Bone marrow Ki-67 index is of prognostic value in newly diagnosed multiple myeloma.

BACKGROUND: Ki-67 is an index of proliferative activity and is an established predictive and prognostic marker in multiple malignancies. However, its prognostic relevance in multiple myeloma (MM) is unclear. We investigated the relationship between Ki-67 expression and survival outcomes in MM in the era of novel therapies. METHODS: We interrogated our database to identify patients with MM, newly diagnosed between July 1, 2013 and December 31, 2020, with Ki-67 expression assessed by immunohistochemistry (IHC) on bone marrow biopsies. Using an established threshold of 5% we defined Ki-67low (≤5%) and Ki-67high (>5%) subgroups for association with progression-free survival (PFS) and overall survival (OS). RESULTS: Of 167 patients included: 53 (31.7%) had Ki-67high and 114 had Ki-67low. More patients with R-ISS 3 had Ki-67high (22.2% vs. 9.7%). The gain of 1q21 was overrepresented in the Ki-67high group (28% vs. 8%). Median PFS in the Ki-67low group was 3.1 years, and in the Ki-67high group 1.6 years (log-rank p < .001, HR: 1.9). Median OS was not reached in the Ki-67low vs. 4.8 years in the Ki-67high cohort (HR: 1.9; log-rank test: p = .018). In the multivariable modeling, after adjusting for other risk factors, HR for Ki-67high versus Ki-67low was 2.4 (p < .001) for PFS and 2.1 (p = .026) for OS. CONCLUSIONS: Our results demonstrate that a high Ki-67 index (>5%) is an independent prognostic marker associated with worse OS and PFS in newly diagnosed MM. IHC staining for Ki-67 on bone marrow biopsies could be easily adopted as a prognostic biomarker for MM in economically constrained healthcare settings.

Teclistamab, a B-cell maturation antigen × CD3 bispecific antibody, in patients with relapsed or refractory multiple myeloma (MajesTEC-1): a multicentre, open-label, single-arm, phase 1 study.

BACKGROUND: There is a need for novel therapies for relapsed or refractory multiple myeloma, and B-cell maturation antigen (BCMA) is a validated target. Teclistamab is a bispecific antibody that binds BCMA and CD3 to redirect T cells to multiple myeloma cells. The aim of the MajesTEC-1 study was to evaluate the safety, tolerability, and preliminary efficacy of teclistamab in patients with relapsed or refractory multiple myeloma. METHODS: This open-label, single-arm, phase 1 study enrolled patients with multiple myeloma who were relapsed, refractory, or intolerant to established therapies. Teclistamab was administered intravenously (range 0·3-19·2 µg/kg [once every 2 weeks] or 19·2-720 µg/kg [once per week]) or subcutaneously (range 80-3000 µg/kg [once per week]) in different cohorts, with step-up dosing for 38·4 µg/kg or higher doses. The primary objectives were to identify the recommended phase 2 dose (part one) and characterise teclistamab safety and tolerability at the recommended phase 2 dose (part two). Safety was assessed in all patients treated with at least one dose of teclistamab. Efficacy was analysed in response-evaluable patients (ie, patients who received at least one dose of teclistamab and had at least one post-baseline response evaluation). This ongoing trial is registered with ClinicalTrials.gov, NCT03145181. FINDINGS: Between June 8, 2017, and March 29, 2021, 219 patients were screened for study inclusion, and 157 patients (median six previous therapy lines) were enrolled and received at least one dose of teclistamab (intravenous n=84; subcutaneous n=73). 40 patients were administered the recommended phase 2 dose, identified as once per week subcutaneous administration of teclistamab at 1500 µg/kg, after 60 µg/kg and 300 µg/kg step-up doses (median follow-up 6·1 months, IQR 3·6-8·2). There were no dose-limiting toxicities at the recommended phase 2 dose in part one. In the 40 patients treated at the recommended phase 2 dose, the most common treatment-emergent adverse events were cytokine release syndrome in 28 (70%; all grade 1 or 2 events) and neutropenia in 26 (65%) patients (grade 3 or 4 in 16 [40%]). The overall response rate in response-evaluable patients treated at the recommended phase 2 dose (n=40) was 65% (95% CI 48-79); 58% achieved a very good partial response or better. At the recommended phase 2 dose, the median duration of response was not reached. 22 (85%) of 26 responders were alive and continuing treatment after 7·1 months' median follow-up (IQR 5·1-9·1). At the recommended phase 2 dose, teclistamab exposure was maintained above target exposure levels, and consistent T-cell activation was reported. INTERPRETATION: Teclistamab is a novel treatment approach for relapsed or refractory multiple myeloma. At the recommended phase 2 dose, teclistamab showed promising efficacy, with durable responses that deepened over time, and was well tolerated, supporting further clinical development. FUNDING: Janssen Research & Development.

