Impact of pretransplant therapy and depth of disease response before autologous transplantation for multiple myeloma

Optimizing Autologous Stem Cell Transplantation in Multiple Myeloma: The Impact of Intensive Chemomobilization

Most transplant-eligible multiple myeloma (MM) patients undergo autologous peripheral blood stem cell collection (PBSC) using G-CSF with on-demand plerixafor (G ± P). Chemomobilization (CM) can be used as a salvage regimen after G ± P failure or for debulking residual tumor burden ahead of autologous peripheral blood stem cell transplantation (ASCT). Prior studies utilizing cyclophosphamide-based CM have not shown long-term benefits. At our center, intensive CM (ICM) using a PACE- or HyperCVAD-based regimen has been used to mitigate "excessive" residual disease based on plasma cell (PC) burden or MM-related biomarkers. Given the lack of efficacy of non-ICM, we sought to determine the impact of ICM on event-free survival (EFS), defined as death, progressive disease, or unplanned treatment escalation. We performed a retrospective study of newly diagnosed MM patients who collected autologous PBSCs with the intent to proceed immediately to ASCT at our center between 7/2020 and 2/2023. Patients were excluded if they underwent a tandem autologous or sequential autologous-allogeneic transplant, had primary PC leukemia, received non-ICM treatment (i.e., cyclophosphamide and/or etoposide), or had previously failed G ± P mobilization. To appropriately evaluate the impact of ICM among those who potentially could have received it, we utilized a propensity score matching (PSM) approach whereby ICM patients were compared to a cohort of non-CM patients matched on pre-ASCT factors most strongly associated with the receipt of ICM. Of 451 patients identified, 61 (13.5%) received ICM (PACE-based, n = 45; hyper-CVAD-based, n = 16). Post-ICM/pre-ASCT, 11 patients (18%) required admission for neutropenic fever and/or infection. Among 51 evaluable patients, the overall response rate was 31%; however, 46 of 55 evaluable patients (84%) saw a reduction in M-spike and/or involved free light chains. Among those evaluated with longitudinal peripheral blood flow cytometry (n = 8), 5 patients (63%) cleared circulating blood PCs post-ICM. Compared to patients mobilized with non-CM, ICM patients collected a slightly greater median number of CD34+ cells (10.8 versus 10.2 × 10⁶/kg, P = .018). The median follow-up was 30.6 months post-ASCT. In a PSM multivariable analysis, ICM was associated with significantly improved EFS (hazard ratio [HR] 0.30, 95% CI 0.14 to 0.67, P = .003), but not improved OS (HR 0.38, 95% CI 0.10 to 1.44, P = .2). ICM was associated with longer post-ASCT inpatient duration (+4.1 days, 95% CI, 2.4 to 5.8, P < .001), more febrile days (+0.96 days, 95% CI 0.50 to 1.4, P < .001), impaired platelet engraftment (HR 0.23, 95% CI 0.06 to 0.87, P = .031), more bacteremia (OR 3.41, 95% CI 1.20 to 9.31, P = .018), and increased antibiotic usage (cefepime: +2.3 doses, 95% CI 0.39 to 4.1, P = .018; vancomycin: +1.0 doses, 95% CI 0.23 to 1.8, P = .012). ICM was independently associated with improved EFS in a matched analysis involving MM patients with excessive disease burden at pre-ASCT workup. This benefit came at the cost of longer inpatient duration, more febrile days, greater incidence of bacteremia, and increased antibiotic usage in the immediate post-ASCT setting. Our findings suggest that ICM could be considered for a subset of MM patients, but its use must be weighed carefully against additional toxicity.

Optimizing high dose melphalan

Melphalan, has been a major component of myeloma therapy since the 1950s. In the context of hematopoietic cell transplantation (HCT), high dose melphalan (HDM) is the most common conditioning regimen used due to its potent anti-myeloma effects and manageable toxicities. Common toxicities associated with HDM include myelosuppression, gastrointestinal issues, and mucositis. Established approaches to reduce these toxicities encompass dose modification, nausea prophylaxis with 5HT3 receptor antagonists, cryotherapy, amifostine use, and growth factors. Optimization of melphalan exposure through personalized dosing and its combination with other agents like busulfan, or bendamustine show promise. Propylene glycol-free melphalan (Evomela) represents a novel formulation aiming to enhance drug stability and reduce adverse effects. This review explores strategies to enhance the efficacy and mitigate the toxicity of HDM in multiple myeloma. Future directions involve exploring these strategies in clinical trials to improve the safety and efficacy of HDM, thereby enhancing outcomes for multiple myeloma patients undergoing autologous HCT.

Impact of residual tumor cells in the stem cell collection on multiple myeloma patients receiving autologous stem cell transplantation

Autologous stem cell transplantation (ASCT) is the standard therapy for patients with transplant-eligible multiple myeloma (TEMM). However, the ideal depth of response required before ASCT and the impact of residual tumor cells in the stem cell collection (SCC) on survival remains unclear. Here we collected data of 89 patients with TEMM undergoing ASCT and analyzed the minimal residual disease of SCC (cMRD) and bone marrow (BM) (mMRD) before transplantation. Before ASCT, 31.5% and 76.4% of patients achieved MRD negativity in BM and SCC, respectively. Tumor cells were less in SCC samples than that in BM samples. Neoplastic cells in SCC could be observed in patients with different responses after induction therapy, and there were no significant differences in the percentage and level of cMRD among these subgroups (P > 0.05). No correlation was found between the cMRD status and the response patients achieved after ASCT (P > 0.05). The median follow-up was 26.8 months. mMRD negativity before ASCT was associated with longer PFS (55.9 vs. 27.1 months; P = 0.009) but not OS (not reached vs. 58.9 months; P = 0.115). Patients with different cMRD statuses before ASCT experienced similar PFS (40.5 vs. 76.4 months for negativity vs. positivity; P = 0.685) and OS (not reached vs. 58.8 months for negativity vs. positivity; P = 0.889). These results suggested that detectable cMRD does not significantly predict the inferior post-ASCT response or shorter survival, and patients are eligible to undergo ASCT upon achieving partial response.

