Current status of autologous stem cell transplantation for multiple myeloma

Favorable Long-Term Outcomes with Autologous Stem Cell Transplantation for High-Risk Multiple Myeloma Patients with a Positive Result On 18F-FDG PET/CT at Baseline

BACKGROUND

18F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is a useful tool for identifying high-risk features in patients with newly diagnosed multiple myeloma (NDMM). This study evaluated the role of autologous stem cell transplantation (ASCT) in patients presenting with positive results on PET/CT scans.

MATERIALS AND METHODS

The medical records of 210 patients who underwent PET/CT at diagnosis were retrospectively reviewed. Eligible patients for transplantation proceeded to upfront ASCT with high-dose chemotherapy (HDT) after induction therapy with novel agents.

RESULTS

The presence of a number of focal lesions (FL) >3 and extramedullary disease (EMD) occurred in 111 and 35 patients, respectively. ASCT was performed in 54 patients. Among patients with FL > 3, those treated with ASCT showed a prolonged 2-year progression-free survival (PFS) and overall survival (OS) rates compared to those not treated with ASCT (PFS, 60.2% vs. 23.5%, P < 0.001; OS, 91.7% vs. 63.6%, P = 0.005). In patients with FL ≤ 3, treatment by ASCT was associated with a higher 2-year PFS rate than no treatment by ASCT (74.0% vs. 54.9%, P = 0.040). The OS of patients treated with ASCT was not significantly longer than that of patients not treated with ASCT (P = 0.115). In multivariate analysis, FL > 3, Revised International Staging System (R-ISS), and upfront ASCT were independent prognostic factors for PFS and OS.

CONCLUSION

Presenting FL > 3 on baseline PET/CT represents a high-risk feature in patients with NDMM. Frontline ASCT with HDT prolonged the survival of patients with FL > 3.

Comprehensive Updates in the Role of Imaging for Multiple Myeloma Management Based on Recent International Guidelines

The diagnostic and treatment methods of multiple myeloma (MM) have been rapidly evolving owing to advances in imaging techniques and new therapeutic agents. Imaging has begun to play an important role in the management of MM, and international guidelines are frequently updated. Since the publication of 2015 International Myeloma Working Group (IMWG) criteria for the diagnosis of MM, whole-body magnetic resonance imaging (MRI) or low-dose whole-body computed tomography (CT) and ¹⁸F-fluorodeoxyglucose positron emission tomography/CT have entered the mainstream as diagnostic and treatment response assessment tools. The 2019 IMWG guidelines also provide imaging recommendations for various clinical settings. Accordingly, radiologists have become a key component of MM management. In this review, we provide an overview of updates in the MM field with an emphasis on imaging modalities.

Aberrant Plasma Cell Contamination of Peripheral Blood Stem Cell Autografts, Assessed by Next-Generation Flow Cytometry, Is a Negative Predictor for Deep Response Post Autologous Transplantation in Multiple Myeloma; A Prospective Study in 199 Patients

High-dose chemotherapy with autologous stem cell support (ASCT) is the standard of care for eligible newly diagnosed Multiple Myeloma (MM) patients. Stem cell graft contamination by aberrant plasma cells (APCs) has been considered a possible predictive marker of subsequent clinical outcome, but the limited reports to date present unclear conclusions. We prospectively estimated the frequency of graft contamination using highly sensitive next-generation flow cytometry and evaluated its clinical impact in 199 myeloma patients who underwent an ASCT. Contamination (con+) was detected in 79/199 patients at a median level 2 × 10^-5. Its presence and levels were correlated with response to induction treatment, with 94%, 71% and 43% achieving CR, VGPR and PR, respectively. Importantly, con+ grafts conferred 2-fold and 2.8-fold higher patient-risk of not achieving or delaying reaching CR (4 vs. 11 months) and MRD negativity (5 vs. 18 months) post ASCT, respectively. Our data also provide evidence of a potentially skewed bone marrow (BM) reconstitution due to unpurged grafts, since con+ derived BM had significantly higher prevalence of memory B cells. These data, together with the absence of significant associations with baseline clinical features, highlight graft contamination as a potential biomarker with independent prognostic value for deeper responses, including MRD negativity. Longer follow-up will reveal if this corresponds to PFS or OS advantage.

Flow cytometric myeloma measurable residual disease testing in the era of targeted therapies

Therapies in myeloma are rapidly advancing with a host of new targeted therapies coming to market. While these drugs offer significant survival benefits and better side-effect profiles compared with conventional chemotherapeutics, they raise significant difficulties in monitoring post-therapy disease status by flow cytometry due to assay interference and/or selection of phenotypically different sub-clones. The principal culprit, anti-CD38 monoclonal antibodies, limits the ability to detect plasma cells based on classical CD38/CD45 gating. Other markers, such as CD138, are known to be suboptimal by flow cytometry. Various techniques have been proposed to overcome this problem. The most promising of these techniques has been the marker VS38c, a monoclonal antibody targeting an endoplasmic reticulum protein which has shown high sensitivity for plasma cells. Alternative techniques for gating plasma cells, while variably effective in the near term are already the subject of several targeted therapies rendering their usefulness limited in the longer term. Likewise, future targets of these therapies may render present aberrancy markers ineffective in MRD testing. These therapies pose challenges that must be overcome with new markers and novel panels in order for flow cytometric MRD testing to remain relevant.

Selinexor for the treatment of patients with previously treated multiple myeloma

INTRODUCTION

Multiple myeloma (MM) is an increasingly treatable but still incurable hematologic malignancy. Prognosis has improved significantly over recent years, although further advances remain urgently needed, especially for patients with heavily pre-treated and resistant disease for whom there are limited options. Selinexor is a first-in-class, oral, selective inhibitor of nuclear export (SINE) compound that triggers apoptosis in malignant cells by inducing nuclear retention of oncogene messenger RNAs (mRNAs) and reactivation of tumor suppressor proteins (TSPs). In clinical studies of patients with relapsed and/or refractory MM, selinexor has demonstrated both manageable toxicity and encouraging efficacy.

AREAS COVERED

This review will provide an overview of the mechanism of action of selinexor as well as the efficacy and safety data from clinical studies using selinexor for the treatment of multiple myeloma.

EXPERT OPINION

Long-term outcomes for patients with MM will continue to improve due to numerous recent and imminent therapeutic advances, although critical areas of unmet need remain. Oral selinexor is likely to contribute to the meeting of these needs and the further advancement of MM therapy in a meaningful way.

Full or intensity-reduced high-dose melphalan and single or double autologous stem cell transplant with or without bortezomib consolidation in patients with newly diagnosed multiple myeloma

OBJECTIVE

A post hoc subgroup analysis of two phase III trials (NCT00416273, NCT00416208) was carried out to investigate the influence of 100/140 and 200 mg/m² melphalan as well as single/double autologous stem cell transplantation (ASCT) on progression-free survival (PFS). Additionally, the effect of bortezomib consolidation on PFS was analyzed.

METHODS

Following induction therapy and high-dose melphalan with subsequent ASCT, patients with newly diagnosed multiple myeloma (NDMM) were randomized 1:1 to either four 35-day cycles of bortezomib consolidation (1.6 mg/m² IV on days 1, 8, 15, 22) or observation.

RESULTS

Of the 340 patients included in this analysis, 13.5% received 1 × MEL100/140, 22.9% 2 × MEL100/140, 31.2% 1 × MEL200, and 32.4% 2 × MEL200. With higher cumulative melphalan dose, PFS improved (P = .0085). PFS curves of patients treated with 2 × MEL100/140 and 1 × MEL200 were very similar. The superior dose effect of MEL200 over MEL100/140 was non-existent in the bortezomib consolidation arm but pronounced in the observation arm (P = .0015). Similarly, double ASCT was only beneficial in patients without bortezomib consolidation (P = .0569).

