Clinical course and outcomes of patients with multiple myeloma who relapse after autologous stem cell therapy

The Impact of Socioeconomic Risk Factors on the Survival Outcomes of Patients With Newly Diagnosed Multiple Myeloma: A Cross-analysis of a Population-based Registry and a Tertiary Care Center

BACKGROUND

Multiple myeloma (MM) is a heterogeneous clonal plasma cell disorder leading to differences in clinical outcomes such as overall survival (OS) among patients. We hypothesized that with expensive, novel therapeutic agents and paradigm shifts to maintain continuous therapy and improvement in OS, patients with MM are subject to the pressures of financial toxicity and the need for social support, which may be of prognostic importance.

MATERIALS AND METHODS

In this study, we examined the records of 122,458 patients from the National Cancer Database (NCDB) to determine the significance of socioeconomic factors such as estimated annual household income and education level, which were based on the patient's ZIP Code and the United States Census Bureau's 5-year report from 2008 to 2012. These socioeconomic factors, in addition to marital status, were then assessed individually and as a cumulative socioeconomic score for prognostic significance in a cohort of 2543 patients treated at a tertiary care center utilizing known biologic risk factors, such as cytogenetic risk, International Staging System classification, and serum lactate dehydrogenase levels.

RESULTS

Only marital status and estimated annual household income at diagnosis negatively impacted OS in a univariate analysis, but not in the context of a multivariable analysis incorporating known biologic risk factors.

CONCLUSION

Future analyses in other academic and non-academic centers located in urban and rural regions are required to understand the socioeconomic drivers of OS disparity among patients with MM observed nationally.

Tumor microenvironment-targeted nanoparticles loaded with bortezomib and ROCK inhibitor improve efficacy in multiple myeloma

Drug resistance and dose-limiting toxicities are significant barriers for treatment of multiple myeloma (MM). Bone marrow microenvironment (BMME) plays a major role in drug resistance in MM. Drug delivery with targeted nanoparticles have been shown to improve specificity and efficacy and reduce toxicity. We aim to improve treatments for MM by (1) using nanoparticle delivery to enhance efficacy and reduce toxicity; (2) targeting the tumor-associated endothelium for specific delivery of the cargo to the tumor area, and (3) synchronizing the delivery of chemotherapy (bortezomib; BTZ) and BMME-disrupting agents (ROCK inhibitor) to overcome BMME-induced drug resistance. We find that targeting the BMME with P-selectin glycoprotein ligand-1 (PSGL-1)-targeted BTZ and ROCK inhibitor-loaded liposomes is more effective than free drugs, non-targeted liposomes, and single-agent controls and reduces severe BTZ-associated side effects. These results support the use of PSGL-1-targeted multi-drug and even non-targeted liposomal BTZ formulations for the enhancement of patient outcome in MM.

Efficacy of proteasome inhibitor-based maintenance following autologous transplantation in multiple myeloma: A systematic review and meta-analysis

INTRODUCTION

Lenalidomide maintenance, commonly prescribed in the postautologous transplantation (AHCT) setting for multiple myeloma (MM), is associated with development of secondary primary malignancies (SPM). Proteasome inhibitor maintenance (PIM) has also been evaluated in MM. We conduct a systematic review/meta-analysis to assess the efficacy of PIM in MM.

METHODS

Performing a comprehensive search of the medical literature using PubMed/Medline and EMBASE on September 11, 2019, we extracted data on clinical outcomes related to benefits (OS, PFS, and depth of hematologic response [DOHR]) and harms (SPM and adverse events). 2144 references were identified; three studies were eligible for inclusion.

RESULTS

A total of 1760 patients were included in the analysis; 507 patients received bortezomib and 395 received ixazomib maintenance. Control arms were either placebo (n = 261) or thalidomide (n = 358). PIM did not improve OS (HR 0.88, 95% CI 0.73-1.05, P = .15) but improved PFS (HR 0.77, 95% CI 0.69-0.86, P ≤ .00001) and DOHR (HR 0.88, 95% CI 0.79-0.98, P = .02) compared with control. There were no significant differences between PIM and control regarding SPM (p = NS) and ≥grade 3 peripheral neuropathy (PN) (p = NS).

