have traditionally been treated with chemo and radiotherapy approaches. Introduction of immunotherapies for treatment of these diseases has led to patient remissions that would not have been possible with traditional approaches. In this critical review we identify main disease characteristics, symptoms, and current treatment options. Five common immunotherapies, namely checkpoint inhibitors, vaccines, cell-based therapies, antibodies, and oncolytic viruses, are described, and their applications in hematological cancers are critically discussed.

Real World Adherence to and Persistence With Oral Oncolytics in Multiple Myeloma: A Systematic Review and Meta-analysis

INTRODUCTION

Oral oncolytic treatments (OOTs) have improved the prognosis of patients with multiple myeloma (MM). However, the effectiveness of these therapies is undermined by poor adherence. We aimed to characterize the real-world adherence to, and persistence with, OOTs for MM.

MATERIALS AND METHODS

MEDLINE, EMBASE, and the International Pharmaceutical abstracts databases were searched for relevant observational studies published in English up to November 21, 2021. This was supplemented by manual searches of abstracts from the annual meetings of the American Society of Hematology, the American Society for Clinical Oncology, and the European Hematology Association as well as screening the references of included articles. Random-effects meta-analysis was performed.

RESULTS

Following screening of 11,557 articles, 19 studies involving 27,129 patients in 8 countries (France, the US, Germany, Italy, the UK, Brazil, South Korea, and Belgium) prescribed OOTs (lenalidomide, thalidomide, pomalidomide, panobinostat, ixazomib, and melphalan) for MM were included. The overall pooled proportion of adherent patients was 67.9% (95% confidence interval [CI]: 57.1%-77.8%). The pooled proportion of adherent patients was higher in self-reported questionnaire-based studies compared to those using prescription/dispensing data (81.6% vs. 61.0%; P-value for difference = .08). Across 5 studies involving 15,363 patients, a pooled proportion of 35.8% (95% CI: 22.0-50.9) discontinued treatment. Factors reported to be associated with nonadherence included increasing age, higher comorbidity, polypharmacy, and a lack of social support.

CONCLUSION

In patients with MM, adherence to and persistence with OOTs remains suboptimal. To achieve desired clinical outcomes, interventions to improve adherence and minimize discontinuation may be warranted.

AIMP1 promotes multiple myeloma malignancy through interacting with ANP32A to mediate histone H3 acetylation

BACKGROUND

Multiple myeloma (MM) is the second most common hematological malignancy. An overwhelming majority of patients with MM progress to serious osteolytic bone disease. Aminoacyl-tRNA synthetase-interacting multifunctional protein 1 (AIMP1) participates in several steps during cancer development and osteoclast differentiation. This study aimed to explore its role in MM.

METHODS

The gene expression profiling cohorts of MM were applied to determine the expression of AIMP1 and its association with MM patient prognosis. Enzyme-linked immunosorbent assay, immunohistochemistry, and Western blotting were used to detect AIMP1 expression. Protein chip analysis, RNA-sequencing, and chromatin immunoprecipitation and next-generation sequencing were employed to screen the interacting proteins and key downstream targets of AIMP1. The impact of AIMP1 on cellular proliferation was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in vitro and a xenograft model in vivo. Bone lesions were evaluated using tartrate-resistant acid phosphatase staining in vitro. A NOD/SCID-TIBIA mouse model was used to evaluate the effect of siAIMP1-loaded exosomes on bone lesion formation in vivo.

RESULTS

AIMP1 expression was increased in MM patients and strongly associated with unfavorable outcomes. Increased AIMP1 expression promoted MM cell proliferation in vitro and in vivo via activation of the mitogen-activated protein kinase (MAPK) signaling pathway. Protein chip assays and subsequent experiments revealed that AIMP1 interacted with acidic leucine-rich nuclear phosphoprotein 32 family member A (ANP32A) to regulate histone H3 acetylation. In addition, AIMP1 increased histone H3 acetylation enrichment function of GRB2-associated and regulator of MAPK protein 2 (GAREM2) to increase the phosphorylation of extracellular-regulated kinase 1/2 (p-ERK1/2). Furthermore, AIMP1 promoted osteoclast differentiation by activating nuclear factor of activated T cells c1 (NFATc1) in vitro. In contrast, exosome-coated small interfering RNA of AIMP1 effectively suppressed MM progression and osteoclast differentiation in vitro and in vivo.

