Update on risk stratification and treatment of newly diagnosed multiple myeloma

Abnormal PTBP1 Expression Sustains the Disease Progression of Multiple Myeloma

Multiple myeloma (MM) is a hematopoietic malignancy characterized by heterogeneity, which corresponds to alternative splicing (AS) profiles and disadjust gene expression. Bioinformatics analysis of AS factors possibly related to MM progression identified the polypyrimidine tract binding protein (PTBP1) as candidate. The purpose of this study was to confirm the incidence and prognostic value of PTBP1 in MM patients. Several cohorts of 2971 patients presenting newly diagnosed and relapsed MM were enrolled. Correlations between PTBP1 expression and clinicopathological characteristics, proliferative activity, and response to therapy of myeloma cells were analyzed. Moreover, the effect of PTBP1 on the AS pattern of specific aerobic glycolysis-related genes was explored in MM patients. Clinically, PTBP1 expression was present at all stages; it increased with disease progression and poor prognosis, which was even stronger elevated in patients with high tumor burden and drug resistance. Mechanistically, PTBP1 modulated AS of PKM2 and aerobic glycolysis-related genes in MM patients, which play synergistic or additive effects in clinical outcome. PTBP1 may be a novel marker for prognostic prediction and a promising therapeutic target for the development of anti-MM treatments.

PLP2 Expression as a Prognostic and Therapeutic Indicator in High-Risk Multiple Myeloma

Multiple myeloma (MM) is a devastating cancer with a highly heterogeneous outcome. Because of the heterogeneity of myeloma cells, risk stratification is important for making therapeutic regimens. Nevertheless, no immunohistochemical predictive and prognostic marker has been constructed yet. In the present study, we explored the prognostic value of proteolipid protein 2 (PLP2) in MM patients using immunohistochemistry (IHC). We assessed PLP2 expression in bone marrow (BM) biopsy specimens obtained from 87 newly diagnosed MM (NDMM) patients. Correlations between PLP2 expression and clinicopathological features were analyzed. PLP2 expression was present in high-risk MM patients, which was increased with disease progression and poor prognosis. PLP2 was increasing in parallel with high beta-2 microglobulin (β2-MG) and lactate dehydrogenase (LDH). Furthermore, MM patients with low PLP2 expression could achieve a favorable treatment response. PLP2 may be a novel biomarker for prognostic prediction and a therapeutic target for anti-MM treatments.

A DNA target-enrichment approach to detect mutations, copy number changes and immunoglobulin translocations in multiple myeloma

Genomic lesions are not investigated during routine diagnostic workup for multiple myeloma (MM). Cytogenetic studies are performed to assess prognosis but with limited impact on therapeutic decisions. Recently, several recurrently mutated genes have been described, but their clinical value remains to be defined. Therefore, clinical-grade strategies to investigate the genomic landscape of myeloma samples are needed to integrate new and old prognostic markers. We developed a target-enrichment strategy followed by next-generation sequencing (NGS) to streamline simultaneous analysis of gene mutations, copy number changes and immunoglobulin heavy chain (IGH) translocations in MM in a high-throughput manner, and validated it in a panel of cell lines. We identified 548 likely oncogenic mutations in 182 genes. By integrating published data sets of NGS in MM, we retrieved a list of genes with significant relevance to myeloma and found that the mutational spectrum of primary samples and MM cell lines is partially overlapping. Gains and losses of chromosomes, chromosomal segments and gene loci were identified with accuracy comparable to conventional arrays, allowing identification of lesions with known prognostic significance. Furthermore, we identified IGH translocations with high positive and negative predictive value. Our approach could allow the identification of novel biomarkers with clinical relevance in myeloma.

Translocation t(11;14) Is Associated With Adverse Outcome in Patients With Newly Diagnosed AL Amyloidosis When Treated With Bortezomib-Based Regimens

Purpose

Bortezomib has become a cornerstone in the treatment of AL amyloidosis. In this study, we addressed the prognostic impact of cytogenetic aberrations for bortezomib-treated patients.