Viral, immunologic, and clinical features of primary effusion lymphoma.

Primary effusion lymphoma (PEL) is an aggressive HIV-associated lymphoma with a relatively poor prognosis in the era of effective HIV therapy. Kaposi sarcoma herpesvirus (KSHV) is the etiologic agent, and ∼80% of tumors are coinfected with Epstein-Barr virus (EBV). A better understanding of how KSHV-related immune dysregulation contributes to the natural history of PEL will improve outcomes. Twenty patients with PEL diagnosed between 2000 and 2013, including 19 treated with modified infusional etoposide, vincristine, and doxorubicin with cyclophosphamide and prednisone (EPOCH), were identified. We compared their clinical, virologic, and immunologic features vs 20 patients with HIV-associated diffuse large B-cell lymphoma and 19 patients with symptomatic interleukin (IL)-6 related KSHV-associated multicentric Castleman disease. Survival analyses of treated patients with PEL were then performed to identify prognostic factors and cancer-specific mortality. Compared with HIV-associated diffuse large B-cell lymphoma, PEL was associated with significant hypoalbuminemia (P < .0027), thrombocytopenia (P = .0045), and elevated IL-10 levels (P < .0001). There were no significant differences in these parameters between PEL and KSHV-associated multicentric Castleman disease. Median overall survival in treated patients with PEL was 22 months, with a plateau in survival noted after 2 years. Three-year cancer-specific survival was 47%. EBV-positive tumor status was associated with improved survival (hazard ratio, 0.27; P = .038), and elevated IL-6 level was associated with inferior survival (hazard ratio, 6.1; P = .024). Our analysis shows that IL-6 and IL-10 levels contribute to the natural history of PEL. Inflammatory cytokines and tumor EBV status are the strongest prognostic factors. Pathogenesis-directed first-line regimens are needed to improve overall survival in PEL.

Cost saving, patient centered algorithm for progenitor cell mobilization for autologous hematopoietic cell transplantation.

Administration of plerixafor with granulocyte-colony stimulating factor (G-CSF) mobilizes CD34+ cells much more effectively than G-CSF alone, but cost generally limits plerixafor use to patients at high risk of insufficient CD34+ cell collection based on low peripheral blood (PB) CD34+ counts following 4 days of G-CSF. We analyzed costs associated with administering plerixafor to patients with higher day 4 CD34+ cell counts to decrease apheresis days and explored the use of a fixed split dose of plerixafor instead of weight-based dosing. We analyzed 235 patients with plasma cell disorders or non-Hodgkin's lymphoma who underwent progenitor cell mobilization and autologous hematopoietic cell transplantation (AHCT) between March 2014 and December 2017. Two hundred ten (89%) received G-CSF plus Plerixafor and 25 (11%) received G-CSF alone. Overall, 180 patients (77%) collected in 1 day, 53 (22%) in 2 days and 2 (1%) in 3 days. Based on our data, we present a probabilistic algorithm to identify patients likely to require more than one day of collection using G-CSF alone. CD34+ cell yield, ANC and platelet recovery were not significantly different between fixed and standard dose plerixafor. Plerixafor enabled collection in 1 day and with estimated savings of $5000, compared to patients who did not receive plerixafor and required collection for three days. While collection and processing costs and patient populations vary among institutions, our results suggest re-evaluation of current algorithms.

