Utilizing 3D Models to Unravel the Dynamics of Myeloma Plasma Cells' Escape from the Bone Marrow Microenvironment.

Recent therapeutic advancements have markedly increased the survival rates of individuals with multiple myeloma (MM), doubling survival compared to pre-2000 estimates. This progress, driven by highly effective novel agents, suggests a growing population of MM survivors exceeding the 10-year mark post-diagnosis. However, contemporary clinical observations indicate potential trends toward more aggressive relapse phenotypes, characterized by extramedullary disease and dominant proliferative clones, despite these highly effective treatments. To build upon these advances, it is crucial to develop models of MM evolution, particularly focusing on understanding the biological mechanisms behind its development outside the bone marrow. This comprehensive understanding is essential to devising innovative treatment strategies. This review emphasizes the role of 3D models, specifically addressing the bone marrow microenvironment and development of extramedullary sites. It explores the current state-of-the-art in MM modelling, highlighting challenges in replicating the disease's complexity. Recognizing the unique demand for accurate models, the discussion underscores the potential impact of these advanced 3D models on understanding and combating this heterogeneous and still incurable disease.

Racial and ethnic differences in clinical outcomes among patients with multiple myeloma treated with CAR T-cell therapy.

ABSTRACT: Idecabtagene vicleucel (ide-cel) was the first chimeric antigen receptor T-cell therapy to gain US Food and Drug Administration approval for patients with relapsed/refractory multiple myeloma (RRMM). The clinical outcomes of standard of care (SOC) ide-cel in racially and ethnically diverse populations have been understudied. This study pooled data from 207 patients with RRMM (28% patients of racial and ethnic minority groups) treated with SOC ide-cel across 11 institutions to examine racial and ethnic differences in the incidence of toxicities and adverse events, response to ide-cel, and survival. This study included 22 (11%) Hispanic, 36 (17%) non-Hispanic Black, and 149 (72%) non-Hispanic White patients with RRMM. Compared with Hispanic and non-Hispanic White patients, non-Hispanic Black patients had higher median levels of C-reactive protein (1.0, 0.8, and 3.5 mg/dL, respectively; P = .02) and baseline ferritin (362.0 vs 307.0 vs 680.5, respectively; P = .08) and were more likely to develop cytokine release syndrome (77%, 85%, and 97%, respectively; P = .04). Although best overall response rate was lower among Hispanic patients (59%) than among non-Hispanic Black (86%) and White patients (86%; P = .01), there were no racial and ethnic differences in progression-free or overall survival. We provide, to our knowledge, the first and largest investigation of clinical outcomes of SOC ide-cel by race and ethnicity. Despite differences in safety and response to ide-cel, our findings encourage the use of ide-cel in all patients with RRMM. These findings should be confirmed in larger samples of diverse patients with RRMM, with longer follow-up time.

Frontline therapy with bendamustine rituximab (BR) and rituximab cyclophosphamide vincristine prednisone (RCVP) confers similar long-term outcomes in patients with treatment naïve Waldenström macroglobulinemia in a real-world setting: a population-based analysis.

We report on outcomes of 111 patients with treatment naïve Waldenström macroglobulinemia (TN WM) treated with frontline bendamustine-rituximab (BR) (n = 57) or rituximab-cyclophosphamide-vincristine-prednisone (RCVP) (n = 54). Median follow-up was 60.7 months (range 1.9-231.6). Median progression-free survival (PFS) was 60.5 months (95% CI 47.6-73.4) for BR and 79.0 months (95% CI 31.3-126.8) for RCVP (p = .96). Median overall survival (OS) was not reached for BR and 153.4 months (95% CI 114.5-192.4) for RCVP (p = .37). While overall and major response rates did not differ between treatment groups, BR had numerically higher rate of very good partial response or better response (51% vs. 37%, p = .30) and complete response (26% vs. 13%, p = .13). RCVP confers comparable outcomes to BR in a real-world population of TN WM patients and remains an effective regimen, particularly when tolerance or frailty is an issue, or in resource-limited settings.

Simple Score of Albumin and CRP Predicts High-Grade Toxicity in Patients with Multiple Myeloma Receiving CAR-T Therapy.