CONCLUSIONS

Full dose melphalan and double transplantation seem advantageous only as long as patients are not receiving bortezomib consolidation afterwards.

Initial Therapeutic Approaches to Patients with Multiple Myeloma

Multiple Myeloma (MM) is part of a spectrum of plasma cell disorders that may result in end organ damage. MM is subclassified into high and standard risk based on cytogenetic and laboratory markers. The treatment of newly diagnosed multiple myeloma is constantly changing with the advent of novel therapies. Recent advances in therapies have resulted in longer time to remission and overall survival. the introduction of targeted therapy with monoclonal antibodies such as Daratumumab has improved stringent complete response to 39%. In this review, we outline the current approach to diagnosis, prognosis, and management of newly diagnosed multiple myeloma in both transplant eligible and ineligible patients.

Echocardiographic predictors of new-onset atrial arrhythmias in patients undergoing hematopoietic stem cell transplantation

BACKGROUND

Atrial arrhythmias following hematopoietic stem cell transplantation (HSCT) have been associated with increased length of stay, need for intensive care, and increased mortality within one-year post-transplant. We sought to identify echocardiographic parameters that may predict the development of new atrial arrhythmias post-HSCT.

METHODS

We performed a retrospective chart review of 753 consecutive patients who underwent HSCT at the University of Chicago from January 2015 through December 2019. Patients with baseline echocardiogram within 6 months prior to transplantation were included. Those with prior transplants, history of atrial arrhythmias, or unavailable echocardiographic images were excluded, resulting in 187 patients included for final analysis. Baseline clinical and demographic variables, as well as echocardiographic parameters, were compared between patients who developed new atrial arrhythmias post-HSCT versus those who did not.

RESULTS

Of the 187 patients included for analysis, 25 (13%) developed new atrial arrhythmias, with 13 of these occurring within 30 days of transplantation. Despite no significant difference in left atrial (LA) end-systolic volume between those with and without new arrhythmia following HSCT (OR 1.04; 95% CI 0.91-1.09, p = 0.233), univariable analysis demonstrated that patients who developed atrial arrhythmias had reduced LA function, as reflected by lower LA emptying fraction (OR 0.94; 95% CI 0.91-0.98, p = 0.003) and lower LA reservoir strain (OR 0.95; 95% CI 0.92-0.99, p = 0.009).

CONCLUSIONS

Echocardiographic indices of LA function, namely LA emptying fraction and LA reservoir strain, can identify patients at risk for developing new atrial arrhythmias post-HSCT, prior to the development of morphologic changes in the LA.

Cyclophosphamide plus etoposide is a safe and effective mobilization regimen in patients with multiple myeloma

High-dose chemotherapy followed by autologous stem cell transplantation is a major component in the treatment of patients with multiple myeloma. As a prerequisite, the successful collection of a sufficient number of viable peripheral blood hematopoietic CD34+ cells is critical. A common standard protocol for mobilization is currently not defined and critically discussed especially in German-speaking Europe. In times of the Covid-19 pandemic, safe and effective strategies have to be chosen to minimize hospitalization times and severe courses. In this single-center retrospective analysis, safety and efficacy of cyclophosphamide plus etoposide (CE) and growth-factor support (n = 33) was compared to cyclophosphamide mono treatment and growth-factor support (n = 49) in 82 patients with multiple myeloma at first diagnosis. CE was superior to cyclophosphamide mono with a significantly higher number of collected CD34+ cells (15.46 × 10⁶ CD34⁺ cells/kg vs. 9.92 × 10⁶ CD34⁺ cells/kg), significantly faster engraftment of granulocytes after stem cell transplantation (day 10.5 vs. day 11.6), shorter duration of the inpatient stay (17.47 days vs. 19.16 days) and significantly less transfusions (8.82 % vs. 30.61 % patients receiving transfusions). The safety profile was comparable in both groups and in line with published data. We conclude that CE is a safe and highly effective mobilization protocol in patients with multiple myeloma at first diagnosis and appears to be superior to the commonly used cyclophosphamide mono regimen.

Metabolic Changes Are Associated with Melphalan Resistance in Multiple Myeloma

Multiple myeloma is an incurable hematological malignancy that impacts tens of thousands of people every year in the United States. Treatment for eligible patients involves induction, consolidation with stem cell rescue, and maintenance. High-dose therapy with a DNA alkylating agent, melphalan, remains the primary drug for consolidation therapy in conjunction with autologous stem-cell transplantation; as such, melphalan resistance remains a relevant clinical challenge. Here, we describe a proteometabolomic approach to examine mechanisms of acquired melphalan resistance in two cell line models. Drug metabolism, steady-state metabolomics, activity-based protein profiling (ABPP, data available at PRIDE: PXD019725), acute-treatment metabolomics, and western blot analyses have allowed us to further elucidate metabolic processes associated with melphalan resistance. Proteometabolomic data indicate that drug-resistant cells have higher levels of pentose phosphate pathway metabolites. Purine, pyrimidine, and glutathione metabolisms were commonly altered, and cell-line-specific changes in metabolite levels were observed, which could be linked to the differences in steady-state metabolism of naïve cells. Inhibition of selected enzymes in purine synthesis and pentose phosphate pathways was evaluated to determine their potential to improve melphalan's efficacy. The clinical relevance of these proteometabolomic leads was confirmed by comparison of tumor cell transcriptomes from newly diagnosed MM patients and patients with relapsed disease after treatment with high-dose melphalan and autologous stem-cell transplantation. The observation of common and cell-line-specific changes in metabolite levels suggests that omic approaches will be needed to fully examine melphalan resistance in patient specimens and define personalized strategies to optimize the use of high-dose melphalan.

Iguratimod-encapsulating PLGA-NPs induce human multiple myeloma cell death via reactive oxygen species and Caspase-dependent signalling

Human multiple myeloma (MM) is a currently incurable haematopoietic malignancies. Our research investigate the anti-tumour effect of iguratimod (IGU) encapsulated in poly(lactic-co-glycolic acid) PLGA nanoparticles (IGU-PLGA-NPs) on MM cells in vitro and in vivo. A significant inhibitory effect of IGU-PLGA-NPs on MM cancer cells and MM CSCs was demonstrated by the Cell Counting Kit-8 (CCK-8) assay. Treatment with IGU-PLGA-NPs induced significant cell cycle arrest at G1 in MM cells and reduced tumour colony formation in MM CSCs. Mechanistically, IGU-PLGA-NPs increase apoptosis in MM cells by activating Caspase-dependent signalling pathway to increase the levels of bax, cytochrome c (cyt-c), caspase-9 and caspase-3 proteins. Moreover, IGU-PLGA-NPs effectively increase ROS production assayed using a DCFH-DA fluorescent probe in MM cells. The data indicate that IGU-PLGA-NPs induce a significant reduction in the tumour volume and a marked increase in the survival rate in a mouse model of multiple myeloma. Overall, our findings indicate that IGU-PLGA-NPs are a potential therapeutic strategy that may contribute to the therapy of MM and elimination of MM CSCs in future clinical trials.

Lebanese Real-World Experience in Treating Multiple Myeloma: A Multicenter Retrospective Study

OBJECTIVE

The present retrospective multicenter study aims at documenting characteristics of multiple myeloma (MM) patients and the effect of autologous stem cell transplant (ASCT) on survival.

METHODS

A total of 134 adult patients initiating any new MM therapy from January 2002 till December 2019 were included. Enrollment was stratified by disease subtype, induction protocol and transplant status. The characteristics and survival outcomes were recorded.

