17p Deletion Research Articles

Spatially Resolved Transcriptomics Unveils Unique T-Cell Dysfunctional States and Prognostic Gene Expression Signatures in TP53-Mutated Acute Myeloid Leukemia

Introduction Somatic TP53 mutations and 17p deletions with genomic loss of TP53 occur in 8% to 10% of AML and correlate with primary induction failure, high risk of relapse, and dismal prognosis. We have previously shown that TP53 abnormalities are associated with a pro-inflammatory and immunosuppressive tumor microenvironment (TME), including high CD274 and FoxP3 expression, with dysfunctional natural killer (NK)/CD8 + T-cell states and with response to flotetuzumab, a CD123 × CD3 bispecific T-cell engager. In the current study, we explore the cellular neighborhoods of TP53-mutated ( TP53-m) AML using spatially resolved transcriptomics and we employ machine learning to identify prognostic RNA signatures. Methods We analyzed the expression of >1,800 immune and TME genes in bone marrow (BM) formalin-fixed paraffin-embedded (FFPE) sections (5-µm) from a discovery cohort of 11 patients with chemotherapy-naïve AML (N=5 TP53-m and N=6 TP53-wt cases) using the GeoMx™ Digital Spatial Profiling (DSP) platform (Cancer Transcriptome Atlas with next generation sequencing read-out; NanoString Technologies, Seattle, WA). Imaging was performed at 20× magnification and a total of 151 circular regions of interest (ROIs) with a 300-600 µm diameter were selected (Fig. 1A). We then generated a ROI-by-gene count matrix for deconvolution and downstream pathway analysis. For each ROI, enrichment scores reflecting immune senescence/dysfunction and leukemia stemness were calculated with gene set variation analysis (GSVA), using a manually curated compendium of published gene signatures as input. We also employed public bulk and single-cell RNA-sequencing (sc-RNA-seq) AML cohorts for in silico modeling and validation. Results We initially captured transcripts from ROIs of TP53-m and TP53-wt AML with varying degrees of BM infiltration with T cells (CD3 hotspots) and AML blasts, and we found that TP53-m is enriched in T cell-specific, type I/II interferon (IFN) and pro-inflammatory genes ( IL1B), as well as leukemia stem cell (LSC)-related gene programs (LSC17). After dichotomizing ROIs based on a median split of CD3D RNA expression, we observed that T-cell low ROIs express higher levels of monocyte-macrophage and myeloid derived suppressor cell (MDSC)-related genes, including S100A9 and S100A8. These findings point to previously unappreciated links between BM infiltration with immune-modulatory myeloid cell types and leukemia stemness / T-cell abundance. We then tested for differential cell density in neighborhoods (regions of transcriptionally similar cells) across TP53-m and TP53-wt AML using MiloR in a sc-RNA-seq AML dataset annotated by cell type (N=42 cases, of which N=3 with TP53-m; Lasry A, et al. Nat. Cancer 2023). This orthogonal approach highlighted a significantly higher frequency (FDR <0.05) of multipotent and granulocyte-macrophage progenitor neighborhoods in TP53-m AML, alongside suppression of adaptive immune system pathways (Fig. 1B). We next inferred active receptor-ligand pairs mediating the crosstalk between T cells and leukemic blasts in the TME of TP53-m AML, and we uncovered decreased MHC class I/II-mediated signaling, curbed CD8 +/CD4 + T cell-to-AML interactions and enhanced CD6/ CDCP1( CD318) signaling (Fig. 1C). We also found that CD8 + and CD4 + T cells from TP53-m AML are enriched in effector memory (T EM) / terminally differentiated effector memory (T EMRA) and regulatory T-cell gene programs, respectively, compared with their cellular counterparts from TP53-wt patients (Fig. 1D). In particular, T EM cells from TP53-m AML expressed genes known to regulate T-cell dysfunctionality, foremost PRDM1, and transcription factors ( ZEB2) expected to drive the differentiation of killer cell lectin-like receptor (KLR) + exhausted T-cell states with residual cytolytic potential. Finally, we applied the least absolute shrinkage and selection operator (LASSO) statistical method for feature selection to our discovery AML dataset, and we constructed a TP53-m-related ‘spatial metagene’ that predicted poor overall survival in TCGA-LAML (N=170) and Beat-AML2 cases (N=444; Fig. 1E). Conclusions Spatial gene programs of leukemia stemness, T-cell dysfunction and immune suppression are enriched in TP53-m AML. It remains to be determined whether TP53-m AML with a pre-existing but ineffective T-cell response may be amenable to T cell-targeting immunotherapies.