Patients and Methods

We analyzed a consecutive series of 101 patients with AL amyloidosis treated with bortezomib-dexamethasone as first-line treatment by interphase fluorescence in situ hybridization (iFISH). Patients were ineligible for high-dose chemotherapy, which would put them at risk for cardiac or renal failure, and thus represented a poor-risk group.

Results

Presence of t(11;14), versus its absence, was associated with inferior hematologic event-free survival (median, 3.4 v 8.8 months, respectively; P = .002), overall survival (median, 8.7 v 40.7 months, respectively; P = .05), and remission rate (≥ very good partial remission; 23% v 47%, respectively; P = .02). In multivariable Cox regression models incorporating established hematologic and clinical risk factors, t(11;14) was an independent adverse prognostic marker for hematologic event-free survival (hazard ratio, 2.94; 95% CI, 1.37 to 6.25; P = .006) and overall survival (hazard ratio, 3.13; 95% CI, 1.16 to 8.33; P = .03), but not for remission (≥ very good partial remission). Markedly, the multiple myeloma high-risk iFISH aberrations t(4;14), t(14;16), del(17p), and gain of 1q21 conferred no adverse prognosis in this bortezomib-dexamethasone–treated group. After backward variable selection, the final multivariable model was validated in a consecutive series of 32 patients treated with bortezomib, dexamethasone, and cyclophosphamide.

Conclusion

iFISH results are important independent prognostic factors in AL amyloidosis. In contrast to our recently published results with melphalan and dexamethasone standard therapy, bortezomib is less beneficial to patients harboring t(11;14), whereas it effectively alleviates the poor prognosis inherent to high-risk aberrations. Given the discrepant response to different treatment modalities, iFISH may help to guide therapeutic choices in these poor-risk patients requiring rapid hematologic response.

GP130 activation induces myeloma and collaborates with MYC

Multiple myeloma (MM) is a plasma cell neoplasm that results from clonal expansion of an Ig-secreting terminally differentiated B cell. Advanced MM is characterized by tissue damage that involves bone, kidney, and other organs and is typically associated with recurrent genetic abnormalities. IL-6 signaling via the IL-6 signal transducer GP130 has been implicated as an important driver of MM pathogenesis. Here, we demonstrated that ectopic expression of constitutively active GP130 (L-GP130) in a murine retroviral transduction-transplantation model induces rapid MM development of high penetrance. L-GP130-expressing mice recapitulated all of the characteristics of human disease, including monoclonal gammopathy, BM infiltration with lytic bone lesions, and protein deposition in the kidney. Moreover, the disease was easily transplantable and allowed different therapeutic options to be evaluated in vitro and in vivo. Using this model, we determined that GP130 signaling collaborated with MYC to induce MM and was responsible and sufficient for directing the plasma cell phenotype. Accordingly, we identified Myc aberrations in the L-GP130 MM model. Evaluation of human MM samples revealed recurrent activation of STAT3, a downstream target of GP130 signaling. Together, our results indicate that deregulated GP130 activity contributes to MM pathogenesis and that pathways downstream of GP130 activity have potential as therapeutic targets in MM.

First line and salvage therapy with total therapy 3-based treatment for multiple myeloma- an extended single center experience

Total therapy 3 is an intensified protocol for multiple myeloma (MM). The "real life" outcomes of this protocol were seldom reported. Data was obtained for 81 patients (newly diagnosed, n=49; progressive MM, n=32), most of which had high-risk parameters. Overall response rate following (V)DT-PACE was 96% and 75% for the newly diagnosed and progressive groups, respectively. Median progression-free survival was 42.5 and 9 months, respectively. The 2-year overall survival was 88% and 40%, respectively. Treatment with (V)DT-PACE achieves high response rate among patients with high-risk disease, which can be translated into long-term remission only for newly diagnosed patients.