Administration of chimeric-antigen receptor T-cell (CAR-T) therapy is complex and associated with unique toxicities. Identifying patients at risk for inferior outcomes is important for individualized management. The Glasgow-prognostic score (GPS) is a simple score shown to be highly prognostic of outcomes in the setting of traditional chemotherapy or checkpoint inhibitor administration. We sought to evaluate the value of the GPS to predict outcomes of patients with relapse refractory multiple myeloma (RRMM) receiving anti-BCMA CAR-T therapy. We included all patients treated with commercial CAR-T therapy for RRMM between 5/1/2021 and 2/1/2023 at the Moffitt Cancer Center. The GPS (CRP >1 mg/dL, 1 point; albumin <3.5, 1 point) was calculated for all patients at lymphodepletion (day -6) and patients were grouped as high-risk GPS (score = 2) or low-risk GPS (0 or 1). The primary endpoint was overall survival (OS) at day 100. A total of 139 pts were included, with a median follow-up of 6.7 months (95% CI, 6.2 to 8.9 months). Pts were treated with either idecabtagene vicleucel (83%) or ciltacabtagene autoleucel (17%). In total, 14% were classified with high-risk GPS, with significantly increased risk for grade 3 cytokine release syndrome (P = .003) and ICANS of any grade (P < .001). Patients in the high-risk GPS group had significantly lower day-100 OS (68.4% versus 97.3%, P < .001), OS at 6 months (56% versus 91.8% P = .0019) and PFS at 6 months (38.3% versus 72.3%, P = .03). The association of GPS with day-100 OS remained significant in a multivariable model. In conclusion, the GPS identifies a group of high-risk patients with RRMM receiving CAR-T therapy who experience increased rates of immune-mediated toxicity and are at higher risk for early mortality.

Survivin Dendritic Cell Vaccine Safely Induces Immune Responses and Is Associated with Durable Disease Control after Autologous Transplant in Patients with Myeloma.

PURPOSE: We investigated whether a dendritic cell (DC) vaccine transduced with an adenoviral vector encoded with full-length survivin (Ad-S), with mutations neutralizing its antiapoptotic function, could safely generate an immune response and deepen clinical responses when administered before and after autologous stem cell transplant (ASCT) for multiple myeloma. PATIENTS AND METHODS: This phase I first-in-human trial (NCT02851056) evaluated the safety of DC:Ad-S in newly diagnosed multiple myeloma not having achieved complete response with induction, given 7 to 30 days prior to stem cell collection and 20 to 34 days after ASCT. Anti-survivin antibodies and CD4+ and CD8+ specific T cells were quantified. RESULTS: A total of 14 patients were treated and 13 included in the primary efficacy analysis. No serious adverse events were attributed to DC:Ad-S vaccine. Detectable anti-survivin antibodies increased from baseline in 9 of 13 (69%) patients, and 11 of 13 (85%) mounted either a cellular or humoral immune response to survivin. Seven patients had an improved clinical response at day +90, all of whom had mounted an immune response, and 6 of 7 patients remain event-free at a median follow-up of 4.2 years. Estimated progression-free survival at 4 years is 71% (95% confidence interval, 41-88). CONCLUSIONS: Two doses of DC:Ad-S, one given immediately before and another after ASCT, were feasible and safe. A high frequency of vaccine-specific immune responses was seen in combination with durable clinical outcomes, supporting ongoing investigation into the potential of this approach. See related commentary by Dhodapkar, p. 4524.

The CAR-HEMATOTOX score as a prognostic model of toxicity and response in patients receiving BCMA-directed CAR-T for relapsed/refractory multiple myeloma.