RESULTS

Mean age at diagnosis was 61.91 ± 10.83 years, with 62.7% male patients. Regarding the prognostic MM International Staging System (ISS), stage 3 was the most common at diagnosis with 50.8% of patients followed by stage 1 (25.4%) and stage 2 (23.8%). Maintenance treatment was given in 88.5% of the patients. 24.6% patients were transplanted, 41% were not and the remaining were unknown or still in induction. 86.1% of patients were alive at data cut off. A significantly higher mean progression free survival (PFS) was found in transplant patients (p=0.016). Using cox regression, creatinine >2 mg/dl (HR3.78) and hypercalcemia >11 mg/dl (HR=6.48) were significantly associated with a shorter PFS1. A significantly shorter overall survival (OS) was associated with hypercalcemia (HR=6.58), as well as male gender though not statistically significant in the latter. Difference in survival distributions by treatment was not statistically significant (bortezomib thalidomide dexamethasone (VTD) (p=0.211), bortezomib cyclophosphamide dexamethasone (VCD) (p=0.111) or bortezomib Revlimid dexamethasone (VRD) (p=0.312)). The interaction between ISS stage on diagnosis and transplant was not significantly associated with the overall survival.

CONCLUSION

The results of our retrospective study are in conformity with international data emphasizing the role of transplant in the treatment algorithm of newly diagnosed transplant-eligible multiple myeloma patients.

Use of Backup Stem Cells for Stem Cell Boost and Second Transplant in Patients with Multiple Myeloma Undergoing Autologous Stem Cell Transplantation

Autologous hematopoietic stem cell transplantation (ASCT) is a standard treatment for multiple myeloma (MM). Consensus guidelines recommend collecting sufficient stem cells in case there is a need for stem cell boost for delayed/poor engraftment or for future second ASCT. However, collecting and storing backup stem cells in all patients requires significant resources and cost, and the rates of backup stem cell utilization are not well studied. We sought to examine the utilization of backup stem cells (BSCs) in patients with MM undergoing ASCT. Patients with MM aged ≥18 years old who underwent first ASCT at our institution from January 2010 through December 2015 and collected sufficient stem cells for at least 2 transplants were included in this single-center retrospective study. This timeframe was selected to allow for adequate follow-up. A total of 393 patients were included. The median age was 58 years (range, 25-73). After a median follow-up of 6 years, the median progression-free survival (PFS) of the cohort was 3 years. Sixty-one percent (n = 240) of patients progressed or relapsed. Chemotherapy-based mobilization was used in almost all patients (98%). The median total CD34+ cells collected was 18.2 × 106/kg (range, 3.4-112.4). A median of 5.7 × 106 CD34+ cells/kg (range, 1.8-41.9) was infused during the first ASCT, and a median of 10.1 × 106 CD34+ cells/kg (range, 1.5-104.5) was cryopreserved for future use. Of the patients, 6.9% (n = 27) used backup stem cells, with 2.3% (n = 10) using them for stem cell boost, 4.6% (n = 18) for a second salvage ASCT, including 1 patient for both stem cell boost and second ASCT. Rates of backup stem cell use among patients aged <60, 60-69, and ≥70 years were 7.8%, 5.7%, and 5.9%, respectively. There was a trend toward higher rates of backup stem cell use for second ASCT in patients who were younger, had suboptimal disease control at time of first ASCT, and longer PFS. The median dose of stem cell boost given was 5.6 × 106 CD34+ cells/kg (range, 1.9-20). The median time from stem cell boost to neutrophil, hemoglobin, and platelet engraftment was 4 (range, 2-11), 15 (range, 4-34), and 12 (range, 0-34) days, respectively. Lower CD34+ dose and older age at time of ASCT predicted need for stem cell boost. With new salvage therapies for relapsed MM, the rates of second ASCT are very low. The low rates of use suggest that institutional policies regarding universal BSC collection and long-term storage should be reassessed and individualized. However, need for stem cell boost in 2.3% of patients may present a challenge to that.

Stem Cell Mobilization in Multiple Myeloma: Comparing Safety and Efficacy of Cyclophosphamide +/- Plerixafor versus Granulocyte Colony-Stimulating Factor +/- Plerixafor in the Lenalidomide Era

Growth factor and chemotherapy-based stem cell mobilization strategies are commonly used to treat patients with multiple myeloma. We retrospectively compared 398 patients mobilized between 2017 and 2020 using either cyclophosphamide (4 g/m²) plus granulocyte colony-stimulating factor (G-CSF) or G-CSF alone, with on demand plerixafor (PXF) in both groups. Although total CD34⁺ yield was higher after chemomobilization compared with G-CSF +/- PXF (median, 13.6 × 10⁶/kg versus 4.4 × 10⁶/kg; P < .01), achievement of ≥2 × 10⁶ CD34⁺ cells (95% versus 93.7%; P = .61) and rates of mobilization failure (5% versus 6.3%; P = .61) were similar. Fewer patients required PXF with chemomobilization (12.3% versus 49.5%; P < .01), and apheresis sessions were fewer (median, 1 [range, 1 to 4] versus 2 [range, 1 to 5]). The rate of complications, including neutropenic fever, emergency department visits, and hospitalizations, was higher after chemomobilization (30% versus 7.4%; P < .01). Previous use of ≤6 cycles of lenalidomide did not impair cell yield in either group. The median cost of mobilization was 17.4% lower in the G-CSF +/- PXF group (P = .01). Between group differences in time to engraftment were not clinically significant. Given similar rates of successful mobilization, similar engraftment time, and less toxicity and lower costs compared with chemomobilization, G-CSF with on-demand PXF may be preferable in myeloma patients with adequate disease control and limited lenalidomide exposure.

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

Multiple myeloma (MM) accounts for 10% of all hematological malignancies, and it is the second most common hematological neoplasm for which chemotherapy is an important pharmacological treatment. High dose melphalan followed by autologous stem cell transplantation remains the standard of treatment for transplant-eligible patients with MM. In this review, we describe aspects of the pharmacokinetics and pharmacodynamics of melphalan therapy and related compounds. In addition, we describe the use of melphalan in innovative therapies for the treatment of MM, including the development of drug carriers to reduce systemic toxicity, combination therapy to improve the effectiveness of cancer therapy, and the chemical modification of the melphalan molecule to improve antitumor activity.

Overcoming the Immunosuppressive Tumor Microenvironment in Multiple Myeloma

Simple Summary

This article provides a comprehensive review of new and emerging treatment strategies against multiple myeloma that employ precision medicines and/or drugs capable of improving the ability of the immune system to prevent or slow down the progression of multiple myeloma. These rationally designed new treatment methods have the potential to change the therapeutic landscape in multiple myeloma and improve the long-term survival outcome.

Abstract

SeverFigurel cellular elements of the bone marrow (BM) microenvironment in multiple myeloma (MM) patients contribute to the immune evasion, proliferation, and drug resistance of MM cells, including myeloid-derived suppressor cells (MDSCs), tumor-associated M2-like, “alternatively activated” macrophages, CD38+ regulatory B-cells (Bregs), and regulatory T-cells (Tregs). These immunosuppressive elements in bidirectional and multi-directional crosstalk with each other inhibit both memory and cytotoxic effector T-cell populations as well as natural killer (NK) cells. Immunomodulatory imide drugs (IMiDs), protease inhibitors (PI), monoclonal antibodies (MoAb), adoptive T-cell/NK cell therapy, and inhibitors of anti-apoptotic signaling pathways have emerged as promising therapeutic platforms that can be employed in various combinations as part of a rationally designed immunomodulatory strategy against an immunosuppressive tumor microenvironment (TME) in MM. These platforms provide the foundation for a new therapeutic paradigm for achieving improved survival of high-risk newly diagnosed as well as relapsed/refractory MM patients. Here we review the scientific rationale and clinical proof of concept for each of these platforms.