Summary of the 2019 Blood and Marrow Transplant Clinical Trials Network Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling.

The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Myeloma Intergroup has organized an annual workshop focused on minimal residual disease (MRD) testing and immune profiling (IP) in multiple myeloma since 2016. In 2019, the workshop took place as an American Society of Hematology (ASH) Friday Scientific Workshop titled "Immune Profiling and Minimal Residual Disease Testing in Multiple Myeloma." This workshop focused on 4 main topics: the molecular and immunologic evolution of plasma cell disorders, development of new laboratory- and imaging-based MRD assessment approaches, chimeric antigen receptor T cell therapy research, and statistical and regulatory issues associated with novel clinical endpoints. In this report, we provide a summary of the workshop and discuss future directions.

A Review of Growth Factor Support in Bloodless Autologous Hematopoietic Stem Cell Transplant.

Bloodless autologous hematopoietic cell transplantation is associated with risks of severe bleeding and profound anemia. RBC or platelet transfusions are often used to prevent these hematologic complications. However, in patients such as Jehovah's Witnesses who refuse major blood components, the lack of transfusion support is not an absolute contraindication to an autologous hematopoietic cell transplant. Pennsylvania Hospital performed the world's first bloodless hematopoietic cell transplant more than 15 years ago and has gradually improved its technique with a sizable patient population. Erythropoiesis-stimulating agents were successfully employed as part of their pretransplant regimen to prevent severe anemia. Thrombopoietin agonists' potential role in bloodless transplant is also currently being explored. Although there is limited literature, available reports in combination with physiologic reasoning may support the use of these growth factors to promote transplant success. These agents offer potential benefit and may be of utility in minimizing complications of a bloodless transplant. In this review, we summarize the available literature and offer insight into how we may incorporate growth factors to allow bloodless autologous hematopoietic cell transplantation to be an available option to patients who may otherwise be denied.

Peripheral Immunotype Correlates with Minimal Residual Disease Status and Is Modulated by Immunomodulatory Drugs in Multiple Myeloma.

Data indicate reversal of immune dysfunction with active treatment; however, the precise contribution of specific immune effector and immune suppressor components to achieve a minimal residual disease (MRD) state and immunomodulatory drug-mediated immunomodulatory effects in multiple myeloma (MM) patients remains poorly understood. In this prospective proof-of-principle study we sought to determine the dynamic alterations in natural killer (NK), NK-T, and T cells, including maturation and activating/inhibitory repertoire associated with MRDpos versus MRDneg status after autologous stem cell transplantation (ASCT) and during lenalidomide-based maintenance therapy. Of the 46MM patients enrolled, 36 had bone marrow MRD assessment 60+ days post-ASCT, 30 had longitudinal blood immunotyping during maintenance (pretherapy and after cycles 1, 3, and 6), and 20 had both MRD assessment and longitudinal immunotyping. Multicolor flow cytometry was used for MRD and immunotyping. Although the absolute number of NK cells was significantly lower in patients with MRDpos response, phenotypically NK cells in these patients displayed higher expression of activating receptors KIRDS4 and decreased expression of inhibitory molecules NKG2A compared with the MRDneg group. Furthermore, we observed significantly lower frequencies of T cells displaying KIR3DL1 in MRDpos versus MRDneg patients. Longitudinal immunotyping during lenalidomide maintenance showed loss of mature NK effector function, augmentation of NK-T effector function, and acquisition of PD1 independent anergic state. Our findings also suggest skewing of T cells toward an exhausted state during the maintenance phase in MRDpos patients. Put together, these observations provide a distinctive signature for MRDneg and MRDpos groups. These data support exploration of immune profiling in prospective clinical trials according to MRD-defined responses to identify patients that may benefit from maintenance intensification/modification or maintenance withdrawal.