Definers and drivers of functional high-risk multiple myeloma: insights from genomic, transcriptomic, and immune profiling

Traditional prognostic models for newly diagnosed patients with multiple myeloma (MM), including International Staging System criteria and number of high-risk chromosomal abnormalities, are based on disease characteristics at diagnosis. However, the identification of patients at risk of more rapidly progressive MM is inherently a dynamic assessment. In a subset of patients with MM, adverse disease biology only becomes evident after the failure of first-line therapy. We define this entity as functional high-risk MM (FHRMM), encompassing relapse within 18 months of treatment initiation and/or within 12 months of frontline autologous stem cell transplantation. FHRMM is not adequately captured by traditional prognostic models, and there is a need for better understanding of mechanisms or risk factors for early relapse or progression. In this review, we explore potential definitions of FHRMM before delving into its underlying drivers based on genetic, transcriptomic, and immune cell profiling studies. Emerging data suggest that specific features of both myeloma cells and immune cells can enable the FHRMM phenotype. We conclude our review by discussing ongoing and future studies that seek to identify and intervene upon patients with FHRMM preemptively.

Response-Adapted Therapy for Newly Diagnosed Multiple Myeloma

PURPOSE OF REVIEW

The development of potent novel agents has improved outcomes for patients with multiple myeloma (MM). Heterogeneity of response to therapy, an expanding arsenal of treatment options, and cost are however major challenges for physicians making treatment decisions. Response-adapted therapy is hence an attractive strategy for sequencing of therapy in MM. Despite its successful application in other haematologic malignancies, response-adapted therapy is yet to become a standard of care for MM. We provide our perspective on response-adapted therapeutic strategies evaluated thus far and how they may be implemented and improved on in treatment algorithms of the future.

RECENT FINDINGS

While older studies suggested that early response based on International Myeloma Working Group response criteria could impact long-term outcomes, recent data have contradicted these findings. The advent of minimal residual disease (MRD) as a powerful prognostic factor in MM has raised the promise of MRD-adapted treatment strategies. The development of more sensitive techniques for paraprotein quantification as well as imaging modalities to detect extramedullary disease is likely to change response assessment in MM. These techniques combined with MRD assessment may provide sensitive and holistic response assessments which could be evaluated in clinical trials. Response-adapted treatment algorithms have the potential to allow an individualised treatment strategy, maximising efficacy, while minimising toxicities and cost. Standardisation of MRD methodology, incorporation of imaging into response assessment, and the optimal management of MRD positive patients are key questions to be addressed in future trials.

[Multiple Myeloma Treatment Guidelines by the Portuguese Group of Multiple Myeloma]

The treatment of multiple myeloma has profoundly changed with the introduction of several innovative therapies. The optimization of therapeutic sequencing through the combined use of the various drugs developed in recent years and the attention given to the characteristics of patients have allowed the reduction of toxicities and increased survival and quality of life of patients with multiple myeloma. These treatment recommendations from the Portuguese Multiple Myeloma Group offer guidance for first-line treatment and progression/relapse situations. These recommendations are given highlighting the data that justify each choice and referring to the respective levels of evidence that support these options. Whenever possible, the respective national regulatory framework is presented. These recommendations constitute an advance towards the best treatment of multiple myeloma in Portugal.

Busulfan plus melphalan versus high-dose melphalan as a conditioning regimen for autologous stem cell transplantation in multiple myeloma with high-risk features (KMM 2015)

Despite the development of effective agents for multiple myeloma (MM), the management of patients with high-risk MM (HRMM) is challenging. High-dose treatment followed by autologous stem cell transplantation (ASCT) is regarded as upfront treatment for transplant-eligible patients with HRMM. In the present study, we retrospectively investigated the efficacies of two conditioning regimens for upfront ASCT in newly diagnosed patients with MM and high-risk features: high-dose melphalan (HDMEL; 200 mg/m²) and busulfan plus melphalan (BUMEL). In total, 221 patients underwent ASCT between May 2005 and June 2021; among these 221 patients, 79 had high-risk cytogenetic abnormalities. In patients with high-risk cytogenetics, BUMEL showed a tendency toward longer overall survival (OS) and progression-free survival (PFS) compared to HDMEL (median OS; not reached vs. 53.2 months; P = 0.091, median PFS; not reached vs. 31.7 months; P = 0.062). Additionally, multivariate analysis revealed that BUMEL was significantly associated with PFS (hazard ratio = 0.37, 95% confidence interval = 0.15-0.89, P = 0.026). We compared BUMEL with HDMEL in patients with other high-risk features, such as high lactate dehydrogenase level, extramedullary disease, and poor response to frontline therapy. Notably, among patients with less than very good partial response (VGPR) to frontline therapy, median PFS was significantly longer in the BUMEL group than in the HDMEL group (55.1 vs. 17.3 months, respectively; P = 0.011). These findings indicate that BUMEL may be an effective conditioning regimen for upfront ASCT in MM patients with high-risk cytogenetics; BUMEL may be more appropriate than HDMEL for patients with less than VGPR to frontline therapy.

ASTCT Clinical Practice Recommendations for Transplantation and Cellular Therapies in Multiple Myeloma

Over the past decade, therapeutic options in multiple myeloma (MM) have changed dramatically. Given the unprecedented efficacy of novel agents, the role of hematopoietic cell transplantation (HCT) in MM remains under scrutiny. Rapid advances in myeloma immunotherapy including the recent approval of chimeric antigen receptor (CAR) T-cell therapy will impact the MM therapeutic landscape. The American Society for Transplantation and Cellular Therapy convened an expert panel to formulate clinical practice recommendations for role, timing, and sequencing of autologous (auto-HCT), allogeneic (allo-HCT) and CAR T-cell therapy for patients with newly diagnosed (NDMM) and relapsed/refractory MM (RRMM). The RAND-modified Delphi method was used to generate consensus statements. Twenty consensus statements were generated. The panel endorsed continued use of auto-HCT consolidation for patients with NDMM as a standard-of-care option, whereas in the front line allo-HCT and CAR-T were not recommended outside the setting of clinical trial. For patients not undergoing auto-HCT upfront, the panel recommended its use in first relapse. Lenalidomide as a single agent was recommended for maintenance especially for standard risk patients. In the RRMM setting, the panel recommended the use of CAR-T in patients with 4 or more prior lines of therapy. The panel encouraged allo-HCT in RRMM setting only in the context of clinical trial. The panel found RAND-modified Delphi methodology effective in providing a formal framework for developing consensus recommendations for the timing and sequence of cellular therapies for MM.