BACKGROUND: BCMA-directed CAR T-cell therapy (CAR-T) has altered the treatment landscape of relapsed/refractory (r/r) multiple myeloma, but is hampered by unique side effects that can lengthen hospital stays and increase morbidity. Hematological toxicity (e.g. profound and prolonged cytopenias) represents the most common grade ≥ 3 toxicity and can predispose for severe infectious complications. Here, we examined the utility of the CAR-HEMATOTOX (HT) score to predict toxicity and survival outcomes in patients receiving standard-of-care idecabtagene vicleucel and ciltacabtagene autoleucel. METHODS: Data were retrospectively collected from 113 r/r multiple myeloma patients treated between April 2021 and July 2022 across six international CAR-T centers. The HT score-composed of factors related to hematopoietic reserve and baseline inflammatory state-was determined prior to lymphodepleting chemotherapy. RESULTS: At lymphodepletion, 63 patients were HTlow (score 0-1) and 50 patients were HThigh (score ≥ 2). Compared to their HTlow counterparts, HThigh patients displayed prolonged severe neutropenia (median 9 vs. 3 days, p < 0.001), an increased severe infection rate (40% vs. 5%, p < 0.001), and more severe ICANS (grade ≥ 3: 16% vs. 0%, p < 0.001). One-year non-relapse mortality was higher in the HThigh group (13% vs. 2%, p = 0.019) and was predominantly attributable to fatal infections. Response rates according to IMWG criteria were higher in HTlow patients (≥ VGPR: 70% vs. 44%, p = 0.01). Conversely, HThigh patients exhibited inferior progression-free (median 5 vs. 15 months, p < 0.001) and overall survival (median 10.5 months vs. not reached, p < 0.001). CONCLUSIONS: These data highlight the prognostic utility of the CAR-HEMATOTOX score for both toxicity and treatment response in multiple myeloma patients receiving BCMA-directed CAR-T. The score may guide toxicity management (e.g. anti-infective prophylaxis, early G-CSF, stem cell boost) and help to identify suitable CAR-T candidates.

Relapse Timing Is Associated With Distinct Evolutionary Dynamics in Diffuse Large B-Cell Lymphoma.

PURPOSE: Diffuse large B-cell lymphoma (DLBCL) is cured in more than 60% of patients, but outcomes remain poor for patients experiencing disease progression or relapse (refractory or relapsed DLBCL [rrDLBCL]), particularly if these events occur early. Although previous studies examining cohorts of rrDLBCL have identified features that are enriched at relapse, few have directly compared serial biopsies to uncover biological and evolutionary dynamics driving rrDLBCL. Here, we sought to confirm the relationship between relapse timing and outcomes after second-line (immuno)chemotherapy and determine the evolutionary dynamics that underpin that relationship. PATIENTS AND METHODS: Outcomes were examined in a population-based cohort of 221 patients with DLBCL who experienced progression/relapse after frontline treatment and were treated with second-line (immuno)chemotherapy with an intention-to-treat with autologous stem-cell transplantation (ASCT). Serial DLBCL biopsies from a partially overlapping cohort of 129 patients underwent molecular characterization, including whole-genome or whole-exome sequencing in 73 patients. RESULTS: Outcomes to second-line therapy and ASCT are superior for late relapse (>2 years postdiagnosis) versus primary refractory (<9 months) or early relapse (9-24 months). Diagnostic and relapse biopsies were mostly concordant for cell-of-origin classification and genetics-based subgroup. Despite this concordance, the number of mutations exclusive to each biopsy increased with time since diagnosis, and late relapses shared few mutations with their diagnostic counterpart, demonstrating a branching evolution pattern. In patients with highly divergent tumors, many of the same genes acquired new mutations independently in each tumor, suggesting that the earliest mutations in a shared precursor cell constrain tumor evolution toward the same genetics-based subgroups at both diagnosis and relapse. CONCLUSION: These results suggest that late relapses commonly represent genetically distinct and chemotherapy-naïve disease and have implications for optimal patient management.

Relapse timing is associated with distinct evolutionary dynamics in DLBCL.

Diffuse large B-cell lymphoma (DLBCL) is cured in over 60% of patients, but outcomes are poor for patients with relapsed or refractory disease (rrDLBCL). Here, we performed whole genome/exome sequencing (WGS/WES) on tumors from 73 serially-biopsied patients with rrDLBCL. Based on the observation that outcomes to salvage therapy/autologous stem cell transplantation are related to time-to-relapse, we stratified patients into groups according to relapse timing to explore the relationship to genetic divergence and sensitivity to salvage immunochemotherapy. The degree of mutational divergence increased with time between biopsies, yet tumor pairs were mostly concordant for cell-of-origin, oncogene rearrangement status and genetics-based subgroup. In patients with highly divergent tumors, several genes acquired exclusive mutations independently in each tumor, which, along with concordance of genetics-based subgroups, suggests that the earliest mutations in a shared precursor cell constrain tumor evolution. These results suggest that late relapses commonly represent genetically distinct and chemotherapy-naïve disease.

