How to select among available options for the treatment of multiple myeloma.

The introduction of novel agents (thalidomide, bortezomib and lenalidomide) in the frontline therapy of multiple myeloma has markedly improved the outcome both in younger patients who are candidates for high-dose therapy plus autologous stem-cell transplantation (HDT/ASCT) and in elderly patients. In the HDT/ASCT paradigm, novel agents may be used as induction therapy or after HDT/ASCT as consolidation and/or maintenance therapy. It is now possible to achieve up to 70% complete plus very good partial remission after HDT/ASCT and 70% 3-year progression-free survival (PFS). However long-term non-intensive therapy may also yield high response rates and prolonged PFS. Randomized trials comparing these two strategies are underway. In elderly patients, six randomized studies show the benefit of adding thalidomide to melphalan-prednisone (MP). a large randomized trial has also shown that the combination of bortezomib-MP is superior to MP for all parameters measuring the response and outcome. Finally, the role of maintenance is currently evaluated and a randomized trial shows that low-dose lenalidomide maintenance prolongs PFS.

Combination of rituximab, bortezomib, doxorubicin, dexamethasone and chlorambucil (RiPAD+C) as first-line therapy for elderly mantle cell lymphoma patients: results of a phase II trial from the GOELAMS.

BACKGROUND: There is no consensual first-line chemotherapy for elderly patients with mantle cell lymphoma (MCL). The GOELAMS (Groupe Ouest-Est des Leucémies Aiguës et Maladies du Sang) group previously developed the (R)VAD+C regimen (rituximab, vincristine, doxorubicin, dexamethasone and chlorambucil), which appeared as efficient as R-CHOP (rituximab, cyclophosphamide, doxorubicine, vincristine, prednisone) while less toxic. Based on this protocol, we now added bortezomib (RiPAD+C: rituximab, bortezomib, doxorubicin, dexamethasone and chlorambucil) given its efficacy in relapsed/refractory MCL patients. The goal of the current phase II trial was to evaluate the feasibility and efficacy of the RiPAD+C regimen as frontline therapy for elderly patients with MCL. PATIENTS AND METHODS: Patients between 65 and 80 years of age with newly diagnosed MCL received up to six cycles of RiPAD+C. RESULTS: Thirty-nine patients were enrolled. Median age was 72 years (65-80). After four cycles of RiPAD+C, the overall response rate was 79%, including 51% complete responses (CRs). After six cycles, CR rate increased up to 59%. After a 27-month follow-up, median progression-free survival (PFS) is 26 months and median overall survival has not been reached. Four patients (10%) discontinued the treatment because of a severe toxicity and seven patients (18%) experienced grade 3 neurotoxicity. CONCLUSION: The bortezomib-containing RiPAD+C regimen results in high CR rates and prolonged PFS with predictable and manageable toxic effects in elderly patients with MCL.

Reduced-intensity conditioning allogeneic stem cell transplantation for relapsed/refractory mantle cell lymphoma: a multicenter experience.

BACKGROUND: Despite therapeutic approach that combines rituximab-containing chemotherapy, followed or not by autologous stem cell transplantation (auto-SCT), mantle cell lymphoma (MCL) patients experience relapses. Reduced-intensity conditioning allogeneic stem cell transplantation (RIC-allo-SCT) at time of relapse may represent an attractive strategy. PATIENTS AND METHODS: We report a multicenter retrospective analysis. Seventy MCL patients underwent RIC-allo-SCT in 12 centers. RESULTS: Median age at transplantation was 56 years and median time from diagnosis to transplantation was 44 months. The median number of previous therapies was 2 (range, 1-5) including autologous transplantation in 47 cases. At time of transplantation, 35 patients were in complete remission, 20 were in partial response and 15 in stable disease or progressive disease. The median follow-up for living patients was 24 months. The 2-year event-free survival (EFS) and overall survival (OS) rates were 50% and 53%, respectively. The 1- and 2-year transplant-related mortality rates were 22% and 32%, respectively. The statistical analysis demonstrated that disease status at transplantation was the only parameter influencing EFS and OS. CONCLUSIONS: These results suggest that RIC-allo-SCT may be an effective therapy in MCL patients with a chemo-sensitive disease at time of transplantation, irrespective of the number of lines of prior therapy. Studies are warranted to investigate the best type of RIC regimen.

Bortezomib appears to overcome the poor prognosis conferred by chromosome 13 deletion in phase 2 and 3 trials.

