Chimeric antigen receptor T-cell therapy for multiple myeloma: a consensus statement from The European Myeloma Network.

Adoptive cellular therapy using chimeric antigen receptor T-cell (CART) therapy is currently being evaluated in patients with relapsed / refractory multiple myeloma (MM). The majority of CAR-T cell programs now being tested in clinical trials are targeting B-cell maturation antigen. Several recent phase I / II trials show promising preliminary results in patients with MM progressing on proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies targeting CD38. CAR-T cell therapy is a potentially life-threatening strategy that can only be administered in experienced centers. For the moment, CAR-T cell therapy for MM is still experimental, but once this strategy has been approved in relapsed/refractory MM, it will become one of the most important indications for this therapy in Europe and world-wide. This manuscript proposes practical considerations for the use of CAR-T cell therapy in MM, and discusses several important issues for its future development.

Correction: Early myeloma-related death in elderly patients: development of a clinical prognostic score and evaluation of response sustainability role.

Following the publication of this article, the author notes that the following information was missed from the acknowledgments section.

Lenalidomide plus dexamethasone versus observation in patients with high-risk smouldering multiple myeloma (QuiRedex): long-term follow-up of a randomised, controlled, phase 3 trial.

BACKGROUND: The standard of care for smouldering multiple myeloma is observation. We did the QuiRedex study to compare early treatment with lenalidomide plus dexamethasone with observation in patients with high-risk smouldering multiple myeloma. Here we report the long-term follow-up results of the trial. METHODS: We did this open-label, randomised, controlled phase 3 study at 19 centres in Spain and three centres in Portugal. Patients aged 18 years or older with high-risk smouldering multiple myeloma were randomly assigned (1:1), via a computerised random number generator, to receive either early treatment with lenalidomide plus dexamethasone or observation, with dynamic balancing to maintain treatment balance within the two groups. Randomisation was stratified by time from diagnosis of smouldering multiple myeloma to study enrolment (≤6 months vs >6 months). Patients in the treatment group received nine 4-week induction cycles (lenalidomide 25 mg per day on days 1-21, plus dexamethasone 20 mg per day on days-1-4 and days 12-15), followed by maintenance therapy (lenalidomide 10 mg per day on days 1-21 of each 28-day cycle) up to 2 years. Group allocation was not masked from study investigators or patients. The primary endpoint was time from randomisation to progression to symptomatic myeloma. The primary analysis was based on the per-protocol population, restricted to patients who fulfilled the protocol in terms of eligibility. Safety assessments were based on the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00480363. FINDINGS: Between Nov 8, 2007, and June 9, 2010, 125 patients were enrolled and underwent randomisation. 119 patients comprised the per-protocol population and were randomly assigned to receive either lenalidomide plus dexamethasone (n=57) or observation (n=62). The cutoff date for this update was June 30, 2015. Median follow-up for surviving patients was 75 months (IQR 67-85). Lenalidomide plus dexamethasone continued to provide a benefit on time to progression compared with observation (median time to progression not reached [95% CI 47 months-not reached] vs 23 months [16-31]; hazard ratio [HR] 0·24 [95% CI 0·14-0·41]; p<0·0001). Progression to multiple myeloma occurred in 53 (86%) of 62 patients in the observation group compared with 22 (39%) of 57 patients in the treatment group. At data cutoff, ten (18%) patients had died in the treatment group and 22 (36%) patients had died in the observation group; median overall survival from the time of study entry had not been reached in either group (95% CI 65 months-not reached vs 53 months-not reached; HR 0·43 [95% CI 0·21-0·92], p=0·024). Survival in patients who had received subsequent treatments at the time of progression to active disease did not differ between groups (HR 1·34 [95% CI 0·54-3·30]; p=0·50). The most frequently reported grade 3 adverse events in patients given lenalidomide plus dexamethasone were infection (four [6%]), asthenia (four [6%]), neutropenia (three [5%]), and skin rash (two [3%]); these events all occurred during induction therapy. No grade 4 adverse events occurred, but one (2%) patient in the lenalidomide plus dexamethasone group died from a respiratory infection during induction therapy The frequency of second primary malignancies was higher in patients in the treatment group than in those in the observation group (six [10%] of 62 patients vs one [2%] of 63 patients), but the cumulative risk of development did not differ significantly between the groups (p=0·070). INTERPRETATION: This study is, to our knowledge, the first randomised trial in which early treatment has been assessed in selected patients with high-risk smouldering multiple myeloma. Positive results from ongoing trials would support the use of early treatment for patients with high-risk disease in the near future. FUNDING: Pethema (Spanish Program for the Treatment of Hematologic Diseases).