Immune Dynamics Associated with Patient Outcomes Identified By Multimodal Single-Cell Analysis in Multiple Myeloma Patients Receiving Talquetamab Monotherapy

Background: Talquetamab (Tal) is a CD3xGPRC5D bispecific antibody (BiAb) that redirects endogenous T cells to mediate killing of GPRC5D-expressing multiple myeloma (MM) cells. In the recent phase I/II MonumenTAL-1 trial (NCT03399799), Tal showed ≥ 70% response rate when given at the recommended phase 2 doses (RP2D) in heavily pretreated MM patients (Chari A et al., NEJM 2022). However, there is still a need to identify predictive biomarkers and better understand the immune dynamics associated with treatment response and durability with this novel agent. Methods:We identified 30 patients who received Tal monotherapy and had bone marrow (BM) and peripheral blood (PB) samples collected at baseline and PB collected at cycle 3 day 1 (C3D1). Cellular indexing of transcriptomes and epitopes (CITE)-seq was performed to understand transcriptional changes and cell surface proteomics. Total cells were isolated by Ficoll separation from PB and BM samples and were then analyzed separately and only samples of good quality were included in the analysis. Samples were filtered for good quality based on total cell count: at least 1000 cells with more than 500 unique molecular identifiers (UMIs) or genes and less than 4-5 standard deviations above median for UMI, genes and mitochondrial transcripts. A total of 60,851 BM cells (15 pts at baseline) and 299,996 PB cells (23 pts at baseline and 17 pts on C3D1) were analyzed. Downstream analysis was performed using the Seurat R package. All patients included in this study had signed consent for an IRB-approved institutional sub-study (GCO # 18-00456). Results: The 30 patients had a median age of 66.2 years and 57% were female. They received a median of 6 prior lines of therapy, with 83% being triple-class refractory and 50% penta-drug refractory. Only 2 patients were previously treated with anti-BCMA CAR-T cell therapy and none were treated with other BiAbs. 43% of patients had high-risk cytogenetics (including t(4;14), t(14;16) and 17p deletion) and 13% had extramedullary disease at time of initiating therapy. Ten patients (30%) received the recommended phase 2 dose (RP2D) of Tal (0.4 mg/kg weekly or 0.8 mg/kg every other week). Patients were followed for a median of 32.5 months and had a median progression-free survival (PFS) of 6.7 months. 22/30 patients (73%) achieved a partial response (PR) or better, and 14 patients had a short PFS of <150 days. There was no association between the prevalence of different immune cell subsets and depth of response, but rather with PFS. In the baseline BM, a longer PFS was associated with a higher percentage of CD8+ cytotoxic T cells (central memory p=0.00031, effector memory p=0.0022, EMRA p=0.014) and a trend towards higher CD4+ cytotoxic T cells (p=0.072). Of note, we did not find the same associations in the baseline PB samples, which may indicate that the PB may not always reflect the tumor microenvironment in the BM. When we next looked at immune changes in the PB of patients with longer PFS, we found that they exhibited higher percentage of NK cells (p=0.0018 for CD56 low, p=0.04 for CD56 high) and Gamma Delta T cells (p=0.04) at C3D1. Gamma Delta T cells are novel players that warrant further investigation, as they only constitute 1-5% of the T cell repertoire yet are involved in early immune response and do not require major histocompatibility complex (MHC) antigen presentation to function. Profiling of activation and exhaustion markers of these immune subsets is underway. Conclusion: Our findings highlight that the baseline BM immune repertoire and the PB immune changes during Tal treatment may predict long term outcomes. Further in vitro mechanistic studies of T cell function and fitness and validation of these results in independent cohorts will be critical to develop these into predictive biomarkers of long-term response to Tal.