Prolonged Lenalidomide Therapy Does Not Impact Autologous Peripheral Blood Stem Cell Mobilization and Collection in Multiple Myeloma Patients: A Single-Center Retrospective Analysis

Since the introduction of lenalidomide into induction therapy for multiple myeloma (MM), there have been conflicting reports about its impact on autologous peripheral blood stem cell (PBSC) mobilization. We evaluated the impact of previous lenalidomide exposure in a large cohort of patients with MM undergoing mobilization and collection at a tertiary stem cell transplantation center. We hypothesized that collection of PBSCs is feasible even with a prolonged duration of previous lenalidomide therapy. We examined patients with MM who attempted stem cell mobilization and collection, seen at our center between January 2012 and July 2015. The patients were categorized into 3 groups for analysis: (1) patients with previous receipt of >6 cycles lenalidomide, (2) patients with previous receipt of ≤6 cycles of lenalidomide, and (3) patients without previous lenalidomide exposure. We compared collection yields and days of apheresis among the 3 groups using linear regression analysis. We identified 297 patients with MM who underwent mobilization of PBSCs. Of these, 35 had received >6 cycles of lenalidomide (median, 8 cycles; range, 7 to 25 cycles), 156 had received ≤6 cycles of lenalidomide (median, 4 cycles; range, 1 to 6 cycles), and 106 had received no lenalidomide. Prior lenalidomide exposure did not have a statistically significant impact on the absolute number of CD34⁺ cells collected or on the duration of collection based on a multivariate linear regression analysis for association between receipt of >6 cycles of lenalidomide. In this retrospective analysis of MM patients undergoing autologous PBSC transplantation, we show that the duration of previous lenalidomide exposure does not impact the total number of PBSCs collected or the number of days of apheresis. These data suggest that longer courses of induction therapy with lenalidomide-containing regimens to achieve a maximum response can be safe without impairing the ability to collect PBSCs, and that limiting lenalidomide use before mobilization does not appear warranted in all cases.

Myeloma-Secreted Galectin-1 Potently Interacts with CD304 on Monocytic Myeloid-Derived Suppressor Cells

Progression of multiple myeloma is regulated by factors intrinsic to the clonal plasma cells (PC) and by the immune effector cells in the tumor microenvironment. In this study, we investigated the interaction between CD304 expression on myeloid-derived suppressor cells (MDSC) and galectin-1 from malignant PCs in the context of autologous stem cell transplantation (ASCT) for multiple myeloma. Using high-throughput screening, CD304 expression on circulating monocytic MDSCs (M-MDSC; CD14⁺HLA-DR^low/-) was compared before and after ASCT. There was a significantly higher M-MDSC expression of CD304 before ASCT and a clear correlation between circulating pre-ASCT M-MDSC frequency and serum galectin-1 concentration. Treatment of pre-ASCT M-MDSCs, but not post-ASCT M-MDSCs, with galectin-1 in vitro expanded the M-MDSC population and increased expression of CD304. High galectin-1 expression by malignant PCs was associated with poor clinical outcomes. M-MDSC development and expression of CD304 were differentially induced when healthy donor peripheral blood mononuclear cells were cultured with the human multiple myeloma cell lines RPMI-8226 and JJN3, which express high and low galectin-1, respectively. Inhibition of galectin-1 reduced M-MDSC proliferation induced by RPMI-8226 cells but not by JJN3 cells, and blockade of CD304 reduced M-MDSC migration induced by RPMI-8226 cells but not by JJN3 cells. In addition, blockade of CD304 reversed suppression of the in vitro cytotoxic effect of melphalan by pre-ASCT M-MDSCs. Our data demonstrate that multiple myeloma-derived galectin-1 could mediate the tumor-promoting effect of M-MDSCs through its interaction with CD304 on M-MDSCs and contribute to multiple myeloma progression after ASCT.See related Spotlight on p. 488.

Oral ixazomib, lenalidomide, and dexamethasone for transplant-ineligible patients with newly diagnosed multiple myeloma

Addition of ixazomib to Rd in nontransplant NDMM patients resulted in a nonstatistically significant increase in PFS (HR, 0.830; P = .073).

Ixazomib-Rd is a feasible and tolerable all-oral triplet regimen in this setting, with a well-characterized and manageable safety profile.

Continuous lenalidomide-dexamethasone (Rd)-based regimens are among the standards of care in transplant-ineligible newly diagnosed multiple myeloma (NDMM) patients. The oral proteasome inhibitor ixazomib is suitable for continuous dosing, with predictable, manageable toxicities. In the double-blind, placebo-controlled TOURMALINE-MM2 trial, transplant-ineligible NDMM patients were randomized to ixazomib 4 mg (n = 351) or placebo (n = 354) plus Rd. After 18 cycles, dexamethasone was discontinued and treatment was continued using reduced-dose ixazomib (3 mg) and lenalidomide (10 mg) until progression/toxicity. The primary endpoint was progression-free survival (PFS). Median PFS was 35.3 vs 21.8 months with ixazomib-Rd vs placebo-Rd, respectively (hazard ratio [HR], 0.830; 95% confidence interval, 0.676-1.018; P = .073; median follow-up, 53.3 and 55.8 months). Complete (26% vs 14%; odds ratio [OR], 2.10; P < .001) and ≥ very good partial response (63% vs 48%; OR, 1.87; P < .001) rates were higher with ixazomib-Rd vs placebo-Rd. In a prespecified high-risk cytogenetics subgroup, median PFS was 23.8 vs 18.0 months (HR, 0.690; P = .019). Overall, treatment-emergent adverse events (TEAEs) were mostly grade 1/2. With ixazomib-Rd vs placebo-Rd, 88% vs 81% of patients experienced grade ≥3 TEAEs, 66% vs 62% serious TEAEs, and 35% vs 27% TEAEs resulting in regimen discontinuation; 8% vs 6% died on study. Addition of ixazomib to Rd was tolerable with no new safety signals and led to a clinically meaningful PFS benefit of 13.5 months. Ixazomib-Rd is a feasible option for certain patients who can benefit from an all-oral triplet combination. This trial was registered at www.clinicaltrials.gov as #NCT01850524.

Boosting Immunity against Multiple Myeloma

Despite the improvement of patient's outcome obtained by the current use of immunomodulatory drugs, proteasome inhibitors or anti-CD38 monoclonal antibodies, multiple myeloma (MM) remains an incurable disease. More recently, the testing in clinical trials of novel drugs such as anti-BCMA CAR-T cells, antibody-drug conjugates or bispecific antibodies broadened the possibility of improving patients' survival. However, thus far, these treatment strategies have not been able to steadily eliminate all malignant cells, and the aim has been to induce a long-term complete response with minimal residual disease (MRD)-negative status. In this sense, approaches that target not only myeloma cells but also the surrounding microenvironment are promising strategies to achieve a sustained MRD negativity with prolonged survival. This review provides an overview of current and future strategies used for immunomodulation of MM focusing on the impact on bone marrow (BM) immunome.

Multi-omics tumor profiling technologies to develop precision medicine in multiple myeloma

Multiple myeloma (MM), the second most common hematologic cancer, is caused by accumulation of aberrant plasma cells in the bone marrow. Its molecular causes are not fully understood and its great heterogeneity among patients complicates therapeutic decision-making. In the past decades, development of new therapies and drugs have significantly improved survival of MM patients. However, resistance to drugs and relapse remain the most common causes of mortality and are the major challenges to overcome. The advent of high throughput omics technologies capable of analyzing big amount of clinical and biological data has changed the way to diagnose and treat MM. Integration of omics data (gene mutations, gene expression, epigenetic information, and protein and metabolite levels) with clinical histories of thousands of patients allows to build scores to stratify the risk at diagnosis and predict the response to treatment, helping clinicians to make better educated decisions for each particular case. There is no doubt that the future of MM treatment relies on personalized therapies based on predictive models built from omics studies. This review summarizes the current treatments and the use of omics technologies in MM, and their importance in the implementation of personalized medicine.

