Current Status on Management of Primary Plasma Cell Leukemia.

PURPOSEOF REVIEW: Plasma Cell Leukemia (PCL) is a very rare and highly aggressive form of plasma cell dyscrasia. This review seeks to evaluate the outcomes of PCL in the context of combination novel agent therapy and stem cell transplant (SCT) protocols. RECENT FINDINGS: The diagnostic criteria for PCL have now evolved to include patients with 5% circulating PC. While management remains challenging, the incorporation of novel agent-based induction regimen has significantly improved early mortality and reduced attrition of patients proceeding to SCT. In recent prospective clinical trials, patients with PCL demonstrated an overall response rates of 69% to 86%, with progression-free and overall survival ranging from 13.8 to 15.5 months and 24.8 to 36.3 months, respectively. B-cell lymphoma 2 (BCL2) inhibitors, such as venetoclax present a targeted intervention opportunity for patients with PCL with t(11;14). Dedicated clinical trials tailored to PCL are crucial, integrating newer therapies in the frontline setting to further optimize responses and enhance overall outcomes.

Timing of Toxicities and Non-Relapse Mortality Following CAR T Therapy in Myeloma.

BCMA-directed chimeric antigen receptor T-cell (CAR T) therapies, including idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel), have transformed the treatment landscape for relapsed-refractory multiple myeloma (RRMM), offering remarkable efficacy with hallmark toxicity risks of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The FDA mandates a 4-week monitoring period at the treatment center as part of a Risk Evaluation and Mitigation Strategy (REMS) to monitor and manage these toxicities, which, while prudent, may add unnecessary challenges related to access and socioeconomic disparities. We sought to assess CRS and ICANS onset and duration, as well as causes of non-relapse mortality (NRM) in real-world BCMA CAR T recipients in order to better inform future changes to the monitoring guidelines for CAR T recipients. This is a retrospective study across four academic centers that examined 129 ide-cel and cilta-cel recipients that received CAR T cell infusions from May 2021 to June 2023. Infusion and toxicities were managed per institutional guidelines in accordance with previously published guidelines. While differences were noted in the incidence and duration of CRS/ ICANS between ide-cel and cilta-cel, late-onset CRS and ICANS were rare after 2 weeks following infusion (0% and 1.6%, respectively). NRM was driven by hemophagocytic lymphohistiocytosis and infections in the early follow-up period (1.1% until Day 29), then by infections through three months post-infusion (1.2%). Our findings suggest that 25% of patients had to relocate for 4 weeks due to distance from the treatment center. With the low risk of CRS and ICANS after 2 weeks, a flexible shorter monitoring period may be reasonable, emphasizing collaboration with referring oncologists to improve NRM.

Outpatient Administration of CAR T-cell Therapies Using a Strategy of No Remote Monitoring and Early CRS Intervention.

Recent studies demonstrating the feasibility of outpatient chimeric antigen receptor modified (CAR) T-cell therapy administration are either restricted to CARs with 41BB costimulatory domains or employ intensive at-home monitoring. We report outcomes of outpatient administration of all commercially available CD19- and BCMA-directed CAR-T therapy using a strategy of no remote at-home monitoring and an early cytokine release syndrome (CRS) intervention strategy. Patients with hematologic malignancies who received CAR T-cell therapy in the outpatient setting during 2022-23 were included. Patients were seen daily in the cancer center day hospital for the first 7-10 days and then twice weekly through day 30. The primary endpoint was to determine 3-, 7- and 30-day post CAR T-cell infusion hospitalizations. Early CRS intervention involved administering tocilizumab as an outpatient for grade ≥1 CRS. 58 patients received outpatient CAR T-cell infusion (33 myeloma, 24 lymphoma and 1 acute lymphoblastic leukemia). Of these, 17 (41%), 16 (38%), and 9 (21%) patients were admitted between days 0-3, 4-7 and 8-30 post-CAR T-cell infusion, respectively. The most common reason for admission was CAR T-cell-related toxicities (33/42). Hospitalization was prevented in 15 out of 35 patients who received tocilizumab for CRS as an outpatient. The non-relapse mortality rates were 1.7% at 1 month and 3.4% at 6 months. In conclusion, we demonstrate that the administration of commercial CAR T-cell therapies in an outpatient setting is safe and feasible without intensive remote monitoring employing an early CRS intervention strategy.