Extended Follow-up and Resistance Mutations in CLL Patients Treated with Acalabrutinib

Background: Covalent Bruton tyrosine kinase inhibitor (cBTKi) is a standard treatment for chronic lymphocytic leukemia (CLL). Understanding of acquired resistance to cBTKi therapy has largely come from data on patients (pts) treated with the first-in-class cBTKi ibrutinib. Mutations in BTK C481 and to a lesser extent PLCG2 are frequently detected in ibrutinib-treated pts at the time of progressive disease (PD). In contrast, much less is known about genetic mechanisms of drug resistance in pts treated with next generation cBTKi acalabrutinib and zanubrutinib. A recent study identified 3 pts with BTK C481 mutations and no pts with PLCG2 mutations among 8 acalabrutinib-treated pts with progressive disease (PD) (Black, et al. Blood 2022). A second study found a kinase-dead BTK L528W mutation in 7/13 zanubrutinib-treated pts (Blombery, et al. Blood Adv 2022). Although cBTKi share the same mechanism of action by binding to BTK C481, the latter report discloses differences in clonal selection and underscores the need for further investigation in pts treated with next generation cBTKi. In a phase 2 study of acalabrutinib in pts with treatment naïve (TN) CLL or small lymphocytic lymphoma (SLL) with 17p deletion, or TP53 or NOTCH1 mutation, or relapsed/refractory (R/R) CLL/SLL regardless of cytogenetics or somatic mutations (Sun, et al. Blood 2020), we sought to understand clonal evolution during treatment. Methods: Peripheral blood mononuclear cells (PBMCs) were collected from 48 pts at baseline, after 6 months, then annually on treatment until PD. Current analysis includes 14 PD pts [excluding 3 Richter transformation (RT) pts] comprising 10 R/R and 4 TN CLL pts. Additionally, paired baseline and PD bone marrow (BM) from 6 pts and lymph node (LN) samples from 2 pts were included. Targeted next-generation sequencing of ~700 recurrently mutated genes in hematological malignancies (Collins, et al. Leuk Lymphoma. 2021) was performed using DNA isolated from CD19 + enriched cryopreserved PBMCs and BM aspirates, as well as fresh-frozen core LN biopsies. Filtered variants in putative CLL driver genes (Knisbacher, et al. Nat Genet. 2022) with variant allele frequencies (VAF) ≥1% for BTK and PLCG2, ≥5% for variants with known oncological significance, and ≥7.5% for all other variants were included in downstream analysis. Results: After a median follow-up of 6.5 years (IQR 2.9-6.3), 23/48 (48%) pts developed PD (20 CLL, 3 RT). PD occurred in 17/32 (53%) R/R pts and 6/16 (38%) TN pts. Median progression-free survival was reached at 6.0 years. Best response was complete remission in 2/20 (10%) pts and partial remission in 18/20 (90%) pts with CLL PD. IGHV was unmutated in all but one PD patient. At baseline, 34 CLL driver genes were mutated in 41/45 pts (91%; excluding 3 RT pts) with most mutations in NOTCH1, TP53, ATM, SF3B1, BIRC3, and NFKBIE. During acalabrutinib treatment but before PD, 14/45 pts (31%; 8 R/R and 6 TN) acquired mutations in 11 driver genes, most commonly in BRAF (n=4), CREBBP (n=4), and KMT2D (n=2). At the time of PD, 11/14 pts (79%) had newly acquired mutations in 4 genes, predominantly BTK (n=6) and PLCG2 (n=4). BTK C481 mutations (VAF 2-42%) were detected in 6/14 (43%; 4 R/R and 2 TN) pts and T474I mutation (VAF 4-46%) in 3/14 (21%; 1 R/R and 2 TN) pts. Paired BM samples in 2 pts and LN samples in 2 pts showed the same BTK mutations as PBMCs with similar VAFs. PLCG2 mutations (VAF 1-8%) were found in 4/14 (29%; 2 R/R and 2 TN) pts. BTK C481 co-occurred with BTK T474I in 3 pts, but on different sequencing reads suggesting independent subclones, and with a PLCG2 mutation in 1 pt. There have been no pts with BTK L528 mutations. In conclusion, mutations in BTK and PLCG2 are the predominant resistance mechanism to acalabrutinib. Among BTK mutations, C481 was the most common. All T474I mutations co-occurred with C481.