Multi-omics tumor profiling technologies to develop precision medicine in multiple myeloma

Multiple myeloma (MM), the second most common hematologic cancer, is caused by accumulation of aberrant plasma cells in the bone marrow. Its molecular causes are not fully understood and its great heterogeneity among patients complicates therapeutic decision-making. In the past decades, development of new therapies and drugs have significantly improved survival of MM patients. However, resistance to drugs and relapse remain the most common causes of mortality and are the major challenges to overcome. The advent of high throughput omics technologies capable of analyzing big amount of clinical and biological data has changed the way to diagnose and treat MM. Integration of omics data (gene mutations, gene expression, epigenetic information, and protein and metabolite levels) with clinical histories of thousands of patients allows to build scores to stratify the risk at diagnosis and predict the response to treatment, helping clinicians to make better educated decisions for each particular case. There is no doubt that the future of MM treatment relies on personalized therapies based on predictive models built from omics studies. This review summarizes the current treatments and the use of omics technologies in MM, and their importance in the implementation of personalized medicine.

Low-Dose Cyclophosphamide versus Intermediate-High-Dose Cyclophosphamide versus Granulocyte Colony-Stimulating Factor Alone for Stem Cell Mobilization in Multiple Myeloma in the Era of Novel Agents: A Multicenter Retrospective Study

The optimal stem cell (SC) mobilization strategy for patients with multiple myeloma (MM) remains a matter of debate. Possible approaches include low or high doses of cyclophosphamide (Cy), other chemotherapeutic agents, or granulocyte colony-stimulating factor (G-CSF) alone. The scope of the study was to compare low-dose Cy plus G-CSF versus intermediate-high-dose Cy plus G-CSF versus G-CSF alone for SC mobilization in MM, in terms of efficacy and safety. We retrospectively analyzed 422 MM patients undergoing SC mobilization in 6 Italian centers, including 188 patients who received low-dose Cy (LD-Cy group, defined as 2 g/m²), 163 patients who received intermediate-high-dose Cy (HD-Cy group, defined as ≥ 3 g/m²), and 71 patients who received G-CSF alone (G-CSF group). The median peak of circulating CD34+ cells was 77/µL in the LD-Cy group, 92/µL in the HD-Cy group, and 55/µL in the G-CSF group (P = .0001). The median amount of SCs collected was 9.1 × 10⁶/kg, 9.7 × 10⁶/kg, and 5.6 × 10⁶/kg in the 3 groups, respectively (P = .0001). The rate of mobilization failure (defined as failure to collect ≥2 × 10⁶/kg) was 3.7% in the LD-Cy group, 3.4% in the HD-Cy group, and 4.3% in the G-CSF group (P = .9). The target SC dose of at least 4 × 10⁶/kg was reached in 90.4%, 91.1%, and 78.6% of the patients in these 3 groups, respectively (P = .014). The "on demand" use of plerixafor was higher in the G-CSF group (76%) compared with the LD-Cy group (19%) and the HD-Cy group (6%). In multivariate analysis, G-CSF mobilization and previous use of melphalan or radiotherapy were independently associated with failure to collect the target SC dose of ≥4 × 10⁶/kg. No impacts of age, blood counts, or previous treatment with lenalidomide, bortezomib, or carfilzomib were observed. Our results suggest that LD-Cy may be considered for successful SC mobilization in patients with MM.

Belantamab Mafodotin to Treat Multiple Myeloma: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple myeloma (MM) is a hematologic malignancy characterized by excessive clonal proliferation of plasma cells. The treatment of multiple myeloma presents a variety of unique challenges due to the complex molecular pathophysiology and incurable status of the disease at this time. Given that MM is the second most common blood cancer with a characteristic and unavoidable relapse/refractory state during the course of the disease, the development of new therapeutic modalities is crucial. Belantamab mafodotin (belamaf, GSK2857916) is a first-in-class therapeutic, indicated for patients who have previously attempted four other treatments, including an anti-CD38 monoclonal antibody, a proteosome inhibitor, and an immunomodulatory agent. In November 2017, the FDA designated belamaf as a breakthrough therapy for heavily pretreated patients with relapsed/refractory multiple myeloma. In August 2020, the FDA granted accelerated approval as a monotherapy for relapsed or treatment-refractory multiple myeloma. The drug was also approved in the EU for this indication in late August 2020. Of note, belamaf is associated with the following adverse events: decreased platelets, corneal disease, decreased or blurred vision, anemia, infusion-related reactions, pyrexia, and fetal risk, among others. Further studies are necessary to evaluate efficacy in comparison to other standard treatment modalities and as future drugs in this class are developed.

Gut Microbiota Influence in Hematological Malignancies: From Genesis to Cure

Hematological malignancies, including multiple myeloma, lymphoma, and leukemia, are a heterogeneous group of neoplasms that affect the blood, bone marrow, and lymph nodes. They originate from uncontrolled growth of hematopoietic and lymphoid cells from different stages in their maturation/differentiation and account for 6.5% of all cancers around the world. During the last decade, it has been proven that the gut microbiota, more specifically the gastrointestinal commensal bacteria, is implicated in the genesis and progression of many diseases. The immune-modulating effects of the human microbiota extend well beyond the gut, mostly through the small molecules they produce. This review aims to summarize the current knowledge of the role of the microbiota in modulating the immune system, its role in hematological malignancies, and its influence on different therapies for these diseases, including autologous and allogeneic stem cell transplantation, chemotherapy, and chimeric antigen receptor T cells.

Treatment pathways and disease journeys differ before and after introduction of novel agents in newly diagnosed multiple myeloma in Taiwan

Limited real-world data are available regarding treatment practices and outcomes of multiple myeloma (MM) in Asia. We conducted a retrospective cohort study using the Taiwan National Healthcare Insurance Research database and Taiwan Death Registry and used a Markov model to describe disease progression and outcomes in 4092 patients newly diagnosed with MM from 01-Jan-2007 to 31-Dec-2015. We observed marked differences in the characteristics, length and outcome of the clinical journey between patients who did/did not receive autologous stem cell transplant, and between patients initiated on novel agents versus other treatment regimens. In transplant recipients, initiation with combined thalidomide + bortezomib increased over time (12.2–77.5%). Progression-free survival after first-line treatment improved and a lower percentage of patients died. Lenalidomide in second and third-line regimens increased (15.5–31.5%). In non-transplanted patients, initiation with novel agents increased (17.5–54.6%), but death rates remained high (60.3%). The treatment landscape of MM in Taiwan has evolved, with increased use of combined bortezomib + thalidomide for first-line and lenalidomide for second/third-line but many patients die before receiving second-line treatment. Novel agents with different modes of action should be used as early as possible to maximize their benefits. Improved MM treatments remains a critical medical need.

CD34+ hematopoietic progenitor cell dose as a predictor of engraftment and survival in multiple myeloma patients undergoing autologous stem cell transplantation

Background/aim

High-dose melphalan and autologous hematopoietic stem cell transplantation (AHSCT) is the standard treatment strategy for multiple myeloma (MM) patients who are eligible for it. The recommended dose of CD34+ hematopoietic progenitor cells (HPCs) for adequate engraftment is above 2 × 106/kg. The aim of this study was to evaluate the relationship between the dose of CD34+HPCs and survival in MM patients who underwent AHSCT at a tertiary care center.

