A comparison of allografting with autografting for newly diagnosed myeloma

Bone marrow transplantation generates T cell-dependent control of myeloma in mice

Transplantation with autologous hematopoietic progenitors remains an important consolidation treatment for patients with multiple myeloma (MM) and is thought to prolong the disease plateau phase by providing intensive cytoreduction. However, transplantation induces inflammation in the context of profound lymphodepletion that may cause hitherto unexpected immunological effects. We developed preclinical models of bone marrow transplantation (BMT) for MM using Vk*MYC myeloma-bearing recipient mice and donor mice that were myeloma naive or myeloma experienced to simulate autologous transplantation. Surprisingly, we demonstrated broad induction of T cell-dependent myeloma control, most efficiently from memory T cells within myeloma-experienced grafts, but also through priming of naive T cells after BMT. CD8+ T cells from mice with controlled myeloma had a distinct T cell receptor (TCR) repertoire and higher clonotype overlap relative to myeloma-free BMT recipients. Furthermore, T cell-dependent myeloma control could be adoptively transferred to secondary recipients and was myeloma cell clone specific. Interestingly, donor-derived IL-17A acted directly on myeloma cells expressing the IL-17 receptor to induce a transcriptional landscape that promoted tumor growth and immune escape. Conversely, donor IFN-γ secretion and signaling were critical to protective immunity and were profoundly augmented by CD137 agonists. These data provide new insights into the mechanisms of action of transplantation in myeloma and provide rational approaches to improving clinical outcomes.

Long-term follow up of tandem autologous-allogeneic hematopoietic cell transplantation for multiple myeloma

We previously reported initial results in 102 multiple myeloma (MM) patients treated with sequential high-dose melphalan and autologous hematopoietic cell transplantation followed by 200 cGy total body irradiation with or without fludarabine 90 mg/m² and allogeneic hematopoietic cell transplantation. Here we present long-term clinical outcomes among the 102 initial patients and among 142 additional patients, with a median follow up of 8.3 (range 1.0-18.1) years. Donors included human leukocyte antigen identical siblings (n=179) and HLA-matched unrelated donors (n=65). A total of 209 patients (86%) received tandem autologous-allogeneic upfront, while thirty-five patients (14%) had failed a previous autologous hematopoietic cell transplantation before the planned autologous-allogeneic transplantation. Thirty-one patients received maintenance treatment at a median of 86 days (range, 61-150) after allogeneic transplantation. Five-year rates of overall survival (OS) and progression-free survival (PFS) were 54% and 31%, respectively. Ten-year OS and PFS were 41% and 19%, respectively. Overall non-relapse mortality was 2% at 100 days and 14% at five years. Patients with induction-refractory disease and those with high-risk biological features experienced shorter OS and PFS. A total of 152 patients experienced disease relapse and 117 of those received salvage treatment. Eighty-three of the 117 patients achieved a clinical response, and for those, the median duration of survival after relapse was 7.8 years. Moreover, a subset of patients who became negative for minimal residual disease (MRD) by flow cytometry experienced a significantly lower relapse rate as compared with MRD-positive patients (P=0.03). Our study showed that the graft-versus-myeloma effect after non-myeloablative allografting allowed long-term disease control in standard and high-risk patient subsets. Ultra-high-risk patients did not appear to benefit from tandem autologous/allogeneic hematopoietic cell transplantation because of early disease relapse. Incorporation of newer anti-MM agents into the initial induction treatments before tandem hematopoietic cell transplantation and during maintenance might improve outcomes of ultra-high-risk patients. Clinical trials included in this study are registered at: clinicaltrials.gov identifiers: 00075478, 00005799, 01251575, 00078858, 00105001, 00027820, 00089011, 00003196, 00006251, 00793572, 00054353, 00014235, 00003954.

Outcomes of Haploidentical Transplantation in Patients with Relapsed Multiple Myeloma: An EBMT/CIBMTR Report

Allogeneic hematopoietic cell transplantation (allo-HCT) using siblings and matched donors has the potential for long-term disease control in a subset of high-risk patients with multiple myeloma (MM); however, the data on using haploidentical donors in this disease are limited. We conducted a retrospective analysis to examine the outcomes of patients with MM who underwent haploidentical allo-HCT within European Society for Blood and Marrow Transplantation/Center for International Blood and Marrow Transplant Research centers. A total of 96 patients underwent haploidentical allo-HCT between 2008 and 2016. With a median follow-up of 24.0 months (range, 13.2 to 24.9 months), 97% (95% confidence interval [CI], 93% to 100%) of patients had neutrophil engraftment by day 28, and 75% (95% CI, 66% to 84%) achieved platelet recovery by day 60. Two-year progression-free survival (PFS) was 17% (95% CI, 8% to 26%), and overall survival (OS) was 48% (95% CI, 36% to 59%). At 2 years, the cumulative risk of relapse/progression was 56% (95% CI, 45% to 67%), and 1-year nonrelapse mortality (NRM) was 21% (95% CI, 13% to 29%). The incidences of acute graft-versus-host-disease (GVHD) grades II-IV by 100 days and chronic GVHD at 2 years were 39% (95% CI, 28% to 49%) and 46% (95% CI, 34% to 59%), respectively. On univariate analysis, use of post-transplantation cyclophosphamide (PT-Cy) (54% [95% CI, 41% to 68%] versus 25% [95% CI, 1% to 48%]; P =.009) and use of bone marrow as source of stem cells (72% [95% CI, 55% to 89%] versus 31% [95% CI, 17% to 46%]; P = .001) were associated with improved OS at 2 years. Disease status, patient sex, intensity of conditioning regimen, recipient/donor sex mismatch, and cytomegalovirus serostatus had no impact on OS, PFS, or NRM. Haploidentical transplantation is feasible for patients with multiply relapsed or high-risk MM, with an encouraging 2-year OS of 48% and an NRM of 21% at 1 year, supporting further investigation of haploidentical allo-HCT in suitable candidates with MM.