Whole-epigenome analysis in multiple myeloma reveals DNA hypermethylation of B cell-specific enhancers.

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.

International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma.

This International Myeloma Working Group consensus updates the disease definition of multiple myeloma to include validated biomarkers in addition to existing requirements of attributable CRAB features (hypercalcaemia, renal failure, anaemia, and bone lesions). These changes are based on the identification of biomarkers associated with near inevitable development of CRAB features in patients who would otherwise be regarded as having smouldering multiple myeloma. A delay in application of the label of multiple myeloma and postponement of therapy could be detrimental to these patients. In addition to this change, we clarify and update the underlying laboratory and radiographic variables that fulfil the criteria for the presence of myeloma-defining CRAB features, and the histological and monoclonal protein requirements for the disease diagnosis. Finally, we provide specific metrics that new biomarkers should meet for inclusion in the disease definition. The International Myeloma Working Group recommends the implementation of these criteria in routine practice and in future clinical trials, and recommends that future studies analyse any differences in outcome that might occur as a result of the new disease definition.

NADPH oxidases as therapeutic targets in chronic myelogenous leukemia.

PURPOSE: 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. EXPERIMENTAL DESIGN: 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. RESULTS: 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. CONCLUSION: 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.

Induction therapy for newly diagnosed multiple myeloma.

Treatment options for patients with newly diagnosed myeloma have evolved significantly over the past 10 years. Although response rates after induction for older or younger patients were limited, with few patients achieving complete remission, more recent combinations have cleared the way for major response and even complete remissions after induction therapy. As a consequence of these changes, patients are now achieving more durable and longer remissions, which have ultimately improved overall survival for patients with myeloma. The age-appropriate use of induction therapy, autologous transplant, and maintenance therapy, all keeping in mind the specific genetic risk group of a given patient, requires a long-term treatment plan for each patient defined early in the treatment course.

Current challenges in the management of patients with relapsed/refractory multiple myeloma.

When treating patients with relapsed/refractory multiple myeloma, clinicians should maximize the efficacy of treatment through use of the most appropriate combinations and sequences of agents. Treatment options depend on the duration and magnitude of response to previous therapies; the type and aggressiveness of the relapse; and patient factors such as comorbidities, performance status/quality of life, bone marrow reserve, renal function, previous toxicities (eg, peripheral neuropathy, venous thromboembolism), age, insurance coverage, distance from the hospital, and life expectancy. Patients who relapse within 1 year of a stem-cell transplant (SCT) may require multidrug rescue therapy, followed by allogeneic SCT with reduced-intensity conditioning or consolidation/maintenance therapy. Those with a long duration of remission (3 to 4 years) may undergo a second autologous SCT, using the original effective treatment protocol or a different combination as reinduction. Patients with intermediate remission duration (2 to 3 years) may benefit from the sequential use of novel agents as salvage therapy. In elderly patients, considerations of quality of life and cost constraints should be carefully weighed. At first relapse, the initial option would be to use a new scheme that is different from the one used for induction, unless the first remission was long enough to merit considering retreatment with the same scheme. At second or subsequent relapse, usually after having been treated with bortezomib (Velcade) and at least one immunomodulatory drug, enrollment in a clinical trial with experimental agents should be encouraged. This article describes the current evidence available for various treatment options as well as a personal approach to individualized therapy for relapsing patients.