Real-World Utilization of Daratumumab in Front-Line Treatment of Newly Diagnosed Multiple Myeloma: A Retrospective Observational Study

Introduction: Daratumumab (DARA), a CD38 monoclonal antibody, has demonstrated remarkable efficacy among newly diagnosed (ND) and relapsed/refractory multiple myeloma (MM) patients. The introduction of a quadruplet therapy with an addition of DARA per the GRIFFIN trial has improved the treatment paradigm. However, the real-world data on treatment patterns and utilization of DARA in front-line treatment are limited. This study aimed to evaluate the real-world utilization of DARA in front-line treatment and examine factors that may impact the utilization of DARA-based regimen in NDMM. Methods: We conducted a retrospective observational study of all patients, age ≥ 18, with clinical MM who were newly diagnosed and treated within the Yale New Haven Health (YNHH) system between August 1, 2020 and August 31, 2022. We manually reviewed clinical presentation, age at diagnosis, gender, race, ethnicity, Revised International Staging System (R-ISS) stage, Eastern Cooperative Oncology Group (ECOG) performance status (PS), insurance type, practice setting, immunoglobulin (Ig) isotype, hemoglobin (Hb), creatinine (Cr), and calcium (Ca) at diagnosis, presence of bone lesion, bone marrow plasma cell (BMPC) %, cytogenetic abnormalities, transplant eligibility, and treatment response based on the International Myeloma Working Group (IMWG) criteria at 3 months after front-line therapy. Descriptive statistics were performed with Pearson's χ²-test using GraphPad PRISM version 9.0.0. Results: We identified 241 patients with NDMM during the study period within the YNHH system. Overall median age at diagnosis was 69 years (interquartile range: 61-78). 60.2% (n=145) were male, 68% (n=164) identified themselves as white and 90% (n=217) as non-Hispanic. 51.9% (n=125) had R-ISS stage II and 65.6% (n=158) had ECOG PS of 0-1. 63.1% (n=152) were treated at a community practice setting and 53.9% (n=130) had commercial insurance. 55.6% (n=134) had IgG isotype and 41.1% (n=99) had unfavorable risk cytogenetics which was defined as a 17p deletion, t(4;14), t(14;16), t(14;20), gain or amplification of 1q, 1p deletion, and chromosome 1 translocations. 28.2% (n=68) received front-line quadruplet therapy: DARA+lenalidomide (LEN)+bortezomib (BORTE)+dexamethasone (DEX) (n=54), DARA+cyclophosphamide+BORTE+DEX (n=10), or DARA+LEN+carfilzomib (CARFIL)+DEX (n=4). 58.5% (n=141) received triplet therapy, 8.3% (n=20) received doublet therapy, 0.83% (n=2) received monotherapy, and 4.1% (n=10) opted for hospice care. 41.5% (n=100) received DARA in front-line treatment: quadruplet as above (n=68), triplet of DARA+LEN+DEX, DARA+BORTE+DEX, or DARA+CARFIL+DEX (n=31), and doublet of DARA+DEX (n=1). Factors including gender (male vs. female, p=0.018), practice setting (academic vs community, p=0.014), R-ISS stage (I vs II vs III vs unknown, p=0.003), Ig isotype (IgG vs IgA vs light chain vs other, p=0.006), cytogenetic abnormalities (standard risk vs unfavorable risk, p=0.02), and transplant eligibility (transplant eligible vs transplant ineligible, p=0.001) were associated with the adoption of DARA in front-line treatment. While 51.7% (n=46) of the patients treated at an academic practice setting received DARA in front-line treatment, only 35.5% (n=54) of the patients treated at a community practice setting received such treatment. 69% (n=69) of those who received DARA-based regimen in front-line treatment achieved at least a very good partial response (VGPR) at 3 months compared to 54.6% (n=77) of those who received non-DARA-based regimen. There were no significant differences in age, race, ethnicity, ECOG PS, insurance type, laboratory data (Hb, Cr, and Ca) at diagnosis, presence of bone lesion, and BMPC % between the group treated with DARA-based regimen and the group treated with non-DARA-based regimen. Conclusion: This analysis of real-world data from patients with NDMM highlighted underutilization of DARA in front-line treatment, especially at a community practice setting. Gender, practice setting, R-ISS stage, Ig isotype, cytogenetic abnormalities, and transplant eligibility were significantly associated with the adoption of DARA in front-line treatment. Additionally, utilization of DARA in front-line treatment was associated with a better treatment response at 3 months, suggesting that interventions to promote the utilization of DARA will help improve outcomes of NDMM patients.