Allogeneic transplantation of multiple myeloma patients may allow long-term survival in carefully selected patients with acceptable toxicity and preserved quality of life

Despite significantly improved survival and response rates in patients diagnosed with multiple myeloma, it still remains an incurable disease with a poor outcome, especially in high-risk groups. Allogeneic stem cell transplantation offers a potentially curative option but remains controversial due to considerable treatment-related toxicity. We analyzed 109 consecutive myeloma patients who had received reduced-intensity conditioning allogeneic transplantation at the Freiburg University Medical Center between 2000 and 2016. Although most patients were heavily pre-treated in high-risk constellations, the overall response rate was high with 70%, the median overall survival (OS) 39.2%, and the median progression-free survival (PFS) 14.2 months, with a median follow up of 71.5 months. Survival was significantly better in patients with response to previous therapies than in those with progressive disease (median OS 65 vs. 11.5 months, P=0.003; median PFS 18.4 vs. 5.1 months, P=0.001). Moreover, survival of patients transplanted in first-line was significantly prolonged compared to relapsed/refractory disease (median OS not reached vs. 21.6 months, P<0.001; median PFS 47.7 vs. 9.6 months, P<0.001). The non-relapse mortality was relatively low with a cumulative incidence of 12.4% at ten years. Acute graft-versus-host disease (GvHD) grade II-IV was observed in 25%, and moderate or severe chronic GvHD in 24%. Quality of life (QoL) assessed with the revised Myeloma Comorbidity Index before and after transplantation remained unchanged. Our data suggest that allogeneic transplantation in the context of novel immunotherapeutic approaches may enable long-term survival and even a potential cure in a carefully selected subgroup of high-risk multiple myeloma patients with acceptable toxicity and preserved QoL.

Programmed environmental illumination during autologous stem cell transplantation hospitalization for the treatment of multiple myeloma reduces severity of depression: A preliminary randomized controlled trial

BACKGROUND

Over a third of multiple myeloma (MM) patients report clinical levels of depression during autologous stem cell transplant (ASCT) hospitalization. We report preliminary results from a randomized clinical trial investigating the effect of Programmed Environmental Illumination (PEI) of hospital rooms on depression.

METHODS

Patients (N = 187) scheduled to receive an ASCT were assessed for eligibility. Those who met study eligibility criteria (n = 44) were randomly assigned to one of two PEI conditions involving delivery of either circadian active bright white light (BWL) or circadian inactive dim white light (DWL) throughout the room from 7 to 10 am daily during hospitalization. Patients completed the Center for Epidemiological Studies Depression Scale (CES-D) prior to hospitalization, at days 2 and 7 post-transplant, and on the third day of engraftment.

RESULTS

General linear model analyses revealed no difference between the groups in CES-D total score at baseline (P = 0.7859). A longitudinal linear mixed model analysis revealed a significant interaction between time of assessment and light condition [F(3,107) = 2.90; P = 0.0386; ɳ2  = 0.08)], indicating that PEI prevented the development of depression during hospitalization, with effects reaching significance by the third day of engraftment. At the third day of engraftment, 68.4% of the participants in the DWL comparison condition met the criteria for clinically significant depression compared to 42.1% in the BWL condition.

CONCLUSION

These findings demonstrate that PEI using BWL during MM ASCT hospitalization is effective in reducing the development of depression. Future studies should examine the mechanisms whereby PEI improves depression.

Multiple myeloma: 2018 update on diagnosis, risk‐stratification, and management

Disease overview

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

Diagnosis

The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hyperc alcemia, r enal failure, a nemia, or lytic b one lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging.

Risk stratification

Patients with del(17p), t(14;16), and t(14;20) have high-risk multiple myeloma. Patients with t(4;14) translocation and gain(1q) have intermediate-risk. All others are considered standard-risk.

Risk-adapted initial therapy

Initial treatment consists of bortezomib, lenalidomide, dexamethasone (VRd). In high-risk patients, carfilzomib, lenalidomide, dexamethasone (KRd) is an alternative to VRd. In eligible patients, initial therapy is given for approximately 3–4 cycles followed by autologous stem cell transplantation (ASCT). Standard risk patients can opt for delayed ASCT at first relapse. Patients not candidates for transplant are treated with VRd for approximately 8–12 cycles followed by lenalidomide or lenalidomide plus dexamethasone.

Maintenance therapy

After ASCT, lenalidomide maintenance is recommended for standard risk patients, while maintenance with a bortezomib-based regimen is needed for patients with intermediate or high-risk disease.

Management of refractory disease

Most patients require a triplet regimen at relapse, with the choice of regimen varying with each successive relapse. Aggressive relapse with extramedullary plasmacytomas or plasma cell leukemia may require anthracycline containing combination chemotherapy regimens.

Allogeneic stem-cell transplantation for multiple myeloma: a systematic review and meta-analysis from 2007 to 2017

Background

Despite recent advances, multiple myeloma (MM) remains incurable. However, the appearance of allogeneic stem cell transplantation (allo-SCT) through graft-versus-myeloma effect provides a potential way to cure MM to some degree. This systematic review aimed to evaluate the outcome of patients receiving allo-SCT and identified a series of prognostic factors that may affect the outcome of allo-SCT.

Patients/methods

We systematically searched PubMed, Embase, and the Cochrane Library from 2007.01.01 to 2017.05.03 using the keywords ‘allogeneic’ and ‘myeloma’.

Results

A total of 61 clinical trials involving 8698 adult patients were included. The pooled estimates (95% CI) for overall survival (OS) at 1, 2, 3 and 5 years were 70 (95% CI 56–84%), 62 (95% CI 53–71%), 52 (95% CI 44–61%), and 46 (95% CI 40–52%), respectively; for progression-free survival were 51 (95% CI 38–64%), 40 (95% CI 32–48%), 34 (95% CI 27–41%), and 27 (95% CI 23–31%), respectively; and for treatment-related mortality (TRM) were 18 (95% CI 14–21%), 21 (95% CI 17–25%), 20 (95% CI 13–26%), and 27 (95% CI 21–33%), respectively. Additionally, the pooled 100-day TRM was 12 (95% CI 5–18%). The incidences of grades II–IV acute graft-versus-host disease (GVHD) and chronic GVHD were 34 (95% CI 30–37%) and 51 (95% CI 46–56%), respectively. The incidences of relapse rate (RR) and death rate were 50 (95% CI 45–55%) and 51 (95% CI 45–57%), respectively. Importantly, disease progression was the most major cause of death (48%), followed by TRM (44%). The results failed to show an apparent benefit of allo-SCT for standard risk patients, compared with tandem auto-SCT. In contrast, all 14 trials in our study showed that patients with high cytogenetic risk after allo-SCT had similar OS and PFS compared to those with standard risk, suggesting that allo-SCT may overcome the adverse prognosis of high cytogenetic risk.

Conclusion

Due to the lack of consistent survival benefit, allo-SCT should not be considered as a standard of care for newly diagnosed and relapsed standard-risk MM patients. However, for patients with high-risk MM who have a poor long-term prognosis, allo-SCT may be a strong consideration in their initial course of therapy or in first relapse after chemotherapy, when the risk of disease progression may outweigh the transplant-related risks. A large number of prospective randomized controlled trials were needed to prove the benefits of these therapeutic options.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0553-8) contains supplementary material, which is available to authorized users.