Improvement in Post-Autologous Stem Cell Transplant Survival of Multiple Myeloma Patients: A Long-Term Institutional Experience

Multiple myeloma (MM) represents 1.8% of all new cancer cases in the U.S. While not curable, advances in treatment, including autologous stem cell transplant (ASCT) and maintenance therapy, have dramatically improved progression-free survival (PFS) and overall survival (OS). We performed a retrospective survival analysis on newly diagnosed MM (NDMM) patients receiving ASCT from 1992−2016 at the Ohio State University. A total of 1001 consecutive NDMM patients were eligible. Patients were split into five groups based on historic changes in novel agents for the treatment of MM. Across the years (1992−2016), there was a statistically significant improvement in both PFS (p < 0.01) and OS (p < 0.01). Significant improvements in both PFS and OS were seen in patients ≤65 years (p < 0.001 and p = 0.002) and >65 years old (p < 0.001 and p = 0.001), respectively. Improved PFS and OS were seen in both standard-risk (p < 0.001 and p < 0.001) and high-risk patients (p < 0.001 and p = 0.019). The post-transplant response showed statistically significant improvement across the years (p < 0.01). Survival rates for NDMM patients have significantly improved primarily due to the inclusion of novel therapies and post-ASCT maintenance.

Prognostic impact of natural killer cell recovery on minimal residual disease after autologous stem cell transplantation in multiple myeloma

INTRODUCTION

Natural killer cells are a potent effector lymphocyte subset that can induce cytotoxicity without the need for antigen sensitization or presentation. NK cells are a tempting target -for immune therapy, monoclonal antibody, or genetic engineering-to enhance immune surveillance mechanisms against myeloma cells.

MATERIALS AND METHODS

We hypothesized an association between natural killer cell recovery after autologous stem cell transplantation (ASCT) and disease outcomes in multiple myeloma patients. We concluded a prospective study that started enrolling patients in January 2020 to identify the association between absolute NK cell count two to three after ASCT and disease outcomes after autologous stem cell transplantation in multiple myeloma using univariate and multivariate analysis.

RESULTS

Natural killer cell recovery was evaluated during the third month after ASCT, day +60 to +90 post-ASCT. Our patients had a mean NK cell count of 90.53, ranging from 14 to 282 Cell/μL (Std Dev 84.64 Cell/μL). The odds of having a minimal residual disease (MRD-positivity) among patients with partial remission before transplantation is four times higher than patients with very good partial response or better (95% confidence interval 0.45-35.79). Our patients were classified into two groups based on MRD status after ASCT, an MRD-negative group of eight participants and an MRD-positive group of seven participants. The mean absolute NK cell count was significantly higher in the MRD-negative cohort, 131.38 Cell/μL, versus 43.86 Cell/μL in the MRD-positive group (p = 0.049).

CONCLUSION

We conclude that for multiple myeloma patients treated with ASCT, high absolute NK cell counts two to three months after ASCT is an independent predictor for MRD negativity.

Recommendations on the management of multiple myeloma in 2020

With the introduction of immunomodulatory drugs, proteasome inhibitors, and anti-CD38 monoclonal antibodies, major improvements have been achieved in the treatment of multiple myeloma (MM), with a significant impact on the outcome of this disease. Different treatment combinations are now in use and other therapies are being developed. Based on an extensive review of the recent literature, we propose practical recommendations on myeloma management, to be used by hematologists as a reference for daily practice.

Autologous stem cell transplantation for multiple myeloma in the novel agent era: Systematic review of Indian data and implications for resource constrained settings

Treatment of multiple myeloma has undergone significant advances in the last two decades, leading to meaningful improvement in overall and progression free survival. The incurable nature of disease necessitates serial sequencing of treatment options and continuous therapy once disease remission is achieved. Autologous stem cell transplantation (ASCT) has continued to offer a meaningful survival advantage with a consistent reduction in toxicity and costs. Despite the advent of newer drugs leading to deeper and sustained responses, ASCT continues to be the standard of care for all eligible patients and is ostensibly more cost effective than continued treatment with newer agents. However, ASCT continues to be underutilized in India, due to concerns about cost, safety, and sporadic expertize. We present a systematic review of available data on ASCT for multiple myeloma from India to evaluate safety and efficacy of the procedure, and provide evidence re-affirming its utility in resource constrained settings.

Relationship of tumor load parameters before and after autologous stem cell transplantation with clinical prognosis in transplant-eligible patients with multiple myeloma: A retrospective analysis

We retrospectively examined 57 patients with multiple myeloma who underwent autologous stem cell transplantation (ASCT) at our institution. A receiver-operating characteristic curve (ROC) analysis showed that the reduction rate of quantitative serum monoclonal protein (M-protein) before ASCT and the difference in involved and uninvolved free light chains (dFLC) 30 days after ASCT, respectively, had the greatest predictive value for all patients (area under the curve [AUC] 0.791 and 0.660, respectively). Based on the ROC curve-based cutoff values of tumor burden parameters, progression-free survival (PFS) in the high serum M-protein reduction (≥90 %) group was significantly better than that in the low serum M-protein reduction group (<90 %) (2-year PFS 79.5 % vs. 17.0 %, p < 0.001), but there were no significant differences in PFS between the low (<5.2 mg/L) and high (≥5.2 mg/L) dFLC groups (2-year PFS, 72.0 % vs. 46.0 %; p = 0.149). A multivariate analysis identified the reduction in serum M-protein as an independent predictive factor before ASCT for PFS (hazard ratio [HR] 0.287, p = 0.022) and high dFLC on day 30 after ASCT for PFS (HR 3.902, p = 0.040). These results demonstrate that a good prognosis can be expected with a reduction of serum M-protein before and after ASCT.

Management of suboptimal response to induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma: Re-induction therapy or direct to Radiotherapy?

BACKGROUND

Unsatisfactory tumor response to induction chemotherapy (IC) is an adverse prognostic factor of locoregionally advanced nasopharyngeal carcinoma (LANPC). A re-induction strategy which applies additional cycles of an alternative IC regimen prior to radiotherapy (RT) has been adopted.

METHODS

A total of 419 LANPC patients who attained suboptimal response (stable disease or disease progression) according to the Response Evaluation in Solid Tumors (RECIST) guideline after initial IC were retrospectively included. They were divided into those who received additional cycles of re-induction regimen prior to RT (re-induction group, n = 87) and those who had no additional chemotherapy (direct to RT group, n = 332). Propensity score matching (PSM) was used to adjust for potential confounders. Tumor response and long-term survival were compared between two groups.

RESULTS

After receiving a second IC regimen, 39.1% of the patients in re-induction group attained partial response; however, the tumor control of subsequent RT was not significantly improved when compared with direct to RT group (patients attaining complete response after RT 55.2% vs. 52.5%, P = 0.757). Patients who received re-induction therapy showed worse locoregional relapse-free survival (LRFS) and progression-free survival (PFS) than those proceeded directly to RT (3-year LRFS 75.7% vs. 83.1%, P = 0.005; 3-year PFS 62.4% vs. 68.3%, P = 0.037). The increased hematological toxicities were observed in re-induction group that included grade 3-4 anemia, thrombocytopenia and liver enzyme increase.

