Second malignancies in multiple myeloma; emerging patterns and future directions

Current understanding and management of CAR T cell-associated toxicities

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of several haematological malignancies and is being investigated in patients with various solid tumours. Characteristic CAR T cell-associated toxicities such as cytokine-release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are now well-recognized, and improved supportive care and management with immunosuppressive agents has made CAR T cell therapy safer and more feasible than it was when the first regulatory approvals of such treatments were granted in 2017. The increasing clinical experience with these therapies has also improved recognition of previously less well-defined toxicities, including movement disorders, immune effector cell-associated haematotoxicity (ICAHT) and immune effector cell-associated haemophagocytic lymphohistiocytosis-like syndrome (IEC-HS), as well as the substantial risk of infection in patients with persistent CAR T cell-induced B cell aplasia and hypogammaglobulinaemia. A more diverse selection of immunosuppressive and supportive-care pharmacotherapies is now being utilized for toxicity management, yet no universal algorithm for their application exists. As CAR T cell products targeting new antigens are developed, additional toxicities involving damage to non-malignant tissues expressing the target antigen are a potential hurdle. Continued prospective evaluation of toxicity management strategies and the design of less-toxic CAR T cell products are both crucial for ongoing success in this field. In this Review, we discuss the evolving understanding and clinical management of CAR T cell-associated toxicities.

Extramedullary relapse of multiple myeloma presenting as space-occupying lesion in liver treated with daratumumab, pomalidomide, dexamethasone and bendamustine

Extramedullary relapse in patients with multiple myeloma (MM) is often associated with loss of biochemical response and the appearance of measurable residual disease in the bone marrow. Fever is an unusual presenting manifestation of MM. Treatment of extramedullary relapse in patients progressing on proteasome inhibitors, anti-CD38 monoclonal antibodies and immunomodulatory drugs is challenging, as access to chimeric antigen receptor T-cells and bispecific antibodies is limited. We report a case of relapsed MM who presented with fever and hepatic space-occupying lesion mimicking hepatocellular carcinoma. In this case report, we also present our experience of using a novel combination regimen comprising Dara-Pom-Benda-Dexa (daratumumab, pomalidomide, dexamethasone and bendamustine) for relapsed MM.

Effects of methane emissions on multiple myeloma-related mortality rates: A World Health Organization perspective

In this research, it was aimed to evaluate effects of methane emissions on multiple myeloma related mortality rates. Two countries in Europe (Germany and Netherlands) and 1 country for each region (Turkey, USA, Brazil, Egypt, and Australia) were selected within The World Health Organization Database. Multiple myeloma mortality rates of countries between 2009 and 2019 were used as dependent variable of the research. Methane emission level and agriculture methane levels of countries were used as independent variables from The World Bank Database. Current health expenditure and healthy life expectancy were used as controlling variables. Multiple myeloma-related mortality rate was the highest in the USA, followed by Germany, Brazil, Turkey, Australia, Netherlands, and Egypt. Difference analysis results were significant (P < .05). Methane and agriculture methane emissions were the highest in the USA. Multiple myeloma mortality was positively correlated with methane emissions (R = 0.504; P < .01), agricultural methane emissions (R = 0.705; P < .01), and current health expenditure (R = 0.528; P < .01). According to year and country controlled correlation analysis results, multiple myeloma mortality (MMM) was positively correlated with methane emissions (R = 0.889; P < .01), agricultural methane emissions (R = 0.495; P < .01), and current health expenditure (R = 0.704; P < .01). Methane emission (B = 0.01; P < .05), Germany (B = 9010.81; P < .01), the USA (B = 26516.77; P < .01), and Brazil (B = 4886.14; P < .01) had significant effect on MMM. Nonagricultural methane production has an increasing effect on MMM. Therefore, by looking at the differences between agricultural methane emissions and general methane emissions, studies can be conducted that allow for more effective global comparisons.

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.

Isolated Non-Secretory Extramedullary Relapse of Multiple Myeloma Responded Completely to Localized Radiotherapy

Introduction

Non-secretory multiple myeloma (NSMM) is a rare form of multiple myeloma (MM) that is often difficult to detect and has not yet been well characterized. This is due to the lack of production or the presence of monoclonal protein (MP) levels below levels detectable by testing such as serum/urine electrophoresis and immunofixation.