Materials and methods

Enrolled in this study were 271 MM patients who underwent AHSCT between 2003 and 2019. Clinical characteristics of the patients, disease status pre-AHSCT, reinfused CD34+ cell doses, and neutrophil and platelet engraftment days were recorded, retrospectively. The patients were divided into 2 groups according to whether the dose of reinfused CD 34+ HPCs was <5 × 106/kg or ≥5 × 106/kg. The groups were compared in terms of engraftment and overall survival (OS) times.

Results

The median age of the patients was 54.8 (33–76) years. The median dose of infused CD34+ HPCs was 5.94 × 106/kg (1.47–59.5 × 106/kg). The median follow-up period was 54 months (4–211). The median OS of the patients was 103 months (11–144). The median neutrophil and platelet engraftment time was 10 (8–24) and 11 (7–40) days. Doses of <5 × 106/kg and ≥5 × 106/kg CD34+ HPC were reinfused in 38.1% and 61.9% of the patients, respectively. There was a negative significant correlation between the reinfused CD34+cell level and neutrophil/platelet engraftment times (r = –0.32, P < 0.001; r = –0.27, P < 0.001, respectively). The median OS times were observed as 103 months (11–144) and 145 months (123–166) for patients who had been administered <5 × 106/kg and ≥5 × 106/kg of CD34+ HPCs, respectively (P = 0.009).

Conclusion

The increased amount of CD34+ autologous hematopoietic stem cell dose after high dose melphalan chemotherapy in MM patients shortened the platelet and neutrophil engraftment time and increased OS. Early platelet engraftment and administration of a CD34+ HPC count that is ≥5 × 106/kg can be considered as predictors of better survival in patients.

Outcomes of Non-Cryopreserved Versus Cryopreserved Peripheral Blood Stem Cells for Autologous Stem Cell Transplantation in Multiple Myeloma

BACKGROUND Autologous stem cell transplantation (ASCT) has become a standard procedure in multiple myeloma (MM) patients. Cryopreservation (CRYO) of stem cells may be associated with adverse reactions of dimethyl sulfoxide. Previous studies showed that stem cell storage at 4°C (non-cryopreserved [NC] method) may have some advantages. This analysis focused on comparing the transplant-related outcomes of the 2 preservation methods. MATERIAL AND METHODS This was a cohort study of consecutive MM patients who underwent ASCT at Chiang Mai University from 2014 to 2019. Primary outcomes were time to neutrophil and platelet engraftment. Key secondary outcomes were the incidence of infusion reactions, duration of hospitalization, cost, and survival. RESULTS A total of 42 MM patients underwent ASCT. Of these, 26 patients and 16 patients underwent NC and CRYO stem cell collections, respectively. There was no difference in time to neutrophil engraftment (median 12 vs. 10.5 days, P=0.203) or platelet engraftment (median 14 vs. 12 days, P=0.809) between groups. The incidence of infusion reactions and duration of hospitalization were similar in both groups. The average cost of ASCT was 10% lower in the NC group. There was no difference in progression-free survival (median 16 vs. 22 months, P=0.701) or overall survival between NC and CRYO groups. CONCLUSIONS ASCT in MM using the NC preservation method is effective and safe compared to the CRYO method in both short-term and survival outcomes.

Autologous stem cell transplantation (ASCT) outcome for multiple myeloma in a tertiary referral centre in Malaysia

Background

Multiple Myeloma (MM) is characterized by the presence of clonal plasma cells. These often result in complications including bone destruction, hypercalcemia, renal insufficiency, and anaemia. Induction with a triplet or quadruplet regimen followed by autologous stem cell transplantation (ASCT) has been the standard of care for transplant eligible patients to achieve durable remission.

Purpose

This is a retrospective analytical study to determine the outcome of Multiple Myeloma patients who underwent ASCT in Ampang Hospital.

Materials and Methods

We included a 5-year cohort of patients transplanted from 1st July 2014 to 30th June 2019. Data were obtained through electronic medical records. Prognostic factors for progression-free survival (PFS) and overall survival (OS) were analyzed using simple and multiple Cox proportional hazard regression analysis. All analyses were done using software R version 3.6.2 with validated statistical packages.

Results

139 patients were analyzed. The median age at transplant was 56 years old and 56.1% are males (n＝78). The most common subtype is IgG Kappa (n＝67, 48.2%). Only 93 patients in which the International Staging System (ISS) could be determined, and among them, 33.3% of patients (n＝31) have advanced stage Ⅲ disease. The most common induction received before ASCT was a bortezomib based regimen and/or an immunomodulatory (IMiD) based regimen. 63.3% of patients achieved at least a very good partial response (VGPR) before ASCT. Most patients received myeloablative conditioning (MAC) (n＝119, 85.6%). The mean cell dose is 3.68×10⁶/kg. The median time to engraftment was 11 days for both platelet and absolute neutrophil count (ANC). With the median follow-up of 17.3 (range, 6.2-33.4) months, the median OS and PFS were not reached. The 1-year and 2-year PFS were 75% (95% CI 66-82%) and 52% (95% CI 42-62%), respectively. The 1-year and 2-year OS were 82% (95% CI 74-88%) and 70% (95% CI 60-78%), respectively. 6 patients (4.3%) had transplant-related mortality (TRM). IgA subtype was found to adversely affect PFS. Maintenance therapy and the absence of renal impairment was associated with better PFS and OS.

Discussion and Conclusions

Our study found that ASCT following induction treatment is safe and beneficial to achieve a deeper remission status. In our study, the addition of maintenance therapy is associated with an improved outcome in PFS and OS.

Relapsed/Progressive Disease and Its Prognostic Factors among Multiple Myeloma Patients Receiving Novel Agent Treatment in North East Peninsular Malaysia: A Single Centre Experience

Background

Some multiple myeloma (MM) patients still relapse/progress despite novel agent therapy and relapse/progression in MM is therefore a vital area of ongoing research in the novel treatment era. This retrospective cohort study aimed to evaluate the time to relapse/progression (TTP) among MM patients who received novel agents and to determine the associated prognostic factors.

Methods

This study included 89 MM patients treated at Hospital Universiti Sains Malaysia. We analysed the TTP and the type of relapse/progression (biochemical versus clinical), and a Cox proportional hazard model was used to identify the significant prognostic factors.

Results

Sixty-four percent of patients had biochemical relapse/progression. The overall median TTP among MM patients who received the novel agent(s) was 29.33 months (95% CI: 21.36–37.29). The type of paraprotein at diagnosis (P = 0.026, P = 0.228), International Staging System (ISS) score (P = 0.036, P = 0.067) and autologous stem cell transplant (ASCT) (P = 0.002) were prognostic factors for relapse/progression by simple Cox regression, but ASCT was the only significant predictor detected by multiple Cox regression (P = 0.003).

Conclusion

Our study reflects the importance of paraprotein monitoring to detect early features of relapse/progression. ASCT is the most prognostic factor that may lengthen the TTP.

Integrating evolutionary dynamics into cancer therapy

Many effective drugs for metastatic and/or advanced-stage cancers have been developed over the past decade, although the evolution of resistance remains the major barrier to disease control or cure. In large, diverse populations such as the cells that compose metastatic cancers, the emergence of cells that are resistant or that can quickly develop resistance is virtually inevitable and most likely cannot be prevented. However, clinically significant resistance occurs only when the pre-existing resistant phenotypes are able to proliferate extensively, a process governed by eco-evolutionary dynamics. Attempts to disrupt the molecular mechanisms of resistance have generally been unsuccessful in clinical practice. In this Review, we focus on the Darwinian processes driving the eco-evolutionary dynamics of treatment-resistant cancer populations. We describe a variety of evolutionarily informed strategies designed to increase the probability of disease control or cure by anticipating and steering the evolutionary dynamics of acquired resistance.