CONCLUSION

Re-induction therapy decreased LRFS and PFS and increased toxicities among patients who attain suboptimal response to initial IC regimen, as compared with direct to RT strategy.

Autologous Stem-Cell Transplantation for Multiple Myeloma in the Era of Novel Therapies

Despite the evolution of the therapeutic arsenal for the treatment of multiple myeloma (MM) over the past decade, autologous stem-cell transplantation (ASCT) remains an integral part of the treatment of patients with both newly diagnosed and relapsed MM. The advent of novel therapies, such as immunomodulatory agents, proteasome inhibitors, and monoclonal antibodies, has led to unprecedented levels of deep hematologic responses. Nonetheless, studies show that ASCT has an additive effect leading to additional deepening of responses. As the therapeutic agents for MM continue to evolve, the timing, duration, and sequence of their use in combination with ASCT will be crucial to understand to obtain the deepest response and survival benefit for patients with MM. This review aims to discuss the role of ASCT for the management of MM, with a particular focus on the role of ASCT in the context of novel therapies and minimal residual disease.

Outcomes after delayed and second autologous stem cell transplant in patients with relapsed multiple myeloma

We evaluated the outcomes of 168 patients undergoing delayed or second autologous stem cell transplant (ASCT) for relapsed multiple myeloma (MM) from 2010 to 2019. Overall, 21% (n = 35) patients had received a prior transplant and 69% (n = 116) underwent transplant at first relapse. Overall, 27% patients had high-risk cytogenetics and 15% had ISS stage III disease. Stem cell collection was performed after relapse in 72% and 35% of patients received maintenance therapy. Median PFS from salvage treatment and transplant were 28 and 19 months, respectively. Median OS from salvage treatment and transplant was 69 and 55 months. Multivariate analysis revealed that ASCT in first relapse was associated with superior PFS (HR 0.63, p = 0.03) and OS (HR 0.59, p = 0.04) compared to later lines of therapy. In addition, PFS of ≥36 months with prior therapy was associated with improved PFS (HR 0.62, p = 0.04) and OS (HR 0.41, p = 0.01). Ninety-five patients underwent delayed transplant at first relapse, median PFS and OS from start of therapy was 30 and 69 months, and median OS from diagnosis was 106 months. These data may serve as a guide when counseling patients undergoing ASCT for relapsed MM and provide a benchmark in designing clinical trials of transplantation/comparative treatments for relapsed MM.

Prognostic impact of early-versus-late responses to different induction regimens in patients with myeloma undergoing autologous hematopoietic cell transplantation: Results from the CALM study by the CMWP of the EBMT

BACKGROUND

In autologous stem cell transplant (ASCT)-eligible myeloma patients, prolonged induction does not necessarily improve the depth of response.

METHOD

We analyzed 1222 ASCT patients who were classified based on (a) the interval between induction and stem cell collection, (b) the type of induction regimen: BID (Bortezomib, IMiDs, and Dexamethasone), Bortezomib-based, or CTD (Cyclophosphamide, Thalidomide, and Dexamethasone), and (c) the time to best response (Early ie, best response within 4 or 5 months, depending on the regimen vs Late; Good ie, VGPR or better vs Poor).

RESULTS

The length of induction treatment required to achieve a Good response did not affect PFS (P = .65) or OS (P = .61) post-ASCT. The three types of regimen resulted in similar outcomes: median PFS 31, 27.7 and 30.8 months (P = .31), and median OS 81.7, 92.7, and 77.4 months, respectively (P = .83). On multivariate analysis, neither the type nor the duration of the induction regimen affected OS and PFS, except for Early Good Responders who had a better PFS compared to Early Poor Responders (HR = 1.21, P-value = .02). However, achieving a Good response at induction was associated with a better response (≥VGPR) post-transplant.

CONCLUSION

The kinetics of response did not affect outcomes.

Disease monitoring with quantitative serum IgA levels provides a more reliable response assessment in multiple myeloma patients

Unlike IgG monoclonal proteins (MCPs), IgA MCP quantification is unreliable due to beta-migration of IgA MCPs on serum protein electrophoresis (SPEP). The utility of nephelometric quantitative IgA (qIgA) to monitor IgA multiple myeloma (MM) is unclear. We retrospectively studied disease response kinetics using qIgA versus MCPs by SPEP, and developed and validated novel qIgA disease assessment criteria in 491 IgA MM patients. The SPEP MCP nadir occurred a median of 41 (IQR 0-102) days before the qIgA. The median time to achieve a partial response (PR) was shorter using standard IMWG versus qIgA response criteria (32 vs 58 days, p < 0.001). Stratification by qIgA criteria, unlike IMWG criteria, led to clear separation of the progression-free survival curves of patients achieving a PR or very good PR. There was a consistent trend toward earlier detection of disease progression using qIgA versus IMWG progression criteria. In conclusion, monitoring IgA MM using MCP-based IMWG criteria may be falsely reassuring, given that MCP levels on SPEP decrease faster than qIgA levels. The qIgA response criteria more accurately stratify patients based on the progression risk and may detect disease progression earlier, which may lead to more consistent measurement of trial endpoints and improved patient outcomes.

Role of Stem Cell Transplantation in Multiple Myeloma

Autologous stem cell transplantation (auto-SCT) has been the standard of care in eligible newly diagnosed multiple myeloma (MM) patients. Outcomes of patients with MM have improved significantly due to the advent of several novel drugs. Upfront use of these drugs in induction therapy has significantly increased the rate and depth of responses that have translated into longer remission and survival. This has now raised a debate regarding the role and relevance of auto-SCT in the management of myeloma. However, clinical trials have confirmed the utility of auto-SCT even in the era of novel drugs. Tandem auto-SCT followed by maintenance has shown a progression-free survival (PFS) benefit in high-risk MM, and hence can be considered in young and fit patients with high-risk disease. Auto-SCT has the advantages of resetting the bone marrow microenvironment, short-lived toxicity compared to the long-term physical and financial toxicities of continued chemotherapy in the absence of SCT, very low transplant-related mortality (TRM) in high volume centers, and providing longer disease-free survival when followed by maintenance therapy. Allogeneic SCT is one potentially curative option for MM, albeit with an increased risk of death due to high TRM. Strategies to modulate the graft-versus-host disease (GVHD) while maintaining or improving the graft-versus-myeloma (GVM) effect could place allogeneic SCT back in the treatment armamentarium of MM.