Case Presentation

Two patients of ours were being treated for MM with typical courses of systemic therapy. By the third-line therapy, both developed an extramedullary mass, one in the pelvis and the other in the neck. In both cases, blood work showed no measurable MP, normal free light chain levels, and unremarkable skeletal surveys. Secondary malignancies were suspected due to the clinical presentation in each case, and biopsies confirmed the presence of non-secretory plasmacytomas. Both patients were only treated with localized radiotherapy with a total dose of 2,000 cGy in 5 fractions over 1 week. Ultimately, this resolved the original masses with no residual tumors. No changes had to be made to their systemic therapies, and both patients remained stable.

Conclusion

NSMM relapse is not unusual and should be suspected in patients with relapsed refractory disease. Relapse should be confirmed by a tissue biopsy, and secondary malignancies should be ruled out. Radiotherapy is an excellent option to treat localized relapse and preserve the current line of systemic anti-myeloma therapy.

Aiming for the cure in myeloma: Putting our best foot forward

Frontline therapy for multiple myeloma (MM) is evolving to include novel combinations that can achieve unprecedented deep response rates. Several treatment strategies exist, varying in induction regimen composition, use of transplant and or consolidation and maintenance. In this sea of different treatment permutations, the overarching theme is the powerful prognostic factors of disease risk and achievement of minimal residual disease (MRD) negativity. MM has significant inter-patient variability that requires treatment to be individualized. Risk-adapted and response-adapted strategies which are increasingly being explored to define the extent and duration of therapy, and eventually aim for functional curability. In addition, with T-cell redirection therapies rapidly revolutionizing myeloma treatments, the current standard of care for myeloma will change. This review analyzes the current relevant literature in upfront therapy for fit myeloma patients and provides suggestions for treatment approach while novel clinical trials are maturing.

Other malignancies in the history of CLL: an international multicenter study conducted by ERIC, the European Research Initiative on CLL, in HARMONY

Background

Patients with chronic lymphocytic leukemia (CLL) have a higher risk of developing other malignancies (OMs) compared to the general population. However, the impact of CLL-related risk factors and CLL-directed treatment is still unclear and represents the focus of this work.

Methods

We conducted a retrospective international multicenter study to assess the incidence of OMs and detect potential risk factors in 19,705 patients with CLL, small lymphocytic lymphoma, or high-count CLL-like monoclonal B-cell lymphocytosis, diagnosed between 2000 and 2016. Data collection took place between October 2020 and March 2022.

Findings

In 129,254 years of follow-up after CLL diagnosis, 3513 OMs were diagnosed (27.2 OMs/1000 person-years). The most common hematological OMs were Richter transformation, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Non-melanoma skin (NMSC) and prostate cancers were the most common solid tumors (STs).The only predictor for MDS and AML development was treatment with fludarabine and cyclophosphamide with/without rituximab (FC ± R) (OR = 3.7; 95% CI = 2.79-4.91; p < 0.001). STs were more frequent in males and patients with unmutated immunoglobulin heavy variable genes (OR = 1.77; 95% CI = 1.49-2.11; p < 0.001/OR = 1.89; 95% CI = 1.6-2.24; p < 0.001).CLL-directed treatment was associated with non-melanoma skin and prostate cancers (OR = 1.8; 95% CI = 1.36-2.41; p < 0.001/OR = 2.11; 95% CI = 1.12-3.97; p = 0.021). In contrast, breast cancers were more frequent in untreated patients (OR = 0.17; 95% CI = 0.08-0.33; p < 0.001).Patients with CLL and an OM had inferior overall survival (OS) than those without. AML and MDS conferred the worst OS (p < 0.001).

Interpretation

OMs in CLL impact on OS. Treatment for CLL increased the risk for AML/MDS, prostate cancer, and NMSC. FCR was associated with increased risk for AML/MDS.

Funding

AbbVie, and EU/EFPIAInnovative Medicines Initiative Joint Undertaking HARMONY grant n° 116026.

Multiple Myeloma in Adolescent and Young Adults: An ASCO CancerLinQ and SEER Analysis

BACKGROUND

Multiple myeloma (MM) is exceedingly rare in adolescents and young adults (AYAs) < 45 years of age.