CONCLUSIONS

Our data demonstrate that AIMP1 is a novel regulator of histone H3 acetylation interacting with ANP32A in MM, which accelerates MM malignancy via activation of the MAPK signaling pathway.

Recent developments on the application of molecular probes in multiple myeloma: Beyond [18F]FDG

Multiple myeloma (MM) is a neoplastic plasma cell proliferative disorder characterized by various osteolytic bone destruction as a radiological morphological marker. Functional imaging, particularly nuclear medicine imaging, is a promising method to visualize disease processes before the appearance of structural changes by targeting specific biomarkers related to metabolism ability, tumor microenvironment as well as neoplastic receptors. In addition, by targeting particular antigens with therapeutic antibodies, immuno-PET imaging can support the development of personalized theranostics. At present, various imaging agents have been prepared and evaluated in MM at preclinical and clinical levels. A summary overview of molecular functional imaging in MM is provided, and commonly used radiotracers are characterized.

Targeting macrophages in hematological malignancies: recent advances and future directions

Emerging evidence indicates that the detection and clearance of cancer cells via phagocytosis induced by innate immune checkpoints play significant roles in tumor-mediated immune escape. The most well-described innate immune checkpoints are the "don't eat me" signals, including the CD47/signal regulatory protein α axis (SIRPα), PD-1/PD-L1 axis, CD24/SIGLEC-10 axis, and MHC-I/LILRB1 axis. Molecules have been developed to block these pathways and enhance the phagocytic activity against tumors. Several clinical studies have investigated the safety and efficacy of CD47 blockades, either alone or in combination with existing therapy in hematological malignancies, including myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and lymphoma. However, only a minority of patients have significant responses to these treatments alone. Combining CD47 blockades with other treatment modalities are in clinical studies, with early results suggesting a synergistic therapeutic effect. Targeting macrophages with bispecific antibodies are being explored in blood cancer therapy. Furthermore, reprogramming of pro-tumor macrophages to anti-tumor macrophages, and CAR macrophages (CAR-M) demonstrate anti-tumor activities. In this review, we elucidated distinct types of macrophage-targeted strategies in hematological malignancies, from preclinical experiments to clinical trials, and outlined potential therapeutic approaches being developed.

SPAG5 as a novel biomarker and potential therapeutic target via regulating AKT pathway in multiple myeloma

SPAG5, as a spindle-associated protein in mitosis, has been observed to have oncogenic activities in solid tumors. Here, we identified that SPAG5 expression was correlated with the deterioration of plasma cell malignancy and SPAG5 overexpression (OE) predicted unfavorable outcomes in multiple myeloma (MM). SPAG5 knockdown led to anti-MM effects in MM cell lines and animal xenograft models by regulating cell growth and apoptosis. Furthermore, gene set enrichment analysis (GSEA) revealed that PI3K/AKT/mTOR pathway was enriched in MM samples with highly expressed SPAG5 from GSE datasets. There was a concurrent downregulation of phosphorylation levels in the AKT/mTOR pathway. Yet OE of SPAG5 could restore the cell growth and p-AKT levels in MM cells after treatment with the AKT inhibitor MK2206. Taken together, SPAG5 could serve as a novel biomarker, and targeting the SPAG5 might have therapeutic potential in MM.