Depth of response prior to autologous stem cell transplantation predicts survival in light chain amyloidosis

The goal of therapy in AL amyloidosis is to inhibit further production of the amyloidogenic light chains, thereby allowing organ recovery and improving survival. We aimed to assess the impact of depth of hematologic response prior to ASCT on survival. We conducted a retrospective study of 128 newly diagnosed AL amyloidosis patients who received induction prior to ASCT between January 2007 and August 2017 at Mayo Clinic. The overall response rate to induction was 86% (CR 18%, VGPR 31% and PR 38%). With a median follow up of 52 months, the median PFS and OS was 48.5 months and not reached, respectively. Response depth to induction therapy was associated with improved PFS and OS. The median PFS was not reached for patients achieving ≥VGPR prior to ASCT and 34.1 months for patients achieving PR or less (P = 0.0009). The median OS was longer in patients with deeper responses (not reached for ≥VGPR vs. 128 months for PR or less (P = 0.02)). On multivariable analysis, independent predictors of OS were melphalan conditioning dose (RR = 0.42; P = 0.036) and depth of response prior to transplant (RR 0.37; P = 0.0295). Hematologic response prior to transplant predicts improved post transplant outcomes in AL amyloidosis.

Novel prognostic scoring system for autologous hematopoietic cell transplantation in multiple myeloma

We studied 2,528 patients with upfront autologous haematopoietic cell transplantation (AHCT) for multiple myeloma (MM) from 2008-2017 to develop a prognostic model to predict outcomes. High-risk cytogenetics included t(4;14), t(14;16), t(14;20), del13q on karyotype, del17p, +1q or 1pdel. A Cox model identified factors prognostic of progression/relapse in a training subset (n = 1,246). A weighted score using these factors was assigned to a validation cohort (n = 774). Presence of high-risk cytogenetics [hazard ratio, (HR) 1·68 (1·3-2·17)] and pre-AHCT bone marrow plasma cells (BMPCs) ≥10% [1·68 (1·33-2·12)] were assigned 4 points each; albumin at diagnosis <3·5 g/dl [1·31 (1·07-1·61)] 2; standard risk cytogenetics 1, and no cytogenetics abnormality, BMPCs <10% at AHCT and albumin ≥3·5 g/dl at diagnosis 0 points each. A three-category system with low risk (0-3), intermediate risk (4-8) and high risk (9-10) showed 3-year progression-free survival in the low vs. intermediate vs. high risk of 58% (95% CI: 52-63) vs. 49% (95% CI: 43-56) vs. 31% (95% CI: 12-51), P < 0.001 respectively, and 3-year OS in low vs. intermediate vs. high risk of 88% (95% CI: 84-91) vs. 81% (95% CI: 76-86) vs. 64% (95% CI: 39-80); P < 0·001. Our prognostic scoring system can identify MM patients at risk for early relapse after AHCT.

The impact of response kinetics for multiple myeloma in the era of novel agents

Rapid remission by induction therapy has long been recognized as an important predictor for long-time survival in acute leukemia. However, the impact of response kinetics on multiple myeloma (MM) seems to be different and remains unexplored. The relationship between response kinetics and outcome were assessed in 626 patients with newly diagnosed MM who were included in a prospective, nonrandomized clinical trial (BDH 2008/02). Patients were assigned to either immunomodulatory drug- or proteasome inhibitor-based therapy. The response depth, time to best response (T_BR) and duration of best response (D_BR) were collected. Depth of response was associated with superior outcomes, consistent with findings from other studies. However, the early responders (defined as T_BR ≤3 months) showed significantly worse survival compared with late responders. We found that patients with rapid complete remission experienced inferior survivals comparable to those attaining a gradual partial remission. Moreover, 4 distinct response kinetics patterns were identified. Patients with gradual and sustained remission ("U-valley" pattern) experienced superior outcomes, whereas poor outcomes were observed in rapid and transient responders ("roller coaster" pattern) (median overall survival, 126 vs 30 months). The effects of response patterns on survival were confirmed in patients at different stages of disease and cytogenetic risk, including transplant-eligible patients and those attaining different extents of response depth. Collectively, our data indicated that slow and gradual response is a favorable prognostic factor in MM. In addition to response depth, the kinetic pattern of response is a simple and powerful predictor for survival even in the era of novel agents.

Impact of Pre-transplant and Post-transplant Remission Status of Patients on Survival in Newly Diagnosed Multiple Myeloma

The overall survival (OS) in patients with multiple myeloma (MM) has increased in the last decade due to the introduction of proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies as well as an extensive combination of autologous stem cell transplantation (ASCT) for suitable patients. The objective of this study was to examine the impact of pre-transplant and post-transplant remission status of patients on survival in newly diagnosed multiple myeloma. Two hundred and four patients with newly diagnosed MM who received an ASCT in our HSC transplant center at Hacettepe University Hospital between the years of 2001 and 2018 were evaluated in a retrospective manner. The median follow-up period was 35.9 months (range 4.2-206.4) for the entire group. The 5-year OS for pre-transplant remission status CR/VGPR patients and pre-transplant remission status PR or less patients were 79% and 68%, respectively (p = 0.09). The 5-year PFS for pre-transplant remission status CR/VGPR patients and pre-transplant remission status PR or less patients were 62% and 45%, respectively (p = 0.23). The 5-year OS for post-transplant remission status CR/VGPR group was 72% and for post-transplant remission status PR or less group was 60% (p = 0.02). The 5-year PFS in post-transplant remission status CR/VGPR patients was 48% and post-transplant remission status PR or less patients was 36% (p = 0.03). This study focuses on determination of survival outcome based on the best response obtained before and after ASCT and particularly highlights the significance of reaching CR and VGPR.

Stem-cell transplantation in multiple myeloma: how far have we come?

High-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) has historically been an essential part of multiple myeloma (MM) management since early studies demonstrated its efficacy in relapsed disease, and subsequent phase III trials demonstrated better responses and improved survival with this modality compared with standard chemotherapy. With further advances in the MM treatment landscape, including the development of potent novel agents, there has been an increasing debate around various aspects of ASCT, including the optimal timing, role of single versus tandem ASCT, and the practice of consolidation and maintenance therapy post-ASCT. Routine incorporation of the novel agents at each of the treatment phases, induction, consolidation when used, and maintenance has led to better responses as reflected by increasing rates of minimal residual disease (MRD) negativity, longer progression-free survival (PFS) with improvement in overall survival (OS) and in some of the trials. The phase III trials over the last decade have provided significant clarity on the current approach, and have raised important questions regarding the applicability of this modality in all patients. This review aims to summarize the latest literature in the field and discusses how these findings impact the practice of ASCT today.