The Role of Allogeneic Transplantation for Multiple Myeloma in the Era of Novel Agents: A Study from the Japanese Society of Myeloma

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered a potentially curative therapy for patients with multiple myeloma, the role of allo-HSCT remains unclear in the novel agent era. We conducted a retrospective study of 65 patients with multiple myeloma who underwent allo-HSCT at 19 institutions from 2009 to 2016. Patients received a median of 3 (range, 1 to 7) lines of prior therapy, including at least 1 novel agent, except for autologous HSCT. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 18.8% (95% confidence interval [CI], 9.6% to 30.3%) and 47.2% (95% CI, 33.9% to 59.4%), respectively. In a multivariate analysis, an age ≥50 years and less than a very good partial response (VGPR) before allo-HSCT were independent significant adverse factors for PFS (hazard ratio [HR], 2.30, P = .0063; HR, 2.86; P = .0059) and OS (HR, 2.37, P = .013; and HR, 2.74; P = .040). In contrast, the 3-year PFS and OS rates in patients <50 years of age who achieved a VGPR or better before allo-HSCT were 64.3% (95% CI, 29.8% to 85.1%) and 80.2% (95% CI, 40.3% to 94.8%), respectively. The overall response rate was 86.4% (95% CI, 75.0% to 94.0%). The proportion of VGPR or better increased from 29% before allo-HSCT to 71% after allo-HSCT. The nonrelapse mortality at 3 years was 23.4% (95% CI, 13.8% to 34.4%). Only an age ≥50 years was associated with higher nonrelapse mortality (HR, 4.71; P = .015). We showed that allo-HSCT is feasible for heavily pretreated patients with multiple myeloma, even in the novel agent era. Allo-HSCT in particular is a promising therapy for young and chemosensitive patients.

The evolution of stem-cell transplantation in multiple myeloma

Autologous stem-cell transplantation (ASCT) remains an integral part of treatment for previously untreated, and may have value in the treatment of relapsed patients with, multiple myeloma (MM). The addition of novel agents like immunomodulators and proteasome inhibitors as induction therapy before and as consolidation/maintenance therapy after ASCT has led to an improvement in complete response (CR) rates, progression-free survival (PFS) and overall survival (OS). With advances in supportive care, older patients and patients with renal insufficiency are now able to safely undergo the procedure. The data concerning the timing of ASCT (early in the disease course or at first relapse), single versus tandem (double) ASCT and the role and duration of consolidation and maintenance therapy post ASCT remain conflicting. This review aims to discuss the evolution of stem-cell transplant over the past 3 decades and its current role in the context of newer, safer and more effective therapeutic agents.

From transplant to novel cellular therapies in multiple myeloma: European Myeloma Network guidelines and future perspectives

Survival of myeloma patients has greatly improved with the use of autologous stem cell transplantation and novel agents, such as proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies. Compared to bortezomib- and lenalidomide-based regimens alone, the addition of high-dose melphalan followed by autologous transplantation significantly improves progression-free survival, although an overall survival benefit was not observed in all trials. Moreover, follow up of recent trials is still too short to show any difference in survival. In the light of these findings, novel agent-based induction followed by autologous transplantation is considered the standard upfront treatment for eligible patients (level of evidence: 1A). Post-transplant consolidation and maintenance treatment can further improve patient outcome (1A). The availability of several novel agents has led to the development of multiple combination regimens such as salvage treatment options. In this context, the role of salvage autologous transplantation and allotransplant has not been extensively evaluated. In the case of prolonged remission after upfront autologous transplantation, another autologous transplantation at relapse can be considered (2B). Patients who experience early relapse and/or have high-risk features have a poor prognosis and may be considered as candidates for clinical trials that, in young and fit patients, may also include an allograft in combination with novel agents (2B). Ongoing studies are evaluating the role of novel cellular therapies, such as inclusion of antibody-based triplets and quadruplets, and chimeric antigen receptor-T cells. Despite encouraging preliminary results, longer follow up and larger patient numbers are needed before the clinical use of these novel therapies can be widely recommended.

Allograft for Myeloma: Examining Pieces of the Jigsaw Puzzle

Multiple myeloma (MM) cure remains elusive despite the availability of newer anti-myeloma agents. Patients with high-risk disease often suffer from early relapse and short survival. Allogeneic hematopoietic cell transplantation (allo-HCT) is an “immune-based” therapy that has the potential to offer long-term remission in a subgroup of patients, at the expense of high rates of transplant-related morbidity and mortality. Donor lymphocyte infusion (DLI) upon disease relapse after allo-HCT is able to generate an anti-myeloma response suggestive of a graft-versus-myeloma effect. Allo-HCT provides a robust platform for additional immune-based therapy upon relapse including DLI and, maintenance with immunomodulatory drugs and immunosuppressive therapy. There have been conflicting findings from randomized prospective trials questioning the role of allo-HCT. However, to this date, allo-HCT remains the only potential curable treatment for MM and its therapeutic role needs to be better defined especially for patients with high-risk disease. This review examines different aspects of this treatment and summarizes ongoing attempts at improving its therapeutic index.

Prognostic significance of tumor burden assessed by whole-body magnetic resonance imaging in multiple myeloma patients treated with allogeneic stem cell transplantation

Allogeneic stem cell transplantation is a therapeutic option under dispute but nonetheless chosen with increasing frequency for patients suffering from multiple myeloma in Europe. To study possible predictors of survival, 79 patients were investigated using whole-body magnetic resonance imaging to assess the visible tumor burden before and after allogeneic stem cell transplantation. Statistical analysis of clinical and imaging parameters included Cox regression models and distribution of survival time estimates (Kaplan-Meier method). Log rank test was used to determine the prognostic impact of the presence of focal lesions on survival. A higher tumor burden according to the lesion count was associated with a shorter overall survival (univariable/multivariable Cox regression: 1^st magnetic resonance imaging P=0.028/P=0.048; 2^nd magnetic resonance imaging P=0.008/P=0.024). Focal infiltration pattern itself seemed to be an additional adverse prognostic factor for overall survival (2^nd MRI P=0.048), although no definite cut-off could be defined. Kaplan-Meier estimates at 60 months of follow up show a significant difference (Log rank P=0.04) for overall survival rates between patients with focal infiltration (32%) and those without (75%). Since this subgroup of patients may benefit from maintenance therapy, adoptive immunotherapy, or local interventions, whole-body imaging is an appropriate and highly recommendable diagnostic approach for detection of prognostically relevant lesions before and after treatment.