Baseline peripheral neuropathy was associated with age and a prognostic factor in newly diagnosed multiple myeloma patients

Multiple myeloma (MM) is an incurable plasma cell hematological malignancy. Bortezomib has become the primary drug in the treatment of patients with MM. However, its negative effects, especially peripheral neuropathy (PN), affect the patients’ life quality and treatment continuity. However, there are few studies on baseline PN of MM, and little is known of the impact of baseline PN on the prognosis of MM patients. Therefore, we reviewed the clinical data of newly diagnosed MM patients in our center, explored the influencing factors of baseline PN, and evaluated PN’s influence on the prognosis of MM patients undergoing induction therapy with bortezomib. According to the inclusion and exclusion criteria, 155 MM patients were eligible for the retrospective study. The multivariate regression analysis, generalized additive fitting smooth curve, the receiver operating characteristic curve (ROC) and K-M curve were conducted in this study. We found that baseline PN in patients with MM was age-related; MM patients with baseline PN have more severe bortezomib induced PN (BiPN) during the four courses of induction therapy with bortezomib as the primary regimen and worse PN outcome after induction therapy. Additionally, the progression-free survival (PFS) and overall survival (OS) of MM patients with baseline PN were worse than those of the MM patients without baseline PN.

Targeting the oncogenic transcription factor c-Maf for the treatment of multiple myeloma

Multiple myeloma (MM) is a hematologic malignancy derived from clonal expansion of plasma cells within the bone marrow and it may progress to the extramedullary region in late stage of the disease course. c-Maf, an oncogenic zipper leucine transcription factor, is overexpressed in more than 50% MM cell lines and primary species in association with chromosomal translocation, aberrant signaling transduction and modulation of stability. By triggering the transcription of critical genes including CCND2, ITGB7, CCR1, ARK5, c-Maf promotes MM progress, proliferation, survival and chemoresistance. Notably, c-Maf is usually expressed at the embryonic stage to promote cell differentiation but less expressed in healthy adult cells. c-Maf has long been proposed as a promising therapeutic target of MM and a panel of small molecule compounds have been identified to downregulate c-Maf and display potent anti-myeloma activities. In the current article, we take a concise summary on the advances in c-Maf biology, pathophysiology, and targeted drug discovery in the potential treatment of MM.

Evaluation of Proteasome Inhibitors in the Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common form of idiopathic interstitial pneumonia, and it has a worse prognosis than non-small cell lung cancer. The pathomechanism of IPF is not fully understood, but it has been suggested that repeated microinjuries of epithelial cells induce a wound healing response, during which fibroblasts differentiate into myofibroblasts. These activated myofibroblasts express α smooth muscle actin and release extracellular matrix to promote matrix deposition and tissue remodeling. Under physiological conditions, the remodeling process stops once wound healing is complete. However, in the lungs of IPF patients, myofibroblasts re-main active and deposit excess extracellular matrix. This leads to the destruction of alveolar tissue, the loss of lung elastic recoil, and a rapid decrease in lung function. Some evidence has indicated that proteasomal inhibition combats fibrosis by inhibiting the expressions of extracellular matrix proteins and metalloproteinases. However, the mechanisms by which proteasome inhibitors may protect against fibrosis are not known. This review summarizes the current research on proteasome inhibitors for pulmonary fibrosis, and provides a reference for whether proteasome inhibitors have the potential to become new drugs for the treatment of pulmonary fibrosis.

Tetrahydrobiopterin induces proteasome inhibitor resistance and tumor progression in multiple myeloma

Multiple myeloma (MM) still remains an incurable disease due to widespread drug resistance and high frequency of relapse. In this study, we found that tetrahydrobiopterin (BH4) promotes MM cell proliferation and tumor growth in vivo. BH4 also increases MM bortezomib (Bor) resistance in vitro and in vivo. We show that BH4 increases the expressions of USP7 and USP46 in MM cells, which are responsible for MM Bor resistance primed by BH4. BH4 promotes the degradation of P53 and the activation of NF-κB signaling through the up-regulation of USP7 and USP46. Furthermore, the inhibition of USPs increases the therapeutic effects of Bor in MM tumor bearing mice. Our results demonstrate the important role of BH4 in MM Bor resistance and tumor progression in vivo. These findings could potentially have clinical implications.