CONCLUSIONS

PIM following AHCT in MM improves PFS and DOHR without an increase in development of SPM or severe PN compared with placebo/thalidomide.

The impact of response kinetics for multiple myeloma in the era of novel agents

Rapid remission by induction therapy has long been recognized as an important predictor for long-time survival in acute leukemia. However, the impact of response kinetics on multiple myeloma (MM) seems to be different and remains unexplored. The relationship between response kinetics and outcome were assessed in 626 patients with newly diagnosed MM who were included in a prospective, nonrandomized clinical trial (BDH 2008/02). Patients were assigned to either immunomodulatory drug- or proteasome inhibitor-based therapy. The response depth, time to best response (T_BR) and duration of best response (D_BR) were collected. Depth of response was associated with superior outcomes, consistent with findings from other studies. However, the early responders (defined as T_BR ≤3 months) showed significantly worse survival compared with late responders. We found that patients with rapid complete remission experienced inferior survivals comparable to those attaining a gradual partial remission. Moreover, 4 distinct response kinetics patterns were identified. Patients with gradual and sustained remission ("U-valley" pattern) experienced superior outcomes, whereas poor outcomes were observed in rapid and transient responders ("roller coaster" pattern) (median overall survival, 126 vs 30 months). The effects of response patterns on survival were confirmed in patients at different stages of disease and cytogenetic risk, including transplant-eligible patients and those attaining different extents of response depth. Collectively, our data indicated that slow and gradual response is a favorable prognostic factor in MM. In addition to response depth, the kinetic pattern of response is a simple and powerful predictor for survival even in the era of novel agents.

Enrichment of circulating myeloma cells by immunomagnetic beads combined with flow cytometry for monitoring minimal residual disease and relapse in patients with multiple myeloma

Difficulty in regularly analyzing marrow myeloma cells (MMCs) and low frequency of circulating myeloma cells (CMCs) in blood presents challenges for monitoring minimal residual disease (MRD) in multiple myeloma (MM). We have developed a set of method for enrichment of CMCs by immunomagetic beads (IMB) combined with flow cytometry (IMB-FCM) based on CD38-APC/CD138-APC antibodies in U266-spiked samples and in 122 patient samples. U266 cell capture efficiency of CD38/CD138-IMB-FCM (6.960, 2.574) was 6- and 2-fold higher than that of FCM (1.032), and the sensitivity of FCM and IMB-FCM was 0.01% and 0.001%, respectively. In MM cohort, the positive rate of CMCs by IMB-FCM increased from 60.5~70.0 to 85~87.2% in newly diagnosed/relapsed and partial remission (PR) patients compared with by FCM (P < 0.05). Two complete remission (CR) patients contain certain amounts of CMCs by IMB-FCM while no CMCs and MMCs were detectable by FCM. Patients exhibiting PR and CR upon therapy had much lower CMC and MMC counts than newly diagnosed/relapsed patients (P < 0.005). Based on MRD measurement in BM and PB samples, all FCM-negative BM samples were also paired with FCM/IMB-FCM-negative PB samples among newly diagnosed, relapsed, and PR patients, and FCM-positive BM samples were accompanied by IMB-FCM-positive results in 88% of corresponding PB samples. CMCs strongly associated with other clinical biomarkers of disease burden, including elevated MMCs, β2-MG, sCrea, and DS and ISS stages, and more serious anemia, bone destruction, and renal impairment (P < 0.05). Logistic regression analysis revealed that elevated β2-MG and moderate-to-more anemia were significant risk factors for the presence of CMCs (P < 0.05). As a noninvasive "liquid biopsy" of monitoring MRD, the potential of IMB-FCM for CMC detection may complement or minimize bone marrow aspiration in future treatment of MM patients.