Salvage therapy versus upfront autologous stem cell transplantation in multiple myeloma patients with progressive disease after first-line induction therapy

It is a matter of debate whether myeloma patients with progressive disease (PD) after induction should receive salvage therapy or proceed directly to autologous stem cell transplantation. We performed a retrospective analysis of 1599 patients treated between 1991 and 2016 at the University Hospital of Heidelberg and other centers. Deepening of response through salvage therapy did not lead to better progression-free or overall survival (PD versus salvage therapy patients: HR = 0.71, 95% CI [0.28, 1.80], p = 0.5 and HR = 0.77, 95% CI [0.30, 1.95], p = 0.6, respectively), neither in patients treated with novel agents (HR = 0.66, 95% CI [0.23, 1.85], p = 0.4 and HR = 0.76, 95% CI [0.27, 2.15], p = 0.6) nor older regimens (HR = 0.86, 95% CI [0.36, 2.07], p = 0.7 and HR = 0.8, 95% CI [0.34, 1.91], p = 0.6). Therefore, primary nonresponders might benefit from a direct transplant rather than salvage induction, although the analyzed salvage therapy cohort was small (n = 23) and cytogenetics was not included in the multivariable analysis.

The impact of re-induction prior to salvage autologous stem cell transplantation in multiple myeloma

Autologous stem cell transplantation (ASCT) is an integral component of the therapeutic arsenal in multiple myeloma. Given that overall survival (OS) is comparable between patients receiving up-front or delayed ASCT, some opt to collect stem cells and postpone transplant until the time of disease progression (i.e. salvage ASCT). It is unknown if induction should be repeated prior to salvage ASCT, or if patients should proceed directly. We identified 234 patients who underwent salvage ASCT at our institution: 188 (80%) were re-induced, whereas 46 (20%) proceeded directly without re-induction. There was no significant difference in time to next therapy (TNT) or OS from Day 0 between the two groups. Patients who were re-induced had a nonsignificant trend towards a higher rate of complete response post-ASCT (45% vs. 33%, p= .12). In multivariate models, re-induction did not affect TNT/OS. In the subgroup of 188 patients who were re-induced, patients with relapsed/refractory disease at the time of ASCT had significantly shorter TNT/OS compared to patients with deeper pre-ASCT responses. In summary, there was no survival difference for patients who were re-induced before salvage ASCT. However, many factors affect the decision to re-induce, and prospective studies would be required to discern its role definitively.

Clinical Outcomes in Multiple Myeloma Post-Autologous Transplantation-A Single Centre Experience

There is paucity of data from developing countries on the clinical outcomes in myeloma post-autologous transplantation. In this retrospective study, we used hospital records to retrieve data of patients with multiple myeloma undergoing autologous stem cell transplantation (ASCT) from January 1995 to December 2014 at our centre. During the study period, 245 patients underwent ASCT for myeloma. Of these, 19%, 37% and 37% were in complete response, very good partial response and partial response respectively at the time of ASCT. Only in 14 (5.7%) patients, the stem cells were cryopreserved. The transplant related mortality was 2.86%. The median follow up was 40.7 months (range 0-237.4 months). The 5-year overall survival (OS) and progression-free survival (PFS) for the entire cohort was 61.6% ± 3.8% and 37.2% ± 3.9% respectively. Independent predictors of OS included mononuclear cell dose infused, pre- and post-transplant response; and the use of maintenance therapy. Independent predictors of PFS included age at diagnosis, pre- and post-transplant response; and the use of maintenance therapy. In a resource limited setting, ASCT for myeloma is associated with low transplant related mortality. Pre- and post-transplant response and maintenance therapy are predictors of survival.

Treatment of Multiple Myeloma: ASCO and CCO Joint Clinical Practice Guideline

PURPOSE

To provide evidence-based recommendations on the treatment of multiple myeloma to practicing physicians and others.

METHODS

ASCO and Cancer Care Ontario convened an Expert Panel of medical oncology, surgery, radiation oncology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and some phase II studies published from 2005 through 2018. Outcomes of interest included survival, progression-free survival, response rate, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 124 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed for patients with multiple myeloma who are transplantation eligible and those who are ineligible and for patients with relapsed or refractory disease.

Utilization of hematopoietic stem cell transplantation for the treatment of multiple myeloma: a Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus statement

Over the last two decades, the utilization of various novel therapies in the upfront or salvage settings has continued to improve survival outcomes for patients with Multiple Myeloma (MM). Thus, the conventional role for hematopoietic stem cell transplantation (HSCT) in MM either in the form of an autologous stem cell transplant (ASCT) or an allogeneic stem cell transplant (Allo-SCT) warrants re-evaluation, given the aforementioned clinical advances. Here, we present a consensus statement of our multidisciplinary group of over 30 Mayo Clinic physicians with a special interest in the care of patients with MM and provide evidence-based recommendations on the use of HSCT in MM. We specifically address topics that include the role and timing of an ASCT for MM in the era of novel agents, eligibility for an ASCT, post-ASCT consolidation, and maintenance options, and finally the utility of an upfront tandem ASCT, salvage second ASCT, and an allo-SCT in MM.

Pros and cons of frontline autologous transplant in multiple myeloma: the debate over timing

The treatment landscape for multiple myeloma has dramatically changed over the past decade with the introduction of several new classes of drugs, which are very effective at controlling the disease for prolonged periods of time, especially when used in multidrug combinations. Prior to the advent of these new agents, peripheral blood autologous stem cell transplantation (ASCT) was the mainstay of therapy for patients who were eligible to undergo the procedure, with deep and durable responses in the majority of patients. Despite the introduction of more effective therapies, ASCT continues to play an important role in overall management of younger patients, where it has been integrated with the other therapeutic approaches to provide maximum benefit. Recent phase 3 trials have once again confirmed the survival benefit associated with ASCT in myeloma. Retrospective studies have also demonstrated the feasibility of using ASCT at the time of first relapse rather than as a component of the initial treatment. Significant geographical variations exist in the use of ASCT, especially between the United States and Europe in terms of its use as part of upfront therapy. Much of these differences are driven by the availability of drugs and drug combinations for initial therapy of myeloma as well as maintenance approaches post-ASCT. It is amply clear from these trials that ASCT will continue to play an important role in management of myeloma and is likely to be used as a platform for enhancing the efficacy of other treatment modalities that are currently in development.