Discovery of novel and orally bioavailable CDK 4/6 inhibitors with high kinome selectivity, low toxicity and long-acting stability for the treatment of multiple myeloma

Multiple myeloma (MM) ranks second in malignant hematopoietic cancers, and the most common anti-MM drugs easily generate resistance. CDK4/6 have been validated to play determinant roles in MM, but no remarkable progress has been obtained from clinical trials of CDK4/6 inhibitors for MM. To discover novel CDK6 inhibitors with better potency and high druggability, structure-based virtual screening was conducted to identify compound 10. Further chemical optimization afforded a better derivative, compound 32, which exhibited strong inhibition of CDK4/6 and showed high selectivity over 360+ kinases, including homologous CDKs. The in vivo evaluation demonstrated that compound 32 possessed low toxicity (LD₅₀ > 10,000 mg/kg), favorable bioavailability (F% = 51%), high metabolic stability (t_1/2 > 24 h) and strong anti-MM potency. In summary, we discovered a novel CDK4/6 inhibitor bearing favorable drug-like properties and offered a great candidate for MM preclinical studies.

The changing landscape of relapsed and/or refractory multiple myeloma (MM): fundamentals and controversies

The increase in the number of therapeutic alternatives for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM) patients has widened the clinical scenario, leading to a level of complexity that no algorithm has been able to cover up to date. At present, this complexity increases due to the wide variety of clinical situations found in MM patients before they reach the status of relapsed/refractory disease. These different backgrounds may include primary refractoriness, early relapse after completion of first-line therapy with latest-generation agents, or very late relapse after chemotherapy or autologous transplantation. It is also important to bear in mind that many patient profiles are not fully represented in the main randomized clinical trials (RCT), and this further complicates treatment decision-making. In RRMM patients, the choice of previously unused drugs and the number and duration of previous therapeutic regimens until progression has a greater impact on treatment efficacy than the adverse biological characteristics of MM itself. In addition to proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies and corticosteroids, a new generation of drugs such as XPO inhibitors, BCL-2 inhibitors, new alkylators and, above all, immunotherapy based on conjugated anti-BCMA antibodies and CAR-T cells, have been developed to fight RRMM. This comprehensive review addresses the fundamentals and controversies regarding RRMM, and discusses the main aspects of management and treatment. The basis for the clinical management of RRMM (complexity of clinical scenarios, key factors to consider before choosing an appropriate treatment, or when to treat), the arsenal of new drugs with no cross resistance with previously administered standard first line regimens (main phase 3 clinical trials), the future outlook including the usefulness of abandoned resources, together with the controversies surrounding the clinical management of RRMM patients will be reviewed in detail.

RNA demethylase ALKBH5 promotes tumorigenesis in multiple myeloma via TRAF1-mediated activation of NF-κB and MAPK signaling pathways

N⁶-methyladenosine (m⁶A), an internal modification in mRNA, plays a critical role in regulating gene expression. Dysregulation of m⁶A modifiers promotes oncogenesis through enzymatic functions that disrupt the balance between the deposition and removal of m⁶A modification on critical transcripts. However, the roles of mRNA m⁶A in multiple myeloma (MM) are poorly understood. The present study showed that RNA demethylase ALKBH5 was overexpressed in MM and associated with a poor prognosis in MM patients. Knocking down ALKBH5 induced apoptosis and inhibited the growth of MM cells in vitro. Xenograft models and gene set enrichment analysis with patient transcriptome datasets also supported the oncogenic role of ALKBH5 in MM. Mechanistic studies showed that ALKBH5 exerted tumorigenic effects in myeloma in an m⁶A-dependent manner, and TNF receptor-associated factor 1 (TRAF1) was a critical target of ALKBH5. Specifically, ALKBH5 regulated TRAF1 expression via decreasing m⁶A abundance in the 3'-untranslated region (3'-UTR) of TRAF1 transcripts and enhancing TRAF1 mRNA stability. As a result, ALKBH5 promoted MM cell growth and survival through TRAF1-mediated activation of NF-κB and MAPK signaling pathways. Collectively, our data demonstrated that ALKBH5 played a critical role in MM tumorigenesis and suggested that ALKBH5 could be a novel therapeutic target in MM.