METHODS

Real-world data from ASCO's CancerLinQ DiscoveryⓇ (CLQD) MM dataset and SEER were utilized to characterize demographics and outcomes of AYA MM patients in the United States in the modern treatment era. Frequencies of SPMs, VTEs, and infections were assessed, as were OS and cause of death.

RESULTS

A total of 1946 AYA MM patients from SEER and 1334 from CancerLinQ were included. In terms of SPMs, AYAs were more likely to develop ALL (RR 2.6, P = .003) and AML (RR 1.7, P = .034), and less likely to develop nonmelanoma skin cancer (RR 0.2, P = .001) and prostate cancer (RR 0.1, P = .013) than MM patients ≥ 45. AYAs were at lower risk of VTE (RR 0.75, P = .002) and slightly higher risk of infections (RR 1.11, P = .002). Median OS among AYA MM patients was significantly longer than MM patients ≥ 45 in both datasets. In the SEER cohort, female sex (HR 0.74, P = .003), non-Hispanic ethnicity (HR 0.73, P = .005), and annual household income ≥ $65,000 per year (HR 0.67, P = .001) were associated with lower hazards of mortality. In the CLQD cohort, OS was significantly influenced by female sex (HR 0.6, P = .048). Race did not have a statistically significant impact OS in either cohort. Most AYAs died of MM (68.3%), other primary malignancy (7.5%, mostly leukemia), and cardiovascular events (5.2%). Infections accounted for 3.2% of deaths.

CONCLUSION

This analysis highlights some unique characteristics of AYA MM patients in the United States in the modern era.

Outcome of Second Primary Malignancies Developing in Multiple Myeloma Patients

BACKGROUND

There is an increased risk of second primary malignancies (SMPs) in patients with multiple myeloma (MM). This multinational 'real-world' retrospective study analyzed the characteristics and outcomes of MM patients that developed SPMs.

RESULTS

165 patients were analyzed: 62.4% males; 8.5% with a prior cancer; 113 with solid SPMs, mainly ≥stage 2; and 52 with hematological SPM (hemato-SPM), mainly MDS/AML. Patients with hemato-SPM were younger (p = 0.05) and more frequently had a prior AutoHCT (p = 0.012). The time to SPM was shorter in the older (>65 years) and more heavily pretreated patients. One hundred patients were actively treated at the time of SPM detection. Treatment was discontinued in 52, substituted with another anti-MM therapy in 15, and continued in 33 patients. Treatment discontinuation was predominant in the patients diagnosed with hemato-SPM (76%). The median OS following SPM detection was 8.5 months, and the main cause of death was SPM. A poor ECOG status predicted a shorter OS (PS 3 vs. 0, HR = 5.74, 2.32-14.21, p < 0.001), whereas a normal hemoglobin level (HR = 0.43, 0.19-0.95, p = 0.037) predicted longer OS.

CONCLUSIONS

With the continuing improvement in OS, a higher proportion of MM patients might develop SPM. The OS following SPM diagnosis is poor; hence, frequent surveillance and early detection are imperative to improve outcomes.

The Effects of Second Primary Malignancies and Frailty on Overall Survival and Mortality in Geriatric Turkish Patients with Multiple Myeloma

The study aims to investigate second primary malignancy (SPM) development and frailty in Turkish geriatric patients with multiple myeloma (MM) and to assess the relationship between overall survival (OS) and various characteristics including SPM and frailty. Seventy-two patients diagnosed with and treated for MM were enrolled in the study. Frailty was determined by the IMWG Frailty Score. Fifty-three participants (73.6%) were found to have clinically-relevant frailty. Seven patients (9.7%) had SPM. Median follow-up was 36.5 (22-48.5) months, and 17 patients died during the follow-up period. Overall (OS) was 49.40 (45.01-53.80) months. Shorter OS was found in patients with SPM (35.29 (19.66-50.91) months) compared to those without (51.05 (46.7-55.4) months) (Kaplan-Meier; p = 0.018). The multivariate cox proportional hazards model revealed that patients with SPM had 4.420-fold higher risk of death than those without (HR: 4.420, 95% CI: 1.371-14.246, p = 0.013). Higher ALT levels were also independently associated with mortality (p = 0.038). The prevalence of SPM and frailty was high in elderly patients with MM in our study. The development of SPM independently reduces survival in MM; however, frailty was not found to be independently associated with survival. Our results suggest the importance of individualized approaches in the management of patients with MM, particularly with regard to SPM development.