Molecular determinants of clinical outcomes in a real-world diffuse large B-cell lymphoma population.

Molecular heterogeneity of diffuse large B-cell lymphoma (DLBCL) underlies the variable outcomes achieved with immunochemotherapy. However, outcomes of gene expression profiling (GEP)-defined molecular subgroups in a real-world DLBCL population remain unknown. Here we examined the prevalence and outcomes of molecular subgroups in an unselected population of 1149 patients with de novo DLBCL in British Columbia, Canada. Evaluable biopsies were profiled by fluorescence in situ hybridization (FISH), immunohistochemistry, and digital GEP to assign cell-of-origin and the so-called "double-hit signature" (DHITsig)-a signature originally described as being characteristic for high-grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBCL-DH-BCL2). DHITsig was expressed in 21% of 431 germinal center B-cell-like (GCB)-DLBCL and all 55 Burkitt lymphomas examined. Reflecting this latter finding, DHITsig has been renamed the "dark zone signature" (DZsig). DZsigpos-DLBCL, non-DZsigpos GCB-DLBCL and activated B-cell-like (ABC)-DLBCL were associated with a 2 year overall survival of 57%, 89%, and 71%, respectively. 62% of DZsigpos tumors were negative for HGBCL-DH-BCL2 by FISH, but were associated with outcomes similar to HGBCL-DH-BCL2. A small group of HGBCL-DH-BCL2 that lacked DZsig expression had different molecular features compared with DZsig-expressing HGBCL-DH-BCL2 and were associated with favorable outcomes comparable to DLBCL, not otherwise specified. DZsigpos and ABC-DLBCL had a shorter diagnosis-to-treatment interval (DTI) than GCB-DLBCL, with this metric being associated with outcome. In conclusion, DZsig expression extends beyond HGBCL-DH-BCL2 and captures a poor-prognosis DLBCL subgroup with short DTI, including patients unidentifiable by routine FISH testing, that should be considered for treatment intensification or novel therapies in prospective trials.

Fitness and frailty in myeloma.

As the aging population grows, so too does the number of well-tolerated antimyeloma therapies. Physicians will see an increasing volume of patients for subsequent lines of therapy, which could now extend this relationship for over a decade. For younger patients, treatment choices are infrequently impacted by concerns of fitness, but instead about effecting the deepest, most durable response. Older adults, in contrast, are more likely to experience under- than overtreatment, and therefore more objective (and ideally straightforward) ways to evaluate their fitness and ability to tolerate therapy will increasingly assist in decision-making. Post hoc analyses categorizing the fitness of trial patients in the modern treatment era globally demonstrate that even in highly selected populations, those that are recategorized as less fit or frail are consistently at higher risk of inferior outcomes and increased toxicities. Real-world data are comparatively lacking but do demonstrate that most patients with myeloma are not representative of those enrolled on clinical trials, generally more heavily burdened by comorbidities and more likely to be categorized as "less than fit." Simultaneously, the number of therapeutic options open to patients in the relapsed setting continues to grow, now including T-cell engagers and cellular therapies, with their unique toxicity profiles. The aim of this review is to summarize the available data, highlight some of the approaches possible to easily assess fitness and how results might inform treatment selection, and illustrate ways that patients' condition can be optimized rather than lead to exclusion from the more complex therapies newly available.

The outcome of older adults with classic Hodgkin lymphoma in British Columbia.

Outcomes in older adults with classic Hodgkin lymphoma (cHL) have traditionally been poor, in part, related to poor tolerance to standard chemotherapy. Herein, we evaluated the survival of patients with cHL aged ≥60 years in British Columbia in a population-based analysis. From 1961 to 2019, 744 patients with newly diagnosed cHL were identified. With a median follow-up of 9 years, 5-year disease-specific survival (DSS) and overall survival (OS) have improved by decade comparison (both P < .001), remaining stable in the past 20 years (DSS, P = .35; OS, P = .26). In the modern management era (2000-present), 361 of 401 patients (90%) received active therapy for cHL and had a 5-year OS of 60%. For those who received curative-intent therapy (n = 327), the 5-year progression-free survival (PFS), OS, and DSS were 60%, 65%, and 76%, respectively, and estimates were superior in those who were 60 to 69 years of age (72%, 77%, and 83%, respectively) compared with those who were 70 to 79 years of age (54%, 57%, and 70%, respectively) and ≥80 years of age (28%, 39%, and 63%, respectively) (P < .05 for all). Overall, pulmonary toxicity occurred in 58 of 279 patients (21%) treated with bleomycin, with 22 of 58 (38%) occurring after cycles 1 or 2, accounting for 8 of 20 (40%) treatment-related deaths. Outcomes in older adults with cHL have improved in recent decades; however, they remain poor for those aged ≥70 years, even in the modern treatment era. Furthermore, treatment-related toxicity remains a significant concern and use of bleomycin should be avoided in most patients.