Utility of flow cytometry immunophenotyping in multiple myeloma and other clonal plasma cell-related disorders.

In recent years, multiparameter flow cytometry (MFC) immunophenotyping has become mandatory in the clinical management of hematological malignancies, both for diagnostic and monitoring purposes. Multiple myeloma (MM) and other clonal plasma cell-related (PC) disorders should be no exception to this paradigm, but incorporation of immunophenotypic studies in the management of patients with PC disorders is still far from being routinely established in many diagnostic flow cytometry laboratories. For clonal PC disorders, MFC is of clear and established clinical relevance in: (1) the differential diagnosis between MM and other PC-related disorders; (2) the identification of high-risk MGUS and smoldering MM; (3) minimal residual disease investigation after therapy; additionally it may also be useful for (4) the definition of prognosis-associated antigenic profiles; and (5) the identification of new therapeutic targets. In this article, we review the clinical value of MFC in the study of PC disorders, with specific emphasis in those areas where consensus exists on the need to incorporate MFC into routine evaluation of MM and other clonal PC-related disorders.

Effects of imatinib mesylate on normal bone marrow cells from chronic myeloid leukemia patients in complete cytogenetic response.

Information on the effects of imatinib mesylate (IM) on the non-clonal bone marrow (BM) cell compartment is scanty. We have analyzed the gene expression profile of BM hematopoietic cells after IM therapy in 20 patients with chronic myeloid leukaemia (CML) in complete cytogenetic response (CCyR) and compared it with that of normal volunteer donors by oligonucleotide microarrays. In CCyR CML samples, IM induces a decrease in proliferation as well as increase in apoptosis and ubiquitination in residual non-clonal BM cells. In addition, IM diminishes cell-to-cell adhesion and downregulates the expression of the erythropoietin (EPO) receptor gene. The latter was confirmed by RT-PCR.

CD34+ cells from acute myeloid leukemia, myelodysplastic syndromes, and normal bone marrow display different apoptosis and drug resistance-associated phenotypes.

Myelodysplastic syndromes and acute myeloid leukemia (AML) are heterogeneous disorders in which conflicting results in apoptosis and multidrug resistance (MDR) have been reported. We have evaluated by multiparameter flow cytometry the expression of apoptosis- (APO2.7, bcl-2, and bax) and MDR-related proteins [P-glycoprotein (P-gp), multidrug resistance protein (MRP), and lung resistance protein (LRP)] specifically on bone marrow (BM) CD34+ cells, and their major CD32-/dim and CD32+ subsets, in de novo AML (n=90), high-risk myelodysplastic syndrome (n=9), and low-risk myelodysplastic syndrome (n=21) patients at diagnosis, and compared with normal BM CD34+ cells (n=6). CD34+ myeloid cells from AML and high-risk myelodysplastic syndrome patients displayed higher expression of bcl-2 (P <0.0001) and lower reactivity for APO2.7 (P=0.002) compared with low-risk myelodysplastic syndrome and normal controls. Similar results applied to the two predefined CD34+ myeloid cell subsets. No significant differences were found in the expression of P-gp, MRP, and LRP between low-risk myelodysplastic syndrome patients and normal BM, but decreased expression of MRP (P <0.03) in AML and high-risk myelodysplastic syndromes and P-gp (P=0.008) in high-risk myelodysplastic syndromes were detected. Hierarchical clustering analysis showed that low-risk myelodysplastic syndrome patients were clustered next to normal BM samples, whereas high-risk myelodysplastic syndromes were clustered together and mixed with the de novo AML patients. In summary, increased resistance to chemotherapy of CD34+ cells from both AML and high-risk myelodysplastic syndromes would be explained more appropriately in terms of an increased antiapoptotic phenotype rather than a MDR phenotype. In low-risk myelodysplastic syndromes abnormally high apoptotic rates would be restricted to the CD34- cell compartments.