Cost-effectiveness of daratumumab in combination with lenalidomide and dexamethasone for relapsed and/or refractory multiple myeloma

OBJECTIVE

This study evaluates the cost-effectiveness of daratumumab (D) in combination with lenalidomide and dexamethasone (Rd) for treatment of relapsed and/or refractory multiple myeloma in patients who have received at least one prior therapy in Singapore.

METHODS

A 3-state partitioned survival model was developed to evaluate the cost-effectiveness of lenalidomide and dexamethasone with or without daratumumab from a healthcare system perspective over 10 years. Clinical inputs were obtained from the POLLUX trial. Health state utilities were derived from the literature and direct medical costs obtained from public healthcare institutions. Sensitivity and scenario analyses were conducted to explore uncertainties.

RESULTS

DRd was associated with a high base-case incremental cost-effectiveness ratio (ICER) of US$576,247 per quality-adjusted life year (QALY) gained, compared with Rd. According to one-way sensitivity analysis, ICER was most heavily influenced by time horizon, discount rate for outcomes, progression-free utility and cost of daratumumab. Regardless of the variation, DRd remained not cost-effective. Even when the cost of both daratumumab and lenalidomide dropped by 20% and 80%, the ICERs remained high at US$470,400 and US$152,860 per QALY gained.

CONCLUSIONS

At current prices, the addition of daratumumab to lenalidomide and dexamethasone does not represent cost-effective use of healthcare resources in Singapore.

Genome Instability in Multiple Myeloma: Facts and Factors

Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-producing B lymphocytes called plasma cells. MM is the second most common hematologic malignancy, and it poses a heavy economic and social burden because it remains incurable and confers a profound disability to patients. Despite current progress in MM treatment, the disease invariably recurs, even after the transplantation of autologous hematopoietic stem cells (ASCT). Biological processes leading to a pathological myeloma clone and the mechanisms of further evolution of the disease are far from complete understanding. Genetically, MM is a complex disease that demonstrates a high level of heterogeneity. Myeloma genomes carry numerous genetic changes, including structural genome variations and chromosomal gains and losses, and these changes occur in combinations with point mutations affecting various cellular pathways, including genome maintenance. MM genome instability in its extreme is manifested in mutation kataegis and complex genomic rearrangements: chromothripsis, templated insertions, and chromoplexy. Chemotherapeutic agents used to treat MM add another level of complexity because many of them exacerbate genome instability. Genome abnormalities are driver events and deciphering their mechanisms will help understand the causes of MM and play a pivotal role in developing new therapies.

Quercetin inhibits the proliferation of multiple myeloma cells by upregulating PTPRR expression

Multiple myeloma (MM) is an incurable disease characterized by malignant plasma cell clonal expansion in the bone marrow; therefore, inhibiting the proliferation of plasma cells is an important approach to overcome the progression of MM. Quercetin (Que) is a promising flavonoid with broad-spectrum anti-tumor activity against various cancers, including MM; however, the underlying mechanism is not yet understood. The present study aimed to reveal the gene expression profile of Que-treated MM cells and clarify its potential mechanism. The 30% inhibitory concentration (IC30) of Que against MM cells was calculated, and the proliferation rate was significantly reduced after Que treatment. Next, 495 dysregulated genes were identified via RNA sequencing in Que-treated MM cells. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses indicated that the dysregulated genes were enriched in various apoptosis-related GO terms and amino acid metabolism-related pathways. qPCR validation showed that protein tyrosine phosphatase receptor-type R (PTPRR) had the highest verified log2 FC (abs) among the top 15 dysregulated genes. Overexpression of PTPRR increased the sensitivity of MM cells against Que, significantly inhibiting their proliferation and colony formation ability; silencing of PTPRR showed the opposite results. Furthermore, bioinformatics analyses and PPI network construction of PTPRR indicated that dephosphorylation of ERK might be the potential pathway for the PTPRR-induced inhibition of MM cell proliferation. In summary, our study identified the gene expression profile in Que-treated MM cells and demonstrated that the upregulation of PTPRR was one of the important mechanisms for the Que-induced inhibition of MM cell proliferation.