Charting the Course: Sequencing Immunotherapy for Multiple Myeloma.

Multiple chimeric antigen receptor (CAR) T-cell and bispecific antibody (bsAb) therapies have been approved, demonstrating impressive clinical efficacy in relapsed/refractory multiple myeloma (MM). Currently, these treatment share overlapping approval indications in the relapsed/refractory space, highlighting the importance of optimal selection and sequencing to maximize clinical efficacy. For patients previously unexposed to T-cell-directed therapies, several factors should be weighed when both options are available. These factors include access and logistical challenges associated with CAR T-cell therapy, disease-specific factors such as tempo of disease relapse, in addition to patient-specific factors such as frailty, and distinct toxicity profiles across these agents. Sequential therapy, whether it involves CAR T-cell therapy followed by bsAb or vice versa, has demonstrated clinical efficacy. When sequencing these agents, it is crucial to consider various factors that contribute to treatment resistance with careful selection of treatments for subsequent therapy in order to achieve favorable long-term patient outcomes.

Risk stratification in multiple myeloma: Are we there yet?

The second revision of international staging system (R2-ISS) shows promise in patients with multiple myeloma treated with a regimen of novel agent-based induction therapy, autologous stem cell transplant and maintenance therapy, but challenges persist. This study by Alzahrani et al. underscores the importance of refining risk assessment tools for tailored treatment strategies. Commentary on: Alzahrani et al. Impact of revised international staging system 2 (R2-ISS) risk stratification on outcomes of patients with multiple myeloma receiving autologous hematopoietic stem cell transplantation. Br J Haematol 2024;204:1944-1952.

Teclistamab in relapsed refractory multiple myeloma: multi-institutional real-world study.

The objective of our study was to report real-world data on the safety and efficacy of standard-of-care teclistamab in patients with relapsed/refractory multiple myeloma (MM). This is a multi-institutional retrospective cohort study and included all consecutive patients that received at least one dose of teclistamab up until August 2023. One hundred and ten patients were included, of whom, 86% had triple-class refractory disease, 76% penta-refractory disease, and 35% had prior exposure to B-cell maturation antigen (BCMA)-targeting therapies. The overall response rate (ORR) in our cohort was 62%, with a ≥ very good partial remission (VGPR) rate of 51%. The ORR in patients with and without prior BCMA-targeted therapies was 54% vs 67%, respectively (p = 0.23). At a median follow-up of 3.5 months (range, 0.39-10.92), the estimated 3 month and 6 month progression free survival (PFS) was 57% (95% CI, 48%, 68%) and 52% (95% CI, 42%, 64%) respectively. The incidence of cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) was 56% and 11% respectively, with grade ≥3 CRS and ICANS noted in 3.5% and 4.6% of patients respectively. 78 unique infections were diagnosed in 44 patients, with the incidence of all-grade and grade ≥3 infections being 40% vs 26% respectively. Primary prophylaxis with intravenous immunoglobulin (IVIG) was associated with a significantly lower infection risk on multivariate analysis (Hazard ratio [HR] 0.33; 95% CI 0.17, 0.64; p = 0.001).

Autologous stem cell boost improves persistent immune effector cell associated hematotoxicity following BCMA directed chimeric antigen receptor T (CAR T) cell therapy in multiple myeloma.

Persistent Immune Effector Cell Associated Hematotoxicity (ICAHT) is a significant side effect of BCMA CAR T-Cell therapy in patients with relapsed multiple myeloma (MM). The use of stem cell boosts in ICAHT has been described, however studies have been limited by small patient numbers and short follow up. Herein, we report on our multi-institutional experience of ICAHT, defined by an absolute neutrophil count (ANC) of ≤ 1000, thrombocytopenia with a platelet count ≤ 50,000 or/and anemia as hemoglobin (hgb) ≤9 g/dL, in patients who received BCMA CAR T therapy, and the effects of subsequent stem cell boost on hematopoietic reconstitution and clinical outcome. In this study, ICAHT was observed in 60% (n = 61/101) of patients at D + 21, and risk factors for its development included history of a prior ASCT, higher number of prior lines of therapy, a decreased platelet count prior to lymphodepletion and history of ICANS. 28% of patients with ICAHT received a stem cell boost at a median of 116 days due to profound and prolonged cytopenias often requiring ongoing transfusion support. Stem cell boost significantly improved cytopenias at 3 and 6 months follow up without any adverse effects on PFS and OS, underscoring the safety of this procedure.

