The purpose of this study was to confirm overall survival (OS) and other clinical benefits with bortezomib, melphalan, and prednisone (VMP) versus melphalan and prednisone (MP) in the phase III VISTA ...(Velcade as Initial Standard Therapy in Multiple Myeloma) trial after prolonged follow-up, and evaluate the impact of subsequent therapies.
Previously untreated symptomatic patients with myeloma ineligible for high-dose therapy received up to nine 6-week cycles of VMP (n = 344) or MP (n = 338).
With a median follow-up of 36.7 months, there was a 35% reduced risk of death with VMP versus MP (hazard ratio, 0.653; P < .001); median OS was not reached with VMP versus 43 months with MP; 3-year OS rates were 68.5% versus 54.0%. Response rates to subsequent thalidomide- (41% v 53%) and lenalidomide-based therapies (59% v 52%) appeared similar after VMP or MP; response rates to subsequent bortezomib-based therapy were 47% versus 59%. Among patients treated with VMP (n = 178) and MP (n = 233), median survival from start of subsequent therapy was 30.2 and 21.9 months, respectively, and there was no difference in survival from salvage among patients who received subsequent bortezomib, thalidomide, or lenalidomide. Rates of adverse events were higher with VMP versus MP during cycles 1 to 4, but similar during cycles 5 to 9. With VMP, 79% of peripheral neuropathy events improved within a median of 1.9 months; 60% completely resolved within a median of 5.7 months.
VMP significantly prolongs OS versus MP after lengthy follow-up and extensive subsequent antimyeloma therapy. First-line bortezomib use does not induce more resistant relapse. VMP used upfront appears more beneficial than first treating with conventional agents and saving bortezomib- and other novel agent-based treatment until relapse.
Mesenchymal stem cells are multilineage non-hematopoietic progenitor cells that play a key role in supporting the lymphohematopoietic system. Their distribution in bone marrow and secondary lymphoid ...organs allows an intimate interaction with T- and B-lymphocytes. While their effect on T-lymphocytes has been extensively analyzed, data on the effect of mesenchymal stem cells on B cells are more limited. We analyzed the effects of mesenchymal stem cells on B-lymphocytes and the pathways involved in these effects.
The effect of MSC on the proliferation and viability of B cells was evaluated using MTT assays, annexin/7-amino-actinomycin D and propidium iodide staining. The B-cell maturation pattern was established using flow cytometry based on the expression of different markers related to the differentiation of B cells, such as CD38, CD138, CD19 and CCR7, and to the expression of surface and intracellular immunoglobulins. Finally, western blot assays were used to identify the pathways involved in the effects of mesenchymal stem cells on B-lymphocytes.
Mesenchymal stem cells increased viability and blocked the cell cycle of B-lymphocytes in the G(0)/G(1) phase. In vitro exposure of B cells to plasmacytoid dendritic cells induced B-cell differentiation as shown by an increased number of CD38(++)/CD138(++) cells, which also displayed higher levels of cytoplasmic immunoglobulin and lower levels of CD19, CCR7 and surface immunoglobulin. Interestingly, this maturation pattern was inhibited by adding mesenchymal stem cells to the culture. Finally, mesenchymal stem cells modified the phosphorylation pattern of the extracellular response kinase 1/2 and p38 pathways which are both involved in B-cell viability, proliferation and activation.
Mesenchymal stem cells increase B-cell viability while inhibiting proliferation, arresting B-lymphocytes in the G(0)/G(1) phase of the cell cycle. The presence of mesenchymal stem cells blocked B-cell differentiation as assessed by flow cytometry. Finally, mesenchymal stem cells modified the activation pattern of the extracellular response kinase and the p38 mitogen-activated protein kinase pathways in B-lymphocytes.
Genetic aberrations detected in multiple myeloma (MM) have also been reported in the premalignant conditions monoclonal gammopathy of undetermined significance (MGUS) and smoldering MM (SMM). Our aim ...was to investigate in depth the level of clonal heterogeneity of recurrent genetic abnormalities in these conditions.