Clinicopathologic Features of Therapy-Related Myeloid Neoplasms in Patients with Myeloma in the Era of Novel Therapies

The development of therapy-related myeloid neoplasms (t-MN) is a rare complication that can occur in myeloma patients treated primarily with novel therapies. To better understand t-MNs in this context, we reviewed 66 such patients and compared them with a control group of patients who developed t-MN after cytotoxic therapies for other malignancies. The study group included 50 men and 16 women, with a median age of 68 years (range, 48-86 years). Therapies included proteasome inhibitors, immunomodulatory agents, and high-dose melphalan-based autologous stem cell transplantation (HDM-ASCT) in 64 (97%), 65 (98.5%), and 64 (97%) patients, respectively; 29 (43.9%) patients were exposed to other cytotoxic drugs besides HDM. The latency interval from therapy to t-MN was 4.9 years (range, 0.6-21.9 years). Patients who received HDM-ASCT in addition to other cytotoxic therapies had a longer latency period to t-MN compared with patients who only received HDM-ASCT (6.1 vs 4.7 years, P = .009). Notably, 11 patients developed t-MN within 2 years. Therapy-related myelodysplastic syndrome was the most common type of neoplasm (n = 60), followed by therapy-related acute myeloid leukemia (n = 4) and myelodysplastic syndrome/myeloproliferative neoplasm (n = 2). The most common cytogenetic aberrations included complex karyotypes (48.5%), del7q/-7 (43.9%), and/or del5q/-5 (40.9%). The most frequent molecular alteration was TP53 mutation, in 43 (67.2%) patients and the sole mutation in 20 patients. Other mutations included DNMT3A, 26.6%; TET2, 14.1%; RUNX1, 10.9%; ASXL1, 7.8%; and U2AF1, 7.8%. Other mutations in less than 5% of cases included SRSF2, EZH2, STAG2, NRAS, SETBP, SF3B1, SF3A1, and ASXL2. After a median follow-up of 15.3 months, 18 patients were alive and 48 died. The median overall survival after the diagnosis of t-MN in the study group was 18.4 months. Although the overall features are comparable to the control group, the short interval to t-MN (<2 years) underscores the unique vulnerable status of myeloma patients.

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.

Management of Multiple Myeloma: A Review for General Practitioners in Oncology

Multiple myeloma (MM) is a malignant clonal plasma cell disorder in the bone marrow and is the second-most common hematologic malignancy in adults. Although patients with MM have a moderate life expectancy, it remains a heterogeneous disease that often requires multiple lines of chemotherapy for durable control and long-term survival. This review outlines current management strategies for both transplant-eligible and transplant-ineligible patients as well as for relapsed and refractory disease. Advances in drug therapies have widened management options and improved survival. In this paper, we also discuss implications for special populations and survivorship care.

Multiple myeloma, a quintessential malignant disease of aging: a geroscience perspective on pathogenesis and treatment

Multiple myeloma (MM) is an incurable plasma cell malignancy, which is predominantly a disease of older adults (the median age at diagnosis is 70 years). The slow progression from asymptomatic stages and the late-onset of MM suggest fundamental differences compared to many other hematopoietic system-related malignancies. The concept discussed in this review is that age-related changes at the level of terminally differentiated plasma cells act as the main risk factors for the development of MM. Epigenetic and genetic changes that characterize both MM development and normal aging are highlighted. The relationships between cellular aging processes, genetic mosaicism in plasma cells, and risk for MM and the stochastic processes contributing to clonal selection and expansion of mutated plasma cells are investigated. In line with the DNA damage accumulation theory of aging, in this review, the evolution of monoclonal gammopathy to symptomatic MM is considered. Therapeutic consequences of age-dependent comorbidities that lead to frailty and have fundamental influence on treatment outcome are described. The importance of considering geriatric states when planning the life-long treatment course of an elderly MM patient in order to achieve maximal therapeutic benefit is emphasized.