Tandem autologous/allogeneic hematopoietic cell transplantation with bortezomib maintenance therapy for high-risk myeloma

We evaluated tandem autologous/allogeneic hematopoietic cell transplantation followed by bortezomib maintenance therapy in a prospective phase 2 trial of treatment of high-risk multiple myeloma. The high-dose conditioning regimen for autologous hematopoietic cell transplantation consisted of melphalan 200 mg/m². The nonmyeloablative conditioning regimen for the allogeneic transplant involved low-dose total body irradiation (2 Gy) with or without fludarabine (30 mg/m² × 3 days). Among the 31 patients enrolled, 26 (84%) proceeded to HLA-matched allogeneic hematopoietic cell transplantation at a median of 61 (range, 41-168) days following the autologous transplant. Twenty-one patients (68%) started bortezomib (1.6 mg/m² IV or 2.6 mg/m² subcutaneously every 14 days for 9 months) at a median of 79 (range, 63-103) days after allogeneic transplantation. With a median follow-up of 51 (range, 16-86) months and based on intention to treat, the 2-year and 4-year progression-free survival and overall survival estimates among 24 newly diagnosed high-risk patients were 71% and 75%, and 52% and 61%, respectively. The 7 patients enrolled with relapsed or persistent disease had a 2-year and 4-year progression-free survival and overall survival rates of 14% and 43%, and 14% and 29%, respectively. These findings suggest that for patients with newly diagnosed high-risk multiple myeloma, bortezomib maintenance therapy after tandem autologous/allogeneic hematopoietic cell transplantation is safe and may prevent disease progression until full establishment of a graft-versus-myeloma effect. This benefit, however, does not extend to patients who enroll after unsuccessful prior therapy. This trial was registered at www.clinicaltrials.gov as #NCT00793572.

Autologous/Allogeneic Hematopoietic Cell Transplantation versus Tandem Autologous Transplantation for Multiple Myeloma: Comparison of Long-Term Postrelapse Survival

We compared postrelapse overall survival (OS) after autologous/allogeneic (auto/allo) versus tandem autologous (auto/auto) hematopoietic cell transplantation (HCT) in patients with multiple myeloma (MM). Postrelapse survival of patients receiving an auto/auto or auto/allo HCT for MM and prospectively reported to the Center for International Blood and Marrow Transplant Research between 2000 and 2010 were analyzed. Relapse occurred in 404 patients (72.4%) in the auto/auto group and in 178 patients (67.4%) in the auto/allo group after a median follow-up of 8.5 years. Relapse occurred before 6 months after a second HCT in 46% of the auto/allo patients, compared with 26% of the auto/auto patients. The 6-year postrelapse survival was better in the auto/allo group compared with the auto/auto group (44% versus 35%; P = .05). Mortality due to MM was 69% (n = 101) in the auto/allo group and 83% (n = 229) deaths in auto/auto group. In multivariate analysis, both cohorts had a similar risk of death in the first year after relapse (hazard ratio [HR], .72; P = .12); however, for time points beyond 12 months after relapse, overall survival was superior in the auto/allo cohort (HR for death in auto/auto =1.55; P = .005). Other factors associated with superior survival were enrollment in a clinical trial for HCT, male sex, and use of novel agents at induction before HCT. Our findings shown superior survival afterrelapse in auto/allo HCT recipients compared with auto/auto HCT recipients. This likely reflects a better response to salvage therapy, such as immunomodulatory drugs, potentiated by a donor-derived immunologic milieu. Further augmentation of the post-allo-HCT immune system with new immunotherapies, such as monoclonal antibodies, checkpoint inhibitors, and others, merit investigation.

Allogeneic Hematopoietic Cell Transplantation for Myeloma: When and in Whom Does It Work

The growing list of available therapies for patients with multiple myeloma has resulted in tremendously high response rates and prolonged survival. However, the cure remains elusive. A continued effort at developing strategies to utilize all available treatment modalities in the most effective manner is needed. Allogeneic hematopoietic cell transplantation (allo-HCT) is a robust platform, associated with high response rates, and provides a unique foundation on which immune therapies and novel agents can be employed to improve clinical outcomes. Patients with high-risk myeloma and those relapsing after novel agent-based therapies or early after an autologous HCT should be considered for allo-HCT, ideally in a clinical trial setting. Results from several ongoing studies are expected to provide important information that will help determine the place of allo-HCT in the myeloma treatment algorithm.

Impact of New Drugs on the Long-Term Follow-Up of Upfront Tandem Autograft-Allograft in Multiple Myeloma

Before the introduction of "new drugs," we designed a trial in which 162 newly diagnosed myeloma patients were biologically randomized to receive either an autologous stem cell transplant (auto-SCT) followed by a nonmyeloablative allogeneic stem cell transplant (allo-SCT) or a double auto-SCT. Fifty-eight patients in the allo-SCT arm and 46 in the double auto-SCT arm completed the assigned treatment. At a median follow-up of 12.3 years from allo-SCT and 12.1 years from second auto-SCT, median overall survival (OS) was 11.4 in the allo-SCT arm and 3.9 years in the auto-SCT -arm (P = .007), whereas event-free survival was 3.6 and 1.5 years (P < .001), respectively. A subset of allo-SCT patients showed persistent molecular remission. Two-year cumulative incidence of chronic graft-versus-host disease was 67.2%. At 5 years, 39% of these patients were alive, disease-free, and off immunosuppression; 36.6% had relapsed and 12.2% were still on immunosuppression. Thirty-three of 58 patients (allo-SCT arm) and 39 of 46 (auto-SCT arm) relapsed at least once and were rescued with new drugs. In the allo-SCT arm, 2 patients in biochemical relapse did not reach clinical criteria for treatment. Overall 28 (90%) were treated with new drugs and 14 (45%) received donor lymphocyte infusions (DLIs). In 28 of 31 patients (90%) DLIs were given with new drugs. Median OS from first relapse was 7.5 years in the allo-SCT arm and 2 years in the auto-SCT arm (P = .01). Patients who received DLI showed significantly longer OS (hazard ratio, .38; P = .042) as compared with auto-SCT patients. This difference was slightly lower when only allo-SCT patients who did not receive DLIs were considered (hazard ratio, .56; P = .154). In summary, long-term disease-free survival and survival outcomes after treating relapse with new drugs with or without DLIs were better in allo-SCT patients.

A View from the Plateau: Is There a Role for Allogeneic Stem Cell Transplantation in the Era of Highly Effective Therapies for Multiple Myeloma?

Allogeneic hematopoietic cell transplant (allo-HCT) represents the earliest form of immunotherapy used to treat multiple myeloma (MM). Since the first successful myeloablative allografts were performed in the early 1980s, highly effective new agents to treat this disease have been identified at an unprecedented pace. Currently, sixteen FDA-approved therapies are available to treat MM. As a consequence of these advances, the median overall survival for standard risk MM patients has extended to over 7 years. In light of the effective treatment options available, and as a consequence of high rates of toxicity, the role of allo-HCT to treat MM has been called into question. Patients with high-risk disease however continue to face early relapse and death, underscoring the need for approaches that more effectively treat this group. Moreover, allo-HCT remains the only mechanism through which MM patients are reliably cured and for the high-risk population represent an important treatment option that provides them access to an otherwise elusive survival plateau.

