Treatment of Multiple Myeloma and the Role of Melphalan in the Era of Modern Therapies-Current Research and Clinical Approaches

Assessing Outcomes in Patients With Multiple Myeloma Postautologous Stem Cell Transplantation: Contrasting the Effects of Melphalan Dosages at 200 mg/m2 versus 140 mg/m2

BACKGROUND

No standard criteria for dose reduction exists for high-dose melphalan for autologous stem cell transplantation (ASCT) for multiple myeloma (MM) due to limited and conflicting evidence.

OBJECTIVE

To evaluate efficacy and safety of standard dose (200 mg/m2 = Mel200) versus reduced dose 140 mg/m2 = Mel140) of melphalan in patients with MM undergoing ASCT.

DESIGN

A single-center retrospective review of adults with MM for their first ASCT between January 1, 2010, and November 1, 2022, who received Mel200 or Mel140 as conditioning. Primary endpoint was progression-free survival (PFS). Secondary safety and efficacy endpoints included overall survival (OS), incidence of febrile neutropenia and acute kidney injury, and time to engraftment. Subgroup analyses were performed based on patient age and renal function.

RESULTS

A total of 322 patients were included in the study, 240 in the Mel200 group and 82 in the Mel140 group. Baseline demographics were similar except patients receiving Mel140 were on average older and had worse kidney function. PFS at 2 years was not different between groups (P = .2335). No difference existed in 2 year PFS or OS for patients < 65 years of age versus ≥ 65 years of age or for patients with CrCl 30-59 mL/min versus CrCl ≥ 60 mL/min within either Mel200 group or Mel140 group (all P > .05). No differences existed between groups across all secondary outcomes.

CONCLUSION

Reduced doses melphalan showed no differences in safety or efficacy outcomes versus standard dose even when analyzed based on age and renal function. Larger randomized controlled trials need to be performed to validate these findings.

Recent advancements in nanomedicine as a revolutionary approach to treating multiple myeloma

Multiple myeloma, the second most common hematological malignancy, remains incurable with a 5-year survival rate of approximately 50 % and recurrence rates near 100 %, despite significant attempts to develop effective medicines. Therefore, there is a pressing demand in the medical field for innovative and more efficient treatments for MM. Currently, the standard approach for treating MM involves administering high-dose chemotherapy, which frequently correlates with improved results; however, one major limiting factor is the significant side effects of these medications. Furthermore, the strategies used to deliver medications to tumors limit their efficacy, whether by rapid clearance from circulation or an insufficient concentration in cancer cells. Cancer treatment has shifted from cytotoxic, nonspecific chemotherapy regimens to molecularly targeted, rationally developed drugs with improved efficacy and fewer side effects. Nanomedicines may provide an effective alternative way to avoid these limits by delivering drugs into the complicated bone marrow microenvironment and efficiently reaching myeloma cells. Putting drugs into nanoparticles can make their pharmacokinetic and pharmacodynamic profiles much better. This can increase the drug's effectiveness in tumors, extend its time in circulation in the blood, and lower its off-target toxicity. In this review, we introduce several criteria for the rational design of nanomedicine to achieve the best anti-tumoral therapeutic results. Next, we discuss recent advances in nanomedicine for MM therapy.

Rising Prevalence of Low-Frequency PPM1D Gene Mutations after Second HDCT in Multiple Myeloma

Multiple myeloma (MM) first-line treatment algorithms include immuno-chemotherapy (ICT) induction, high-dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT) consolidation, followed by lenalidomide maintenance. After these initial therapies, most patients suffer a disease relapse and require subsequent treatment lines including ICT, additional HDCT and ASCT, or novel immunotherapies. The presence of somatic mutations in peripheral blood cells has been associated with adverse outcomes in a variety of hematological malignancies. Nonsense and frameshift mutations in the PPM1D gene, a frequent driver alteration in clonal hematopoiesis (CH), lead to the gain-of-function of Wip1 phosphatase, which may impair the p53-dependent G1 checkpoint and promote cell proliferation. Here, we determined the presence of PPM1D gene mutations in peripheral blood cells of 75 subsequent myeloma patients in remission after first or second HDCT/ASCT. The prevalence of truncating PPM1D gene mutations emerged at 1.3% after first HDCT/ASCT, and 7.3% after second HDCT/ASCT, with variant allele frequencies (VAF) of 0.01 to 0.05. Clinical outcomes were inferior in the PPM1D-mutated (PPM1Dmut) subset with median progression-free survival (PFS) of 15 vs. 37 months (p = 0.0002) and median overall survival (OS) of 36 vs. 156 months (p = 0.001) for the PPM1Dmut and PPM1Dwt population, respectively. Our data suggest that the occurrence of PPM1D gene mutations in peripheral blood cells correlates with inferior outcomes after ASCT in patients with multiple myeloma.