Summary of the Second Annual BMT CTN Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling.

The second annual Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling was convened on December 7, 2017, at the American Society of Hematology (ASH) meeting. During this workshop, investigators from around the world presented their latest research involving assessment of minimal residual disease (MRD) and immune profiling (IP) in myeloma. This document summarizes the workshop presentations as well as relevant ASH abstracts and focuses on the regulatory issues involved in the integration of MRD and IP assessment in clinical trial design and practice.

Daratumumab, pomalidomide, and dexamethasone as a bridging therapy to autologous stem cell transplantation in a case of systemic light-chain amyloidosis with advanced cardiac involvement.

Systemic light-chain (AL) amyloidosis is a rare hematologic disorder where proteins infiltrate tissues leading to organ failure and death. Cardiac involvement, present in ∼70% of patients, determines stage and prognosis of the disease, with advanced involvement having a median survival of six months. The treatment of light-chain amyloidosis is directed at recovering organ function with therapeutic strategies following those of multiple myeloma with plasma cell-directed therapies. The use of single agent daratumumab has been reported in light-chain amyloidosis achieving rapid and deep responses. The combination of daratumumab, pomalidomide, and dexamethasone (DaraPomD) is particularly interesting for severe AL based on success in multiple myeloma. A 43-year-old female with light-chain amyloidosis and concomitant multiple myeloma presented with severe bowel dysmotility causing abdominal pain, anemia, and a 100-pound unintentional weight loss. A combination of cyclophosphamide, bortezomib, and dexamethasone was initiated but after five cycles her symptoms were progressing and therapy was switched to DaraPomD to optimize response. At the conclusion of two cycles she had achieved an amyloid complete-hematologic response, with her recurring ileus and abdominal pain significantly improved. Additionally, cardiac markers also suggested a rapid response without a common paradoxical worsening of congestive heart failure, and was overall well tolerated. Given the severe symptoms and refractory nature of our patient's disease DaraPomD was reasonable. With the tolerability and response seen, this patient experience supports a formal clinical trial evaluating the safety and efficacy of DaraPomD in light-chain amyloidosis.

Altered cytokine and chemokine profiles in multiple myeloma and its precursor disease.

Currently, no reliable biomarkers are available to predict transformation from smoldering myeloma (SMM) to multiple myeloma (MM). Using an ultrasensitive enzyme-linked immunosorbent assay (ELISA) we assessed the levels of a broad range of cytokines and chemokines in the peripheral blood (PB) and bone marrow (BM) supernatant collected from 14 SMM and 38 MM patients and compared to healthy donors. We found significantly increased levels of key cytokines, in particular CXCL8 (IL-8), associated with progressive disease state (controls→SMM→MM). Cytokine profiles were found similar in PB and BM. Five of fourteen SMM patients (36%) progressed to MM. Our findings, although based on a limited number of patients, suggest that serum-based cytokines may have a future role as biomarkers for disease progression and could potentially be assessed as novel targets for treatment.

Smoldering multiple myeloma: present position and potential promises.

Since smoldering multiple myeloma (SMM) was first described over three decades ago based on a case series of six patients, its definition and our understanding of the entity have evolved considerably. The risk of progression to symptomatic myeloma (MM) varies greatly among individuals diagnosed with myeloma precursor disease. Epidemiologic, molecular, flow cytometric and radiological techniques have demonstrated that this transformation to MM from precursor states is not sudden but rather a continuous overlapping series of events with evidence of end-organ damage that could manifest in the earliest stages of disease. Contemporary antimyeloma therapies can yield rapid, deep, and durable responses with manageable toxicities, and molecular-cell-based measures are now available to rule out minimal residual disease. With this information, clinical studies with correlative measures can now be developed to test the fundamental hypothesis that intervention in early myeloma may provide a measurable clinical benefit to patients by either delaying progression or eradicating plasma cell clones.