Minimal residual disease in multiple myeloma: current status

Multiple myeloma (MM) is a treatable plasma cell cancer with no cure. Clinical evidence shows that the status of minimal residual disease (MRD) after treatment is an independent prognostic factor of MM. MRD indicates the depth of post-therapeutic remission. In this review article, we outlined the major clinical trials that have determined the prognostic value of MRD in MM. We also reviewed different methods that were used for MM MRD assessment. Most important, we reviewed our current understanding of MM MRD biology. MRD studies strongly indicate that MRD is not a uniform declination of whole MM tumor population. Rather, MM MRD exhibits unique signatures of cytogenetic aberration and gene expression profiles, unlike those of MM cells before therapy. Diagnostic high-risk MM and low-risk MM exhibited a diversity of MRD features. Clonal evaluation may occur at the MRD stage in MM. The dynamics from the diagnostic MM to MRD correlate with the disease prognosis. Lastly, on the aspect of omics, we performed data-based analysis to address the biological features underlying the course of diagnostic-to-MRD MM. To summarize, the MRD stage of disease represents a critical step in MM pathogenesis and progression. Demonstration of MM MRD biology should help us to deal with the curative difficulties.

Small-Molecule Inhibitors Overcome Epigenetic Reprogramming for Cancer Therapy

Cancer treatment is a significant challenge for the global health system, although various pharmacological and therapeutic discoveries have been made. It has been widely established that cancer is associated with epigenetic modification, which is reversible and becomes an attractive target for drug development. Adding chemical groups to the DNA backbone and modifying histone proteins impart distinct characteristics on chromatin architecture. This process is mediated by various enzymes modifying chromatin structures to achieve the diversity of epigenetic space and the intricacy in gene expression files. After decades of effort, epigenetic modification has represented the hallmarks of different cancer types, and the enzymes involved in this process have provided novel targets for antitumor therapy development. Epigenetic drugs show significant effects on both preclinical and clinical studies in which the target development and research offer a promising direction for cancer therapy. Here, we summarize the different types of epigenetic enzymes which target corresponding protein domains, emphasize DNA methylation, histone modifications, and microRNA-mediated cooperation with epigenetic modification, and highlight recent achievements in developing targets for epigenetic inhibitor therapy. This article reviews current anticancer small-molecule inhibitors targeting epigenetic modified enzymes and displays their performances in different stages of clinical trials. Future studies are further needed to address their off-target effects and cytotoxicity to improve their clinical translation.

A phase 2, open-label, multicenter study of ixazomib plus lenalidomide and dexamethasone in adult Japanese patients with relapsed and/or refractory multiple myeloma

Background

TOURMALINE-MM1 was a global study that demonstrated a significant improvement in progression-free survival with ixazomib plus lenalidomide and dexamethasone compared with placebo plus lenalidomide and dexamethasone, in patients with relapsed and/or refractory multiple myeloma. The current study was conducted to evaluate further the efficacy and safety of ixazomib plus lenalidomide and dexamethasone in Japanese patients.

Methods

This phase 2, open-label, single-arm, multicenter study enrolled patients aged ≥ 20 years with relapsed and/or refractory multiple myeloma at 16 sites in Japan. Patients refractory to lenalidomide or proteasome inhibitor-based therapy at any line were excluded. The primary endpoint was the rate of very good partial response or better in the response-evaluable analysis set. Secondary endpoints were progression-free survival, overall response rate, duration of response, time to progression, overall survival and safety.

Results

In total, 34 patients were enrolled. The rate of very good partial response or better was 50.0% (95% confidence interval 31.9–68.1) and the overall response rate was 84.4% (95% confidence interval 67.2–94.7). Median progression-free survival was 22.0 months (95% confidence interval 17.3–not evaluable) and median overall survival was not estimable. The safety profile of ixazomib plus lenalidomide and dexamethasone in this study was similar to that in the TOURMALINE-MM1 study.