In multiple myeloma, deletion of chromosome 13 (del(13)) is associated with poor prognosis regardless of treatment. This study analyzed the impact of del(13) status on response and survival following treatment with either bortezomib or high-dose dexamethasone in patients in the SUMMIT and APEX trials. Additionally, matched-pairs subset analyses were conducted of patients with and without del(13), balanced for age and International Staging System parameters. In both SUMMIT and APEX, prognosis appeared to be poorer in bortezomib-treated patients with del(13) compared with patients with no del(13) by metaphase cytogenetics. In the SUMMIT and APEX matched-pairs analysis, response and survival appeared comparable in bortezomib-treated patients with or without del(13) by metaphase cytogenetics. However, patients with del(13) receiving dexamethasone in APEX appeared to have markedly decreased survival compared with those without del(13) by metaphase cytogenetics. These matched-pairs analyses suggest that bortezomib may overcome some of the poor impact of del(13) as an independent prognostic factor. However, sample sizes were very small; these findings require confirmation from further studies.

Heterogeneity of t(4;14) in multiple myeloma. Long-term follow-up of 100 cases treated with tandem transplantation in IFM99 trials.

One hundred de novo multiple myeloma patients with t(4;14) treated with double intensive therapy according to IFM99 protocols were retrospectively analyzed. The median overall survival (OS) and event-free survival (EFS) were 41.4 and 21 months, respectively, as compared to 65 and 37 for patients included in the IFM99 trials without t(4;14) (P<10(-7)). We identified a subgroup of patients presenting at diagnosis with both low beta(2)-microglobulin <4 mg/l and high hemoglobin (Hb) >/=10 g/l (46% of the cases) with a median OS of 54.6 months and a median EFS of 26 months, respectively, which benefits from high-dose therapy (HDT); conversely patients with one or both adverse prognostic factor (high beta(2)-microglobulin and/or low Hb) had a poor outcome. The achievement of either complete response or very good partial response after HDT was also a powerful independent prognostic factor for both OS and EFS.

Acute graft versus host disease due to T lymphocytes recognizing a single HLA-DPB1*0501 mismatch.

Analysis of a large number of unrelated bone marrow transplantations (BMT) has shown that HLA-DP incompatibility did not detectably influence the risk for acute graft-versus-host disease (aGVHD). Accordingly, it was proposed that HLA-DP determinants did not function as transplantation antigens in the same way as HLA-A, -B, or -DR. We have previously shown that HLA-DP (as well as HLA-A, -B, -DQ, or -DR)-specific T cells could be isolated from skin biopsies of patients who developed an aGVHD after semiallogeneic BMT. Nevertheless, whether a single HLA-DP mismatched allele could induce a detectable allo-specific reaction in vivo after BMT remained to be established. To directly address this issue we studied one patient who presented aGVHD after receiving purified CD34+ bone marrow (BM) cells from an unrelated donor with a single HLA-DP mismatch in the GVHD direction. To characterize the immunological events associated with GVHD, we analyzed the peripheral T cell repertoire, the T cell receptor Vbeta diversity, and the specificity of T cells invading a skin biopsy at the onset of GVHD. Our results demonstrated that a large fraction of skin-infiltrating lymphocytes, which expressed diverse T cell receptors, were reactive against this single HLA-DPB1 *0501 mismatch and consequently that a single HLA-DP mismatch between BM donor and recipient can activate a strong T cell response in vivo.

The allogeneic dilemma.

The place of allogeneic SCT in the management of multiple myeloma remains controversial. Although it may induce long-term clinical and molecular remissions, the very high transplant-related toxicity after a myeloablative preparative regimen has limited its role to younger patients as first-line treatment option. Even with this limited indication, toxic death rate related to infections and GVHD is considered too high and this strategy has been almost abandoned. Reduced intensity conditioning (RIC) regimens look promising, as the transplant-related mortality is low even with matched unrelated donors and can be considered for older patients up to the age of 65 years. However when used in patients with a high tumor burden or with chemo-resistant disease, the immunologic effect of the graft is not sufficient to avoid relapses. Therefore, RIC allotransplantation is currently used after tumor mass reduction with high-dose therapy followed by autologous SCT. A recently published Italian study shows that this strategy induces better event-free survival than double autologous SCT due to a reduced relapse rate. The questions raised by this encouraging result are discussed in this paper.

The evolving background for high-dose treatment for myeloma.

In the constantly evolving field of myeloma, this special issue is slanted towards how the newer targeted treatments fit in with various transplantation strategies. High-dose treatment for myeloma with autologous stem cell transplantation started 25 years ago, with the consequence of producing complete remissions and a doubling of survival. Since then, its role has been refined and it has been accepted as standard treatment. The current challenge is to optimize its use into a background of the development, availability and regulatory approval of newer targeted therapies such as Thalidomide, Revlimid (Lenalidomide) and Velcade (Bortezomib). This special issue addresses these problems, and gives particular emphasis on the attainment of very long-term survival, with normal quality of life for patients with myeloma who do not necessarily need to be cured of their molecular disease, that is, they are 'operationally cured.' It is hoped that the reader will find the information in this issue useful in the day-to-day management of patients and we hope that this will also inspire new research directions designed to improve the outcome of patients with myeloma.