Isatuximab-Based Regimens As Salvage Therapy for Patients with Multiple Myeloma: Sardinian, Multicenter, Retrospective Clinical Practice Experience with 27 Cases Outside of Controlled Clinical Trials

Introduction: Isatuximab (Isa), a humanized monoclonal antibody directed against the surface antigen CD38, has been available in Italy since October 2021 for the treatment of relapsed or refractory Multiple Myeloma (RRMM) in combination with Pomalidomide (P) and Dexamethasone (d) (IsaPd) after two lines of therapy with lenalidomide and a proteosome inhibitor, and from April 2022 in combination with carfilzomib (K) after one line of treatment. Patients eligible for these therapies must not be refractory to Daratumumab. Here, we report preliminary efficacy and safety data for Isatuximab in a Sardinian study of RRMM patients treated with IsaPd and IsaKda as salvage therapy outside of controlled clinical trials. The primary objective of this study was to evaluate the toxicity profile and quality of response to Isatuximab-based regimens administered as salvage therapy in a real-world setting. Methods: The 2 cohorts included 27 patients with RRMM from 4 Sardinian centers who received at least one cycle of IsaPd (16 patients) or IsaKd (11 patients) as salvage therapy between January 2022 and March 2023. Patients received Isa 10 mg/kg IV weekly for the first 4 weeks (wks), then every 2 weeks in combination with Pomalidomide and Dexamethasone (4mg PO days 1-21; 40mg [20mg at > 75 years] PO or IV weekly) every 28 days for the IsaPd regimen. The IsaKd regimen consisted of administration of 10 mg/kg Isatuximab intravenously once weekly in the first cycle, then once every 2 weeks in subsequent cycles. Both arms received Carfilzomib at a dose of 20 mg/m2 on days 1 and then 56 mg/m2 on days 8, 9, 15, and 16 of the first cycle, then 56 mg/m2 on days 1, 2, 8, 9, 15, and 16 in subsequent cycles, while 20 mg of Dexamethasone was administered on days 1, 2, 8, 9, 15, 16, 22, and 23 of each cycle. Results: The median age of the 16 IsaPd-treated patients was 67.5 years (range 48-89 years) and 61 years (range 49-84 years) for the IsaKd population; 44% and 64% were male, respectively (Table 1). The median number of prior therapies was 2 (range 2-4) for the IsaPd and 1 (range 1-4) for the IsaKd cohort; 11 (68.75%) and 9 (82%) received prior autologous stem cell transplantation (ASCT), respectively. Four patients in both populations started treatment because of biochemical relapse, and no refractory patients were recorded in the IsaKd cohort. Three patients (2 in the IsaPd population and 1 in the IsaKd cohort) had creatinine clearance ≤30 mL/min. Among the IsaKd-cohort, 5 (46%) had R-ISS 2 stage and three had a 17p deletion. At the last data collection, 13 cases in the IsaPD population were evaluable for response. The median number of courses administered to date was 4 (range, 1-14). The overall response rate (ORR) was 69%, with 2 stringent complete remissions (sCR) (15%) and 1 very good partial remissions (VGPRs) (7.7%). The median time to first response was 1 month, while the median time to best response was 2 months. In the IsaKd population, 10 patients were evaluable with an overall response rate (ORR) of 100%, with 1 complete remission (sCR) (10%), 1 complete remission (10%), and 5 very good partial remissions (VGPRs) (50%). A median time to first response of 1 month was also recorded in this population, whereas the median time to best response was 3 months. Renal insufficiency and age > 70 years had no significant impact on the likelihood of achieving a response in either population.In the IsaPd cohort, after a median follow-up of 6 months (range 1-14 months), 9 patients discontinued treatment, 7 due to disease progression, 1 due to toxicity, and 1 due to patient choice) Six patients died (5 patients from progressive disease and 1 from secondary acute myeloid leukemia). Common grade 3 or 4 adverse events were fatigue (57%), thrombocytopenia (35%), neutropenia (57%), lymphocytopenia (15.9%), anemia (29%), and infection (21%). Infusion reactions occurred in only 2 patients (12.5%) and were grade 1 or 2 without treatment discontinuation. In the IsaKd population, the median follow-up time was 4 months (range 1-8 months). 1 patient discontinued treatment and died due to disease progression. Grade 3 or 4 adverse events were fatigue (18%), thrombocytopenia (18%), neutropenia (18%), anemia (36%), and infection (63%) No infusion reactions occurred. Conclusions: Despite the limited number of cases, our preliminary real-world data confirm that Isa-based treatment is an effective and safe therapy for RRMM patients, broadly consistent with results from controlled clinical trials.