Alterations in chromosome 1q in multiple myeloma randomized clinical trials: a systematic review.

Extra copies of chromosome 1q21 (+1q: gain = 3 copies, amp >= 4 copies) are associated with worse outcomes in multiple myeloma (MM). This systematic review assesses the current reporting trends of +1q, the efficacy of existing regimens on +1q, and its prognostic implications in MM randomized controlled trials (RCTs). Pubmed, Embase and Cochrane Registry of RCTs were searched from January 2012 to December 2022. Only MM RCTs were included. A total of 124 RCTs were included, of which 29 (23%) studies reported on +1q. Among them, 10% defined thresholds for +1q, 14% reported survival data separately for gain and amp, and 79% considered +1q a high-risk cytogenetic abnormality. Amongst RCTs that met the primary endpoint showing improvement in progression free survival (PFS), lenalidomide maintenance (Myeloma XI), selinexor (BOSTON), and isatuximab (IKEMA and ICARIA) were shown to improve PFS for patients with evidence of +1q. Some additional RCT's such as Myeloma XI+ (carfilzomib), ELOQUENT-3 (elotuzumab), and HOVON-65/GMMG-HD4 (bortezomib) met their endpoint showing improvement in PFS and also showed improvement in PFS in the +1q cohort, although the confidence interval crossed 1. All six studies that reported HR for +1q patients vs. without (across both arms) showed worse OS and PFS for +1q. There is considerable heterogeneity in the reporting of +1q. All interventions that have shown to be successful in RCTs and have clearly reported on the +1q subgroup have shown concordant direction of results and benefit of the applied intervention. A more standardized approach to reporting this abnormality is needed.

Severity and organ distribution of chronic graft-versus-host disease with posttransplant cyclophosphamide-based versus methotrexate/calcineurin inhibitor-based allogeneic hematopoietic cell transplantation.

The reduced risk of chronic graft-versus-host-disease (GVHD) with posttransplant cyclophosphamide (ptCy) in the setting of haploidentical related donor and more recently, with HLA-matched related and matched and mismatched unrelated donor allogeneic transplantation has been established. There is, however, paucity of data to show if ptCy impacts chronic GVHD pathogenesis, its phenotype and evolution after HCT regardless of the donor status. We examined the differences in chronic GVHD incidence and presentation in 314 consecutive patients after receiving their first allogeneic transplantation (HCT) using ptCy-based GVHD prophylaxis (ptCy-HCT; n = 120; including 95 with haploidentical related donor) versus conventional calcineurin inhibitor-based prophylaxis (CNI-MUD; n = 194) between 2012 and 2019. The 1-year cumulative incidence of all-grade chronic GVHD and moderate/severe chronic GVHD was 24% and 12%, respectively, after ptCy-HCT and 40% and 23% in the CNI-MUD recipients (p = 0.0003 and 0.007). Multivariable analysis confirmed that use of CNI-based GVHD prophylaxis and peripheral blood stem cell graft as the risk factors for chronic GVHD. The cumulative incidence of visceral (involving ≥1 of the following organs: liver, lungs, gastrointestinal tract, serous membranes) chronic GVHD was significantly higher with CNI-MUD vs. ptCy-HCT (27% vs. 15% at 1 year, p = 0.009). The incidence of moderate/severe visceral chronic GVHD was 20% in CNI-MUD group vs. 7.7% in the ptCy-HCT group at 1 year (p = 0.002). In addition, significantly fewer ptCy-HCT recipients developed severe chronic GVHD in ≥3 organs (0.8%) vs. 8.8% in the CNI-MUD group at 1-year posttransplant (p = 0.004). There was no significant different in relapse, non-relapse mortality, and relapse-free and overall survival between the two groups. Further investigation is needed to confirm that reduced risk and severity of chronic GVHD, less visceral organ distribution with ptCy-HCT leads to improved quality of life.

The changing spectrum of infection with BCMA and GPRC5D targeting bispecific antibody (bsAb) therapy in patients with relapsed refractory multiple myeloma.