Allogeneic stem cell transplantation and subsequent treatments as a comprehensive strategy for long-term survival of multiple myeloma patients

We evaluated 71 patients treated with allogeneic hematopoietic cell transplantation (allo-HCT) for multiple myeloma (MM). Forty-three patients (61%) received allo-HCT after the first line of therapy. Fifty-eight patients (82%) had chemosensitive disease at the time of allo-HCT. A HLA-matched related or unrelated donor was available for 68 patients (96%). Non-myeloablative or reduced-intensity conditioning regimen and peripheral blood hematopoietic cells as a graft source were used in most patients. The cumulative incidence of grade II-IV acute GVHD at day +100 and chronic GVHD at 5 years was 13% (95% CI 7-23%) and 35% (95% CI 24-46), respectively. Non-relapse mortality and relapse/progression incidence at 5 years were 12% (95% CI 5-23) and 65% (95% CI 49-76), respectively. With a median follow-up in survivors of 100 months (range 16-186), the 5-year PFS and OS were 39% (95% CI 27-52) and 60% (95% CI 55-77), respectively. On multivariate analysis: age >55 years was associated with both a reduced PFS (RR 2.11, 95% CI 1.15-3.87) and OS (RR 5.53, 95% CI 2.22-13.76); chemorefractory disease at allo-HCT was associated with both reduced PFS (RR 3.09, 95% CI 1.37-7.00) and OS (RR 3.19, 95% CI 1.23-8.22). At relapse, 24 patients (56%) received bortezomib, 28 (65%) lenalidomide, 11 (26%) pomalidomide, 16 (37%) donor lymphocytes infusion as part of salvage therapy after allo-HCT relapse. Median PFS from time of salvage treatment was 7 months (range 0-113 months) for bortezomib-based therapy, 14 months (range 0-79 months) for lenalidomide and 10 months (range 1-28) for pomalidomide. Allo-HCT is a feasible and effective strategy in selected patients with MM and could be an effective platform for subsequent therapies.

Extracellular vesicles as potential biomarkers of acute graft-vs-host disease

Acute graft-vs-host disease (GVHD) is a serious complication after allografting. We carried out an exploratory study to investigate a potential correlation of surface antigens on extracellular vesicles (EVs) and acute GVHD. EVs were extracted from serum samples from 41 multiple myeloma patients who underwent allografting. EVs were characterized by flow cytometry using a panel of 13 antibodies against specific membrane proteins that were reported to be predictive of acute GVHD. We observed a correlation between three potential biomarkers expressed on EV surface and acute GVHD onset by both logistic regression analysis and Cox proportional hazard model. In our study, CD146 (MCAM-1) was correlated with an increased risk-by almost 60%-of developing GVHD, whereas CD31 and CD140-α (PECAM-1 and PDGFR-α) with a decreased risk-by almost 40 and 60%, respectively. These biomarkers also showed a significant change in signal level from baseline to the onset of acute GVHD. Our novel study encourages future investigations into the potential correlation between EVs and acute GVHD. Larger prospective multicenter studies are currently in progress.

Allogeneic Blood or Marrow Transplantation with Post-Transplantation Cyclophosphamide as Graft-versus-Host Disease Prophylaxis in Multiple Myeloma

Allogeneic blood or marrow transplantation (alloBMT) may lead to long-term disease control in patients with multiple myeloma (MM). However, historically, the use of alloBMT in MM has been limited by its high nonrelapse mortality (NRM) rates, primarily from graft-versus-host disease (GVHD). We previously demonstrated that post-transplantation cyclophosphamide (PTCy) decreases the toxicities of both acute and chronic GVHD after alloBMT. Here, we examine the impact of PTCy in patients with MM undergoing alloBMT at Johns Hopkins Hospital. From 2003 to 2011, 39 patients with MM underwent bone marrow or peripheral blood alloBMT from HLA-matched related/unrelated or haploidentical related donors after either myeloablative or nonmyeloablative conditioning. Post-transplantation GVHD prophylaxis consisted of cyclophosphamide (50 mg/kg) on days +3 and +4 with or without mycophenolate mofetil and tacrolimus. Engraftment was detected in 95% of patients, with neutrophil and platelet recovery at a median of 15 and 16 days, respectively. The cumulative incidences of acute grades 2 to 4 and grades 3 and 4 GVHD were .41 and .08, respectively, and no cases of grade 4 acute GVHD were observed. The cumulative incidence of chronic GVHD was .13. One patient succumbed to NRM. All cases of chronic GVHD involved extensive disease and 60% of these patients received systemic therapy with complete resolution. After alloBMT, the overall response rate was 62% with complete, very good partial, and partial response rates of 26%, 21%, and 15%, respectively. The median progression-free survival was 12 months and was associated with the depth of response but not cytogenetic risk. The estimated cumulative incidence of relapse was .46 (95% confidence interval [CI], .3 to .62) at 1 year and .56 (95% CI, .41 to .72) at 2 years. At last follow-up, 23% of patients remain without evidence of disease at a median follow-up of 10.3 years after alloBMT. The median overall survival was 4.4 years and the 5-year and 10-year overall survival probabilities were 49% (95% CI, 35% to 67%) and 43% (95% CI, 29% to 62%), respectively. The use of PTCy after alloBMT for MM is feasible and results in low NRM and GVHD rates. The safety of this approach may allow the development of novel post-transplantation maintenance strategies to improve long-term disease control.

Immunologic approaches for the treatment of multiple myeloma

The FDA approval of two monoclonal antibodies in 2015has heralded a new era of targeted immunotherapies for multiple myeloma (MM). In this review we discuss the recent approaches using different immunological components to treat MM. In particular, we review current monoclonal antibody based therapies, engineered T- and NK cell products, 'off-target' immunomodulation, and strategies utilizing allogeneic cell transplantation in MM. We discuss how an immunologic approach offers promise for the treatment of this genetically heterogeneous disease, and how patients with acquired drug resistance may particularly benefit from these therapies. We also describe some of the limitations of the current strategies and speculate on the future of personalized immunotherapies for MM.

Role of stem cell transplant and maintenance therapy in plasma cell disorders

Autologous stem cell transplant (ASCT) has been an important component of therapy for myeloma patients eligible for high-dose chemotherapy. Recent studies comparing early transplant to low-dose chemotherapy support the continued use of ASCT as consolidation following induction therapy, even in the era of immunomodulatory drugs, proteasome inhibitors, and other novel agents. Despite the marked improvements in outcomes with this approach, most patients will eventually experience disease progression. Thus, inclusion of post-ASCT consolidation/maintenance strategies is used to improve long-term disease control. Multiple randomized studies support the use of lenalidomide maintenance therapy following ASCT. The next generation of clinical trials will incorporate novel agents such as monoclonal antibodies, proteasome inhibitors, and other novel pathway modulatory agents into post-ASCT treatment strategies with the goal of achieving even deeper responses and longer durations of disease control.