Prognostic value of minimal residual disease and polyclonal plasma cells in myeloma patients achieving a complete response to therapy

Achievement of a complete response has been associated with improved outcomes in patients with multiple myeloma. Recently, increasing application of minimal residual disease (MRD) assessment has shown that MRD negativity is a powerful prognostic factor for survival outcomes. We wanted to examine the impact of the polyclonal plasma cell (pPC) compartment among patients in complete response (CR) but are MRD positive. This is a retrospective cohort study where 460 myeloma patients were identified who met criteria for CR and had multicolor flow cytometry performed on the bone marrow (BM). Monoclonal and pPCs were estimated during MRD testing. Final outcomes including overall survival (OS) and time to next treatment (TTNT) were compared among the groups. The median OS for the entire cohort was not reached (95% CI; 63 mos, NR) and the median TTNT was 31 months (95% CI; 27,36). Among the MRD_neg group, median TTNT was 37.6 months vs 23 months for MRD_pos patients (P < .001); the median OS was not reached for either group, but there was a trend toward better survival for MRD_neg patients. Among the MRD_pos group, median percentage of pPCs was 65% (2.5-98.5), and those with >95% pPCs had a significantly better TTNT (NR vs 23 months; P = .02) and a trend toward better OS. We conclude that achievement of MRD negativity predicts for better response durability and trend toward improved OS and an increased proportion of pPC predicts for better outcomes within those who have residual tumor cells highlighting the importance of marrow normalization.

Utilization of hematopoietic stem cell transplantation for the treatment of multiple myeloma: a Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus statement

Over the last two decades, the utilization of various novel therapies in the upfront or salvage settings has continued to improve survival outcomes for patients with Multiple Myeloma (MM). Thus, the conventional role for hematopoietic stem cell transplantation (HSCT) in MM either in the form of an autologous stem cell transplant (ASCT) or an allogeneic stem cell transplant (Allo-SCT) warrants re-evaluation, given the aforementioned clinical advances. Here, we present a consensus statement of our multidisciplinary group of over 30 Mayo Clinic physicians with a special interest in the care of patients with MM and provide evidence-based recommendations on the use of HSCT in MM. We specifically address topics that include the role and timing of an ASCT for MM in the era of novel agents, eligibility for an ASCT, post-ASCT consolidation, and maintenance options, and finally the utility of an upfront tandem ASCT, salvage second ASCT, and an allo-SCT in MM.

Relapse after complete response in newly diagnosed multiple myeloma: implications of duration of response and patterns of relapse

Achieving a complete response (CR) is associated with improved overall survival (OS) in multiple myeloma (MM), but data on duration of CR (DurCR) are limited. We evaluated 351 patients (2004-2016), achieving CR with first-line therapy. Patients with sustained DurCR ≥ 24 months (n = 177) had better OS; 150 vs. 81 months, p < 0.001. DurCR ≥ 24 months remained a significant predictor for OS (HR: 0.3, 95% CI: 0.2-0.5, p < 0.001) after adjusting for age, revised ISS stage, transplant and maintenance therapy. Landmark analysis at 24 months demonstrated similar results, OS: 150 vs. 83 months, p < 0.001. Survival benefit persisted even after loss of CR, with median OS being 89 vs. 56 months (p = 0.005), respectively. Patterns of loss of CR were heterogeneous, with biochemical relapse in 59 (25%); symptomatic relapse in 58 (24%); positive immunofixation/monoclonal protein rise not meeting relapse/progression criteria in 88 (37%) and abnormal free light chain ratio in LC MM in 34 (14%) patients. OS from start of first-line therapy was superior in patients starting second-line treatment for biochemical vs. symptomatic relapse (125 vs. 81 months, p = 0.001). This is likely attributable to underlying disease biology and prevention of end-organ damage by early treatment initiation, as benefit was independent of R-ISS stage.

