Rajkumar, S. Vincent

Abstract Introduction Surface proteins in cancer not only reflect tumor–microenvironment interactions but also serve as targets for diagnostic flow cytometry and precision therapies, including monoclonal antibodies and CAR-T cell therapies. A better understanding of plasma cell immunophenotypes could inform flow cytometric prognostic assays and development of targeted therapies. Methods RNA-seq and Seq-FISH data from CD138-enriched bone marrow plasma cells, along with corresponding clinical annotations, were obtained from the Multiple Myeloma Research Foundation-CoMMpass Study. A curated list of surface genes was assembled by integrating three sources: the Human Protein Atlas (plasma membrane and cell junction annotations), the Gene-Set Enrichment Analysis membrane-associated gene set (Ontology:0016020), and the Cell Surface Protein Atlas (validated high-confidence category). A total of 4,579 genes coding for cell surface proteins were identified. Genes below the 25th variance percentile were removed. PCA (≥90% variance) followed by k-means (k=2, silhouette) and confirmed by hierarchical clustering. A Plasma Cell Maturity (PBM) score was computed using singscore on 84 mature plasma cell–associated genes to compare cluster phenotypes. Pathway analysis was done using GSEA software for Hallmark pathways. Clinical biomarkers and survival kinetics were compared between the clusters. Results 761 newly diagnosed patients were included. (Age: 27-93 years, median overall survival/OS: 29 months/mo). Clustering revealed two groups which we termed Atypical/Aggressive Cluster 1 (C1, n=105, 13.8%) and Classical Cluster 2 (C2, n=656, 86.2%), based on the patterns and clinical characteristics. Among non-missing cases, high-risk disease per the International Myeloma Society–International Myeloma Working Group (IMS–IMWG) definition was observed in 27.7% of patients in C2 (n = 552) and 24.7% in C1 (n = 90) (p = 0.4).C1 exhibited enrichment for t(14;16)-MAF (OR = 2.6, 95% CI: 1.1–6.1, p = 0.04) and t(11;14)-CCND1 (OR = 1.7, CI: 1.01–2.8, p = 0.04). In contrast, hyperdiploidy was more common in C2 (OR for C1 = 0.6, CI: 0.4–0.9, p = 0.04). Elevated LDH was observed in C1 (OR = 2.6, CI: 1.6–4, p < 0.001). Median serum Beta-2 microglobulin was lower in C1.(p=0.009) Upregulated genes in C1 in decreasing order of log Fold Change(logFC): AHNAK, MT-ND1, EEF2, EZR, HLA-B, TXNIP, HLA-E, TRIB1, MCL1, RHOB, CD74, CFLAR, HLA-A, HERPUD1, RPSA, ERN1, HSP90AB1, RAPGEF2, ADGRE5, and LAPTM5. Downregulated genes in C1 in descending order of |logFC|: B2M, SDC1 (CD138), HSP90B1, SEL1L, CALR, CANX, PECAM1, SLAMF7, STT3A, TNFRSF17 (BCMA), FCRL5, STT3B, PALM2AKAP2, CD53, PARP1, CCR2, RPN1, CD38, EDNRB, and LMAN2. Upregulated pathways in C1: proliferation (MYC, E2F, PI3K/AKT/mTOR, KRAS, Wnt); evasion of apoptosis (p53, TGF-β, Notch, NF-κB, IL6/JAK/STAT3); Epithelial to Mesenchymal Transition (angiogenesis, apical junction); inflammatory (interferon, TNF-α, complement, IL2/STAT5); metabolic reprogramming (oxidative phosphorylation, lipid/cholesterol); and stress (DNA repair, unfolded protein response). The PBM score for C1 was significantly lower, suggesting a less differentiated phenotype. C1 patients had inferior survival (n = 93, median OS 43.9 mo, p = 0.04) compared to those in the C2 cluster (n = 559, median OS 102.5 mo). Patients in the C1 + IMS–IMWG high-risk status had the shortest survival (20.7 mo), compared to C1+low (50 mo), C2/high (68.3 mo), and C2+low (not reached). In a multivariable analysis, C1 status (HR = 1.93; 95% CI: 1.1–3.4, p = 0.02) was an independent predictor, along with older age (1.05), UAMS70 (1.02), EMC-92 (1.4). In C1, early (<18 mo) progression occurred in 76.3% (n=71) (p < 0.001). In patients receiving first line of treatment(LOT1), median PFS was 39.7 mo in C1vs. 47.3 mo in C2 (p=0.8). Among patients who received stem cell transplant in LOT1, the median survival for the C2 was 102.5 mo, compared to 44.5 mo for C1 (n = 52) (p = 0.01). Among non-SCT patients on Immunomodulator + Proteasome Inhibitor therapy, C1 (n=28) had shorter survival of 50.0 vs. 71.7 C2 (n=137; p =0.8). Conclusion Our transcriptomic analysis identified a higher-risk group of patients (C1) exhibiting downregulation of myeloma specific markers (CD38, CD138, BCMA, SLAMF7, FCRL5) and inferior outcomes. It is important to diagnose and find appropriate therapy for these patients as they don't obtain the same benefit from the current standard of therapy as the remaining patients.