Role of stem cell transplant and maintenance therapy in plasma cell disorders

Autologous stem cell transplant (ASCT) has been an important component of therapy for myeloma patients eligible for high-dose chemotherapy. Recent studies comparing early transplant to low-dose chemotherapy support the continued use of ASCT as consolidation following induction therapy, even in the era of immunomodulatory drugs, proteasome inhibitors, and other novel agents. Despite the marked improvements in outcomes with this approach, most patients will eventually experience disease progression. Thus, inclusion of post-ASCT consolidation/maintenance strategies is used to improve long-term disease control. Multiple randomized studies support the use of lenalidomide maintenance therapy following ASCT. The next generation of clinical trials will incorporate novel agents such as monoclonal antibodies, proteasome inhibitors, and other novel pathway modulatory agents into post-ASCT treatment strategies with the goal of achieving even deeper responses and longer durations of disease control.

Efficacy of host-dendritic cell vaccinations with or without minor histocompatibility antigen loading, combined with donor lymphocyte infusion in multiple myeloma patients

Donor lymphocyte infusions (DLI) can induce durable remissions in multiple myeloma (MM) patients, but this occurs rather infrequently. As the graft-versus-tumor (GvT) effect of DLI depends on the presence of host-dendritic cells (DCs), we tested in a phase I/II trial whether the efficacy of DLI could be improved by simultaneous vaccination with host-DCs. We also analyzed the possibility of further improving the GvT effect by loading the DCs with peptides of mismatched hematopoietic cell-specific minor histocompatibility antigens (mHags). Fifteen MM patients not responding to a first DLI were included. Eleven patients could be treated with a second equivalent dose DLI combined with DC vaccinations, generated from host monocytes (moDC). For four patients, the DC products did not meet the quality criteria. In four of the treated patients the DCs were loaded with host mHag peptides. Toxicity was limited and no acute GvHD occurred. Most patients developed objective anti-host T-cell responses and in one patient a distinct mHag-specific T-cell response accompanied a temporary clinical response. These findings confirm that DLI combined with host-DC vaccination, either unloaded or loaded with mHag peptides, is feasible, safe and capable of inducing host-specific T-cell responses. The limited clinical effects may be improved by developing more immunogenic DC products or by combining this therapy with immune potentiating modalities like checkpoint inhibitors.

Outcomes in patients with multiple myeloma with TP53 deletion after autologous hematopoietic stem cell transplant

TP53 gene deletion is associated with poor outcomes in multiple myeloma (MM). We report the outcomes of patients with MM with and without TP53 deletion who underwent immunomodulatory drug (IMiD) and/or proteasome inhibitor (PI) induction followed by autologous hematopoietic stem cell transplant (auto-HCT). We identified 34 patients with MM and TP53 deletion who underwent IMiD and/or PI induction followed by auto-HCT at our institution during 2008-2014. We compared their outcomes with those of control patients (n = 111) with MM without TP53 deletion. Median age at auto-HCT was 59 years in the TP53-deletion group and 58 years in the control group (P = 0.4). Twenty-one patients (62%) with TP53 deletion and 69 controls (62%) achieved at least partial remission before auto-HCT (P = 0.97). Twenty-three patients (68%) with TP53 deletion and 47 controls (42%) had relapsed disease at auto-HCT (P = 0.01). Median progression-free survival was 8 months for patients with TP53 deletion and 28 months for controls (P < 0.001). Median overall survival was 21 months for patients with TP53 deletion and 56 months for controls (P < 0.001). On multivariate analysis of both groups, TP53 deletion (hazard ratio 3.4, 95% confidence interval 1.9-5.8, P < 0.001) and relapsed disease at auto-HCT (hazard ratio 2.0, 95% confidence interval 1.2-3.4, P = 0.008) were associated with a higher risk of earlier progression. In MM patients treated with PI and/or IMiD drugs, and auto-HCT, TP53 deletion and relapsed disease at the time of auto-HCT are independent predictors of progression. Novel approaches should be evaluated in this high-risk population. Am. J. Hematol. 91:E442-E447, 2016. © 2016 Wiley Periodicals, Inc.

Targeting Immune Checkpoints in Hematologic Malignancies

The use of antibodies that target immune checkpoint molecules on the surface of T-lymphocytes and/or tumor cells has revolutionized our approach to cancer therapy. Cytotoxic-T-lymphocyte antigen (CTLA-4) and programmed cell death protein 1 (PD-1) are the two most commonly targeted immune checkpoint molecules. Although the role of antibodies that target CTLA-4 and PD-1 has been established in solid tumor malignancies and Food and Drug Administration approved for melanoma and non-small cell lung cancer, there remains a desperate need to incorporate immune checkpoint inhibition in hematologic malignancies. Unlike solid tumors, a number of considerations must be addressed to appropriately employ immune checkpoint inhibition in hematologic malignancies. For example, hematologic malignancies frequently obliterate the bone marrow and lymph nodes, which are critical immune organs that must be restored for appropriate response to immune checkpoint inhibition. On the other hand, hematologic malignancies are the quintessential immune responsive tumor type, as proven by the success of allogeneic stem cell transplantation (allo-SCT) in hematologic malignancies. Also, sharing an immune cell lineage, malignant hematologic cells often express immune checkpoint molecules that are absent in solid tumor cells, thereby offering direct targets for immune checkpoint inhibition. A number of clinical trials have demonstrated the potential for immune checkpoint inhibition in hematologic malignancies before and after allo-SCT. The ongoing clinical studies and complimentary immune correlatives are providing a growing body of knowledge regarding the role of immune checkpoint inhibition in hematologic malignancies, which will likely become part of the standard of care for hematologic malignancies.

The immunotherapy era of myeloma: monoclonal antibodies, vaccines, and adoptive T-cell therapies

The treatment of multiple myeloma has evolved significantly over the last decades from primarily alkylator-based chemotherapeutic agents with minimal efficacy to the introduction of more effective agents including immune modulators and proteasome inhibitors, which have changed the landscape of therapy for this disease. We are now entering a new era that will increasingly integrate immunotherapy into standard treatment. This review discusses the current immune-based strategies currently approved, as well as various immune approaches being actively investigated including monoclonal antibodies, checkpoint inhibitors, vaccines, and adoptive T-cell therapies.