FLT3-activating mutations are associated with poor prognostic features in AML at diagnosis but they are not an independent prognostic factor.

FLT3: gene alterations (internal tandem duplications - ITDs - and D835 mutations) are thought to be associated with poor-risk acute myeloid leukemia (AML). However, not all studies confirm this association, so it is still a matter of debate. Moreover, their association with other molecular abnormalities is less studied. We have investigated the presence of FLT3-ITD and D835 mutations in AML patients and their correlation with clinical and biological disease characteristics. The presence of ITD was analyzed in diagnostic samples of 176 AML patients and the D835 mutation in 135 of these patients. In all these patients, the presence of four well-known molecular abnormalities were also simultaneously characterized: PML/RARalpha, AML1/ETO, CBFbeta/MYH11 and MLL rearrangements. In all, 41 (23%) patients harbored FLT3 mutations, with 34 (19.3%) of them positive for the ITD, and seven (5%) positive for the D835 mutation. Of the acute promyelocytic leukemia (APL) patients, 16 (27%) showed FLT3 mutations, more frequently in M3 hypogranular cases (62% versus 17%, P=0.001) and cases with the short (bcr3) PML-RARalpha isoform (69%, P=0.002). In contrast, FLT3 was never altered in patients with inv(16), t(8;21) or 11q23 abnormalities. FLT3 mutations were significantly associated with some negative prognostic features at diagnosis (leukocytosis, high blast-cell percentage, and elevated LDH values), but they were not associated with different disease-free or overall survival. Therefore, we confirm a high frequency of FLT3 mutations in APL and in adult AML without recurrent cytogenetic translocations. In addition, they were not found as independent prognostic factors although associated with several adverse features at diagnosis.

Impact of CD34+ cell dose on the outcome of patients undergoing reduced-intensity-conditioning allogeneic peripheral blood stem cell transplantation.

We analyzed the impact of CD34+ cell dose on the outcome of 86 patients undergoing reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell transplantation. The RIC was based on fludarabine 150 mg/m2 and melphalan 140 mg/m2 or busulphan 10 mg/kg. A median of 5.68 x 106 CD34+ cells/kg and 2.86 x 108 CD3+ cells/kg were infused. All patients receiving more than percentile 75 (p75) of CD34+ cells reached complete chimerism in T lymphocytes by days 21 to 28, compared with 44% among those receiving p75 or fewer cells (P =.046). Overall, 30.3% patients developed grade 2 to 4 acute graft-versus-host disease (aGVHD). Among 83 evaluable patients, 55.8% developed chronic GVHD (cGVHD). The dose of CD34+ cells infused did influence the development of cGVHD, with a cumulative incidence of extensive cGVHD of 74% vs 47% (P =.02) among patients receiving more than p75 CD34+ cells vs those receiving p75 or fewer. Projected overall survival (OS) and event-free survival (EFS) at 43 months were 60% and 46%, respectively. Neither the dose of CD34+ cells nor the dose of CD3+ cells infused significantly influenced OS and EFS, although among patients categorized as high-risk, 36% of those receiving p75 or fewer CD34+ cells relapsed or progressed, compared with only 9% among those receiving more than p75 CD34+ cells (P =.07). Among patients receiving p75 or fewer CD34+ cells, 36% of high-risk patients relapsed, compared with 10% of low- and intermediate-risk patients (P =.004), while relapse rates were not significantly different between both subgroups when we infused more than p75 CD34+ cells, thus indicating that infusing high doses of CD34+ cells ameliorates the negative effect of advanced disease status at transplantation. cGVHD was associated with better EFS (63% vs 16% at 43 months for patients with and without cGVHD; P <.0001) and better OS (78% vs 28% for patients with and without cGHVD; P <.001). The number of CD34+ cells infused should be tailored to prevent extensive cGVHD among patients categorized as low-risk, while high-risk patients, in whom the graft-versus-leukemia effect may determine disease outcome, should receive high doses of CD34+ cells.