Revised International Staging System Is Predictive and Prognostic for Early Relapse (<24 months) after Autologous Transplantation for Newly Diagnosed Multiple Myeloma

The revised International Staging System (R-ISS) combines ISS with genetic markers and lactate dehydrogenase and can prognosticate newly diagnosed multiple myeloma (MM). Early relapse (<24 months) after upfront autologous hematopoietic cell transplantation (AHCT) strongly predicts inferior overall survival (OS). We examined the ability of R-ISS in predicting early relapse and its independent prognostic effect on postrelapse survival after an early relapse. Using the Center for International Blood and Marrow Transplant Research database we identified MM patients receiving first AHCT within 18 months after diagnosis with available R-ISS stage at diagnosis (n = 628). Relative risks of relapse/progression, progression-free survival (PFS), and OS were calculated with the R-ISS group as a predictor in multivariate analysis. Among early relapsers, postrelapse survival was tested to identify factors affecting postrelapse OS. The cumulative incidence of early relapse was 23%, 39%, and 50% for R-ISS I, R-ISS II, and R-ISS III, respectively (P < .001). Shorter PFS and OS were seen with higher stage R-ISS. R-ISS was independently predictive for inferior postrelapse OS among early relapsers, as was the presence of ≥3 comorbidities and the use of ≥2 induction chemotherapy lines. R-ISS stage at diagnosis predicts early post-AHCT relapse and independently affects postrelapse survival among early relapsers.

Staging Systems for Newly Diagnosed Myeloma Patients Undergoing Autologous Hematopoietic Cell Transplantation: The Revised International Staging System Shows the Most Differentiation between Groups

The Revised International Staging System (R-ISS) and the International Myeloma Working Group 2014 (IMWG 2014) are newer staging systems used to prognosticate multiple myeloma (MM) outcomes. We hypothesized that these would provide better prognostic differentiation for newly diagnosed multiple myeloma (MM) compared with ISS. We analyzed the Center for International Blood and Marrow Transplant Research database from 2008 to 2014 to compare the 3 systems (N = 628) among newly diagnosed MM patients undergoing upfront autologous hematopoietic cell transplantation (AHCT). The median follow-up of survivors was 48 (range, 3 to 99) months. The R-ISS provided the greatest differentiation between survival curves for each stage (for overall survival [OS], the differentiation was 1.74 using the R-ISS, 1.58 using ISS, and 1.60 using the IMWG 2014) . Univariate analyses at 3 years for OS showed R-ISS I at 88% (95% confidence interval [CI], 83% to 93%), II at 75% (95% CI, 70% to 80%), and III at 56% (95% CI, 3% to 69%; P < .001). An integrated Brier score function demonstrated the R-ISS had the best prediction for PFS, though all systems had similar prediction for OS. Among available systems, the R-ISS is the most optimal among available prognostic tools for newly diagnosed MM undergoing AHCT. We recommend that serum lactate dehydrogenase and cytogenetic data be performed on every MM patient at diagnosis to allow accurate prognostication.

Case-based roundtable on treatment approach for young, fit, newly diagnosed multiple myeloma patients

With the advent new proteasome inhibitors (carfilzomib, ixazomib), new immune-modulatory drugs (pomalidomide), and new monoclonal antibodies (elotuzimab, daratumumab) as approved treatments for myeloma, the therapeutic landscape for this disease has changed. In this chapter, using a case-based approach, I will provide a personal guide of how I approach myeloma therapy in a transplant eligible patient in 2018.

Comparison of conditioning regimen toxicities among autologous stem cell transplantation eligible multiple myeloma patients: High-dose melphalan versus high-dose melphalan and bortezomib

Background Autologous hematopoietic stem cell transplantation (AHSCT) remains the standard of care for younger patients with multiple myeloma (MM). Currently, high-dose melphalan (HDM) is recommended as conditioning regimen before AHSCT. Preclinical data suggest that combining bortezomib and melphalan has synergistic effect against multiple myeloma cells. Bortezomib and HDM (Bor-HDM) combination as conditioning regimen has been investigated by many other investigators. Objective In this retrospective study, we aimed to compare transplant-related toxicities and hematologic recovery of HDM and Bor-HDM conditioning regimens. Method We retrospectively evaluated hematologic recovery and toxicity profile in patients with MM who received AHSCT with either HDM ( n = 114) or Bor-HDM ( n = 53) conditioning regimen. Results Nonhematologic toxicities were comparable between HDM and Bor-HDM conditioning regimen, except mucositis and diarrhea being more frequent in the Bor-HDM group. Neutrophil and platelet engraftment time and duration of hospital stay were significantly shorter for HDM regimen. Conclusions In this retrospective analysis, we observed engraftment kinetics and duration of hospitalization were significantly worse in Bor-HDM conditioning regimen with manageable toxicities. Randomized studies are needed to further compare Bor- HDM regimen to HDM in terms of response rates, toxicities, and transplant-related mortality.

Exploring Big Data in Hematological Malignancies: Challenges and Opportunities

Secondary analysis of large datasets has become a useful alternative to address research questions outside the reach of clinical trials. It is increasingly utilized in hematology and oncology. In this review, we provided an overview of some examples of commonly used large datasets in the USA and described common research themes that can be pursued using such a methodology. We selected a sample of 14 articles on adult hematologic malignancies published in 2015 and highlighted their contributions as well as limitations.

Outcome of autologous hematopoietic stem cell transplantation in refractory multiple myeloma

BACKGROUND

Despite the introduction of effective, novel agents, the outcome of patients with refractory multiple myeloma remains poor, particularly those who are refractory to both proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs). Limited data are available on the role of autologous hematopoietic stem cell transplantation in this population.

METHODS

Patients with refractory myeloma who underwent first autologous hematopoietic stem cell transplantation (auto-HCT) between March 2000 and October 2015 were retrospectively analyzed. Those who had primary refractory disease and those with relapsed and refractory disease were included. Disease that was refractory to at least 1 PI and at least 1 IMiD was classified as double-refractory multiple myeloma (DR-MM).

RESULTS

In total, 233 patients were identified, including 105 (45%) classified with DR-MM and 128 (55%) classified with nondouble-refractory myeloma (NDR-MM). At a median follow-up of 42 months for surviving patients, at least a partial response was observed in 188 patients (81%; 83 patients in the DR-MM group [79%] and 105 patients in the NDR-MM [82%]; P = .77). A near complete response or better was observed in 52 patients (22%; 25 patients in the DR-MM group [24%] and 27 patients in the NDR-MM group [21%]; P = .77). The median progression-free survival was 17.6 months (14.4 months in the DR-MM group and 18.2 months in the NDR-MM group), and the 2-year progression-free survival rate was 38% (35% in the DR-MM group and 40% in the NDR-MM group; P = .40). The median overall survival was 48 months (38.9 months in the DR-MM group and 56.6 months in the NDR-MM group), and the 2-year overall survival rate was 74% (71% in the DR-MM group and 76% in the NDR-MM group; P = .27).