Abstract Background and Significance: Waldenström's Macroglobulinemia (WM) is an indolent B cell disorder characterized by proliferation of clonal lymphoplasmacytic lymphocytes in the bone marrow, lymph nodes, as well as liver and spleen, and secreting a monoclonal IgM Protein. WM is a rare disorder with about 1,700 cases diagnosed in the U.S. each year. There have been significant advances in the management of patients with WM in the last decade, with Bruton's tyrosine kinase (BTK) inhibitors (ibrutinib and zanubrutinib) emerging as a major treatment advancement in this disease. Currently, both BTK inhibitors are approved for the treatment of WM patients with newly diagnosed as well as relapsed/refractory (R/R) disease. BTK inhibitors are effective for the therapy of WM, especially among patients with MYD88 mutation, although the response rates are lower in patients with CXCR4 mutations. In addition, these drugs can cause cardiac side effects such as atrial and ventricular arrhythmias as well as an increased risk of bleeding/bruising. Thus, these drugs can be difficult to use in patients who are older and have cardiac comorbidities. BCL-2 overexpression is well described in a number of B cell malignancies, including WM, leading to inhibition of apoptosis of malignant cells. BCL-2 inhibition with venetoclax has been tested in patients with R/R WM and showed excellent activity with an overall response rate (ORR) of 85% and very good partial response (VGPR) rate of 19%. The therapy was overall well tolerated with no evidence of cardiac toxicity. Given the excellent activity and tolerability of Venetoclax in WM, we are conducting a national cooperative group randomized phase 2 trial comparing ibrutinib+rituximab (IR) vs. venetoclax+rituximab (VR) in patients with newly diagnosed WM. Our hypothesis is that with this trial, we have the potential to develop a more effective therapy targeting BCL-2 for patients with untreated WM, that does not have cardiac or hemostatic toxicity. In addition, we are testing use of a fixed duration therapy with these regimens. Study design and methods: The ongoing clinical trial () is being conducted through the Southwest Oncology Group (SWOG) and is enrolling at multiple SWOG, ECOG, and ALLIANCE centers throughout the US. Major inclusion criteria include 1) newly diagnosed WM confirmed by biopsy and measurable disease (≥0.5 g/dl IgM type paraprotein), 2) meeting WM-related clinical criteria to initiate therapy (cytopenias, B symptoms, bulky lymphadenopathy, neuropathy, hyperviscosity) 3) adequate blood counts (ANC >1000, HGB ≥7.5, PLT ≥50,000), 4) eGFR ≥30 ml/min, 5) adequate liver function tests (total bilirubin ≤1.5 x ULN and AST, ALT and alkaline phosphatase ≤3 x ULN), 6) Zubrod performance status ≤2, 7)prior treatment with single-agent R allowed as long as >6 months prior to registration. Once enrolled the patients will be randomized 1:1 to IR vs. VR. I will be started at 420 mg daily at start of therapy while V will be given at 400mg daily during cycle 1 week 1 and then increased to 800 mg daily from cycle 1 day 8 onwards. R will be given weekly x 4 in cycles 2 and 5. Dose adjustments for both I and V can be done depending on toxicity. Therapy will be given for 2 years and then the patients will be observed off treatment. Patients with disease progression during these 2 years of therapy can cross-over to the other arm. The primary endpoint of the study is rate of VGPR or better. With 41 eligible participants per arm (total N=82), this design has 80% power to reject the null hypothesis of a 25% VGPR rate, given the alternative of a 50% VGPR rate, with a one-sided alpha of 10%. To account for an anticipated 10% ineligibility rate, approximately 46 participants will be accrued per arm (92 total). Current enrollment stands at 15 patients. The secondary end points include ORR, complete response rate, major response rate, progression free and overall survival rates.