There is a paucity of granular data on infection risk with B-cell maturation antigen (BMCA) and GPRC5D bispecific antibodies (bsAb) in relapsed/refractory multiple myeloma (RRMM). The aim of our multi-institutional study was to characterize the incidence, etiologies, and risk factors of infections from the start of therapy to the last follow-up or 90 days after study exit. A total of 66 patients received BCMA bsAb monotherapy, 15 GPRC5D bsAb monotherapy, and 15 GPRC5D bsAb combination therapy with daratumumab and/or pomalidomide. While the infection rate per 100 days was 0.57 for BCMA bsAb, it was 0.62 for GPRC5D bsAb combination and 0.13 for GPRC5D bsAb monotherapy; P=0.05. The proportion of infections that were grade ≥3 was higher in the BCMA bsAb group compared to the GPRC5D groups (58% vs. 36%; P=0.04). Grade 5 events were observed in 8% (n=8) of the patients, all treated with BCMA bsAb. The 9 month cumulative incidence of any grade of infection was similar in the BCMA and GPRC5D-combination groups (57% and 62%) and significantly higher than in the GPRC5D-mono group (16%); P=0.012. The cumulative incidence of grade ≥3 infections was highest in the BCMA group reaching 54% at 18 months; P=0.06. Multivariate analysis showed that BCMA bsAb therapy or GPRC5D combination therapy, history of previous infections, baseline lymphopenia, and baseline hypogammaglobulinemia were significantly associated with a higher risk of grade ≥3 infections. Our results indicate that BCMA bsAb and GPRC5D-combination therapies in RRMM are associated with higher cumulative incidence of infection and grade ≥3 infection compared to GPRC5D bsAb mono.

Chimeric antigen receptor and bispecific T-cell engager therapies in multiple myeloma patients with prior allogeneic transplantation.

Chimeric antigen receptor T-cell (CAR-T) therapy and bispecific T-cell engagers (BsAb) have emerged as promising immunotherapeutic modalities in patients with relapsed and/or refractory multiple myeloma (RRMM). However, there is limited data on the safety and efficacy of CAR-T and BsAb therapies in MM patients with a prior history of allogeneic transplantation (allo-HCT). Thirty-three MM patients with prior allo-HCT received CAR-T (n = 24) or BsAb (n = 9) therapy. CAR-T therapy demonstrated an ORR of 92% (67% ≥ CR), and 73% were MRD negative. BsAb therapy resulted in an ORR of 44% (44% ≥ CR) and 44% MRD negative. Safety analysis showed grade ≥3 AEs in 92% of CAR-T and 56% of BsAb patients. Cytokine release syndrome (CRS) occurred in 83% of CAR-T and 78% of BsAb recipients, while immune effector cell-associated neurotoxicity syndrome (ICANS) was observed in three CAR-T patients. Infections of grade ≥3 were reported in 50% of CAR-T and 44% of BsAb recipients. No exacerbation of graft-versus-host disease occurred except in one BsAb recipient. CAR-T and BsAb therapies appear to be feasible, safe and provide deep and durable responses in MM patients with prior allo-HCT.

Incidence of second primary malignancies in patients with multiple myeloma receiving anti-CD38 monoclonal antibodies: A systematic review and meta-analysis.

Anti-CD38 monoclonal antibodies (mAbs) are commonly used for treating newly diagnosed and relapsed/refractory (r/r) multiple myeloma (MM). However, concerns have been raised about the occurrence of second primary malignancies (SPMs) in patients receiving anti-CD38 mAbs. Assessing the safety data for rare adverse events like SPMs is challenging because individual clinical trials are typically focused on the primary endpoint. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) published between January 2005 and April 2022, including patients with newly diagnosed or r/r MM. Our aim was to compare SPM rate with the use of anti-CD38 mAb-based regimens with other anti-myeloma regimens. After a median follow-up of 35.3 months (range: 8.2-56.2), we found that exposure to anti-CD38 mAbs was associated with an increased risk of developing SPMs compared to the control group (6.8% vs. 5.2%; Peto odds ratio [OR]: 1.53 [95% confidence interval (CI): 1.20-1.95]; I2= 0%, p-value for heterogeneity= 0.44). This increased risk was primarily driven by non-melanoma cutaneous cancers (92 vs. 47; Peto OR: 1.77 [95% CI: 1.25-2.51]; I2 = 0%, p-value for heterogeneity = 0.54). However, there was no significant difference in the incidence of solid tumors (including malignant melanoma) (OR: 1.28 [95% CI: 0.85-1.95]) or hematologic SPMs (OR: 1.86; [95% CI: 0.81-4.27]). In conclusion, the use of anti-CD38 mAb-based combination regimens is associated with a higher risk of non-invasive cutaneous SPMs, but not solid tumors or hematologic SPMs. The increased occurrence of non-invasive cutaneous SPMs may be due to enhanced monitoring resulting from longer treatment duration with anti-CD38 mAbs.