Early cytopenias and infections after standard of care idecabtagene vicleucel in relapsed or refractory multiple myeloma.

Idecabtagene vicleucel (ide-cel) was FDA-approved in March 2021 for the treatment of relapsed/refractory multiple myeloma after 4 lines of therapy. On the KarMMa trial, grade ≥ 3 cytopenias and infections were common. We sought to characterize cytopenias and infections within 100 days after ide-cel in the standard-of-care (SOC) setting. This multi-center retrospective study included 52 patients who received SOC ide-cel; 47 reached day-90 follow-up. Data were censored at day 100. Grade ≥ 3 cytopenia was present among 65% of patients at day 30 and 40% of patients at day 90. Granulocyte colony stimulating factor (G-CSF) was administered to 88%, packed red blood cell transfusions to 63%, platelet transfusions to 42%, thrombopoietin (TPO) agonists to 21%, intravenous immunoglobulin to 13%, and CD34+ stem cell boosts to 8%. At day 100, 19% and 13% of patients had ongoing use of TPO agonists and G-CSF, respectively. Infections occurred in 54% of patients and were grade ≥ 3 in 23%. Earlier infections in the first 30 days were typically bacterial (68%) and severe (50%). Later infections between days 31 and 100 were 50% bacterial and 42% viral; only 13% were grade ≥ 3. On univariate analysis, high pre-CAR-T marrow myeloma burden (≥ 50%), circulating plasma cells at pre-lymphodepletion (LD), and grade ≥ 3 anemia at pre-LD were associated with grade ≥ 3 cytopenia at both days 30 and 90. Longer time from last bridging treatment to LD was the only significant risk factor for infection.

Clinicopathological characteristics and long-term outcomes of plasmablastic lymphoma in British Columbia.

Plasmablastic lymphoma (PBL) is an aggressive and rare subtype of non-Hodgkin lymphoma with no standard-of-care therapy. We reviewed all patients diagnosed with histologically confirmed PBL in British Columbia, Canada between 1997 and 2019. Overall, 42 patients were identified, including 15 (36%) positive for HIV and nine (21%) on chronic immunosuppression. Curative-intent treatment consisting primarily of cyclophosphamide, doxorubicin, vincristine and prednisone was administered to 31 patients, of which 74% achieved response, however 61% relapsed after a median of 7.5 months. At a median follow-up of eight years for the whole cohort, five-year progression-free survival (PFS) and overall survival (OS) were 18% [95% confidence interval (CI): 6%, 30%] and 22% (95% CI: 8%, 36%) with median eight and 15 months respectively. There were no differences in relapse rate (p = 0.962), PFS (p = 0.228) or OS (p = 0.340) according to immune status. For those treated with curative intent, five-year PFS and OS were 24% (95% CI: 8%, 40%) and 31% (95% CI: 13%, 49%) with median 18 and 27 months respectively. In this population-based cohort of PBL patients spanning 20 years, survival outcomes were poor. Ultimately, further research is needed to develop more effective treatment strategies and to improve survival for patients.

Molecular determinants of outcomes in relapsed or refractory mantle cell lymphoma treated with ibrutinib or temsirolimus in the MCL3001 (RAY) trial.