Immunoglobulin heavy chain (IGH) translocations, 13q14 and 17p13 deletions, and 1q21 gains using FISH were evaluated in 90 MGUS, 102 high-risk SMM, and 373 MM. To this end, we not only purified plasma cells (PC) for the FISH analysis (purity > 90%), but subsequently, we examined the correlation between the proportion of PC with cytogenetic changes and the number of clonal PC present in the same sample, as measured by multiparametric flow cytometry.
We observed a significant difference between the proportion of clonal PC with specific genetic abnormalities in MGUS compared with SMM and in SMM compared with MM. Thus, the median proportion of PC with IGH translocations globally considered, t(11;14) and 13q deletions was significantly lower in MGUS than in SMM, and in SMM than in MM IGH translocations: 34% vs. 57% vs. 76%; t(11;14): 38% vs. 61% vs. 81%; and 13q deletion: 37% vs. 61% vs. 74% in MGUS, SMM, and MM, respectively. For t(4;14), the difference was significant in the comparison between MGUS/SMM and MM and for 1q between MGUS and SMM/MM.
This study demonstrates that the progression from MGUS to SMM, and eventually to MM, involves a clonal expansion of genetically abnormal PC.
Circulating myeloma tumor cells (CTCs) as defined by the presence of peripheral blood (PB) clonal plasma cells (PCs) are a powerful prognostic marker in multiple myeloma (MM). However, the biological ...features of CTCs and their pathophysiological role in MM remains unexplored. Here, we investigate the phenotypic, cytogenetic, and functional characteristics as well as the circadian distribution of CTCs vs paired bone marrow (BM) clonal PCs from MM patients. Our results show that CTCs typically represent a unique subpopulation of all BM clonal PCs, characterized by downregulation (P < .05) of integrins (CD11a/CD11c/CD29/CD49d/CD49e), adhesion (CD33/CD56/CD117/CD138), and activation molecules (CD28/CD38/CD81). Fluorescence in situ hybridization analysis of fluorescence-activated cell sorter–sorted CTCs also unraveled different cytogenetic profiles vs paired BM clonal PCs. Moreover, CTCs were mostly quiescent and associated with higher clonogenic potential when cocultured with BM stromal cells. Most interestingly, CTCs showed a circadian distribution which fluctuates in a similar pattern to that of CD34+ cells, and opposite to stromal cell–derived factor 1 plasma levels and corresponding surface expression of CXC chemokine receptor 4 on clonal PCs, suggesting that in MM, CTCs may egress to PB to colonize/metastasize other sites in the BM during the patients' resting period.
•Detailed characterization of myeloma circulating tumor cells shows that these represent a unique subpopulation of BM clonal PCs.•Myeloma CTCs are clonogenic, quiescent, and may represent an ancestral clone potentially driven by circadian rhythms.
The survival of patients with multiple myeloma (MM) has been dramatically improved in the last decade thanks to the incorporation of second-generation proteasome inhibitors (PI), immunomodulatory ...drugs (IMID), and, more recently, anti-CD38 monoclonal antibodies (MoAb). Nevertheless, still, a major proportion of MM patients will relapse, underscoring the need for new therapies in this disease. Moreover, survival in patients failing the current standard of care regimens (including PI, IMIDs, and anti-CD38 MoAb), which is now defined as triple-class refractory, remains dismal, and new drugs with different mechanism of action are needed. B-cell maturation antigen (BCMA)-targeted therapies and in particular chimeric antigen receptor T cell (CAR T-cell) treatment have emerged as promising platforms to overcome refractoriness to conventional drugs. In this manuscript, we review the current available data regarding CAR T-cell therapy for MM, with a special focus on target selection, clinical results, limitations, and future strategies.
Despite advancements, prognosis for patients with relapsed/refractory multiple myeloma (MM) is poor, and novel therapies are needed. Panobinostat is a potent deacetylase inhibitor that elicits ...synergistic effects on MM cells in combination with bortezomib. This phase Ib study sought to determine the maximum-tolerated dose (MTD) of panobinostat plus bortezomib in patients with relapsed or relapsed and refractory MM.