Mechanisms and management of CAR T toxicity.

Chimeric antigen receptor (CAR) T cell therapies have dramatically improved treatment outcomes for patients with relapsed or refractory B-cell acute lymphoblastic leukemia, large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma. Despite unprecedented efficacy, treatment with CAR T cell therapies can cause a multitude of adverse effects which require monitoring and management at specialized centers and contribute to morbidity and non-relapse mortality. Such toxicities include cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, neurotoxicity distinct from ICANS, immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, and immune effector cell-associated hematotoxicity that can lead to prolonged cytopenias and infectious complications. This review will discuss the current understanding of the underlying pathophysiologic mechanisms and provide guidelines for the grading and management of such toxicities.

Efficacy of Selinexor in Relapsed/Refractory Multiple Myeloma (RRMM) Patients with del17p and Other High-Risk Abnormalities (A Retrospective Single-Center Study).

Selinexor (Seli) is a first-in-class, oral selective inhibitor of the nuclear export protein, exportin-1 (XPO1). Seli exhibits its antitumor effect through the blockage of XPO1, which increases nuclear retention of tumor suppressor proteins (TSPs), including p53, thereby limiting the translation of oncogenes, triggering cell cycle arrest and the death of malignant cells. Multiple Myeloma (MM) patients with del17p are deficient in TP53 and have a particularly poor prognosis. Given its unique mechanism of action, we investigated whether Seli has increased efficacy in RRMM patients with del17p compared to other high-risk cytogenetics (OHRC). This is an IRB-approved observational study of RRMM patients with high-risk cytogenetics (del17p, t (4;14), t (14;16) or gain 1q) or standard-risk cytogenetics treated at the Levine Cancer Institute (LCI) with a Seli-based regimen between January 2019 and December 2022. Time-to-event endpoints (PFS, OS) were evaluated using Kaplan-Meier (KM) methods. Log-rank tests compared time-to-event endpoints between cohorts [del17p vs. OHRC vs. standard risk]. We identified 40 RRMM patients with high-risk cytogenetics, including 16 patients with del17p and 24 patients with OHRC, as well as 20 with standard-risk cytogenetics. The median age was 62.5 vs. 69 vs. 65.5 years (del17p group vs. OHRC vs. standard risk). The median prior line of therapies was five (range: 3-16) with similar rates of prior autologous stem cell transplant in all arms (68.8% vs. 62.5% vs. 70.0%). The most frequently used regimens were Seli-Pomalidomide-dexamethasone(dex) or Seli-Carfilzomib-dex (Seli-Kd) in the del17p group and Seli-Kd in the OHRC and standard-risk groups. The median time to start the Seli-based regimen after initial MM diagnosis was 5.6 years for the del17p group, 4.1 years in OHRC, and 4.8 years in the standard-risk group. The median follow-up time after the start of the Seli-based regimen was 10.5 months (mos) in the del17p group, 8.4 mos in OHRC, and 10.3 mos in the standard-risk group. In the del17p group, 50% had an objective response, 41.7% in the OHRC, and 35% in the standard-risk group (p = 0.71). Depth of response was also similar across the arms (12.5% vs. 12.5% vs. 10.0% VGPR p = 0.99). The median OS was 10.9 mos in the del17p group, 10.3 mos in the OHRC, and 10.3 mos in the standard-risk group (p = 0.92). The median OS was 15.5 mos for patients who received Seli as a bridging therapy versus 9 mos for Seli use for other reasons rather than as a bridge. Overall, Seli-based regimens showed promising responses even in this heavily pretreated population. Our analysis suggests that Seli-based regimens lead to similar outcomes among RRMM patients with del17p, OHRC, and standard-risk cytogenetics. This contrasts with previously reported outcomes using combinations of novel therapies in this population, where the del17p patients often have a poorer prognosis. Interestingly, our data suggest that Seli is a particularly effective bridging modality for patients preparing for CAR-T cell therapies in our population. Further investigation into this population is warranted, including in earlier lines of therapy, in hopes of seeing a more durable response.