The Interplay between the DNA Damage Response (DDR) Network and the Mitogen-Activated Protein Kinase (MAPK) Signaling Pathway in Multiple Myeloma

The DNA damage response (DDR) network and the mitogen-activated protein kinase (MAPK) signaling pathway are crucial mechanisms for the survival of all living beings. An accumulating body of evidence suggests that there is crosstalk between these two systems, thus favoring the appropriate functioning of multi-cellular organisms. On the other hand, aberrations within these mechanisms are thought to play a vital role in the onset and progression of several diseases, including cancer, as well as in the emergence of drug resistance. Here, we provide an overview of the current knowledge regarding alterations in the DDR machinery and the MAPK signaling pathway as well as abnormalities in the DDR/MAPK functional crosstalk in multiple myeloma, the second most common hematologic malignancy. We also present the latest advances in the development of anti-myeloma drugs targeting crucial DDR- and MAPK-associated molecular components. These data could potentially be exploited to discover new therapeutic targets and effective biomarkers as well as for the design of novel clinical trials. Interestingly, they might provide a new approach to increase the efficacy of anti-myeloma therapy by combining drugs targeting the DDR network and the MAPK signaling pathway.

Multiple Myeloma: A Review of the Literature and a Case Report Highlighting the Immunocompromised State of Myeloma Patients

Multiple myeloma (MM), a malignancy involving plasma cells, disproportionately affects older adults with an average age of diagnosis of about 70 years. Oftentimes, the therapies used in the treatment of MM are associated with a risk for immunotoxicity, lowering the ability of the immune system to fight off opportunistic infections. This is an important relationship for clinicians to realize as the incidence of opportunistic infections in myeloma patients is increasing. As an example, we present a case of a patient with MM who subsequently developed a cryptococcal infection. Our paper will highlight the key details of the case as well as shed light on the importance of understanding the immunodeficiencies in this patient population. We highlight important aspects of the current literature related to MM and relate them to the associated case.

Exploring the Impact of Cytogenetic Abnormalities on Treatment Responses and Survival Outcomes in Multiple Myeloma: A Single-Centre Experience of 13 Years of Follow-Up

(1) Background: The introduction of novel therapies has led to a considerable evolution in the management of Multiple Myeloma, and chromosomal abnormalities predict the success of treatment. We aimed to characterize cytogenetic abnormalities for risk stratification in the patient population and to evaluate the predictive and prognostic value of the specified abnormalities in distinct treatment modalities. (2) Methods: This study included patients with Multiple Myeloma who applied to the Internal Medicine Clinic of the Cukurova University Faculty of Medicine. Between 2010 and 2023, 98 cases with cytogenetic abnormality data were identified. We analysed the effects of cytogenetic abnormalities on survival and response rates to first chemotherapies. (3) Results: P53 del was the most prevalent abnormality, and t(11;14) was the most common translocation. There was no significant difference in the mean survival and treatment response rates for specific cytogenetic abnormalities. When chemotherapies based on lenalidomide were initiated, patients' life-death statuses differed significantly from those of treatments without lenalidomide. Regardless of the type of chromosomal aberration, lenalidomide-based treatments independently enhanced average survival 14-fold, while there was no significant difference in overall survival among treatments. (4) Conclusions: In individuals with cytogenetic abnormalities, lenalidomide-based treatments should be started regardless of the chemotherapy to be used for the condition.

SOHO State of the Art Updates and Next Questions: Will CAR-T Replace ASCT in NDMM

The treatment landscape for multiple myeloma (MM) has rapidly evolved over the last 2 decades. The development of triplet and quadruplet regimens including proteasome inhibitors (PI), immunomodulatory agents (IMiDs), and anti-CD38 monoclonal antibodies has dramatically extended overall survival. In addition to effective multidrug regimens, autologous stem cell transplant (ASCT) is a cornerstone of management in newly diagnosed multiple myeloma (NDMM). However, despite these combined treatment modalities, curative therapy for MM remains elusive. Recent, novel immunotherapies including chimeric antigen T-cell (CAR-T) therapy have demonstrated deep and durable responses in relapsed and refractory multiple myeloma (RRMM). Currently 2 CAR-T products, ciltacabtagene autoleucel (cilta-cel) and idecabtagene vicleucel (ide-cel), are approved by the FDA for the treatment of RRMM. The success of CAR-T therapy revolutionized the management of RRMM prompting clinical trials studying CAR-T therapy in the first line setting. The ongoing KarMMa-4, CARTITUDE-5, and CARTITUDE-6 clinical trials may establish CAR-T therapy as a first line option potentially supplanting ASCT in the initial treatment of NDMM. In this review, we discuss the current standard of care management of NDMM, trace the evolution of CAR-T clinical trials in RRMM, and survey ongoing clinical trials studying CAR-T therapy in NDMM.

DNA Adducts in Cancer Chemotherapy

DNA adducting drugs, including alkylating agents and platinum-containing drugs, are prominent in cancer chemotherapy. Their mechanisms of action involve direct interaction with DNA, resulting in the formation of DNA addition products known as DNA adducts. While these adducts are well-accepted to induce cancer cell death, understanding of their specific chemotypes and their role in drug therapy response remain limited. This perspective aims to address this gap by investigating the metabolic activation and chemical characterization of DNA adducts formed by the U.S. FDA-approved drugs. Moreover, clinical studies on DNA adducts as potential biomarkers for predicting patient responses to drug efficacy are examined. The overarching goal is to engage the interest of medicinal chemists and stimulate further research into the use of DNA adducts as biomarkers for guiding personalized cancer treatment.