Conclusions

The efficacy and safety of ixazomib plus lenalidomide and dexamethasone in Japanese patients with relapsed and/or refractory multiple myeloma are comparable with reported TOURMALINE-MM1 study results.

Clinicaltrials.gov identifier

NCT02917941; date of registration September 28, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-021-02030-7.

Targeting the Interplay between HDACs and DNA Damage Repair for Myeloma Therapy

Multiple myeloma (MM) is a malignancy of terminally differentiated plasma cells, and accounts for 10% of all hematologic malignancies and 1% of all cancers. MM is characterized by genomic instability which results from DNA damage with certain genomic rearrangements being prognostic factors for the disease and patients’ clinical response. Following genotoxic stress, the evolutionary conserved DNA damage response (DDR) is activated and, in turn, coordinates DNA repair with cell-cycle events. However, the process of carcinogenesis cannot be attributed only to the genetic alterations, but also involves epigenetic processes. Regulation of expression and activity of key players in DNA repair and checkpoint proteins are essential and mediated partly by posttranslational modifications (PTM), such as acetylation. Crosstalk between different PTMs is important for regulation of DNA repair pathways. Acetylation, which is mediated by acetyltransferases (HAT) and histone deacetylases (HDAC), not only affects gene expression through its modulation of histone tails but also has recently been implicated in regulating non-histone proteins. Currently, several HDAC inhibitors (HDACi) have been developed both in pre-clinical and clinical studies, with some of them exhibiting significant anti-MM activities. Due to reversibility of epigenetic changes during the evolutionary process of myeloma genesis, the potency of epigenetic therapies seems to be of great importance. The aim of the present paper is the summary of all data on the role of HDACi in DDR, the interference with each DNA repair mechanism and the therapeutic implications of HDACi in MM.

CAR-T therapy alters synthesis of platelet-activating factor in multiple myeloma patients

The chimera antigen receptor (CAR) T cell therapy is a novel and potential targeted therapy and has achieved satisfactory efficacy in patients with relapsed or refractory multiple myeloma (MM) in recent years. However, cytokine release syndrome (CRS) and clinical efficacy have become the major obstacles which limit the application of CAR-T in clinics. To explore the potential biomarkers in plasma for evaluating CRS and clinical efficacy, we performed metabolomic and lipidomic profiling of plasma samples from 17 relapsed or refractory MM patients received CAR-T therapy. Our study showed that glycerophosphocholine (GPC), an intermediate of platelet-activating factor (PAF)-like molecule, was significantly decreased when the participants underwent CRS, and the remarkable elevation of lysophosphatidylcholines (lysoPCs), which were catalyzed by lysoPC acyltransferase (LPCAT) was a distinct metabolism signature of relapsed or refractory MM patients with prognostic value post-CAR-T therapy. Both GPC and lysoPC are involved in platelet-activating factor (PAF) remodeling pathway. Besides, these findings were validated by LPCAT1 expression, a key factor in the PAF pathway, associated with poor outcome in three MM GEP datasets of MM. In conclusion, CAR-T therapy alters PAF synthesis in MM patients, and targeting PAF remodeling may be a promising strategy to enhance MM CAR-T therapy.

Proteasomal adaptations to FDA-approved proteasome inhibitors: a potential mechanism for drug resistance?

With proteasome inhibitors (PIs) becoming clinically available since 2003, outcomes for patients with multiple myeloma (MM) have dramatically changed, improving quality of life and survival. Despite the impressive treatment success, however, almost all MM patients who initially respond to these PIs eventually develop resistance. Furthermore, a portion of MM patients is inherently unresponsive to the PIs. Extensive mechanistic investigations identified several non-proteasomal signaling pathways suspected to be linked to the PI resistance, for which several excellent reviews are currently available. On the other hand, it is still unclear how cancer cells under high PI environments adapt to spare proteasome activity essential for survival and proliferation regardless of cancer evolution stages. This review outlines current progress towards understanding the proteasomal adaptations of cells in response to PI treatment to maintain necessary proteasome activity. A better understanding of cellular proteasomal changes in response to the PIs could provide a rationale to develop new therapeutics that could be used to overcome resistance to existing PI drugs.