Thalidomide, cyclophosphamide and dexamethasone induction therapy: feasibility for myeloma patients destined for autologous stem cell transplantation

This study explored the effect of thalidomide and cyclophosphamide on stem cell collection, in addition to assessing their efficacy as induction therapy for myeloma patients destined for autologous stem cell transplantation (ASCT). We analyzed newly diagnosed myeloma patients who received TCD (thalidomide 100 mg/day for 28 days, oral cyclophosphamide 150 mg/m 2 /day and dexamethasone 40 mg/day on days 1–4) as induction therapy prior to ASCT. Peripheral stem cells were mobilized with granulocyte colony-stimulating factor and cyclophosphamide. Thirty-six patients (median age 54 years) received TCD chemotherapy (median 4 cycles). The overall response rate to TCD was 77.8% (28/36). The median number of CD34+ cells was 6.5 × 10 6 /kg, and 2 patients failed to achieve the optimal number of CD34+ cells, i.e. 4.0 × 10 6 /kg, although they were able to attain >2.0 × 10 6 /kg. The overall response rate increased up to 94.4% (34/36) after ASCT; this included 9 patients with a stringent complete response without transplantation-related mortality. Four patients died due to disease progression and 17 were found to have progressed after ASCT (the median progression-free survival after ASCT was 19.6 months). TCD chemotherapy can be an effective and feasible induction regimen prior to ASCT for myeloma patients.

Limited value of the international staging system for predicting long-term outcome of transplant-ineligible, newly diagnosed, symptomatic multiple myeloma in the era of novel agents

We retrospectively investigated clinical outcomes and prognostic factors of 131 patients with transplant-ineligible newly diagnosed multiple myeloma (NDMM) who received melphalan and prednisolone (MP) as first-line therapy from 2006 to 2013. Eighty-one patients received salvage therapies incorporating bortezomib, lenalidomide, and/or thalidomide. The overall response rate to MP was 54.2 %, including 9.2 % of better than very good partial response. With a median follow-up period of 30.2 months, median overall survival (OS) and median time to next treatment (TNT) were 54.4 and 19.0 months, respectively. Univariate analysis revealed that performance status and serum calcium level significantly associated with both OS and TNT, and multivariate analysis revealed that the higher serum calcium level had a significantly unfavorable impact on OS and TNT. Importantly, staging informed by the international staging system (ISS) was not predictive for OS or TNT in the analyzed cohort. Our study revealed that, in the context of first-line MP therapy for NDMM, the salvage therapy incorporating novel agents produced a survival period of >30 months after the initiation of second-line therapy, suggesting that the predictive value of ISS for OS and TNT may be limited in the era of novel agents.

Impact of C-Myc gene-related aberrations in newly diagnosed myeloma with bortezomib/dexamethasone therapy

Recent studies have suggested that c-Myc over-expression may be a factor indicating poor prognosis in multiple myeloma (MM), although c-Myc gene-related abnormalities, including translocation and gene amplification, have not been fully investigated in the novel agent era. Additional chromosome 8 may be considered as aggressive disease in the 1990s. To clarify the impact of these aberrations, we retrospectively analyzed newly diagnosed MM (NDMM) and relapsed/refractory MM (RRMM) with bortezomib and dexamethasone induction therapy. In the present study, the high-risk group was defined as having at least one of the following present: non-hyperdiploidy, IgH/FGFR3, and del p53. Forty NDMM cases were analyzed. At the median follow-up duration of 14.1 months, 14 RRMM were recognized. The proportions of patients in the high-risk, c-Myc gene-related aberrations, and additional chromosome 8 groups at diagnosis were 45.5, 22.5, and 10 %, respectively. The proportions of patients who developed RRMM in the high-risk, c-Myc gene-related aberrations, and additional chromosome 8 groups were 41.7, 77.7, and 50 %, respectively. Furthermore, patients with c-Myc gene-related abnormalities tended to exhibit inferior progression-free survival (PFS), and those with c-Myc gene-related abnormalities and/or additional chromosome 8 showed statistically shorter PFS. Therefore, c-Myc gene-related abnormalities and additional chromosome 8 may be related to a poorer prognosis.