Allogeneic Hematopoietic Cell Transplantation in Multiple Myeloma: Focus on Longitudinal Assessment of Donor Chimerism, Extramedullary Disease, and High-Risk Cytogenetic Features

Although generally not applied as first-line treatment of multiple myeloma, allogeneic hematopoietic cell transplantation (allo-SCT) can still be chosen as ultimate escalation approach in high-risk patients, preferentially within the framework of clinical trials. In this study, we investigated whether decreasing donor chimerism (DC) is predictive for relapse. In addition, we comprehensively determined the impact of several other disease- and treatment-related factors on outcome. One hundred fifty-five multiple myeloma patients whose DC status was followed serially by the short tandem repeat-based techniques at a single lab were included in this retrospective study. Outcome variables were studied in univariate and multivariable analyses. Available were 2.324 DC samples (median, 12 per patient). Loss of full DC was associated with shorter progression-free survival (PFS) (HR, 1.7; 95% CI, 1.1 to 2.6) but did not impact overall survival. Two-thirds of patients with International Myeloma Working Group-defined relapses still displayed a full DC in peripheral blood or bone marrow. Extramedullary manifestations were observed in 33% of patients, accounting for the discrepancy between DC analysis and the actual disease status. In multivariable analysis, the 2 most relevant variables for an unfavorable PFS were progressive disease before allo-SCT (HR, 3.0; 95% CI, 1.5 to 5.9) and allo-SCT at least the second relapse (HR, 2.8; 95% CI, 1.5 to 4.9), whereas for overall survival progressive disease or partial response before allo-SCT had the strongest negative effects (HR, 4.2; 95% CI, 1.9 to 9, and HR, 2.0; 95% CI, 1.0 to 3.8, respectively). Adverse cytogenetics such as del17p, t(4,14) or amp(1q21) were not associated with shorter survival after allo-SCT. Extensive DC sampling beyond robust engraftment does not appear to provide additional information helpful for disease management in most patients and is challenged by a significant incidence of extramedullary disease. In our series, allo-SCT overcame unfavorable cytogenetics.

Multiple myeloma: 2016 update on diagnosis, risk-stratification, and management

Multiple myeloma accounts for approximately 10% of hematologic malignancies.The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging. Patients with del(17p), t(14;16), and t(14;20) have high-risk multiple myeloma. Patients with t(4;14) translocation and gain(1q) have intermediate-risk. All others are considered standard-risk. Initial treatment consists of bortezomib, lenalidomide, dexamethasone (VRD). In high-risk patients, carfilzomib, lenalidomide, dexamethasone (KRD) is an alternative to VRD. In eligible patients, initial therapy is given for approximately 3-4 months followed by autologous stem cell transplantation (ASCT). Standard risk patients can opt for delayed ASCT at first relapse. Patients not candidates for transplant are treated with Rd until progression, or alternatively, a triplet regimen such as VRD for approximately 12-18 months. After ASCT, lenalidomide maintenance is considered for standard risk patients especially in those who are not in very good partial response or better, while maintenance with a bortezomib-based regimen is needed for patients with intermediate or high-risk disease. Patients with indolent relapse can be treated with 2-drug or 3-drug combinations. Patients with more aggressive relapse require a triplet regimen or a combination of multiple active agents. Am. J. Hematol. 91:720-734, 2016. © 2016 Wiley Periodicals, Inc.

Management of high-risk Myeloma: an evidence-based review of treatment strategies

INTRODUCTION

Despite the progress made in the treatment of patients with multiple myeloma over recent decades, a significant cohort with high-risk disease as defined by specific clinical and genetic criteria continue to respond poorly to standard treatment. These patients represent a particular challenge to the treating physician and require early identification as well as personalized treatment strategies.

AREAS COVERED

In this review, we discuss the prognostic impact of adverse clinical, radiological and genetic factors, evaluate available scoring systems and highlight key aspects of the therapeutic management of high-risk myeloma. MEDLINE and recent scientific meetings' databases were searched for the keywords 'high-risk' and 'multiple myeloma' and relevant studies relating to both diagnostic and therapeutic approaches were identified. Expert commentary: A case is made for intensive induction using combinations of novel agents, early high-dose therapy supported by autologous stem cell transplantation and the widespread use of maintenance therapies. Novel therapeutic options, especially in the field of immunotherapy, are currently explored in clinical trials and have the potential to further improve outcomes for patients with high-risk multiple myeloma.

Outcomes of unrelated cord blood transplantation in patients with multiple myeloma: a survey on behalf of Eurocord, the Cord Blood Committee of Cellular Therapy and Immunobiology Working Party, and the Chronic Leukemia Working Party of the EBMT

Although allogeneic stem cell transplantation is not a standard therapy for multiple myeloma, some patients can benefit from this intense therapy. There are few reports on outcomes after umbilical cord blood transplantation in multiple myeloma, and investigation of this procedure is warranted. We retrospectively analyzed 95 patients, 85 with multiple myeloma and 10 with plasma cell leukemia, receiving single or double umbilical cord blood transplantation from 2001 to 2013. Median follow up was 41 months. The majority of patients received a reduced intensity conditioning. The cumulative incidence of neutrophil engraftment was 97%±3% at 60 days, and that of 100-day acute graft-versus-host disease grade II-IV was 41%±5%. Chronic graft-versus-host disease at two years was 22%±4%. Relapse and non-relapse mortality was 47%±5% and 29%±5% at three years, respectively. Three-year progression-free survival and overall survival were 24%±5% and 40%±5%, respectively. Anti-thymocyte globulin was associated with decreased incidence of acute graft-versus-host disease, higher non-relapse mortality, decreased overall and progression-free survival. Patients with high cytogenetic risk had higher relapse, and worse overall and progression-free survival. In conclusion, umbilical cord blood transplantation is feasible for multiple myeloma patients.

Tandem autologous versus autologous/allogeneic transplantation for multiple myeloma: propensity score analysis

Autologous hematopoietic stem cell transplantation (auto-HCT) is considered a standard therapy for transplant-eligible patients with multiple myeloma, while allogeneic HCT (allo-HCT) is controversial. We retrospectively analyzed 765 patients with myeloma who underwent tandem transplantation between 1998 and 2012 using Japanese registry data. We evaluated the clinical outcomes of tandem auto-HCT (n = 676) and auto/allo-HCT (n = 89). To adjust for a selection bias, we compared overall survival (OS) between the two groups by a propensity score analysis. The probability of OS at six years was 58.5% for the tandem auto-HCT group and 54.4% for the tandem auto/allo-HCT group (p = 0.47). In a matched-pair analysis based on the propensity score, the difference in survival between the two groups was not statistically significant, although the survival curve appeared to reach a plateau beyond five years in the auto/allo group. Further strategies to reduce treatment-related mortality and enhance a graft-versus-myeloma effect are necessary to improve OS.

The role of tandem stem cell transplantation for multiple myeloma patients

INTRODUCTION

Autologous Stem Cell Transplantation (ASCT) represents the standard treatment in eligible "de-novo" multiple myeloma (MM) patients.

AREAS COVERED

ASCT may be single or tandem, and a single ASCT can be followed by an allogeneic (Allo)-SCT. A systematic review has been conducted to examine the current evidence for the efficacy of using a tandem transplant strategy in MM.