Development of a method for clinical pharmacokinetic testing to allow for targeted Melphalan dosing in multiple myeloma patients undergoing autologous transplant

AIMS

High dose melphalan (HDM) and autologous stem cell transplant (ASCT) is standard of care for multiple myeloma (MM), but there is significant variability in melphalan exposure (area under the plasma drug concentration-time curve, AUC) when using body surface area-based dosing. Our aim was to establish a method of pharmacokinetic (PK) testing for real-time melphalan dose adjustments.

METHODS

We performed a prospective PK study of melphalan 140 or 200 mg/m2 in MM patients undergoing ASCT. Twenty MM patients were administered HDM on days -2 and - 1, with PK sampling at 8-10 time points. PK testing was performed on day -2 in all patients, and on day -1 in 5 patients.

RESULTS

Less than 20% interpatient variation in the day -2 and - 1 AUC was observed. The day -2 range in AUC (4.95-11.28 mg h/L) confirmed significant interpatient variability. The hypothetical total dose ranged from 133-302 mg/m2 to achieve the total median AUC. A 4-time point AUC (0, 30, 150 and 240 min) highly correlated with the AUC from the 8-time point schedule. A higher AUC correlated with increased risk of febrile neutropenia (P = .05).

CONCLUSION

Here we outline the methods to establish novel melphalan dosing using PK testing in MM patients undergoing ASCT to target a desired melphalan AUC.

Prophylactic corticosteroid use prevents engraftment syndrome in patients after autologous stem cell transplantation

Engraftment syndrome (ES) following autologous stem cell transplantation (ASCT) at the time of neutrophil recovery may comprise fever, rash, pulmonary edema, or diarrhea. Usually, ES is easily manageable using corticosteroids but may prolong hospitalization. In two consecutive cohorts of subsequent patients with myeloma, lymphomas, and testicular/germ cell cancer, we assessed the benefit of corticosteroid use to prevent incidence and severity of ES following ASCT. Whereas Cohort A (82 patients) received no prophylactic corticosteroids, corticosteroids (4 mg dexamethasone oral daily) were started in Cohort B (60 patients) at day +9 until day +13 following ASCT. Steroid prophylaxis significantly reduced the incidence of ES (6/60; 10% vs. 33/82; 40%; p < 0.001). Hospitalization duration was longer in patients with ES than in patients without ES within both cohorts (in Cohort A: p = 0.007; and B: p = 0.011), but did not differ significantly between cohorts A and B. Finally, in Cohort A, there was a trend to an inferior 2-year overall survival rate in patients without ES compared to patients with ES (p = 0.067), but definite conclusions are not yet allowed. Our results suggest that corticosteroid prophylaxis from days +9 to +13 following ASCT significantly reduces the risk of ES and shortens hospitalization duration.

Melflufen: A Peptide-Drug Conjugate for the Treatment of Multiple Myeloma

Despite the availability of new therapies that have led to improved outcomes for patients with multiple myeloma, most patients will eventually relapse. With triplet and even quadruplet combination therapies becoming standard in the first and second line, many patients will have few treatment options after second-line treatment. Melflufen (melphalan flufenamide) is a first-in-class peptide-drug conjugate (PDC) that targets aminopeptidases and rapidly releases alkylating agents into tumor cells. Once inside the tumor cells, melflufen is hydrolyzed by peptidases to release alkylator molecules, which become entrapped. Melflufen showed anti-myeloma activity in myeloma cells that were resistant to bortezomib and the alkylator melphalan. In early phase studies (O-12-M1 and HORIZON [OP-106]), melflufen plus dexamethasone has demonstrated encouraging clinical activity and a manageable safety profile in heavily pretreated patients with relapsed/refractory multiple myeloma, including those with triple-class refractory disease and extramedullary disease. The Phase III OCEAN study (OP-104) is further evaluating melflufen plus dexamethasone in patients with relapsed/refractory multiple myeloma. The safety profile of melflufen is characterized primarily by clinically manageable hematologic adverse events. Melflufen, with its novel mechanism of action, has the potential to provide clinically meaningful benefits to patients with relapsed/refractory multiple myeloma, including those with high unmet needs.

Management of newly diagnosed transplant ineligible multiple myeloma

Multiple myeloma (MM) is a chronically managed blood cancer with a median age of 69 years at the time of diagnosis. Although high dose melphalan and autologous stem cell transplantation (ASCT) remains a standard of care for eligible patients, more than half of the newly diagnosed MM patients are deemed ineligible due to comorbidities or complications of the disease by itself. In this setting, where ASCT is deemed inappropriate, patients could still achieve durable and deep responses if given the appropriate treatment plan. The key concepts of optimizing induction and maintenance strategies while minimizing side-effects are discussed in this review, especially in the context of employing novel agent combinations. It is important to understand the balance between safety and efficacy for each regimen, utilizing maintenance strategy and the best supportive care measures (bone health, infection prevention, and treatment, pain management, etc.). Here, we examine the evidence behind each of those principles and review results from clinical trials for transplant-ineligible (TI) MM.

Long-term outcomes of innovator versus generic melphalan formulation in autologous hematopoietic cell transplantation for multiple myeloma

BACKGROUND

Most data on autologous hematopoietic cell transplantation (auto-HCT) in myeloma are based on the use of innovator formulation of melphalan. Comparative bioequivalence and efficacy studies of generic melphalan are lacking.

METHODS

In this retrospective study, we report long-term outcomes of auto-HCT in myeloma using innovator (Alkeran, Aspen Pharma; n = 41) and generic melphalan (Alkacel, Celon Labs, India; n = 55) formulations. All consecutive patients at a single center from the period 2011-2018 were included.

RESULTS

The median follow-up in the innovator and generic groups was 61.7 and 32.5 months, respectively. Both groups were matched for age, sex, stage, and myeloma response. There were significantly more patients in the innovator melphalan group who were administered melphalan at a reduced dose at physician discretion (26.8% vs. 3.6%, p = .001). There were significantly more patients with grade 3 or higher mucositis (68.3% vs. 38.1%, p < .0001) and grade 3 or higher diarrhea (85.4% vs. 50.1%, p < .0001) in the innovator group. The median duration of hospital stay was significantly longer in the innovator group (19 days vs. 15.5 days, p < .0001). There were significantly more patients in the generic group who received standard maintenance (94.5% vs. 34.1%, p < .0001). Despite the differences in the melphalan dose and post-transplant strategies, the 4-year progression-free survival and overall survival were not significantly different in the two groups (58% vs. 63%, p = .7, 71% vs. 72%, p = .4, respectively).

CONCLUSION

Long-term efficacy comparison is helpful in the absence of postmarketing bioequivalence studies of generic melphalan.

Minimal Residual Disease in Multiple Myeloma: Current Landscape and Future Applications With Immunotherapeutic Approaches

The basic principle that deeper therapeutic responses lead to better clinical outcomes in cancer has emerged technologies capable of detecting rare residual tumor cells. The need for ultra-sensitive approaches for minimal residual disease (MRD) detection is particularly evident in Multiple Myeloma (MM), where patients will ultimately relapse despite the achievement of complete remission, which is commonplace due to remarkable therapeutic advances. Consequently, current response criteria on MM have been amended based on MRD status and MRD negativity is now considered the most dominant prognostic factor and the most valuable indicator for a subsequent relapse. However, there are particular limitations and several aspects for MRD assessment that remain open. This review summarizes current data on MRD in the clinical management of MM, highlights open issues and discusses the challenges and the endless opportunities arising for both patients and clinicians. Furthermore, it focuses on the current status of MRD in clinical trials, its dynamics in addressing debatable aspects in the clinical handling and its potential role as the prevailing factor for future MRD-driven tailored therapies.