In vitro and in vivo anti-tumor activity of miR-221/222 inhibitors in multiple myeloma

A rising body of evidence suggests that silencing microRNAs (miRNAs) with oncogenic potential may represent a successful therapeutic strategy for human cancer. We investigated the therapeutic activity of miR-221/222 inhibitors against human multiple myeloma (MM) cells. Enforced expression of miR-221/222 inhibitors triggered in vitro anti-proliferative effects and up-regulation of canonic miR-221/222 targets, including p27Kip1, PUMA, PTEN and p57Kip2, in MM cells highly expressing miR-221/222. Conversely, transfection of miR-221/222 mimics increased S-phase and down-regulated p27Kip1 protein expression in MM with low basal miR-221/222 levels. The effects of miR-221/222 inhibitors was also evaluated in MM xenografts in SCID/ NOD mice. Significant anti-tumor activity was achieved in xenografted mice by the treatment with miR-221/222 inhibitors, together with up-regulation of canonic protein targets in tumors retrieved from animals. These findings provide proof of principle that silencing the miR-221/222 cluster exerts significant therapeutic activity in MM cells with high miR-221/222 level of expression, which mostly occurs in TC2 and TC4 MM groups. These findings suggest that MM genotyping may predict the therapeutic response. All together our results support a framework for clinical development of miR-221/222 inhibitors-based therapeutic strategy in this still incurable disease.

Plasmacytoma-like post-transplant lymphoproliferative disorder seen in pediatric combined liver and intestinal transplant recipients

Post-transplant lymphoproliferative disease (PTLD) is a lymphoproliferative disorder secondary to chronic immunosuppression and is the most common malignancy in transplanted patients [Kamdar et al. Curr Opin Organ Transplant, 2011; 16:274-280]. Although PTLD usually presents as B or T cell lymphoma, plasmacytomas have been reported, mostly in the adult population. Six cases of pediatric plasmacytoma-like PTLD have been reported, all of which were treated with vincristine, adriamycin, and dexamethasone (VAD), high dose dexamethasone alone, or dexamethasone + thalidomide [Tcheng et al. Pediatric Blood Cancer, 2006; 47:218-223; Perry et al. Blood, 2013; 8:1377-1383]. We present two cases of pediatric plasmacytoma-like PTLD in combined liver and small bowel transplant patients both successfully treated with bortezomib and dexamethasone based on multiple myeloma protocols [Kyle and Rajkumar, Clin Lymphoma Myeloma, 2009; 9:278-288; Adams and Kaufmann, Cancer Invest, 2004; 22:304-311].

Validation of the Freiburg Comorbidity Index in 466 multiple myeloma patients and combination with the international staging system are highly predictive for outcome

BACKGROUND

The outcomes of MM patients vary considerably and depend on a variety of host- and disease-related risks. As yet, a comorbidity risk index in MM patients has neither been standardized nor validated.

PATIENTS AND METHODS

We conducted an initial analysis in 127 MM patients and developed the FCI, validating it in an independent cohort of 466 MM patients. The FCI includes patients' Karnofsky Performance Status, renal and lung disease status. We compared the prognostic information of this validated FCI with established comorbidity indices (Hematopoietic Cell Transplantation-Specific Comorbidity Index and Kaplan Feinstein), the International Staging System (ISS), MM therapy, and age.

RESULTS

Our validation confirmed that patients with 0, 1, or 2 to 3 FCI risk factors display significantly different overall survival (OS) of not reached, 86, and 39 months, respectively (P < .0001). Via multivariate analysis including the FCI, ISS, therapy, and age, the FCI retained its independent prognostic significance (P < .0015). The combination of the FCI and ISS allowed definition of 3 distinct subgroups with low-risk (FCI 0 and ISS I-II), intermediate-risk (all remaining), and high-risk (FCI 1-3 and ISS III) with OS probabilities at 5-years of 85%, 74%, and 42%, respectively (P < .0001).

CONCLUSION

Our validation analysis demonstrated that the FCI remains a reliable comorbidity index, is simpler to generate than other available comorbidity scores, and contributes valuable information to the ISS. Their combination allows the definition of low-, intermediate-, and high-risk patients. These results advocate use of the FCI in future prospective studies and might guide personalized treatment strategies.

Impact of genetic abnormalities on the prognoses and clinical parameters of patients with multiple myeloma

Background

We reviewed patients with multiple myeloma (MM) in order to assess the incidence of genetic abnormalities and their associations with clinical parameters, risk groups, and prognosis.