EXPERT OPINION

A tandem ASCT approach should be considered for all patients, although the benefit from the second ASCT in patients who are in complete remission or experience a very good partial response should be answered in a clinical trial. Recent results with the new induction regimens indicate that there is a role for tandem ASCT in the presence of adverse cytogenetic abnormalities. Planned AlloSCT after ASCT has not been found to be superior in the majority of studies and is not recommended outside of a clinical trial. However, single or tandem ASCT are both appropriate options and participation in prospective clinical trials should be encouraged to resolve the debate in the era of novel agents for MM.

Stem cell transplantation in multiple myeloma and other plasma cell disorders (report from an EBMT preceptorship meeting)

The European Society for Blood and Marrow Transplantation Chronic Malignancies Working Party held a preceptorship meeting in Turin, Italy on 25-26 September 2014, to discuss the role of stem cell transplantation (SCT) in the treatment of multiple myeloma and other plasma cell disorders. Scientists and clinicians working in the field gathered to discuss a variety of topics including the results of recent clinical trials, basic research, the concept of minimal residual disease, and immune modulation. As individual presentations revealed, important advances have occurred in our understanding of the pathophysiology of myeloma and the role that SCT, along with other forms of immunotherapy, plays in treating it. Each presentation stimulated discussion and exchange of ideas among the attendants. We decided to summarize and, importantly, to update the meeting proceedings in this review to share stimulating discussions and ideas on potentially novel treatment strategies among clinicians.

Transplantation for Multiple Myeloma

Multiple myeloma is a disorder characterized by accumulation of malignant plasma cells in the bone marrow, hypercalcemia, monoclonal protein, and end organ damage. Recently newer generation proteosome inhibitors, monoclonal antibodies and novel agents have been approved by FDA, which is undoubtedly increasing life expectancy of the patients. However, hematopoietic stem cell transplantation still remains the cornerstone of the treatment. In this chapter, we are discussing the autologous stem cell transplant, allogeneic stem cell transplant and total therapy trials with outcomes.

Moving Beyond Autologous Transplantation in Multiple Myeloma: Consolidation, Maintenance, Allogeneic Transplant, and Immune Therapy

For multiple myeloma, introduction of novel agents as part of the front-line treatment followed by high-dose chemotherapy and autologous hematopoietic stem cell transplantation (ASCT) induces deep responses in a majority of patients with this disease. However, disease relapse is inevitable, and, with each relapse, the remission duration becomes shorter, ultimately leading to a refractory disease. Consolidation and maintenance strategy after ASCT is one route to provide sustained disease control and prevent repeated relapses. Though the consolidation strategy remains largely confined to clinical trials, significant data support the efficacy of consolidation in improving the depth of response and outcomes. There are also increasing rates of minimal residual disease-negativity with additional consolidation therapy. On the other hand, maintenance with novel agents post-transplant is well established and has been shown to improve both progression-free and overall survival. Evolving paradigms in maintenance include the use of newer proteasome inhibitors, immunotherapy maintenance, and patient-specific maintenance-a concept that utilizes minimal residual disease as the primary driver of decisions regarding starting or continuing maintenance therapy. The other approach to overcome residual disease is immune therapeutic strategies. The demonstration of myeloma-specific alloimmunity from allogeneic transplantation is well established. More sophisticated and promising immune approaches include adoptive cellular therapies, tumor vaccines, and immune checkpoint manipulations. In the future, personalized minimal residual disease-driven treatment strategies following ASCT will help overcome the residual disease, restore multiple myeloma-specific immunity, and achieve sustained disease control while minimizing the risk of overtreatment.

Multiple Myeloma: Diagnosis and Treatment

The diagnosis and treatment of multiple myeloma has changed dramatically in the past decade. The disease definition has been updated to include highly specific biomarkers in addition to established markers of end-organ damage. The staging system has been revised to combine both measures of tumor burden and disease biology. Advances in therapy have resulted in a marked improvement in overall survival. New drugs introduced in the past few years include carfilzomib, pomalidomide, panobinostat, ixazomib, elotuzumab, and daratumumab. In this review, we outline the current approach to the diagnosis, prognosis, and management of multiple myeloma.

Management of Transplant-Eligible Patients with Newly Diagnosed Multiple Myeloma

Treatment approaches for newly diagnosed myeloma have changed considerably during the past decade, along with a better understanding of the disease heterogeneity. Availability of new drug classes such as proteasome inhibitors and immunomodulatory drugs, and use of these drugs in combinations have led to higher response rates and deeper responses in the vast majority of patients with newly diagnosed myeloma. In addition to improved efficacy, these regimens are tolerated better than those with conventional chemotherapy drugs, which have reduced the early mortality seen in MM, while allowing for successful stem cell collection in patients undergoing stem cell transplant consolidation. Ongoing clinical trials with newer drugs such as monoclonal antibodies are being explored as options for newly diagnosed MM. The optimal regimen continues to evolve and is often dictated by the intent to transplant, age and comorbidities. Despite the increasing response rates seen with the new regimens, autologous stem cell transplantation remains an effective modality for consolidation, further deepening the responses seen with the initial therapy. Post-transplant approaches have further added to the efficacy of this platform with both post-transplant consolidation and maintenance demonstrating value in clinical trials. Currently, the combination of an effective initial therapy followed by one or two autologous stem cell transplants, with or without consolidation followed by maintenance appear to provide the maximum benefit in terms of duration of disease control for patients with newly diagnosed MM.

Favorable long-term outcome of patients with multiple myeloma using a frontline tandem approach with autologous and non-myeloablative allogeneic transplantation

Despite survival improvement with novel agents and use of autologous hematopoietic stem cell transplantation (HSCT), cure of patients with multiple myeloma (MM) remains anecdotal. Initial observations suggested that chronic GvHD was accompanied by an anti-myeloma effect after myeloablative HSCT, but unfortunately this procedure was hampered by high non-relapse mortality (NRM). To maximize the anti-myeloma effect and minimize NRM, we developed a non-myeloablative (NMA) regimen associated with a high incidence of chronic GvHD and tested its efficacy on patient survival and disease eradication. From 2001 to 2010, 92 patients aged ⩽ 65 years with a compatible sibling donor received autologous HSCT followed by an outpatient NMA allogeneic HSCT using a conditioning of fludarabine and cyclophosphamide. Patient median age was 52 years and 97% presented Durie-Salmon stages II-III disease. After a median follow-up of 8.8 years, probability of 10-year progression free and overall survival were 41% and 62%, respectively. Although the cumulative incidence of extensive chronic GvHD was high (at 79%), the majority of long-term survivors were off immunosuppressive drugs by year 5 and NRM was low (at 10%). Together, our results suggest that potential MM cure can be achieved with NMA transplantation regimens that maximize graft-versus-myeloma effect and minimize NRM.