In the dose-escalation phase (n = 47), panobinostat was administered orally thrice weekly every week in combination with bortezomib (21-day cycles). After MTD determination, patients were evaluated in an expansion phase (n = 15) that incorporated a 1-week treatment holiday of panobinostat, with dexamethasone added in cycle 2. Additional assessments included safety, pharmacokinetics, and efficacy per International Myeloma Working Group criteria.
The MTD was established at panobinostat 20 mg plus bortezomib 1.3 mg/m(2). Grade 3 or 4 adverse events (AEs) included thrombocytopenia (85.1%), neutropenia (63.8%), and asthenia (29.8%) in the escalation phase, and thrombocytopenia (66.7%), neutropenia (46.7%), and fatigue (20.0%) in the expansion phase. At MTD in the escalation phase, eight patients (47.1%) discontinued therapy as a result of AEs, whereas five patients (33.3%) discontinued treatment in the expansion phase. Expansion phase patients demonstrated greater median treatment duration. Overall response rate (ORR) was 73.3% in the expansion phase and 52.9% at the escalation phase MTD. Among bortezomib-refractory patients, the ORR was 26.3%, and 42.1% of patients had ≥ minimal response.
The MTD of panobinostat plus bortezomib was determined and demonstrated activity in patients with relapsed or relapsed/refractory MM, including bortezomib-refractory patients. A phase II/III clinical trial program (Panobinostat or Placebo With Bortezomib and Dexamethasone in Patients With Relapsed Multiple Myeloma PANORAMA) has been initiated.
While analyzing the DNA methylome of multiple myeloma (MM), a plasma cell neoplasm, by whole-genome bisulfite sequencing and high-density arrays, we observed a highly heterogeneous pattern globally ...characterized by regional DNA hypermethylation embedded in extensive hypomethylation. In contrast to the widely reported DNA hypermethylation of promoter-associated CpG islands (CGIs) in cancer, hypermethylated sites in MM, as opposed to normal plasma cells, were located outside CpG islands and were unexpectedly associated with intronic enhancer regions defined in normal B cells and plasma cells. Both RNA-seq and in vitro reporter assays indicated that enhancer hypermethylation is globally associated with down-regulation of its host genes. ChIP-seq and DNase-seq further revealed that DNA hypermethylation in these regions is related to enhancer decommissioning. Hypermethylated enhancer regions overlapped with binding sites of B cell-specific transcription factors (TFs) and the degree of enhancer methylation inversely correlated with expression levels of these TFs in MM. Furthermore, hypermethylated regions in MM were methylated in stem cells and gradually became demethylated during normal B-cell differentiation, suggesting that MM cells either reacquire epigenetic features of undifferentiated cells or maintain an epigenetic signature of a putative myeloma stem cell progenitor. Overall, we have identified DNA hypermethylation of developmentally regulated enhancers as a new type of epigenetic modification associated with the pathogenesis of MM.
MLN9708 (ixazomib citrate), which hydrolyzes to pharmacologically active MLN2238 (ixazomib), is a next-generation proteasome inhibitor with demonstrated preclinical and clinical antimyeloma activity, ...but yet with an unknown effect on myeloma bone disease. Here, we investigated its bone anabolic and antiresorptive effects in the myeloma setting and in comparison with bortezomib in preclinical models.
The in vitro effect of MLN2238 was tested on osteoclasts and osteoclast precursors from healthy donors and patients with myeloma, and on osteoprogenitors derived from bone marrow mesenchymal stem cells also from both origins. We used an in vivo model of bone marrow-disseminated human myeloma to evaluate MLN2238 antimyeloma and bone activities.
Clinically achievable concentrations of MLN2238 markedly inhibited in vitro osteoclastogenesis and osteoclast resorption; these effects involved blockade of RANKL (receptor activator of NF-κB ligand)-induced NF-κB activation, F-actin ring disruption, and diminished expression of αVβ3 integrin. A similar range of MLN2238 concentrations promoted in vitro osteoblastogenesis and osteoblast activity (even in osteoprogenitors from patients with myeloma), partly mediated by activation of TCF/β-catenin signaling and upregulation of the IRE1 component of the unfolded protein response. In a mouse model of bone marrow-disseminated human multiple myeloma, orally administered MLN2238 was equally effective as bortezomib to control tumor burden and also provided a marked benefit in associated bone disease (sustained by both bone anabolic and anticatabolic activities).