Methods

A total of 130 patients with MM were enrolled. The incidences of genetic abnormalities were determined in all patients. The relationships of the genetic abnormalities and clinical parameters were investigated. In addition, a survival analysis was performed.

Results

Abnormal karyotypes were detected in 42.3% (N=55) of the patients, and this was increased to 63.1% (N=82) after including the results determined with interphase FISH. Hypodiploidy was observed in 7.7% (N=10) of the patients, and all were included in the group with complex karyotypes (30.8%, N=40). The 14q32 rearrangements were detected in 29.2% (N=38) of the patients, and these most commonly included t(11;14), which was followed by t(4;14) and t(14;16) (16.2%, 11.5%, and 0.8%, respectively). Abnormal karyotypes and complex karyotypes were associated with disease progression markers, including low hemoglobin levels, low platelet counts, high plasma cell burden, high β2-microglobulin, and high international staging system stages. A high free light chain (FLC) ratio and FLC difference were associated with abnormal karyotypes, complex karyotypes, and higher plasma cell burden. Hypodiploidy and low platelet counts were significant independent prognostic factors and were more important in patient outcome than any single abnormality.

Conclusions

Genetic abnormalities were associated with disease progression markers and prognosis of MM patients.

Multiple myeloma-initiating cells

Multiple myeloma (MM) is characterized by the clonal expansion of malignant plasma cells. As in other cancers, MM plasma cells are thought to be derived from MM-initiating cells, although these remain unidentified. MM patients harbor phenotypic CD19(+) B cells expressing the immunoglobulin gene sequence and the idiotype unique to the individual myeloma clone. Some previous studies have reported that CD19(+) clonotypic B cells can serve as MM-initiating cells. However, we and another group have recently showed that CD19(+) B cells from many MM patients do not reconstitute MM disease upon transplantation into NOD/SCID IL2Rγc(-/-) mice. In the SCID-rab and SCID-hu models, which enable engraftment of human MM in vivo, CD19(-)CD38(++) plasma cells engrafted and rapidly propagated MM, while engraftment of CD19(+) B cells was not detected. Both CD138(-) and CD138(+) plasma cells have the potential to propagate MM clones in vivo in the absence of CD19(+) B cells. Distinct from acute myeloid leukemia-initiating cells, which are derived from undifferentiated stem or progenitor cells, MM-initiating cells are derived from plasma cells, which are terminally differentiated cells. An improved understanding of how the bone marrow microenvironment supports MM-initiating plasma cells, which can initiate MM disease in the SCID-hu (or rab) model, is thus now essential.

Enhancing cytokine-induced killer cell therapy of multiple myeloma

Cytokine-induced killer (CIK) cells are in clinical testing against various tumor types, including multiple myeloma. In this study, we show that CIK cells have activity against subcutaneous and disseminated models of human myeloma (KAS-6/1), which can be enhanced by infecting the CIK cells with an oncolytic measles virus (MV) or by pretreating the myeloma cells with ionizing radiation (XRT). KAS-6/1 cells were killed by coculture with CIK or MV-infected CIK (CIK/MV) cells, and the addition of an anti-NKG2D antibody inhibited cytolysis by 50%. However, human bone marrow stromal cells can reduce CIK and CIK/MV mediated killing of myeloma cells (RPMI 8226, JJN-3 and MM1). In vivo, CIK and CIK/MV prolonged the survival of mice with systemic myeloma, although CIK/MV showed enhanced antitumor activity compared with CIK. Irradiation of the KAS-6/1 cells induced mRNA and protein expression of NKG2D ligands, MICA, and MICB in a dose-dependent manner and enhanced delivery of CIK/MV to the irradiated tumors. In both subcutaneous and disseminated myeloma models, XRT at 2 Gy resulted in superior prolongation of the survival of mice given CIK/MV therapy compared with CIK/MV with no XRT. This study demonstrates the potential of CIK against myeloma and that the combination of virotherapy with radiation could be used to further enhance therapeutic outcome using CIK cells.