Triplet Therapy, Transplantation, and Maintenance until Progression in Myeloma

BACKGROUND

In patients with newly diagnosed multiple myeloma, the effect of adding autologous stem-cell transplantation (ASCT) to triplet therapy (lenalidomide, bortezomib, and dexamethasone [RVD]), followed by lenalidomide maintenance therapy until disease progression, is unknown.

METHODS

In this phase 3 trial, adults (18 to 65 years of age) with symptomatic myeloma received one cycle of RVD. We randomly assigned these patients, in a 1:1 ratio, to receive two additional RVD cycles plus stem-cell mobilization, followed by either five additional RVD cycles (the RVD-alone group) or high-dose melphalan plus ASCT followed by two additional RVD cycles (the transplantation group). Both groups received lenalidomide until disease progression, unacceptable side effects, or both. The primary end point was progression-free survival.

RESULTS

Among 357 patients in the RVD-alone group and 365 in the transplantation group, at a median follow-up of 76.0 months, 328 events of disease progression or death occurred; the risk was 53% higher in the RVD-alone group than in the transplantation group (hazard ratio, 1.53; 95% confidence interval [CI], 1.23 to 1.91; P<0.001); median progression-free survival was 46.2 months and 67.5 months. The percentage of patients with a partial response or better was 95.0% in the RVD-alone group and 97.5% in the transplantation group (P = 0.55); 42.0% and 46.8%, respectively, had a complete response or better (P = 0.99). Treatment-related adverse events of grade 3 or higher occurred in 78.2% and 94.2%, respectively; 5-year survival was 79.2% and 80.7% (hazard ratio for death, 1.10; 95% CI, 0.73 to 1.65).

CONCLUSIONS

Among adults with multiple myeloma, RVD plus ASCT was associated with longer progression-free survival than RVD alone. No overall survival benefit was observed. (Funded by the National Heart, Lung, and Blood Institute and others; DETERMINATION ClinicalTrials.gov number, NCT01208662.).

Immunogenetic clustering of 30 cancers

Human leukocyte antigen (HLA) genes have been implicated in cancer risk and shared heritability of different types of cancer. In this immunogenetic epidemiological study we first computed a Cancer-HLA profile for 30 cancer types characterized by the correlation between the prevalence of each cancer and the population frequency of 127 HLA alleles, and then used multidimensional scaling to evaluate the possible clustering of those Cancer-HLA associations. The results indicated the presence of three clusters, broadly reflecting digestive-skin-cervical cancers, reproductive and endocrine systems cancers, and brain and androgen-associated cancers. The clustering of cancer types documented here is discussed in terms of mechanisms underlying shared Cancer-HLA associations.

miR-451a targeting IL-6R activates JAK2/STAT3 pathway, thus regulates proliferation and apoptosis of multiple myeloma cells

OBJECTIVES

To investigate the effects of miR-451a targeting interleukin-6 (IL-6) on the proliferation and apoptosis of multiple myeloma (MM) cells and its potential mechanism via JAK2/STAT3 pathway.

METHODS

mRNA expression of miR-451a and IL-6R in the plasma of patients with MM and normal controls were determined by RT-qPCR. U266 cells were cultured, transfected with miR-451a mimics, the proliferative ability of U266 cells was determined by CCK-8. Potential targets of miR-451a were predicted with the biological software TargetScan, and the direct relationship between miR-451a and the target IL-6R was analyzed by a dual-luciferase reporter assay. U266 cells were stimulated with IL-6R (100 ng/ml), and the proliferative ability and apoptosis rate were determined by CCK-8 and flow cytometry after 48h.

RESULTS

In the plasma of patients with MM, miR-451a expression was low and IL-6R expression was high. miR-451a targeted and negatively regulated IL-6R. Overexpressing miR-451a inhibited the proliferation and promoted the apoptosis of U266 cells. IL-6R acting on U266 cells promoted the proliferation and inhibited the apoptosis of U266 cells. Overexpressing miR-451a inhibited the activation of JAK2/STAT3 pathway and down-regulating miR-451a promoted the activation of JAK2/STAT3 pathway.

CONCLUSIONS

miR-451a targeting IL-6R activates JAK2/STAT3 pathway, thus regulates the proliferation and apoptosis in MM cells.