Indisulam synergizes with melphalan to inhibit Multiple Myeloma malignancy via targeting TOP2A

Multiple myeloma (MM) is the second most prevalent hematologic malignancy which remains uncurable. Numerous drugs have been discovered to inhibit MM cells. Indisulam, an aryl sulfonamide, has a potent anti-myeloma activity in vitro and in vivo. This study aims to explore the new mechanism of indisulam and investigate its potential use in combination with melphalan. We examined DNA damage in MM cells through various methods such as western blotting (WB), immunofluorescence, and comet assay. We also identified the role of topoisomerase IIα (TOP2A) using bioinformatic analyses. The impact of indisulam on the RNA and protein levels of TOP2A was investigated through qPCR and WB. Cell proliferation and apoptosis were assessed using CCK-8 assays, Annexin V/PI assays and WB. We predicted the synergistic effect of the combination treatment based on calculations performed on a website, and further explored the effect of indisulam in combination with melphalan on MM cell lines and xenografts. RNA sequencing data and basic experiments indicated that indisulam caused DNA damage and inhibited TOP2A expression by decreasing transcription and promoting degradation via the proteasome pathway. Functional experiments revealed that silencing TOP2A inhibited cell proliferation and induced apoptosis and DNA damage. Finally, Indisulam/melphalan combination treatment demonstrated a strong synergistic anti-tumor effect compared to single-agent treatments in vitro and in vivo. These findings suggest that combination therapies incorporating indisulam and melphalan have the potential to enhance treatment outcomes for MM.

Diallyl disulfide synergizes with melphalan to increase apoptosis and DNA damage through elevation of reactive oxygen species in multiple myeloma cells

Diallyl disulfide (DADS), one of the main components of garlic, is well known to have anticancer effects on multiple cancers. However, its efficacy in treating multiple myeloma (MM) is yet to be determined. We explored the effects of DADS on MM cells and investigated the synergistic effects of DADS when combined with five anti-MM drugs, including melphalan, bortezomib, carfilzomib, doxorubicin, and lenalidomide. We analyzed cell viability, cell apoptosis, and DNA damage to determine the efficacy of DADS and the drug combinations. Our findings revealed that DADS induces apoptosis in MM cells through the mitochondria-dependent pathway and increases the levels of γ-H2AX, a DNA damage marker. Combination index (CI) measurements indicated that the combination of DADS with melphalan has a significant synergistic effect on MM cells. This was further confirmed by the increases in apoptotic cells and DNA damage in MM cells treated with the two drug combinations compared with those cells treated with a single drug alone. The synergy between DADS and melphalan was also observed in primary MM cells. Furthermore, mechanistic investigations showed that DADS decreases reduced glutathione (GSH) levels and increases reactive oxygen species (ROS) production in MM cells. The addition of GSH is effective in neutralizing DADS cytotoxicity and inhibiting the synergy between DADS and melphalan in MM cells. Taken together, our study highlights the effectiveness of DADS in treating MM cells and the promising therapeutic potential of combining DADS and melphalan for MM treatment.

Optimizing high dose melphalan

Melphalan, has been a major component of myeloma therapy since the 1950s. In the context of hematopoietic cell transplantation (HCT), high dose melphalan (HDM) is the most common conditioning regimen used due to its potent anti-myeloma effects and manageable toxicities. Common toxicities associated with HDM include myelosuppression, gastrointestinal issues, and mucositis. Established approaches to reduce these toxicities encompass dose modification, nausea prophylaxis with 5HT3 receptor antagonists, cryotherapy, amifostine use, and growth factors. Optimization of melphalan exposure through personalized dosing and its combination with other agents like busulfan, or bendamustine show promise. Propylene glycol-free melphalan (Evomela) represents a novel formulation aiming to enhance drug stability and reduce adverse effects. This review explores strategies to enhance the efficacy and mitigate the toxicity of HDM in multiple myeloma. Future directions involve exploring these strategies in clinical trials to improve the safety and efficacy of HDM, thereby enhancing outcomes for multiple myeloma patients undergoing autologous HCT.

Multiple myeloma and Chagas disease: qPCR as a marker for preemptive antiparasitic therapy: a case reports series and review

Multiple myeloma (MM) associated with Chagas disease is rarely described. This disease and its therapy suppress T cell and macrophage functions and increase regulatory T cell function, allowing the increase of parasitemia and the risk of Chagas Disease Reactivation (CDR). We aimed to analyze the role of conventional (cPCR) and quantitative Polymerase Chain Reaction (qPCR) for prospective monitoring of T. cruzi parasitemia, searching for markers of preemptive antiparasitic therapy in MM patients with Chagas disease. Moreover, we investigated the incidence and management of hematological diseases and CDR both inside and outside the transplant setting in the MEDLINE database. We found 293 studies and included 31 of them. Around 1.9-2.0% of patients with Chagas disease were reported in patients undergoing Stem Cell Transplantation. One case of CDR was described in eight cases of MM and Chagas disease. We monitored nine MM and Chagas disease patients, seven under Autologous Stem Cell Transplantation (ASCT), during 44.56±32.10 months (mean±SD) using parasitological methods, cPCR, and qPCR. From these patients, three had parasitemia. In the first, up to 256 par Eq/mL were detected, starting from 28 months after ASCT. The second patient dropped out and died soon after the detection of 161.0 par Eq/mL. The third patient had a positive blood culture. Benznidazole induced fast negativity in two cases; followed by notably lower levels in one of them. Increased T. cruzi parasitemia was related to the severity of the underlying disease. We recommend parasitemia monitoring by qPCR for early introduction of preemptive antiparasitic therapy to avoid CDR.