International uniform response criteria for multiple myeloma.

New uniform response criteria are required to adequately assess clinical outcomes in myeloma. The European Group for Blood and Bone Marrow Transplant/International Bone Marrow Transplant Registry criteria have been expanded, clarified and updated to provide a new comprehensive evaluation system. Categories for stringent complete response and very good partial response are added. The serum free light-chain assay is included to allow evaluation of patients with oligo-secretory disease. Inconsistencies in prior criteria are clarified making confirmation of response and disease progression easier to perform. Emphasis is placed upon time to event and duration of response as critical end points. The requirements necessary to use overall survival duration as the ultimate end point are discussed. It is anticipated that the International Response Criteria for multiple myeloma will be widely used in future clinical trials of myeloma.

Multiple myeloma treatment at relapse after autologous stem cell transplantation: A practical analysis.

Over the past decade, significant advances have been made in the field of multiple myeloma. Introduction of the so-called novel agents, proteasome inhibitors (PI) and immunomodulatory drugs (IMiD), and improved supportive care have resulted in significantly better outcome. Standard first line treatment in fit patients include PI and IMiD based induction, high dose melphalan with autologous hematopoietic stem cell transplantation (ASCT) and consolidation/maintenance. However, despite these progresses MM remains incurable for the majority of patients and most patients will relapse. Next generation PI (carfilzomib, ixazomib) and IMiD (pomalidomide) and new therapeutic classes: monoclonal antibody (elotuzumab, daratumumab) and pan-deacetylase inhibitors (panobinostat) have been successfully evaluated in relapse multiple myeloma. Some of these new agents are now approved for multiple myeloma treatment at relapse. However choosing the most appropriate treatment at relapse may be difficult. This review sum up the most important studies and provide evidence to choose the most relevant therapeutic strategy for relapse after ASCT, based on disease, patient and previous treatment related parameters.

Ploidy, as detected by fluorescence in situ hybridization, defines different subgroups in multiple myeloma.

Ploidy appears as an important parameter in both the biology and the clinical evolution of multiple myeloma. However, its evaluation requires either a successful karyotyping (obtained in 30% of the patients) or a DNA index calculation by flow cytometry (not routinely performed in myeloma). We validated a novel method based on interphase fluorescence in situ hybridization that can be utilitized to analyze almost all the patients. The method was very specific and sensitive for the detection of hyperdiploidy. Extended studies showed that most recurrent 14q32 translocations occur in nonhyperdiploid clones, and that deletions of chromosome 13 were less frequently observed in hyperdiploid clones (48 vs 66%). Further large studies are ongoing to evaluate the prognostic value of ploidy in myeloma.

Mcl-1 is overexpressed in multiple myeloma and associated with relapse and shorter survival.

We and others have shown that Mcl-1 was essential for the survival of human myeloma cells in vitro. Furthermore, this antiapoptotic protein is upregulated by interleukin-6, which plays a critical role in multiple myeloma (MM). For these reasons, we have evaluated the expression of Mcl-1 in vivo in normal, reactive and malignant plasma cells (PC), that is, myeloma cells from 51 patients with MM and 21 human myeloma cell lines (HMCL) using flow cytometry. We show that Mcl-1 is overexpressed in MM in comparison with normal bone marrow PC. In total, 52% of patients with MM at diagnosis (P=0.017) and 81% at relapse (P=0.014 for comparison with diagnosis) overexpress Mcl-1. Of note, only HMCL but not reactive plasmacytoses have abnormal Mcl-1 expression, although both PC expansions share similar high proliferation rates. Of interest, Bcl-2 as opposed to Mcl-1, does not discriminate malignant from normal PC. Finally, the level of Mcl-1 expression is related to disease severity, the highest values at diagnosis being associated with the shortest event-free survival (P=0.002). In conclusion, Mcl-1, which has been shown to be essential for the survival of human myeloma cells in vitro, is overexpressed in vivo in MM in relation with relapse and shorter survival. Mcl-1 represents a potential therapeutical target in MM.

Heterogeneity of the in vitro responses to glucocorticoids in acute leukemia.

In leukocyte population freshly isolated from the blood of 26 patients with acute leukemia, we have measured several parameters including glucocorticoid receptors, nucleoside incorporation, percentage of cells in S phase, and steroid-induced cell lysis. In addition, in some cases, the short-term response to steroid therapy was determined. Although, in all the patients studied, leukocytes were found to contain glucocorticoid receptors, we failed to demonstrate any correlation between the level of binding sites and the in vitro or in vivo response to glucocorticoids. This absence of correlation could be in part explained by the marked heterogeneity of the steroid response demonstrated in leukocyte subpopulations. It appears, however, that the degree of steroid action in vitro as well as the extent of spontaneous and dexamethasone-induced cell death may be related to the number of cells in the S phase of the cell cycle.