Maintenance therapy after second autologous hematopoietic cell transplantation for multiple myeloma. A CIBMTR analysis

The role of maintenance therapy after high-dose chemotherapy and first autologous transplantation in multiple myeloma (MM) is well established. We explored the effect of maintenance therapy on outcomes after salvage second autologous hematopoietic cell transplant (AHCT2) using the Center for International Blood and Marrow Transplant Research registry. Outcomes of interest included non-relapse mortality (NRM), relapse/progression (REL), progression-free and overall survival (PFS, OS). Of 522 patients who underwent AHCT2 between 2010 and 2018, 342 received maintenance therapy and 180 did not. Maintenance regimens included lenalidomide (42%), pomalidomide (13%), and bortezomib (13%). Median follow up was 58 months in the maintenance group and 61.5 months in the no-maintenance group. Univariate analysis showed superior outcomes at 5 years in maintenance compared to the no-maintenance group: NRM 2 (0.7-3.9)% vs 9.9 (5.9-14.9)%, (p < 0.01), REL 70.2 (64.4-75.8)% vs 80.3 (73.6-86.3)% (p < 0.01), PFS 27.8 (22.4-33.5)% vs. 9.8 (5.5-15.2)% (p < 0.01), and OS 54 (47.5-60.5)% vs 30.9 (23.2-39.2)% (p < 0.01), respectively. Use of maintenance therapy retained its association with improved outcomes in multivariate analysis. There was no difference in second cancers in the two groups (p = 0.39). We conclude that maintenance after AHCT2 is associated with improved 5-year outcomes.

Genome Instability in Multiple Myeloma: Facts and Factors

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

Secondary primary malignancies in patients with multiple myeloma: A single institution experience

The purpose of our study is to highlight the demographic characteristics, pathological features, and clinical course of multiple myeloma (MM) patients with secondary primary malignancies (SPM). A retrospective chart review was performed from January 2009 to February 2020. Patients' demographic, pathologic and cytogenetic features, treatment characteristics and clinical outcomes were collected. We identified 871 MM patients including 40 patients who developed SPM. Among the 40 patients with SPM, 17 patients developed hematological SPM and 23 patients developed solid SPM. The median time from diagnosis of MM to the occurrence of hematological SPM was 6.85 versus 3.91 years in solid SPM, with a median overall survival (OS) after diagnosis of SPM of 120 and 880 days, respectively. Interestingly, we observed that there was no significant difference in OS between MM patients with or without SPM. Multivariable analysis showed that age and autologous stem cell transplantation were independent factors associated with patients' clinical outcomes. Our study highlights the importance of understanding the etiology, biology, clinical outcome and management in MM patients with SPM.

Increased Risk of Second Primary Malignancy and Mortality at ten Years After Stem Cell Transplant for Multiple Myeloma: An Analysis of 14,532 Patients

Background

The landscape for patients with multiple myeloma has improved dramatically over the last 15 years. Immunomodulatory imide drugs (IMiDs) have shown great efficacy in both the setting of initial therapy and as maintenance after autologous stem cell transplant (ASCT). Concern has arisen, however, regarding the risk of second primary malignancies (SPMs) that appear to be associated with the use of IMiD agents. SPMs are a known sequela of multiple myeloma treatment, particularly as a consequence of maintenance lenalidomide status-post stem cell transplant (SCT). The benefit of SCT has become less clear with the utilization of newer, more effective initial therapies.

Objectives

To determine the effect of SCT on SPM risk and overall survival in multiple myeloma patients at 5 and 10 years after treatment initiation.

Methods

We used TriNetX, a global federated health research network providing access to electronic medical records (diagnoses, procedures, medications, laboratory values, genomic information) from approximately 58 million patients in 49 large healthcare organizations. We created two patient cohorts who had all received treatment with thalidomide, lenalidomide, or pomalidomide. One cohort had received SCT while the other had not. Both cohorts were then analyzed for the development of all non-myeloma malignancies which occurred at least one year after initiation of treatment.

Results

At 5 years, SPMs were 5.8% more likely in patients who received stem cell transplant (22.4% vs 16.6%, RR 0.741, p value <0.0001) but 5-year survival favored transplanted patients by 2.38% (64.85% vs 62.474%, p value 0.0044). 10-year survival favored patients who did not receive transplant by 1.44% (42.279% vs 40.838%, p value 0.0279). The Kaplan-Meier curves cross at year 6.