An overview of multiple myeloma: A monoclonal plasma cell malignancy's diagnosis, management, and treatment modalities

Multiple Myeloma (MM) is a plasma cell cancer with high mortality and morbidity rates. Its incidence rate has increased by 143% since 1975. Adipokines, cytokines, chemokines, and genetic variations influence the development and progression of MM. Chromosomal translocations cause mutations associated with MM. The pathogenesis of MM is complicated by novel issues like miRNAs, RANKL, Wnt/DKK1, Wnt, and OPG. Conventional diagnosis methods include bone marrow biopsy, sPEP or uPEP, sIFE and uIFE, and sFLC assay, along with advanced techniques such as FISH, SNPA, and gene expression technologies. A novel therapeutic strategy has been developed recently. Chemotherapy, hematopoietic stem cell transplantation, and a variety of drug classes in combination are used to treat patients with high-risk diseases. Alkylating agents, PIs, and IMiDs have all been developed as effective treatment options for MM in recent years. This review overviews the current recommendations for managing MGUS, SMM, MM, SP and NSMM and discusses practices in diagnosing and treating MM.

Clinical factors associated with autologous stem cell transplantation outcomes in multiple myeloma: upfront transplant with MEL200 remains the standard of care

Autologous stem cell transplantation (ASCT) remains the mainstay of the treatment in newly diagnosed transplant-eligible multiple myeloma (MM) patients. This retrospective study was performed to investigate the potential prognostic markers which may modify transplant course in a total of 256 ASCT recipients [median age: 58 (30-74) years; male/female: 138/118], including pretransplant (PET0) and day + 60 (PET2) PET/CT assessments and comparative analysis of melphalan (Mel) dose. Better responses with significantly higher complete response/very good partial response rates were achieved in patients who proceeded to transplant within 301 days from diagnosis (p < 0.001). Patients who had received < 1.5 lines of treatment prior to transplant had significantly higher probability of overall survival (OS) (p = 0.004) and progression-free survival (PFS) (p < 0.001). The probability of OS was significantly higher in patients with low Eastern Cooperative Oncology Group (ECOG) performance score (PS = 0-1) (p = 0.003) and HCT-Comorbidity Index (HCT-CI = 0) (p = 0.011). The number of involved areas (p = 0.028) and maximum standardized uptake value (SUVmax) (p = 0.021) in PET0 represented significant impact on OS. The probabilities of OS (p < 0.001) and PFS (p = 0.01) were significantly better with Mel200 mg/m2 conditioning compared to Mel140 mg/m2. Conditioning with Mel200 mg/m2, early and upfront ASCT and low pretransplant treatment burden were found to be significantly associated with ASCT outcome in MM patients. Despite its predictor impact on survival and prognosis, further studies are warranted to standardize PET/CT-based response assessments before being used as a guide for treatment decisions in clinical practice.

Differential Diagnosis and Therapeutic Advances in Multiple Myeloma: A Review Article

Multiple myeloma (MM) is a hematologic malignancy characterized by the abnormal clonal proliferation of plasma cells that may result in focal bone lesions, renal failure, anemia, and/or hypercalcemia. Recently, the diagnosis and treatment of MM have evolved due to a better understanding of disease pathophysiology, improved risk stratification, and new treatments. The incorporation of new drugs, including proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies and high-dose chemotherapy followed by hematopoietic stem cell transplantation, has resulted in a significant improvement in patient outcomes and QoL. In this review, we summarize differential diagnoses and therapeutic advances in MM.

Status and Future Directions of Therapeutics and Prognosis of Cardiac Amyloidosis

Accumulation of aberrant proteins in the heart causes cardiac amyloidosis, an uncommon and complicated illness. It can be classified into two main types: light chain (AL) and transthyretin (ATTR). The diagnosis of cardiac amyloidosis is challenging due to its non-specific clinical presentation and lack of definitive diagnostic tests. Diagnostic accuracy has increased with the advent of modern imaging methods, including cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. Depending on the severity of cardiac amyloidosis, a number of treatments may be attempted and specified according to the subtype of amyloidosis and the presence of complications. However, there are still significant challenges in treating this condition due to its complexity and lack of effective treatments. The prognosis for patients with cardiac amyloidosis is poor. Despite recent advances in diagnosis and treatment, there is still a need for more effective treatments to improve outcomes for patients with this condition. Therefore, we aim to review the current and future therapeutics reported in the literature and among ongoing clinical trials recruiting patients with CA.

Revisiting the Role of Alkylating Agents in Multiple Myeloma: Up-to-Date Evidence and Future Perspectives

From the 1960s to the early 2000s, alkylating agents (e.g., melphalan, cyclophosphamide, and bendamustine) remained a key component of standard therapy for newly-diagnosed or relapsed/refractory multiple myeloma (MM). Later on, their associated toxicities (including second primary malignancies) and the unprecedented efficacy of novel therapies have led clinicians to increasingly consider alkylator-free approaches. Meanwhile, new alkylating agents (e.g., melflufen) and new applications of old alkylators (e.g., lymphodepletion before chimeric antigen receptor T-cell [CAR-T] therapy) have emerged in recent years. Given the expanding use of antigen-directed modalities (e.g., monoclonal antibodies, bispecific antibodies, and CAR-T therapy), this review explores the current and future role of alkylating agents in different treatment settings (e.g., induction, consolidation, stem cell mobilization, pre-transplant conditioning, salvage, bridging, and lymphodepleting chemotherapy) to ellucidate the role of alkylator-based regimens in modern-day MM management.