p-Nitrophenyl esters provide new insights and applications for the thiolase enzyme OleA

The OleA enzyme is distinct amongst thiolase enzymes in binding two long (≥C8) acyl chains into structurally-opposed hydrophobic channels, denoted A and B, to carry out a non-decarboxylative Claisen condensation reaction and initiate the biosynthesis of membrane hydrocarbons and β-lactone natural products. OleA has now been identified in hundreds of diverse bacteria via bioinformatics and high-throughput screening using p-nitrophenyl alkanoate esters as surrogate substrates. In the present study, p-nitrophenyl esters were used to probe the reaction mechanism of OleA and shown to be incorporated into Claisen condensation products for the first time. p-Nitrophenyl alkanoate substrates alone were shown not to undergo Claisen condensation, but co-incubation of p-nitrophenyl esters and CoA thioesters produced mixed Claisen products. Mixed product reactions were shown to initiate via acyl group transfer from a p-nitrophenyl carrier to the enzyme active site cysteine, C143. Acyl chains esterified to p-nitrophenol were synthesized and shown to undergo Claisen condensation with an acyl-CoA substrate, showing potential to greatly expand the range of possible Claisen products. Using p-nitrophenyl 1-13C-decanoate, the Channel A bound thioester chain was shown to act as the Claisen nucleophile, representing the first direct evidence for the directionality of the Claisen reaction in any OleA enzyme. These results both provide new insights into OleA catalysis and open a path for making unnatural hydrocarbon and β-lactone natural products for biotechnological applications using cheap and easily synthesized p-nitrophenyl esters.

Bispecific T cell engagers: an emerging therapy for management of hematologic malignancies

Harnessing the power of immune cells, especially T cells, to enhance anti-tumor activities has become a promising strategy in clinical management of hematologic malignancies. The emerging bispecific antibodies (BsAbs), which recruit T cells to tumor cells, exemplified by bispecific T cell engagers (BiTEs), have facilitated the development of tumor immunotherapy. Here we discussed the advances and challenges in BiTE therapy developed for the treatment of hematologic malignancies. Blinatumomab, the first BiTE approved for the treatment of acute lymphocytic leukemia (ALL), is appreciated for its high efficacy and safety. Recent studies have focused on improving the efficacy of BiTEs by optimizing treatment regimens and refining the molecular structures of BiTEs. A considerable number of bispecific T cell-recruiting antibodies which are potentially effective in hematologic malignancies have been derived from BiTEs. The elucidation of mechanisms of BiTE action and neonatal techniques used for the construction of BsAbs can improve the treatment of hematological malignancies. This review summarized the features of bispecific T cell-recruiting antibodies for the treatment of hematologic malignancies with special focus on preclinical experiments and clinical studies.

Novel agents and regimens for hematological malignancies: recent updates from 2020 ASH annual meeting

Antibodies and chimeric antigen receptor-engineered T cells (CAR-T) are increasingly used for cancer immunotherapy. Small molecule inhibitors targeting cellular oncoproteins and enzymes such as BCR-ABL, JAK2, Bruton tyrosine kinase, FLT3, BCL-2, IDH1, IDH2, are biomarker-driven chemotherapy-free agents approved for several major hematological malignancies. LOXO-305, asciminib, "off-the-shelf" universal CAR-T cells and BCMA-directed immunotherapeutics as well as data from clinical trials on many novel agents and regimens were updated at the 2020 American Society of Hematology (ASH) Annual Meeting. Major developments and updates for the therapy of hematological malignancies were delineated at the recent Winter Symposium and New York Oncology Forum from the Chinese American Hematologist and Oncologist Network (CAHON.org). This study summarized the latest updates on novel agents and regimens for hematological malignancies from the 2020 ASH annual meeting.