Enhancing proteasome-inhibitory activity and specificity of bortezomib by CD38 targeted nanoparticles in multiple myeloma

The establishment of more effective treatments that can circumvent chemoresistance in Multiple Myeloma (MM) is a priority. Although bortezomib (BTZ) is one of the most potent proteasome inhibitors available, still possesses limitations related to dose limiting side effects. Several strategies have been developed to improve the delivery of chemotherapies to MM by targeting different moieties expressed on MM cells to nanoparticle delivery systems (NPs), which have failed mainly due to their heterogeneous expression on these cells. Our goal was to test CD38 targeted chitosan NPs as novel targeting moiety for MM to improve the potency and efficacy of BTZ in MM cells and reduce the side effects in healthy tissue. We have showed preferential BTZ release in tumor-microenvironment, specific binding to MM cells, and an improved drug cellular uptake through BTZ diffusion from the surface and endocytosed NPs, which translated in enhanced proteasome inhibition and robust cytotoxic effect on MM cells when BTZ was administered through anti-CD38 chitosan NPs. Furthermore, the anti-CD38 chitosan NPs specifically delivered therapeutic agents to MM cells improving therapeutic efficacy and reducing side effects in vivo. The anti-CD38 chitosan NPs showed low toxicity profile allowing enhancement of proteasome-inhibitory activity and specificity of BTZ by endocytosis-mediated uptake of CD38 representing a promising therapy in MM.

The prognostic significance of polyclonal bone marrow plasma cells in patients with relapsing multiple myeloma

Prior studies have revealed that the presence of increasing number of polyclonal plasma cells (pPCs) in the bone marrow (BM) are associated with better outcomes in newly diagnosed multiple myeloma (MM) patients. This effect has not been studied in patients with MM at the time of disease relapse. We determined the prognostic value of depletion of pPCs in the BM by 7-color multiparameter flow cytometry in a series of 174 relapsing MM patients. The time to next therapy (TTNT) in those with <5% pPCs was 9.4 months versus 13.9 months in those with ≥5% pPCs (P = .0091). The median overall survival (OS) in those with <5% pPCs was 21.4 months, while the median OS was not reached in those patients with ≥5% pPCs (P = .019). Of the 109 patients with standard risk cytogenetics, the median OS of those with <5% pPCs was 28.4 months, while the median OS was not reached in those with ≥5% pPCs (P = .033). As such, <5% pPCs in the BM appears to have prognostic utility in identifying a subset of relapsing MM patients, even with standard-risk cytogenetics, who have a particularly adverse outcome.

Multiple myeloma

Multiple myeloma is a malignancy of terminally differentiated plasma cells, and patients typically present with bone marrow infiltration of clonal plasma cells and monoclonal protein in the serum and/or urine. The diagnosis of multiple myeloma is made when clear end-organ damage attributable to the plasma cell proliferative disorder or when findings that suggest a high likelihood of their development are present. Distinguishing symptomatic multiple myeloma that requires treatment from the precursor stages of monoclonal gammopathy of undetermined significance and smouldering multiple myeloma is important, as observation is the standard for those conditions. Much progress has been made over the past decade in the understanding of disease biology and individualized treatment approaches. Several new classes of drugs, such as proteasome inhibitors and immunomodulatory drugs, have joined the traditional armamentarium (corticosteroids, alkylating agents and anthracyclines) and, along with high-dose therapy and autologous haemopoietic stem cell transplantation, have led to deeper and durable clinical responses. Indeed, an increasing proportion of patients are achieving lasting remissions, raising the possibility of cure for this disease. Success will probably depend on using combinations of effective agents and treating patients in the early stages of disease, such as patients with smouldering multiple myeloma.

The next generation of novel therapies for the management of relapsed multiple myeloma

The advent of various novel therapies such as immunomodulators and proteasome inhibitors has transformed the treatment paradigm for patients with multiple myeloma (MM). As a result, the overall survival has improved dramatically over the last decade. Despite these advances, MM remains mostly incurable and most patients experience disease relapse after enjoying a period of disease control or remission. Fortunately, the scientific community continues to make strides in developing 'next-generation' therapies for the management of patients with relapsed MM. This review will summarize the efficacy of some of the newest therapeutic agents available for the treatment of patients with relapsed MM after their upfront treatment with the original novel agents such as thalidomide, lenalidomide and bortezomib.