Efficacy and Safety of High-Dose Chemotherapy with Treosulfan and Melphalan in Multiple Myeloma

(1) Background: Upfront treatment consolidation with high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) has relevantly contributed to achieving durable remissions following induction treatment in multiple myeloma (MM) patients. The optimization of HDCT regimens can, therefore, essentially contribute to improving the depth and duration of tumor remissions. To date, melphalan at 200 mg/m² is the standard HDCT regimen for fit MM patients. In our previous work, we showed promising efficacy and safety results for treosulfan (14 g/m²) and melphalan (200 mg/m²) (TreoMel) in acute myeloid leukemia (AML) patients receiving ASCT. Based on these data, TreoMel became the standard of care for fit MM patients at our institution. (2) Methods: We identified 115 consecutive MM patients who underwent consolidation with TreoMel between 01/2020 and 08/2022 at the University Hospital of Bern. We analyzed the safety and efficacy data, as well as the treosulfan pharmacokinetics, correlating them with tumor responses. (3) Results: A complete response (CR) rate of 84% was achieved, which is comparable to the CR rate reported for the quadruplet combination. The median PFS was 30 months (95% CI: 20.4-not reached), and the 31-month OS rate was 83%. The median area under the curve (AUC) for treosulfan was 952.5 mg*h/L (range: 527.4-1781.4), and the median peak level was 332.3 mg/L (range: 168-554). The treosulfan pharmacokinetics showed no significant correlation with MM responses after HDCT and ASCT. However, female patients had a significantly higher AUC (p = 0.007) and peak value (p = 0.001), and the higher values were associated with longer hospitalizations. (4) Conclusions: Treatment consolidation with TreoMel HDCT demonstrated a promising efficacy and safety profile in our cohort of MM patients and deserves further investigation in prospective studies.

A rapid and sensitive LC-MS/MS method for simultaneous determination of melphalan and its monohydroxy and dihydroxy metabolites in human plasma

As a hydrolysis mediated drug in vivo, the pharmacokinetics of melphalan are highly variable in patients. Few methodologies could simultaneously measure the concentrations of melphalan and its hydrolyzed metabolites in plasma. The aim of this study was to develop a simple, rapid and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of melphalan and its hydrolyzed metabolites, monohydroxy melphalan (MOH melphalan) and dihydroxy melphalan (DOH melphalan). A simple protein precipitation was employed for sample preparation and melphalan-d8 was used as internal standard. Baseline separation of target analytes was achieved using an XSelect HSS T3 column (2.1 × 50 mm, 5 µm) with a gradient elution at a flow rate of 0.5 mL/min in 5 min. The monitored transitions were m/z 305.1 → 287.7 for melphalan, m/z 287.1 → 228.0 for MOH melphalan, m/z 269.3 → 251.8 for DOH melphalan, and m/z 313.1 → 295.7 for melphalan-d8. The method was fully validated in accordance with the FDA guideline. The calibration curves were established over the range of 5.22-5220 ng/mL for melphalan, 7.94-1588 ng/mL for MOH-melphalan, and 15.0-3000 ng/mL for DOH-melphalan with the regression coefficients greater than 0.99. The intra- and inter-day coefficients of variation for the analytes were ≤11.0% and all the biases were less than 8.3%. The method has been successfully applied to the quantification of melphalan and its metabolites in clinical plasma samples obtained from hematopoietic stem cell transplantation patients who received a dose of melphalan for pre-transplant conditioning.

Anti-Angiogenic Activity of Drugs in Multiple Myeloma

Angiogenesis represents a pivotal hallmark of multiple myeloma (MM) that correlates to patients’ prognosis, overall survival, and drug resistance. Hence, several anti-angiogenic drugs that directly target angiogenic cytokines (i.e., monoclonal antibodies, recombinant molecules) or their cognate receptors (i.e., tyrosine kinase inhibitors) have been developed. Additionally, many standard antimyeloma drugs currently used in clinical practice (i.e., immunomodulatory drugs, bisphosphonates, proteasome inhibitors, alkylating agents, glucocorticoids) show anti-angiogenic effects further supporting the importance of inhibiting angiogenesis from potentiating the antimyeloma activity. Here, we review the most important anti-angiogenic therapies used for the management of MM patients with a particular focus on their pharmacological profile and on their anti-angiogenic effect in vitro and in vivo. Despite the promising perspective, the direct targeting of angiogenic cytokines/receptors did not show a great efficacy in MM patients, suggesting the need to a deeper knowledge of the BM angiogenic niche for the design of novel multi-targeting anti-angiogenic therapies.