Recommendations on prevention of infections during chimeric antigen receptor T-cell and bispecific antibody therapy in multiple myeloma.

Chimeric antigen receptor T (CAR T) cell and bispecific antibody therapies have shown unprecedented efficacy in heavily pretreated patients with multiple myeloma (MM). However, their use is associated with a significant risk of severe infections, which can be attributed to various factors such as hypogammaglobulinemia, neutropenia, lymphopenia, T-cell exhaustion, cytokine-release syndrome and immune-effector cell-associated neurotoxicity syndrome. As these therapies have been recently approved by regulatory agencies, it is crucial to establish practical guidelines for infection monitoring and prevention until robust data from prospective clinical trials become available. To address this issue, a panel of experienced investigators from the Academic Consortium to Overcome Multiple Myeloma through Innovative Trials (COMMIT) developed consensus recommendations for mitigating infections associated with CAR T-cell and bispecific antibody therapies in MM patients.

Concomitant deletion of the short arm (del(1p13.3)) and amplification or gain (1q21) of chromosome 1 by fluorescence in situ hybridization are associated with a poor clinical outcome in multiple myeloma.

BACKGROUND: Chromosome 1 abnormalities in multiple myeloma (MM) are increasingly recognized as high risk-defining features. The authors report the prognostic value of del(1p13.3) by fluorescence in situ hybridization (FISH) at enrollment in subjects treated on total therapy clinical trials 2-6. METHODS: FISH probes were generated from specific BAC DNA clones for the AHCYL1 gene locus (1p13.3) and the CKS1B locus (1q21). RESULTS: A total of 1133 patients were included in this analysis. Although del(1p13.3) was detected in 220 (19.4%) patients, 1q21gain or 1q21amp were observed in 300 (26.5%) and 150 (13.2%) patients, respectively. Concomitant del(1p13.3) with 1q21 gain or amp was observed in 65 (5.7%) and 29 (2.5%) patients, respectively. There was enrichment of high-risk features such as International Staging System (ISS) stage 3 disease and gene expression profiling (GEP)70 high risk (HR) in the group with del(1p13.3). Presence of del(1p13.3) confers inferior progression-free survival (PFS) and overall survival (OS). On multivariate analysis, the presence of ISS stage 3 disease, GEP70 HR, 1q21gain, and 1q21amp were independent predictors of PFS or OS. CONCLUSIONS: The PFS and OS of patients with combined abnormalities of del (1p13.3)/1q21gain or amp was significantly worse compared to del(1p13.3) alone and 1q21gain or 1q21 amp alone, which identifies a subset of patients with poor clinical outcomes.

Clinical efficacy of retreatment of daratumumab-based therapy (D2) in daratumumab-refractory multiple myeloma.

Daratumumab demonstrates activity as a single agent and in combination with either immunomodulatory agents (IMiDs) or proteasome inhibitors (PIs) in relapsed refractory multiple myeloma (RRMM). However, little is known about the benefit of daratumumab retreatment in daratumumab-refractory MM. This study aimed to analyze the clinical efficacy of daratumumab-based retreatment (D2) in patients who are daratumumab refractory MM. Retrospectively, we identified 43 RRMM patients from a single-center database review. The median age was 65 years, 42% patients had high-risk cytogenetics, and 23% had an extramedullary disease, while the median time between D2 and prior daratumumab was 1 (0.25-39) month. All D2 patients received combination therapy with either pomalidomide, carfilzomib, bortezomib, or lenalidomide. The response rate, median progression-free, and overall survival were 49%, 7.97 and 32.6 months, respectively. Our study raises the possibility of re-utilizing daratumumab in combination with different classes of anti-myeloma drugs to generate responses in RRMM patients who are daratumumab-refractory.