Conclusions

It has previously been shown that the use of alkylating agents in myeloma patients significantly increases the risk of SPM, but that difference had curiously not been shown to have a negative impact on survival. Our analysis shows that this negative survival impact does exist but requires six or more years of follow up to become evident. Recent analyses from studies using older regimens show no overall survival benefit from the use of stem cell transplant. As non-transplant regimens become more effective at producing minimal residual disease (MRD) negativity, it seems that transplantation for myeloma patients will soon be regarded as unnecessary or even detrimental.

The mutagenic impact of melphalan in multiple myeloma

The introduction of whole genome and exome sequencing partnered with advanced bioinformatic pipelines has allowed the comprehensive characterization of mutational processes (i.e., mutational signatures) in individual cancer patients. Studies focusing on multiple myeloma have defined several mutational processes, including a recently identified mutational signature (called "SBS-MM1") directly caused by exposure to high-dose melphalan (i.e., autologous stem cell transplant). High-dose melphalan exposure increases both the overall and nonsynonymous mutational burden detected between diagnosis and relapse by ~10-20%. Nevertheless, most of these mutations are acquired within the heterochromatin and late-replicating regions, rarely involving key myeloma driver genes. In this review, we summarize key studies that made this discovery possible, and we discuss potential clinical implications.

Cumulative exposure to melphalan chemotherapy and subsequent risk of developing acute myeloid leukemia and myelodysplastic syndromes in patients with multiple myeloma

OBJECTIVES

The aim of this study was to determine risk factors for development of acute myeloid leukemia/myelodysplastic syndromes (AML/MDS) in patients with multiple myeloma (MM).

METHODS

We identified all patients diagnosed with MM in Sweden from January 1st, 1958 to December 31, 2011. A total of 26 627 patients were diagnosed with MM with during the study period. Of these, 124 patients (0.5%) developed subsequent AML/MDS. For each patient with MM and a subsequent AML/MDS diagnosis, we randomly selected a matched (age, sex, and date of MM diagnosis) MM patient without a subsequent second malignancy diagnosis.

RESULTS

The cumulative melphalan exposure was significantly higher (OR = 2.8, 95% CI 1.7-5.2; P < .001) among cases (median 988 mg; IQR 644-1640) compared with controls (median 578 mg; IQR 360-967). Median time to AML/MDS development was 3.8 years (IQR 2.8-5.8). Risk of AML/MDS was not statistically altered by M protein isotype, anemia, renal failure, hypercalcemia, lytic bone lesions, or radiation therapy.

CONCLUSION

In this nationwide population-based study, we show that increased cumulative doses of alkylating therapy with melphalan increases the subsequent risk of developing AML/MDS in patients with MM. Given improved survival in MM patients over the last decade future studies will be important to better define long-term risks.

Dynamics of minimal residual disease in patients with multiple myeloma on continuous lenalidomide maintenance: a single-arm, single-centre, phase 2 trial

Background Lenalidomide maintenance improves progression-free survival for patients with multiple myeloma, although its optimal duration is unknown. Clearance of minimal residual disease (MRD) in the bone marrow results in superior outcomes, although its attainment or sustainment does not alter clinical decision-making. Studies that have evaluated MRD serially are limited in length. We therefore aimed to evaluate longitudinal changes in MRD-status (dynamics) and their association with progression-free survival in patients with multiple myeloma.

METHODS

In this single-centre, single-arm, phase 2 study, we enrolled patients aged 18 years and older from the Memorial Sloan Kettering Cancer Center (New York, NY, USA) who had newly diagnosed multiple myeloma following unrestricted frontline therapy and an Eastern Cooperative Oncology Group Performance Status of 2 or lower, including patients who started maintenance before study enrolment. All participants received lenalidomide maintenance at 10 mg for 21 days of 28-day cycles until progression or unacceptable toxic effects for up to 5 years on protocol. The primary endpoint was progression-free survival at 60 months per protocol and key secondary endpoints were MRD rates after completion of the 12th, 24th, and 36th cycle of maintenance and the association between progression-free survival and annual measurement of MRD status. MRD was assessed from first-pull bone marrow aspirates at baseline and annually by flow cytometry per International Myeloma Working Group criteria, (limit of detection of at least 1 × 10^-5) up to a maximum of 5 years. Patients who completed at least four cycles of treatment were included in the analysis of the primary endpoint, and patients who had completed at least one dose of treatment on protocol were assessable for secondary endpoints. The study was registered at ClinicalTrials.gov, NCT02538198, and is now closed to accrual.