Background/Objectives: Family history is a known risk factor for multiple myeloma (MM) and its precursor condition, monoclonal gammopathy of undetermined significance (MGUS). Previous genome-wide association studies (GWASs) have identified 35 common loci associated with MM risk and 21 associated with MGUS. The objective of this study was to identify less common and rare genetic loci predisposing to MM/MGUS through whole-exome sequencing (WES)-based linkage analysis. Methods:Multipoint linkage analysis was conducted using the Multipoint Engine for Rapid Likelihood Inference (MERLIN) with the Lander–Green algorithm on germline WES data from 79 pedigrees with 2 or more affected relatives (120 MM, 86 MGUS, and 21 unaffected). Genome-wide linkage was evaluated using 12,946 independent single-nucleotide variants (linkage disequilibrium r2 < 0.05). Results: Significant linkage was observed at chromosome 6q22.33–q24.2 by the non-parametric model (logarithm-of-odds (LOD) = 3.3) and suggestive linkage by the dominant parametric model (heterogeneity LOD (HLOD) = 2.5). Fourteen rare variants within this region were prioritized using family-specific partial LOD scores and in silico functional prediction tools. Nine of these variants, REPS1, THEMIS, TAAR6, AHI1, VNN1, VNN3, MTFR2/FAM54A, LAMA2, and PHACTR2, overlapped immune-regulatory regions in blood cell lines and were not previously identified in GWASs. Conclusions: This study demonstrates the utility of applying a linkage analysis framework to familial WES data for identifying genomic regions and candidate genes that may contribute to MM/MGUS predisposition. These findings provide new insight into the inherited risk and etiology of familial MM and MGUS.

Multiple myeloma (MM) is consistently preceded by monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). While these precursor conditions are asymptomatic, they are not entirely benign and carry a lifelong risk of progression to MM. Unlike other cancers defined by pathology, malignant transformation from MGUS or SMM to MM has so far relied on demonstration of clinical end-organ damage as morphology and cytogenetics cannot reliably distinguish them. In this study, using genomic data from 374 patients with MGUS or SMM (277 training, 97 validation), to our knowledge, we demonstrate for the first time the ability to identify malignant transformation in MGUS and SMM. We introduce the concept of genomic MM and genomic MGUS to differentiate the subsets of MGUS and SMM that are biologically malignant with genomic features indistinguishable from MM from the subset that is premalignant and unlikely to progress to malignancy. Importantly, we find that most SMM has biological features of malignant transformation indistinguishable from MM. As expected, this subset that we consider having genomic MM is associated with a high risk of progression to MM although some patients remained progression-free beyond 5 years. Conversely, 60% of MGUS and 10% of SMM have no evidence of malignant transformation (genomic MGUS), with no progression during follow-up. Integration of genomic features with the 2/20/20 International Myeloma Working Group model significantly improved the prediction of progression among genomic MM. These findings support the use of genomic criteria to refine the classification and the risk stratification in myeloma precursor conditions.