CONCLUSIONS

The current findings indicate that auto-HCT is an effective and safe therapy in patients with refractory multiple myeloma, including those who are refractory to IMiDs and PIs. Cancer 2017;123:3568-75. © 2017 American Cancer Society.

Maintenance versus Induction Therapy Choice on Outcomes after Autologous Transplantation for Multiple Myeloma

Bortezomib (V), lenalidomide (R), cyclophosphamide (C), and dexamethasone (D) are components of the most commonly used modern doublet (RD, VD) or triplet (VRD, CVD) initial induction regimens before autologous hematopoietic cell transplantation (AHCT) for multiple myeloma (MM) in the United States. In this study we evaluated 693 patients receiving "upfront" AHCT after initial induction therapy with modern doublet or triplet regimens using data reported to the Center for International Blood and Marrow Transplant Research from 2008 to 2013. Analysis was limited to those receiving a single AHCT after 1 line of induction therapy within 12 months from treatment initiation for MM. In multivariate analysis, progression-free survival (PFS) and overall survival were similar irrespective of induction regimen. However, high-risk cytogenetics and nonreceipt of post-transplant maintenance/consolidation therapy were associated with higher risk of relapse. Patients receiving post-transplant therapy had significantly improved 3-year PFS versus no post-transplant therapy (55% versus 39%, P = .0001). This benefit was most evident in patients not achieving at least a complete response post-AHCT (P = .005). In patients receiving upfront AHCT, the choice of induction regimen (doublet or triplet therapies) appears to be of lower impact than use of post-transplant therapy.

Myeloma in Elderly Patients: When Less Is More and More Is More

Multiple myeloma is a plasma cell malignancy that occurs among older adults and accounts for 15% of all hematologic malignancies in the United States. Thirty-five percent of patients are diagnosed at age 75 or older. Novel therapeutics and routine use of autologous stem cell transplantation (ASCT) have led to substantial improvements in patient survival, although improvements have been more impressive among patients younger than age 65. Finding the balance between under- and overtreating elderly patients is one of the biggest challenges specific to them as a subgroup of patients with MM. Decision making about which therapies and their dose intensity and duration should be influenced by a patient's functional status, personal preferences, disease characteristics, and ability to tolerate therapy. ASCT should be considered for all patients younger than age 80, assuming that they are not frail. The attainment of a stringent complete response and minimal residual disease negativity is associated with improved progression-free and overall survival. Again, consideration of quality of life for these patients is paramount. Although there is a growing list of tools to sort through these issues, a fully integrated approach has not yet been finely tuned, leaving additional work to be done for the treatment of elderly patients with MM.

Myeloma in Elderly Patients: When Less Is More and More Is More

Multiple myeloma is a plasma cell malignancy that occurs among older adults and accounts for 15% of all hematologic malignancies in the United States. Thirty-five percent of patients are diagnosed at age 75 or older. Novel therapeutics and routine use of autologous stem cell transplantation (ASCT) have led to substantial improvements in patient survival, although improvements have been more impressive among patients younger than age 65. Finding the balance between under- and overtreating elderly patients is one of the biggest challenges specific to them as a subgroup of patients with MM. Decision making about which therapies and their dose intensity and duration should be influenced by a patient's functional status, personal preferences, disease characteristics, and ability to tolerate therapy. ASCT should be considered for all patients younger than age 80, assuming that they are not frail. The attainment of a stringent complete response and minimal residual disease negativity is associated with improved progression-free and overall survival. Again, consideration of quality of life for these patients is paramount. Although there is a growing list of tools to sort through these issues, a fully integrated approach has not yet been finely tuned, leaving additional work to be done for the treatment of elderly patients with MM.

Whole body magnetic resonance imaging in newly diagnosed multiple myeloma: early changes in lesional signal fat fraction predict disease response

Cross-sectional imaging techniques are being increasingly used for disease evaluation in patients with multiple myeloma. Whole body magnetic resonance imaging (WB-MRI) scanning is superior to plain radiography in baseline assessment of patients but changes following treatment have not been systematically explored. We carried out paired WB-MRI scans in 21 newly diagnosed patients prior to, and 8-weeks after, starting chemotherapy, and analysed stringently selected focal lesions (FLs) for parametric changes. A total of 323 FLs were evaluated, median 20 per patient. At 8 weeks, there was a reduction in estimated tumour volume (eTV), and an increase in signal fat fraction (sFF) and apparent diffusion coefficient (ADC) in the group as a whole (P < 0·001). Patients who achieved complete/very good partial response (CR/VGPR) to induction had a significantly greater increase in sFF compared to those achieving ≤ partial response (PR; P = 0·001). When analysed on a per-patient basis, all patients achieving CR/VGPR had a significant sFF increase in their FL's, in contrast to patients achieving ≤PR. sFF changes in patients reaching maximal response within 100 days (fast responders) were greater compared to slow responders (P = 0·001). Receiver Operator Characteristic analysis indicated that sFF changes at 8 weeks were the best biomarker (area under the Curve 0·95) for an inferior response (≤PR). We conclude that early lesional sFF changes may provide important information on depth of response, and are worthy of further prospective study.

Risk stratification in myeloma by detection of circulating plasma cells prior to autologous stem cell transplantation in the novel agent era

The impact of circulating plasma cells (CPCs) prior to autologous stem cell transplantation (ASCT) for multiple myeloma has not been defined in the novel agent era. We evaluated the impact of pre-transplant CPCs, detected by six-color flow cytometry in patients undergoing early ASCT on post-transplant response, progression-free survival (PFS) and overall survival (OS). CPCs were detected in 162 out of 840 (19.3%) patients, with the median number of CPCs being 58 per 150 000 events. Ninety-nine percent of patients had received proteasome inhibitor and/or immunomodulator-based induction. The incidence of post-transplant stringent complete response (sCR) in the subgroups with and without CPCs was 15% and 38%, respectively, (P<0.001). The median PFS in the subgroups with and without CPCs was 15.1 (95% confidence interval (CI), 12.5-17.8) and 29.6 months (95% CI, 26.2-32.8), respectively, and the median OS was 41.0 months (95% CI, 32.6-58.2) and not reached (NR) (95% CI, 99.1-NR), respectively, (P<0.001 for both). On multivariate analysis for OS, factors independently predictive of mortality were the presence of CPCs (hazard ratio (HR) 2.5; 95% CI, 1.8-3.6; P<0.001) and sCR post transplant (HR 0.4; 95% CI, 0.2-0.6; P<0.001). Presence of CPCs prior to transplant has a high prognostic impact and should be prospectively validated in clinical trials.