Newly Synthesized Melphalan Analogs Induce DNA Damage and Mitotic Catastrophe in Hematological Malignant Cancer Cells

Myeloablative therapy with highdoses of the cytostatic drug melphalan (MEL) in preparation for hematopoietic cell transplantation is the standard of care for multiple myeloma (MM) patients. Melphalan is a bifunctional alkylating agent that covalently binds to nucleophilic sites in the DNA and effective in the treatment, but unfortunately has limited therapeutic benefit. Therefore, new approaches are urgently needed for patients who are resistant to existing standard treatment with MEL. Regulating the pharmacological activity of drug molecules by modifying their structure is one method for improving their effectiveness. The purpose of this work was to analyze the physicochemical and biological properties of newly synthesized melphalan derivatives (EE-MEL, EM-MEL, EM-MOR-MEL, EM-I-MEL, EM-T-MEL) obtained through the esterification of the carboxyl group and the replacement of the the amino group with an amidine group. Compounds were selected based on our previous studies for their improved anticancer properties in comparison with the original drug. For this, we first evaluated the physicochemical properties using the circular dichroism technique, then analyzed the zeta potential and the hydrodynamic diameters of the particles. Then, the in vitro biological properties of the analogs were tested on multiple myeloma (RPMI8226), acute monocytic leukemia (THP1), and promyelocytic leukemia (HL60) cells as model systems for hematological malignant cells. DNA damage was assessed by immunostaining γH2AX, cell cycle distribution changes by propidium iodide (PI) staining, and cell death by the activation of caspase 2. We proved that the newly synthesized derivatives, in particular EM-MOR-MEL and EM-T-MEL, affected the B-DNA conformation, thus increasing the DNA damage. As a result of the DNA changes, the cell cycle was arrested in the S and G2/M phases. The cell death occurred by activating a mitotic catastrophe. Our investigations suggest that the analogs EM-MOR-MEL and EM-T-MEL have better anti-cancer activity in multiple myeloma cells than the currently used melphalan.

Assessing Pretransplant and Posttransplant Therapy Response in Multiple Myeloma Patients

Multiple myeloma (MM) is a hematologic cancer defined by an abnormal development of clonal plasma cells in the bone marrow, releasing vast quantities of immunoglobulins and different proteins. In the majority of patients, MM remains incurable despite decades of medical improvement and a number of treatment breakthroughs. Frontline standard-of-care has little long-term success, with the majority of patients eventually relapsing, although the overall progression-free survival (PFS) has improved significantly in the last ten years. Patients who are eligible for a transplant have the highest PFS rate at 5 years, depending on medication response and other various factors that are yet to be discovered. Therefore, the current study aimed to evaluate the response to VCD (bortezomib, cyclophosphamide, dexamethasone) and VTD (bortezomib, thalidomide, dexamethasone) used as pretransplant regimens, as well as to compare responses between thalidomide and lenalidomide used as maintenance therapy posttransplant. This retrospective study was performed on a group of 105 hospitalized patients in the Hematology Department of the Timisoara Municipal Emergency Clinical Hospital between January 2016 and December 2021. Data was collected from the paper records of patients with MM who were under-followed. The treatment regimens used as induction therapy were either VCD or VTD if cyclophosphamide was contraindicated. Of the 105 patients, 27 became eligible for bone marrow transplantation. Furthermore, they received maintenance therapy which was based on either lenalidomide with dexamethasone or thalidomide with dexamethasone. Of the 62 patients treated with VTD, 17.7% were in complete remission before stem cell transplantation. Of the 43 patients treated with VCD, 37.2% were in complete remission. The 5-year mean progression-free survival (PFS) in the entire cohort was better in the group treated with the VTD regimen (31.6 vs. 27.2 months). However, in the 27 patients undergoing maintenance after ASCT, the PFS with thalidomide was 35.5 months (95% CI = 27-42), while the PFS rate in those receiving maintenance treatment with lenalidomide was 46.1 months (95% CI = 20-73). VCD proved to be superior to VTD in inducing complete pretransplant responses. Regarding maintenance therapy, patients from the lenalidomide group had superior responses compared with those under thalidomide.

β-Cyclodextrin-Based Nanosponges Inclusion Compounds Associated with Gold Nanorods for Potential NIR-II Drug Delivery

This article describes the synthesis and characterization of two nanocarriers consisting of β-cyclodextrin-based nanosponges (NSs) inclusion compounds (ICs) and gold nanorods (AuNRs) for potential near-infrared II (NIR-II) drug-delivery systems. These nanosystems sought to improve the stability of two drugs, namely melphalan (MPH) and curcumin (CUR), and to trigger their photothermal release after a laser irradiation stimulus (1064 nm). The inclusion of MPH and CUR inside each NS was confirmed by field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, Fourier transform infrared spectroscopy, (FT-IR) differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and proton nuclear magnetic resonance (1H-NMR). Furthermore, the association of AuNRs with both ICs was confirmed by FE-SEM, energy-dispersive spectroscopy (EDS), TEM, dynamic light scattering (DLS), ζ-potential, and UV–Vis. Moreover, the irradiation assays demonstrated the feasibility of the controlled-photothermal drug release of both MPH and CUR in the second biological window (1000–1300 nm). Finally, MTS assays depicted that the inclusion of MPH and CUR inside the cavities of NSs reduces the effects on mitochondrial activity, as compared to that observed in the free drugs. Overall, these results suggest the use of NSs associated with AuNRs as a potential technology of controlled drug delivery in tumor therapy, since they are efficient and non-toxic materials.