Comparative Efficacy of Talquetamab vs. Current Treatments in the LocoMMotion and MoMMent Studies in Patients with Triple-Class-Exposed Relapsed/Refractory Multiple Myeloma.

INTRODUCTION: Talquetamab, a bispecific antibody targeting GPRC5D × CD3, is approved for the treatment of patients with triple-class -exposed (TCE) relapsed/refractory multiple myeloma (RRMM) on the basis of the results from the phase I/II MonumenTAL-1 trial. The relative effectiveness of talquetamab vs. real-world physician's choice of therapy (RWPC) was assessed using adjusted comparisons. METHODS: An external control arm for MonumenTAL-1 (subcutaneously administered talquetamab 0.4 mg/kg weekly [QW] and 0.8 mg/kg every other week [Q2W]) was created from two observational real-world studies: LocoMMotion and MoMMent. Imbalances in baseline covariates were adjusted using inverse probability weighting. The relative effectiveness of talquetamab vs. RWPC was estimated for overall response rate (ORR), ≥ very good partial response (VGPR), and ≥ complete response (CR); odds ratios and relative response ratios (RRs) were derived from weighted logistic regression. Hazard ratios (HRs) for duration of response (DOR), progression-free survival (PFS), time to next treatment (TTNT), and overall survival (OS) were estimated using a weighted Cox proportional hazards model. RESULTS: After reweighting, baseline characteristics were balanced across cohorts. In adjusted comparisons, patients treated with talquetamab QW (n = 143) had significantly improved outcomes vs. RWPC; RRs were ORR 2.67, p < 0.0001; ≥ VGPR 4.70, p < 0.0001; ≥ CR 78.05, p = 0.0002; and HRs were PFS 0.52, p < 0.0001; TTNT 0.48, p < 0.0001; OS 0.36, p < 0.0001. Patients treated with talquetamab Q2W (n = 145) also had significantly improved outcomes vs. RWPC; RRs were ORR 2.62, p < 0.0001; ≥ VGPR 5.04, p < 0.0001; ≥ CR 101.14, p = 0.0002; and HRs were PFS 0.40, p < 0.0001; TTNT 0.39, p < 0.0001; OS 0.37, p < 0.0001. CONCLUSION: Effectiveness of talquetamab for both schedules was significantly better than RWPC for ORR, ≥ VGPR, ≥ CR, PFS, OS, and TTNT, highlighting its clinical benefit for patients with TCE RRMM. TRIAL REGISTRATION: MonumenTAL-1, ClinicalTrials.gov identifier NCT03399799/NCT04634552; LocoMMotion, ClinicalTrials.gov identifier NCT04035226; MoMMent, ClinicalTrials.gov identifier NCT05160584.

Multiple Myeloma for the Primary Care Provider: A Practical Review to Promote Earlier Diagnosis Among Diverse Populations.

Multiple myeloma is the second most common hematologic malignancy in the United States and the most common hematologic malignancy among Blacks/African Americans. Delay in diagnosis is common and has been associated with inferior disease-free survival and increased rates of myeloma-related complications. Despite a roughly 2-times higher risk of multiple myeloma, diagnostic delay appears more common, and improvements in 5-year survival rates have been slower among Blacks/African Americans than their White counterparts. When patient symptoms and basic laboratory findings are suggestive of multiple myeloma, the primary care provider should initiate extended laboratory work-up that includes serum protein electrophoresis, serum immunoglobulin free light chain assay, and serum immunofixation. Heightened awareness within high-risk populations such as Blacks/African Americans may help to eliminate racial disparities in the diagnosis and treatment of multiple myeloma.