In non-transplant patients with multiple myeloma, the pre-treatment level of clonotypic cells predicts event-free survival

BACKGROUND

In multiple myeloma (MM), the immunoglobulin heavy chain VDJ gene rearrangement is a unique clonotypic signature that identifies all members of the myeloma clone independent of morphology or phenotype. Each clonotypic MM cell has only one genomic copy of the rearranged IgH VDJ.

METHODS

Pre-treatment bone marrow aspirates from myeloma patients at diagnosis or in relapse were evaluated for the number of clonotypic cells using real time quantitative PCR (RPCR). RPCR measured the level of clonal cells, termed VDJ%, in 139 diagnosis and relapse BM aspirates from MM patients.

RESULTS

Patients with a VDJ% below the median had a significantly longer event free survival (EFS) then those with a VDJ% higher than the median (p=0.0077, HR=0.57). Further, although the VDJ% from non-transplant patients predicted EFS (p=0.0093), VDJ% failed to predict outcome after autologous stem cell transplant (p=0.53).

CONCLUSIONS

Our results suggest that for non-transplant patients, the tumor burden before treatment, perhaps reflecting cancer stem cell progeny/output, is an indirect measure that may indicate the number of MM cancer stem cells and hence event free survival.

A phase 1 trial of the anti-KIR antibody IPH2101 in patients with relapsed/refractory multiple myeloma

Natural killer (NK) cells elicit cytotoxicity against multiple myeloma (MM); however, MM cells express HLA class I molecules as ligands to NK cell inhibitory killer immunoglobulin-like receptors (KIRs) as a means of immunoevasion. KIR-ligand mismatch may improve outcomes in allogeneic transplantation for MM. Extrapolating on this concept, we conducted a phase 1 trial of IPH2101, an anti-KIR antibody, in patients with relapsed/refractory MM. IPH2101 was administered intravenously every 28 days in 7 dose-escalated cohorts (0.0003-3 mg/kg) for up to 4 cycles. Pharmacokinetic, pharmacodynamic, and correlative immunologic studies were completed. A total of 32 patients were enrolled. The biologic endpoint of full KIR2D occupancy across the dosing cycle was achieved without dose-limiting toxicity or maximally tolerated dose. One severe adverse event was noted. Pharmacokinetic and pharmacodynamic findings approximated preclinical predictions, and IPH2101 enhanced ex vivo patient-derived NK cell cytotoxicity against MM. No objective responses were seen. No evidence of autoimmunity was observed. These findings suggest that IPH2101 is safe and tolerable at doses that achieve full inhibitory KIR saturation, and this approach warrants further development in MM. This trial was registered at www.clinicaltrials.gov as #NCT00552396.

Monosomy 13 in metaphase spreads is a predictor of poor long-term outcome after bortezomib plus dexamethasone treatment for relapsed/refractory multiple myeloma

We retrospectively investigated the prognostic impact of high-risk cytogenetic abnormalities (CAs) on the outcome of treatment with bortezomib plus dexamethasone (BD) in 43 relapsed/refractory (Rel/Ref) multiple myeloma patients. Fluorescence in situ hybridization (FISH) analysis identified del(13q) in 25 patients, t(4;14) in 14, t(14;16) in 4, 1q21 abnormality in 12 and del(17p) in 2, while G-banding also detected chromosome 13 monosomy (-13) in metaphase spreads from 7 patients. Eighteen of 25 patients with FISH-detected chromosome 13 abnormalities also exhibited other abnormalities. Median observation period was 510 days, and median overall survival (OS) and progression-free survival (PFS) were 912 days and 162 days, respectively. Detection of del(13q), t(4;14), t(14;16) or 1q21 abnormalities by FISH and co-occurrence of chromosome 13 abnormality with other abnormalities were not associated with poorer outcomes. In contrast, detection of -13 by G-banding in metaphase spreads showed significant association with shorter OS, although the overall response rate and PFS were not inferior to those for patients without -13 detected by G-banding. BD therapy may be a potent weapon for overcoming most classical high-risk CAs, while the detection of -13 in metaphase spreads may serve as a predictor of highly progressive disease, even when treated with BD.