Seven-Day Vein-to-Vein Point-of-Care Manufactured CD19 CAR T Cells (GLPG5201) in Relapsed/Refractory CLL/SLL Including Richter's Transformation: Results from the Phase 1 Euplagia-1 Trial

Background Despite treatment advances, chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) remain incurable. Patients (pts) with concurrent Richter's transformation (RT) have poor prognoses with limited treatment options. Chimeric antigen receptor (CAR) T-cell products targeting CD19 have shown activity in pts with CLL/SLL or RT, yet data are limited and no therapies are approved. Due to limited treatment options and short survival of pts with RT, rapid treatment delivery is essential. A novel decentralized and automated point-of-care (PoC) manufacturing model was developed to administer fresh, autologous CAR-T treatments within 7 days of apheresis. An update on the Phase (Ph) 1 Euplagia-1 trial of PoC manufactured GLPG5201 is presented. Methods Euplagia-1 (CTIS: 2022-501686-47-00) is a Ph1/2 study of PoC-manufactured GLPG5201 in pts with R/R CLL or SLL, including pts with RT. Pts with CD19+ R/R CLL/SLL with ≥2 prior therapy lines are eligible. Pts with RT are eligible regardless of prior therapy. GLPG5201, an anti-CD19/41BB CAR-T therapy, is administered as a fresh product following fludarabine/cyclophosphamide lymphodepleting chemotherapy. Upon screening, pts receive daily ibrutinib until leukapheresis. The primary objectives are safety and determining a recommended Ph2 dose (Ph1), and objective response rate (ORR; Ph2). Secondary objectives include additional efficacy measures, pharmacokinetics and feasibility of PoC manufacturing. Results As of April 26, 2023, 12 pts were enrolled in Ph1 at dose level (DL) 1 (35×10 6 CAR+ T cells, n=6) or DL2 (100×10 6 CAR+ T cells, n=6) at a single institution. All pts were diagnosed with R/R CLL, 7/12 with concurrent RT. Median age was 66 years (range 58-71); 8/12 pts were male. Median prior lines of therapy were 4 (range 2-10); 10/12 pts received a BTK inhibitor, 9/12 pts venetoclax, and 1 pt an allogeneic stem-cell transplant. Five of 7 pts with RT relapsed after, or were refractory to, R-CHOP. Six of 12 pts had a TP53 mutation, 1 pt had a 17p deletion; 11 pts had an unmutated IGHV status and 2 had a complex karyotype reported. GLPG5201 was manufactured for all pts and administered as a fresh infusion. Median vein-to-vein time was 7 days (range 7-14). Due to lower manufactured CAR+ T cell yield, 3 pts received DL1 instead of the intended DL2. A preserved early memory phenotype for CD4+ and CD8+ CAR T cells was observed in the final product, compared with apheresis starting material ( Figure). Most treatment emergent adverse events (TEAEs) were Grade 1-2; most Grade ≥3 events were hematological ( Table). Six (50%) pts had Grade 1-2 cytokine release syndrome (CRS), with no CRS Grade ≥3. No neurotoxicity was reported. A dose limiting toxicity occurred in 1 pt (Grade 4 neutropenia, DL2), which was manageable and within expectations in this pt population. No unexpected GLPG5201-related toxicities were observed; no deaths occurred while pts were on study. Eleven pts responded to treatment (best ORR 92%). Complete response (CR) was observed for 9 pts (CR rate [CRR] 75%). ORR and CRR were 83% and 67% at DL1, and 100% and 83% at DL2, respectively. All but 1 pt with RT responded (ORR 86%); CR was achieved by 5/7 pts with RT (CRR 71%). One pt with RT was refractory with CD19-negative disease. At the time of analysis, 9/11 (82%) pts had ongoing responses; duration was up to 9 months post-infusion (median follow-up 3.2 months; range 1-9). Two pts progressed after an initial response, 1 pt with CD19-negative disease. Robust CAR T-cell expansion was observed in all pts by qPCR, with a median maximum expansion of 4.4×10 5 copies/µg DNA (C max). Median T max was 14 days (range 9-20 days). Median AUC 0-28d was 5.3×10 6 copies/µg DNA × days. GLPG5201 could be detected in peripheral blood up to 9 months post-infusion. Conclusion Data from 12 pts enrolled in the Ph1 Euplagia-1 study demonstrate that PoC CAR-T manufacturing with a short vein-to-vein time is feasible. GLPG5201 is administered as a fresh product; median vein-to-vein time is 7 days. There are no unexpected safety findings, and no CRS Grade ≥3 or any ICANS are reported. Efficacy data are encouraging, with a 92% best ORR and 75% CRR; 6/7 pts with RT responded. With this novel PoC manufacturing model, an early phenotype of less differentiated CAR T cells is preserved in the final product. GLPG5201 demonstrates rapid in vivo expansion and durable persistence post-infusion . Euplagia-1 is ongoing, and updated data will be presented.