Multiple Myeloma Therapy: Emerging Trends and Challenges

Multiple myeloma (MM) is a complex hematologic malignancy characterized by the uncontrolled proliferation of clonal plasma cells in the bone marrow that secrete large amounts of immunoglobulins and other non-functional proteins. Despite decades of progress and several landmark therapeutic advancements, MM remains incurable in most cases. Standard of care frontline therapies have limited durable efficacy, with the majority of patients eventually relapsing, either early or later. Induced drug resistance via up-modulations of signaling cascades that circumvent the effect of drugs and the emergence of genetically heterogeneous sub-clones are the major causes of the relapsed-refractory state of MM. Cytopenias from cumulative treatment toxicity and disease refractoriness limit therapeutic options, hence creating an urgent need for innovative approaches effective against highly heterogeneous myeloma cell populations. Here, we present a comprehensive overview of the current and future treatment paradigm of MM, and highlight the gaps in therapeutic translations of recent advances in targeted therapy and immunotherapy. We also discuss the therapeutic potential of emerging preclinical research in multiple myeloma.

Cancer multidrug-resistance reversal by ABCB1 inhibition: A recent update

Chemotherapy is one of the most common treatments for cancer that uses one or more anti-cancer drugs as a part of the standardized chemotherapy regimen. Cytotoxic chemicals delay and prevent cancer cells from multiplying, invading, and metastasizing. However, the significant drawbacks of cancer chemotherapy are the lack of selectivity of the cytotoxic drugs to tumour cells and normal cells and the development of resistance by cells for the particular drug or the combination of drugs. Multidrug resistance (MDR) is the low sensitivity of specific cells against drugs associated with cancer chemotherapy. The most common mechanisms of anticancer drug resistance are: (a) drug-dependent MDR (b) target-dependent MDR, and (c) drug target-independent MDR. In all the factors, the overexpression of multidrug efflux systems contributes significantly to the increased resistance in the cancer cells. Multidrug resistance due to efflux of anticancer drugs by membrane ABC transporters includes ABCB1, ABCC1, and ABCG2. ABCB1 inhibition can restore the sensitivity of the cancerous cells toward chemotherapeutic drugs. In this review, we discussed ABCB1 inhibitors under clinical studies with their mode of action, potency and selectivity. Also, we have highlighted the contribution of repurposing drugs, biologics and nano formulation strategies to combat multidrug resistance by modulating the ABCB1 activity.

The Role of DNA Repair in Genomic Instability of Multiple Myeloma

Multiple Myeloma (MM) is a B cell malignancy marked by genomic instability that arises both through pathogenesis and during disease progression. Despite recent advances in therapy, MM remains incurable. Recently, it has been reported that DNA repair can influence genomic changes and drug resistance in MM. The dysregulation of DNA repair function may provide an alternative explanation for genomic instability observed in MM cells and in cells derived from MM patients. This review provides an overview of DNA repair pathways with a special focus on their involvement in MM and discusses the role they play in MM progression and drug resistance. This review highlights how unrepaired DNA damage due to aberrant DNA repair response in MM exacerbates genomic instability and chromosomal abnormalities, enabling MM progression and drug resistance.

Synthesis and In Vitro Activity of Novel Melphalan Analogs in Hematological Malignancy Cells

Despite the continuous developments in pharmacology and the high therapeutic effect of new treatment options for patients with hematological malignancies, these diseases remain a major health issue. Our study aimed to synthesize, analyze in silico, and determine the biological properties of new melphalan derivatives. We obtained three methyl esters of melphalan having in their structures amidine moieties substituted with thiomorpholine (EM-T-MEL), indoline (EM-I-MEL), or 4-(4-morpholinyl) piperidine (EM-MORPIP-MEL). These have not yet been described in the literature. The in vitro anticancer properties of the analogs were determined against THP1, HL60, and RPMI8226 cells. Melphalan derivatives were evaluated for cytotoxicity (resazurin viability assay), genotoxicity (alkaline comet assay), and their ability to induce apoptosis (Hoechst33342/propidium iodide double staining method; phosphatidylserine translocation; and caspase 3/7, 8, and 9 activity measurements). Changes in mitochondrial membrane potential were examined using the specific fluorescence probe JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazol carbocyanine). The EM-T-MEL derivative had the highest biological activity, showing higher cytotoxic and genotoxic properties than the parent drug. Moreover, it showed a high ability to induce apoptosis in the tested cancer cells. This compound also had a beneficial effect in peripheral blood mononuclear cells (PBMC). In conclusion, we verified and confirmed the hypothesis that chemical modifications of the melphalan structure improved its anticancer properties. The conducted study allowed the selection of the compound with the highest biological activity and provided a basis for chemical structure-biological activity analyses.

Early recruitment of PARP-dependent m8A RNA methylation at DNA lesions is subsequently accompanied by active DNA demethylation

RNA methylation, especially 6-methyladenosine (m⁶A)-modified RNAs, plays a specific role in DNA damage response (DDR). Here, we also observe that RNA modified at 8-methyladenosine (m⁸A) is recruited to UVA-damaged chromatin immediately after microirradiation. Interestingly, the level of m⁸A RNA at genomic lesions was reduced after inhibition of histone deacetylases and DNA methyltransferases. It appears in later phases of DNA damage response, accompanied by active DNA demethylation. Also, PARP inhibitor (PARPi), Olaparib, prevented adenosine methylation at microirradiated chromatin. PARPi abrogated not only m⁶A and m⁸A RNA positivity at genomic lesions, but also XRCC1, the factor of base excision repair (BER), did not recognize lesions in DNA. To this effect, Olaparib enhanced the genome-wide level of γH2AX. This histone modification interacted with m⁸A RNAs to a similar extent as m⁸A RNAs with DNA. Pronounced interaction properties we did not observe for m⁶A RNAs and DNA; however, m⁶A RNA interacted with XRCC1 with the highest efficiency, especially in microirradiated cells. Together, we show that the recruitment of m⁶A RNA and m⁸A RNA to DNA lesions is PARP dependent. We suggest that modified RNAs likely play a role in the BER mechanism accompanied by active DNA demethylation. In this process, γH2AX stabilizes m⁶A/m⁸A-positive RNA-DNA hybrid loops via its interaction with m⁸A RNAs. R-loops could represent basic three-stranded structures recognized by PARP-dependent non-canonical m⁶A/m⁸A-mediated DNA repair pathway.