Addressing the disparities: the approach to the African American patient with multiple myeloma.

There are significant disparities with regards to incidence, timely diagnosis, access to treatment, clinical trial participation and health care utilization that negatively impact outcomes for African American patients with multiple myeloma. Health care providers have a role in ameliorating these disparities with thoughtful consideration of historical, sociocultural, individual and disease characteristics that influence the care provided to African American patient population. This review by a group of experts committed to health disparity in multiple myeloma provides a snapshot of disparities at both biologic and non-biologic levels, barriers to clinical care, and best practices to ensure that African American patients receive the best care available.

Retrospective Review of Outcomes of Multiple Myeloma (MM) Patients With COVID-19 Infection (Two-Center Study).

INTRODUCTION: COVID-19 has profound effects on patients with multiple myeloma (MM) mainly due to underlying immune dysfunction and associated therapies leading to increased susceptibility to infections. The overall risk of morbidity and mortality (M&M) in MM patients due to COVID-19 infection is unclear with various studies suggesting case fatality rate of 22% to 29%. Additionally, most of these studies did not stratify patients by their molecular risk profile. METHODS: Here, we aim to investigate the effects of COVID-19 infection with associated risk factors in MM patients and the effectiveness of newly implemented screening and treatment protocols on outcomes. After obtaining institutional review board approvals from each participating institution, we collected data from MM patients diagnosed with SARS-CoV-2 infection from March 1, 2020, to October 30, 2020, at 2 myeloma centers (Levine Cancer Institute & University of Kansas medical center). RESULTS: We identified a total of 162 MM patients who had COVID-19 infection. The majority of patients were males (57%) with a median age of 64 years. Most patients had an associated comorbid condition. Their myeloma disease status and prior autologous stem cell transplant at the time of infection had no impact on hospitalization or mortality. In univariate analysis, chronic kidney disease, hepatic dysfunction, diabetes, and hypertension were associated with an increased risk of hospitalization. In multivariate analysis regarding survival, increased age and lymphopenia were associated with increased COVID-19-related mortality. CONCLUSION: Our study supports the use of infection mitigation measures in all MM patients, and adjustment of treatment pathways in MM patients diagnosed with COVID-19.

Standardizing Clinical Workflow for Assessing Minimal Residual Disease by Flow Cytometry in Multiple Myeloma.

INTRODUCTION: Minimal residual disease (MRD) status is an established prognostic biomarker for patients with multiple myeloma. Commonly used MRD testing techniques such as next generation sequencing or next generation flow cytometry can detect as little as one or two multiple myeloma plasma cells in 106 normal bone marrow cells. Early pull of bone marrow aspirates (BMA), necessary to achieve such level of sensitivity, can be difficult to secure in routine clinical practice due to the competing need for early pull samples for clinical response assessment, therefore introducing the risk of analytical interference during MRD testing. METHODS: To overcome this challenge, we standardized our workflow for collecting specimens by using a technical first pull after needle repositioning for MRD testing. To capture a comprehensive picture of MRD assay performance and specimen adequacy, we tested for MRD on 556 technical first pull bone marrow aspirates by next generation flow cytometry. Among the specimens, several key multiple myeloma treatment milestones were represented: end of induction therapy, two to three months post-autologous stem cell transplant, early and late stages of maintenance therapy. RESULTS: By using the technical first pull bone marrow aspirate, we achieved an analytical assay input of 10 million nucleated cells for 97.5% of specimens. Our analytical sensitivity reached 10-6; (i.e., 10 multiple myeloma plasma cells in 10 × 106 bone marrow cells). Twenty-four percent of specimens were significantly hemodiluted. Low assay input or hemodilution quantifiably lowered the assay sensitivity. CONCLUSION: Specimen adequacy is, therefore, an important metric to incorporate into MRD status reporting.