Beyond the Primary: Unveiling the Prognostic Value of Secondary Cytogenetic Abnormalities in Multiple Myeloma

Introduction Fluorescent In-Situ Hybridization (FISH) has been an indispensable tool to characterize the cytogenetic landscape of multiple myeloma (MM), mainly for identifying primary abnormalities such as heavy chain gene (IgH) translocations and odd-number chromosome trisomies. These aberrations play a crucial role in risk stratifying the disease given their correlation with disease aggressiveness, treatment response and overall prognosis. High-risk (HR) cytogenetics are identified through the presence of t(14;16), t(14;20) or loss of the p53 gene locus. Less is known about the prognostic implication of secondary abnormalities, in particular gain of 1q21. We aimed to evaluate the association between primary and secondary cytogenetic abnormalities and their impact on overall survival (OS) in MM patients. Methods We performed a retrospective analysis on a FISH records database from three Mayo Clinic campuses. Cohort included patients >18 years of age, diagnosed with multiple myeloma between 2005 and 2022, with FISH performed within two years of diagnosis. Demographics including age, date of diagnoses and OS data were retrieved from electronic medical records. Statistical analyses were done using BlueSky Statistics software. Study was conducted in accordance with the principles of the Declaration of Helsinki; informed consent was obtained from all participants. Results We analyzed a total of 2221 patients, among which 59.8% were male, with a median age of diagnosis 65 years. Hyperdiploidy was the most prevalent primary cytogenetic abnormality observed in 44.3% of patients, followed by t(11;14) as the most common translocation (23%), and t(4;14) (8.2%). Gain(1q21) was assessed in 925 patients, among which 64%, 30.3% and 5.7% had 2, 3 and ≥4 copies respectively. Furthermore, 11.4% (n=253) exhibited either mutated TP53 or del17p, and 37.8% (n=839) presented with 13q loss or monosomy 13. The median follow-up for the overall population was 102 months (8.5 years), with a median OS of 75.5 months. Patients with high-risk translocations had significantly shorter median OS of 40.01 months compared to 80.65 months for those with standard risk translocations (p <0.001). The presence of ≥4 1q copies was associated with significantly reduced overall survival (2 copies: not reached, 3 copies: 69.4 months, ≥4 copies: 40.1774; p <0.001). This was consistent even when considering the presence of high-risk translocations (Figure 1). To confirm the independent significance of these findings, we performed multivariate Cox regression models, incorporating age at diagnosis, year of diagnosis, gender, presence of hyperdiploid disease, and presence of high-risk translocations. Given that overall survival outcomes were analyzed irrespective of treatment received, we incorporated year of diagnosis as a variable to control for potential impact of evolving treatment regimens over the years. The presence of ≥4 1q copies was associated with reduced OS, with a hazard ratio (HR) of 2.12 (CI: 1.38-3.26; p <0.001). The presence of 3 copies also showed prognostic significance (HR: 1.43; p: 0.012). Similarly, both the presence of TP53mut/mon17 (HR: 1.96, CI: 1.66-2.31; p <0.001) and 13qdel/mon13 (HR: 1.21, CI: 1.08-1.38) were