Mantle cell lymphoma (MCL) is a rare, incurable lymphoma subtype characterized by heterogeneous outcomes. To better understand the clinical behavior and response to treatment, predictive biomarkers are needed. Using residual archived material from patients enrolled in the MCL3001 (RAY) study, we performed detailed analyses of gene expression and targeted genetic sequencing. This phase III clinical trial randomized patients with relapsed or refractory MCL to treatment with either ibrutinib or temsirolimus. We confirmed the prognostic capability of the gene expression proliferation assay MCL35 in this cohort treated with novel agents; it outperformed the simplified MCL International Prognostic Index in discriminating patients with different outcomes. Regardless of treatment arm, our data demonstrated that this assay captures the risk conferred by known biological factors, including increased MYC expression, blastoid morphology, aberrations of TP53, and truncated CCND1 3' untranslated region. We showed the negative impact of BIRC3 mutations/deletions on outcomes in this cohort and identified that deletion of chromosome 8p23.3 also negatively impacts survival. Restricted to patients with deletions/alterations in TP53, ibrutinib appeared to abrogate the deleterious impact on outcome. These data illustrate the potential to perform a molecular analysis of predictive biomarkers on routine patient samples that can meaningfully inform clinical practice.

Outcomes of Hodgkin variant Richter transformation in chronic lymphocytic leukaemia and small lymphocytic lymphoma in British Columbia.

Hodgkin variant Richter transformation (HvRT) is a rare and challenging complication of chronic lymphocytic leukaemia (CLL) for which information on prognostic factors and treatment approaches remain limited. We analysed characteristics and survival outcomes of a population-based cohort of 32 patients with HvRT identified in British Columbia over a 40-year period. Median interval from CLL diagnosis to HvRT was 5.6 years (range, 0-33.6), with five cases diagnosed concurrently. Most patients (80%) had treatment for CLL prior to HvRT. Median age at HvRT was 71 years (range, 51-86) and the majority of patients had high-risk disease, including stage 3-4 in 87% and International Prognostic Score (IPS) ≥ 4 in 65%. Two-year progression-free (PFS) and overall survival (OS) from HvRT were 47% (95% CI: 29%-64%) and 57% (95% CI: 38%-72%), respectively. OS from HvRT was significantly worse in those with anaemia (p = 0.02), elevated lactate dehydrogenase (p = 0.04), high IPS (p = 0.04), and worse performance status (p = 0.001). For those treated with curative-intent ABVD/ABVD-like therapy, 2-year PFS and OS were 70% (95% CI: 45%-85%) and 74% (95% CI: 49%-89%), respectively. In this real-world population-based cohort, HvRT was associated with poor clinical outcomes overall; however, those able to tolerate curative-intent therapy had similar survival to older patients with de novo HL.

Bendamustine or high-dose cytarabine-based induction with rituximab in transplant-eligible mantle cell lymphoma.

The objective of this study was to explore differences in outcomes between first-line rituximab plus bendamustine (R-B) and R-CHOP/R-DHAP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone, dexamethasone, cytarabine, cisplatin) in transplant-eligible patients with mantle cell lymphoma (MCL). A population-based cohort of 97 patients aged 18 to 65 years with stage II-IV MCL, consecutively treated with R-B was retrospectively identified at BC Cancer. Baseline characteristics, response rates, and outcomes were compared with the cohort of 232 patients with MCL randomized to the R-CHOP/R-DHAP arm of the MCL Younger trial. The primary endpoint was the hazard ratio (HR) of the progression-free survival (PFS) comparison between both groups, adjusted for MCL International Prognostic Index (MIPI), Ki67 index, and blastoid/ pleomorphic morphology. Ann Arbor stage, lactate dehydrogenase, MIPI, blastoid morphology, and MCL35 assignments were similar between both groups. The overall response rate (ORR) to R-B was 90% (54% complete response [CR]); 77% of patients proceeded to autologous stem cell transplantation (ASCT) and 78% received maintenance rituximab (MR). The ORR to R-CHOP/R-DHAP was 94% (54% CR); 78% proceeded to ASCT and 2% received MR. There were no differences in PFS in unadjusted (HR, 0.87; 95% confidence interval [CI], 0.53-1.41; P = .56) or adjusted (HR, 0.79; 95% CI, 0.45-1.37; P = .40) comparisons. There were no clear differences in secondary endpoints in unadjusted or adjusted analyses. This retrospective adjusted comparison of 2 independent cohorts of younger patients with MCL suggests that R-B with ASCT and maintenance rituximab is a feasible and effective first-line treatment, with outcomes comparable to R-CHOP/R-DHAP with ASCT.