Maintenance Strategies After Hematopoietic Cell Transplantation

Hematopoietic cell transplantation (HCT) is an essential component of potentially curative therapy for patients with hematologic malignancies. High-dose chemotherapy with autologous (auto) stem cell rescue is used to overcome chemoresistance in multiple myeloma, non-Hodgkin lymphoma, and Hodgkin lymphoma. Alternatively, poor-risk acute leukemias rely on the graft versus leukemia effect of allogeneic (allo) products. Long-term remissions are feasible with both auto- and allo-HCT; however, disease relapse is the leading cause of death after HCT for many patients. In recognition of this, novel therapies are being investigated in the upfront, relapsed/refractory, and post-HCT maintenance settings to deepen response and maintain disease control. To date, the most robust data to support this approach are in multiple myeloma, where post-transplant maintenance therapy has improved clinical outcomes. In Hodgkin lymphoma, patients with high-risk features may benefit from post-auto-HCT vedotin (BV) regardless of pre-HCT BV exposure. Apart from mantle cell lymphoma, where rituximab maintenance is generally accepted, post-auto-HCT maintenance in other forms of NHL is less established. In patients who undergo allo-HCT, the utilization of maintenance therapy is an important component of improving post-HCT outcomes, however, an individualized approach that considers patient factors such as residual toxicity from HCT, an immature graft with poor graft function, infection, and graft-versus-host disease create a complex environment for aggressive interventions. Initiation of directed agents in patients with identified mutations prior to allo-HCT, including FLT3 in acute myeloid leukemia and Philadelphia chromosome in acute lymphoid leukemia have generally improved post-HCT outcomes. Ongoing studies are exploring the safety and efficacy of additional maintenance strategies post-allo-HCT in an effort to further improve post-HCT outcomes.

Incorporating hematopoietic stem-cell transplantation after second-line carfilzomib-lenalidomide-dexamethasone (KRd)

Background:

Traditionally believed to be an integral part of multiple myeloma (MM) treatment, the role of hematopoietic stem-cell transplantation (HSCT) is being challenged. As such, we sought to evaluate the impact of HSCT in the era of novel agents.

Methods:

A multicenter, retrospective, longitudinal cohort study was carried out between January 2016 and December 2018. A total of 55 patients who received VTD (bortezomib-thalidomide-dexamethasone) as first-line treatment and KRd (carfilzomib-lenalidomide-dexamethasone) as second-line treatment were analyzed for outcomes.

Results:

The enrolled patients were divided into Group 1, defined as those who continued KRd treatment until progression (n = 41), versus Group 2, defined as those who underwent HSCT after a certain number of cycles of KRd (n = 14). Both groups showed a generally favorable response to KRd, with overall response rate (ORR) of 87.9% and clinical benefit rate of 92.8% after a median of seven cycles in Group 1, and ORR 92.8% and clinical benefit rate 100% after median of five cycles in Group 2. However, significantly poorer progression-free survival (PFS) (p = 0.004) was observed in Group 1 (median 12 months) compared with Group 2 (median not reached). Multivariate analyses identified HSCT after KRd as potential risk factors associated with PFS. Also, in Group 1, bortezomib refractoriness was associated with significantly shorter PFS compared with those who were responsive (median 12 months versus 14 months, respectively, p = 0.039).

Conclusions:

In conclusion, even with the advent of novel agents, HSCT still remains a valuable treatment modality with additive efficacy.

A case report: high dose melphalan as a conditioning regimen for multiple myeloma induces sinus arrest

High dose melphalan is commonly used as a conditioning regimen for autologous stem cell transplantation in multiple myeloma. There are reports of adverse cardiac events with melphalan manifested by supraventricular tachycardia and atrial fibrillation. Here, we report a rare case of a 58 year old female with multiple myeloma, who developed sinus arrest after autologous stem cell transplantation using high dose melphalan as a conditioning regimen. It was severe and rare, therefore, monitoring for cardiac toxicity in patients receiving high-dose melphalan is mandatory.

Identifying and treating candidates for checkpoint inhibitor therapies in multiple myeloma and lymphoma

Introduction: One of the hallmarks of cancerogenesis is the ability of tumor cells to evade the immune system. They can achieve it by abusing inhibitory immune checkpoint pathways, which, under normal circumstances, maintain peripheral tolerance during infection. Immune checkpoint inhibitors, especially anti-PD-1/PD-L1 monoclonal antibodies, currently represent a widely discussed treatment option not only in solid oncology, but in hematology-oncology as well.Areas covered: The manuscript is focused on clinical research concerning PD-1/PD-L1 blockade in lymphoma and multiple myeloma in order to identify the patients who would profit the most from this treatment modality. The authors reviewed articles on the topic on PubMed and relevant clinical trials on clinicaltrials.gov before October 2019.Expert opinion: So far, nivolumab and pembrolizumab have been approved for treating patients with relapsed/refractory classical Hodgkin lymphoma and primary mediastinal B cell lymphoma. Nevertheless, monotherapy alone is not curative and a combinational approach is needed. Modern treatment strategies and combinations are comprehensively summarized in this manuscript. There is no approved immune checkpoint inhibitor for the multiple myeloma indication. Although the combination of PD-1/PD-L1 inhibitors with immunomodulatory agents initially seemed promising, unexpected immune related toxicities have stopped any further development. Novel strategies and more potent combinations in myeloma and lymphoma are further discussed in the manuscript.

Multiple myeloma: Role of autologous transplantation

Autologous stem cell transplantation (ASCT) has been the mainstay of multiple myeloma (MM) treatment for approximately 30 years. Although the continuous introduction of novel agents in the armamentarium against MM has questioned its value, ASCT remains a backbone treatment for fit MM patients. However, there is no unanimous approach for several aspects including the positioning of ASCT in the therapeutic algorithm either upfront or following the first relapse, the need for single or tandem ASCT, as well as the role of ASCT as salvage therapy. Furthermore, the anti-CD38 monoclonal antibodies along with the next generation proteasome inhibitors and immunomodulatory drugs provide a platform for optimizing the induction and consolidation/maintenance regimens. In this review, we present current data pertaining to all aspects of ASCT in MM, whereas we highlight the open issues that should be addressed in the design of future clinical trials in the field.

Delaying the use of high-dose melphalan with stem cell rescue in multiple myeloma is ready for prime time

The significant advances made in the treatment of multiple myeloma (MM) have allowed for a paradigm shift away from the early use of high-dose melphalan with autologous stem cell transplant (HDM-ASCT). In 2015 alone, the US Food and Drug Administration (FDA) approved 4 novel drugs for MM. Novel drugs and regimens have shown unprecedented efficacy, which has increased the tempo of new drug development. Furthermore, the FDA recently approved a diagnostic test to detect minimal residual disease (MRD) that will allow community clinicians to conduct real-time testing of MRD. Most importantly, frontline regimens based on immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have shown a large clinical benefit. The next era has begun, as several 4-drug combinations that include monoclonal antibodies are being evaluated in clinical trials in the attempt to replace HDM-ASCT in the treatment of MM. We and others have therefore questioned the need for early HDM-ASCT, especially in light of the possible complications. HDM-ASCT is associated not only with acute toxicities-cytopenia, infection, and even death-but also an increased risk of developing secondary cancers. This article discusses the historic context of HDM-ASCT, the modern role of HDM-ASCT given the availability of highly sensitive MRD testing, and the likely future of quadruplet treatment. In summary, patients who attain deep responses using IMiD- and PI-based regimens may not require early HDM-ASCT. A delayed approach to this treatment is acceptable, and might be preferred by patients.