Given favorable data on pharmacologic properties and emerging clinical safety profile of MLN9708, it is conceivable that this proteasome inhibitor may achieve bone beneficial effects in addition to its antimyeloma activity in patients with myeloma.
Cancer cells show higher levels of reactive oxygen species (ROS) than normal cells and increasing intracellular ROS levels are becoming a recognized strategy against tumor cells. Thus, diminishing ...ROS levels could be also detrimental to cancer cells. We surmise that avoiding ROS generation would be a better option than quenching ROS with antioxidants. Chronic myelogenous leukemia (CML) is triggered by the expression of BCR-ABL kinase, whose activity leads to increased ROS production, partly through NADPH oxidases. Here, we assessed NADPH oxidases as therapeutic targets in CML.
We have analyzed the effect of different NADPH oxidase inhibitors, either alone or in combination with BCR-ABL inhibitors, in CML cells and in two different animal models for CML.
NADPH oxidase inhibition dramatically impaired the proliferation and viability of BCR-ABL-expressing cells due to the attenuation of BCR-ABL signaling and a pronounced cell-cycle arrest. Moreover, the combination of NADPH oxidase inhibitors with BCR-ABL inhibitors was highly synergistic. Two different animal models underscore the effectiveness of NADPH oxidase inhibitors and their combination with BCR-ABL inhibitors for CML targeting in vivo.
Our results offer further therapeutic opportunities for CML, by targeting NADPH oxidases. In the future, it would be worthwhile conducting further experiments to ascertain the feasibility of translating such therapies to clinical practice.
The value of minimal residual disease (MRD) in multiple myeloma (MM) has been more frequently investigated in transplant-eligible patients than in elderly patients. Because an optimal balance between ...treatment efficacy and toxicity is of utmost importance in patients with elderly MM, sensitive MRD monitoring might be particularly valuable in this patient population. Here, we used second-generation 8-color multiparameter-flow cytometry (MFC) to monitor MRD in 162 transplant-ineligible MM patients enrolled in the PETHEMA/GEM2010MAS65 study. The transition from first- to second-generation MFC resulted in increased sensitivity and allowed us to identify 3 patient groups according to MRD levels: MRD negative (<10−5; n = 54, 34%), MRD positive (between <10−4 and ≥10−5; n = 20, 12%), and MRD positive (≥10−4; n = 88, 54%). MRD status was an independent prognostic factor for time to progression (TTP) (hazard ratio HR, 2.7; P = .007) and overall survival (OS) (HR, 3.1; P = .04), with significant benefit for MRD-negative patients (median TTP not reached, 70% OS at 3 years), and similar poorer outcomes for cases with MRD levels between <10−4 and ≥10−5 vs ≥10−4 (both with a median TTP of 15 months; 63% and 55% OS at 3 years, respectively). Furthermore, MRD negativity significantly improved TTP of patients >75 years (HR, 4.8; P < .001), as well as those with high-risk cytogenetics (HR, 12.6; P = .01). Using second-generation MFC, immune profiling concomitant to MRD monitoring also contributed to identify patients with poor, intermediate, and favorable outcomes (25%, 61%, and 100% OS at 3 years, respectively; P = .01), the later patients being characterized by an increased compartment of mature B cells. Our results show that similarly to transplant candidates, MRD monitoring is one of the most relevant prognostic factors in elderly MM patients, irrespectively of age or cytogenetic risk. This trial was registered at www.clinicaltrials.gov as #NCT01237249.
•MRD monitoring is one of the most relevant prognostic factors in elderly MM patients, irrespective of age or cytogenetic risk.•Second-generation MFC immune profiling concomitant to MRD monitoring also helped to identify patients with different outcomes.
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