ABSTRACT Light chain multiple myeloma (LCMM) is a subtype of multiple myeloma (MM) characterized by the exclusive production of immunoglobulin light chains and accounts for 15%–20% of newly diagnosed MM. A comprehensive comparison of LCMM with MM producing intact immunoglobulin (non‐LCMM) remains limited. In this retrospective study, we described distinct clinical and cytogenetic features and assessed long‐term outcomes in 852 LCMM patients diagnosed between 01/01/2004 and 12/31/2022, compared with non‐LCMM controls matched for age, sex, and year of diagnosis. On univariable analysis, LCMM patients were more likely to present with elevated creatinine (> 2 mg/dL), beta‐2‐microglobulin ≥ 5.5 mg/L, elevated LDH, hypercalcemia, t(11;14), del(13q), and t(6;14). Conversely, IMS‐IMWG high‐risk disease, hyperdiploidy, t(4;14), and serum albumin < 3.5 g/dL were less common. On multivariable analysis, elevated creatinine (OR: 5.1, 95% CI: 1.2–27, p = 0.04), t(11;14) (OR: 2.6, 95% CI: 1.3–5.2, p = 0.006), and del(13q) (OR: 4.1, 95% CI: 2.1–8.2, p < 0.001) were independently associated with LCMM, while IMS‐IMWG high‐risk disease (OR: 0.3, 95% CI: 0.1–0.8, p = 0.02) and hyperdiploidy (OR: 0.3, 95% CI: 0.1–0.7, p = 0.002) were less frequent. Despite these differences, progression‐free survival with frontline treatment (HR: 0.97, 95% CI: 0.84–1.11, p = 0.63) and overall survival (HR: 0.99, 95% CI: 0.87–1.13, p = 0.94) were similar between LCMM and non‐LCMM patients. This study highlights the distinct clinical and cytogenetic features of LCMM, marked by higher rates of renal failure, t(11;14), and del(13q), lower prevalence of IMS‐IMWG high‐risk disease, and comparable survival outcomes.

Abstract This retrospective analysis examined 15 years of autologous stem cell transplantation (ASCT) for light chain (AL) amyloidosis at the Mayo Clinic (2010-2024). We aimed to assess ASCT utilization trends, factors influencing practice changes, and current indications amid newer therapies. Four hundred and forty-one ASCTs were divided into cohort 1 (2010-2019) and cohort 2 (2020-2024), revealing a significant ASCT reduction in cohort 2 (385 vs 56, average 71% annual decrease). Cohort 2 patients were older, more likely to have relapsed/refractory disease, and had higher baseline bone marrow plasma cell burden compared to cohort 1. Pre-ASCT induction was more frequent in cohort 2 (89.3% vs 56.4%), with daratumumab (Dara)–cyclophosphamide-bortezomib-dexamethasone (CyBorD) replacing CyBorD as the predominant induction regimen. Lymphoma-based regimens were also more common in cohort 2 (15.1% vs 5.3%, P = .02). Day-100 satisfactory hematological response improved in cohort 2 (91.1% vs 72.7%, P = .001), although hematological complete response rates did not significantly differ (50.9% vs 38.8%, P = .09). In summary, there is a decrease in the utilization of ASCT in AL amyloidosis. This procedure is primarily reserved for patients with suboptimal responses, relapsed/refractory disease, lymphoplasmacytic clones (predominantly immunoglobulin M amyloidosis), or high bone marrow plasma cell burden (myeloma phenotype). This study underscores a significant shift in ASCT practice, driven by novel therapies, emphasizing more personalized management in AL amyloidosis.