Adhesion molecules on human myeloma cells: significant changes in expression related to malignancy, tumor spreading, and immortalization.

In order to evaluate putative changes of major adhesion molecule expression on plasma cells (PCs) associated with malignant transformation, tumor spreading, and immortalization, we have quantified and compared the expression of CD56, CD44, CD11a, CD49e, and CD45 RO/RA on normal PCs, malignant PCs from multiple myeloma patients in chronic phase, in accelerated phase with or without extramedullary progression, and from human myeloma cell lines. Plasma cell phenotype was defined with the use of two-color immunofluorescence in combination with B-B4 or anti-CD38 antibodies. We found that all the adhesion antigens were expressed on normal PCs. Malignancy was characterized by an overexpression of CD56, whereas extramedullary spreading was associated with a dramatic down expression of CD56. Although CD44 remained unchanged, the subpopulation of PCs expressing CD11a, CD49e, and CD45RA/RO were significantly reduced during malignancy, and each of these negative subpopulations increased during disease acceleration. We demonstrated that CD11a and CD49e expression were correlated and defined the same subpopulation of PCs. The phenotype of HMCLs was similar to the expression profile of patients in accelerated phase with extramedullary spreading. In conclusion, we show that significant changes of PC phenotype were associated with malignancy, were correlated with the disease evolution, and could be of diagnostic and prognostic value in individuals with monoclonal gammopathy and patients with multiple myeloma.

14q32 translocations and monosomy 13 observed in monoclonal gammopathy of undetermined significance delineate a multistep process for the oncogenesis of multiple myeloma. Intergroupe Francophone du Myélome.

Clonal plasma cells in monoclonal gammopathy of undetermined significance (MGUS) have been shown to bear copy number chromosome changes. To extend our knowledge of MGUS to structural chromosomal abnormalities, we have performed fluorescence in situ hybridization experiments with probes directed to the 14q32 and 13q14 chromosomal regions in 100 patients with either MGUS or smoldering multiple myeloma (SMM). 14q32 abnormalities were observed in at least 46% of patients with MGUS/SMM, with these abnormalities being present in the majority of clonal plasma cells. Whereas t(11;14)(q13;q32) occurs in 15% of MGUS/SMM patients, an incidence similar to that of overt multiple myeloma (MM) patients, translocation t(4;14)(p16;q32) is observed in only 2% of these cases [P = 0.002 for difference with t(11;14)], as compared with 12% in MM patients (P = 0.013). Monoallelic deletions of the 13q14 region were found in 21% of patients, with two types of situations. In half of the evaluable patients, and especially in patients with SMM, the deletion is present in the majority of clonal plasma cells, as in MM, whereas in the other half of the evaluable patients (essentially in MGUS patients), it is observed in subclones only. These data enable us to elaborate a plasma cell oncogenesis model from MGUS to MM.

High incidence of translocations t(11;14)(q13;q32) and t(4;14)(p16;q32) in patients with plasma cell malignancies.

Abnormalities involving the 14q32 region are recurrent chromosomal changes in plasma cell malignancies. Recent preliminary molecular analyses found IGH rearrangements in almost 100% of human myeloma cell lines and in 75% of patients. However, no systematic study analyzing the nature of the partner chromosomal regions have been reported thus far. To define the exact incidence of illegitimate IGH rearrangements and the respective incidence of partner genes cloned to date, we analyzed 141 patients with either multiple myeloma (MM, n = 127) or primary plasma cell leukemia (PCL, n = 14) using fluorescence in situ hybridization. The overall incidence of illegitimate recombinations was 57% (80 of 141 patients). Analysis of this incidence according to Durie and Salmon stage, patients' status, i.e., MM versus primary PCL and diagnosis versus relapse, immunoglobulin type and subtype, and beta2-microglobulin value, did not show any correlation. To analyze the nature of the partner chromosomal region, we selected probes specific for the following genes: FGFR3 (4p16), MYC (8q24), CCND1 (11q13), MAF (16q23), and BCL2 (18q21). These probes, combined with differentially labeled 14q32 probes, were used for dual-color fluorescence in situ hybridization on interphase plasma cells. Among the 80 patients with illegitimate IGH rearrangement, we identified 23 IGH-CCND1 fusion cases [i.e., t(11;14)], 17 IGH-FGFR3 fusion cases [i.e., t(4;14)], 3 IGH-MYC fusion cases [i.e., t(8;14)], and only one IGH-MAF fusion case. No IGH-BCL2 fusion case was detected. In 37 of 80 patients, none of these partner genes was involved. Analysis of cases with specific translocations according to their bioclinical features at diagnosis did not show any correlation. This study demonstrated that CCND1 and FGFR3 genes are involved together in about 50% of MM and primary PCL patients with illegitimate IGH rearrangements.