[The effect of lipid derivative of anti-tumor drug sarcolysin embedded in phospholipid nanoparticles in the experiments in vivo]

To improve the therapeutic properties of the antitumor agent Sarcolysin, we have previously developed and characterized a dosage form representing its ester conjugate with decanol embedded in ultra-small phospholipid nanoparticles less than 30 nm in size ("Sarcolysin-NP"). The effect of the resulting composition was investigated in vivo in comparison with the free substance of sarcolysin. The composition intravenous administration to mice showed an improvement in the pharmacokinetic parameters of sarcolysin associated with its initial higher (by 22%) level in the blood and prolonged circulation, which was also observed in mice with P388 tumor. In mice with three types of tumors - lymphocytic leukemia P388, lymphocytic leukemia L1210, and adenocarcinoma of the mammary gland Ca755 - administration of two doses of sarcolysin over a period of 7 days showed its predominant antitumor effect. The maximum tumor growth inhibition was noted for lymphocytic leukemia L1210 and adenocarcinoma of the mouse mammary gland Ca755 (at a dose of Sarcolysin-NP - 8,4 mg/kg), which was higher in comparison with free substance by more than 24% and 17%, respectively. Differences in the life span of the treated animals were revealed significantly at a dose of 10 mg/kg and amounted to 25% and 17,4% for lymphocytic leukemia P388 and L1210, respectively, and 11% for adenocarcinoma Ca755. In an experiment on rats, acute toxicity of Sarcolysin-NP administered intravenously showed that an average LD50 value 2-3 times exceeded a similar parameter for commercial preparations of free sarcolysin (Melphalan and Alkeran), which indicates its lower toxicity.

Immunotherapy of Multiple Myeloma: Promise and Challenges

Whereas the treatment of MM was dependent solely on alkylating agents and corticosteroids during the prior three decades, the landscape of therapeutic measures to treat the disease began to expand enormously early in the current century. The introduction of new classes of small-molecule drugs, such as proteasome blockers (bortezomib and carfilzomib), immunomodulators (lenalidomide and pomalidomide), nuclear export inhibitors (selinexor), and histone deacetylase blockers (panobinostat), as well as the application of autologous stem cell transplantation (ASCT), resulted in a seismic shift in how the disease is treated. The picture changed dramatically once again starting with the 2015 FDA approval of two monoclonal antibodies (mAbs) - the anti-CD38 daratumumab and the anti-SLAMF7 elotuzumab. Daratumumab, in particular, has had a great impact on MM therapy and today is often included in various regimens to treat the disease, both in newly diagnosed cases and in the relapse/refractory setting. Recently, other immunotherapies have been added to the arsenal of drugs available to fight this malignancy. These include isatuximab (also anti-CD38) and, in the past year, the antibody-drug conjugate (ADC) belantamab mafodotin and the chimeric antigen receptor (CAR) T-cell product idecabtagene vicleucel (ide-cel). While the accumulated benefits of these newer agents have resulted in a doubling of the disease's five-year survival rate to more than 5 years and improved quality of life, the disease remains incurable. Almost without exception patients experience relapse and/or become refractory to the drugs used, making the search for innovative therapies all the more essential. This review covers the current scope of anti-myeloma immunotherapeutic agents, both those in clinical use and on the horizon, including naked mAbs, ADCs, bi- and multi-targeted mAbs, and CAR T-cells. Emphasis is placed on the benefits of each along with the challenges that need to be overcome if MM is to be considered curable in the future.

The Impact of Induction Regimes on Immune Responses in Patients with Multiple Myeloma

Current standard frontline therapy for newly diagnosed patients with multiple myeloma (NDMM) involves induction therapy, autologous stem cell transplantation (ASCT), and maintenance therapy. Major efforts are underway to understand the biological and the clinical impacts of each stage of the treatment protocols on overall survival statistics. The most routinely used drugs in the pre-ASCT "induction" regime have different mechanisms of action and are employed either as monotherapies or in various combinations. Aside from their direct effects on cancer cell mortality, these drugs are also known to have varying effects on immune cell functionality. The question remains as to how induction therapy impacts post-ASCT immune reconstitution and anti-tumor immune responses. This review provides an update on the known immune effects of melphalan, dexamethasone, lenalidomide, and bortezomib commonly used in the induction phase of MM therapy. By analyzing the actions of each individual drug on the immune system, we suggest it might be possible to leverage their effects to rationally devise more effective induction regimes. Given the genetic heterogeneity between myeloma patients, it may also be possible to identify subgroups of patients for whom particular induction drug combinations would be more appropriate.