FINDINGS

Between Sept 8, 2015, and Jan 25, 2019, 108 patients (100 evaluable for the primary endpoint) were enrolled. Median follow-up was 40·7 months (95% CI 38·7-45·0). At 60 months, progression-free survival was 64% (95% CI 52-79). Median progression-free survival was unreached (95% CI unreached-unreached). MRD dynamics were assessed using 340 MRD assessments done over 5 years for 103 evaluable patients. Patients who sustained MRD negativity for 2 years (n=34) had no recorded disease progression at median 19·8 months (95% CI 15·8-22·3) past the 2-year maintenance landmark. By contrast, patients who lost their MRD-negative responses (n=10) were more likely to progress than those with sustained MRD negativity (HR infinite; p<0·0001) and those with persistent MRD positivity (HR 5·88, 95% CI 1·18-33·33; p=0·015) at the 2-year landmark. Haematological and non-haematological serious adverse events occurred in 19 patients (18%). The most common adverse events of grade 3 or worse were decreased lymphocyte count in 48 (44%) patients and decreased neutrophil count in 47 (44%) patients. One death occurred on study due to sepsis and heart failure and was considered unrelated to the study drug.

INTERPRETATION

Serial measurements of MRD allow for dynamic assessment of risk for disease progression. Early intervention should be investigated for patients with loss of MRD negativity. Sustained MRD positivity is not categorically an unfavourable outcome and might portend prolonged stability of low-level disease.

FUNDING

Memorial Sloan Kettering and Celgene.

Minimal residual disease in multiple myeloma: defining the role of next generation sequencing and flow cytometry in routine diagnostic use

For patients diagnosed with multiple myeloma (MM) there have been significant treatment advances over the past decade, reflected in an increasing proportion of patients achieving durable remissions. Clinical trials repeatedly demonstrate that achieving a deep response to therapy, with a bone marrow assessment proving negative for minimal residual disease (MRD), confers a significant survival advantage. To accurately assess for minute quantities of residual cancer requires highly sensitive methods; either multiparameter flow cytometry or next generation sequencing are currently recommended for MM response assessment. Under optimal conditions, these methods can detect one aberrant cell amongst 1,000,000 normal cells (a sensitivity of 10^-6). Here, we will review the practical use of MRD assays in MM, including challenges in implementation for the routine diagnostic laboratory, standardisation across laboratories and clinical trials, the clinical integration of MRD status assessment into MM management and future directions for ongoing research.

First reported case of secondary mixed phenotype acute leukemia after multiple myeloma

In recent years the outcome of patients with multiple myeloma (MM) has significantly improved, due to new drugs. However, some agents, i.e. the alkylating drug melphalan, can be associated with an increased incidence of secondary malignancies. Myelodysplastic syndromes and acute myeloid leukemia are reported in the literature, and rarely acute lymphoblastic leukemia. Here we describe a unique case of a 56-years old female patient affected by MM since 2015 in complete remission after autologous stem cell transplant and in lenalidomide maintenance, who developed 2 years later mixed phenotype acute leukemia (MPAL). The patient, refractory to both lymphoblastic and myeloid acute leukemia regimens, achieved complete remission with bi-specific anti-CD19/anti-CD3 monoclonal antibody blinatumomab and with hypomethylating agent azacytidine plus the BCL-2 inhibitor venetoclax. She then underwent hematopoietic stem cell transplantation from HLA-identical sibling donor and she is still in complete remission after 9 months. To the best of our knowledge, there are no cases in the literature describing MPAL after autologous transplant for MM. Our patient was treated with blinatumomab and venetoclax and achieved complete remission 9 months from allogeneic transplant. The mechanism underlying the development of MPAL is not completely understood and therapies are still lacking. In this context the combination of blinatumomab, azacytidine and venetoclax successfully used in this patient may provide food for thought for further studies in this rare setting of patients.