associated with decreased OS. On the other hand, 1p deletion did not have any significant prognostic implications (HR: 1.84, CI: 0.38-1.59; p 0.113). When incorporating all cytogenetic events into a multivariate model, variables associated with reduced OS included age at diagnosis, the presence of both of 3 and ≥4 1q copies, TP53mut/mon17, t(4;14), t(14;16) and t(14;20). However, 13qDel/mon13 lost significance when incorporated with other abnormalities (Table 1). Conclusion Our investigation sheds light on the less explored realm of secondary cytogenetic abnormalities and confirm a strong association between increasing number of 1q copies and reduced overall survival, independent of other cytogenetic abnormalities and treatment regimens. These results underscore the utility of FISH-based comprehensive cytogenetic profiling at baseline, which enables reliable identification of high-risk patients. Future prospective trials should further elucidate the pathogenic mechanism for these findings. Our analysis used OS as primary endpoint and included over 2000 MM patients, reinforcing the clinical relevance of our findings.

Real-World Utilization of Daratumumab-Containing Induction Regimen in Transplant Eligible Newly Diagnosed Multiple Myeloma and Its Role in Patients Historically Excluded from Clinical Trials: A Single Institution Experience

Daratumumab is increasingly being used in the treatment of Multiple Myeloma (MM). However, patients with severe anemia (hgb < 7.5), severe hypercalcemia (serum calcium > 14), creatinine clearance < 30 ml/min, and patients aged > 70 years were excluded from the pivotal clinical trials that investigated first line daratumumab. Here we report how daratumumab is utilized in the treatment of real-world transplant eligible (TE) newly diagnosed multiple myeloma (NDMM) and its safety and efficacy in these vulnerable patient populations. Method: We conducted a retrospective chart review of all adult Multiple Myeloma patients who had autologous stem cell transplant (ASCT) at Vanderbilt University Stem Cell Transplant (VUSCT) program between January 2017 and April 2023. Descriptive statistics was used to summarize patient and disease characteristics. Patients with del 17p, t(4;14), t(14;16), 1q gain and 1p deletion were categorized as high risk. Fisher's exact test and Wilcoxon rank sum test was used to compare variables. Kaplan-Meir curves and log rank tests were used to compare PFS and OS. Binary logistic regression was used to evaluate patient and disease variables associated with daratumumab use. A p-value of <0.05 was considered statistically significant. Result: A total of 508 charts were reviewed. Out of 508, 104 patients had daratumumab containing induction regimen, including 44 patients who took daratumumab starting with the first cycle and 60 patients who had daratumumab added or regimen switched to include daratumumab as part of the induction regimen. Patient, disease, and outcomes of these patients is summarized in table 1. Additional 149 patients received daratumumab post-ASCT during subsequent relapses. Occurrence of relapse was the only variable associated with increased risk of death (HR=4.45, (95% CI: 1.94,10.06) with p-value=0.0003). Having standard cytogenetic risk was associated with decreased utilization of daratumumab in the induction regimen (OR=0.49, (95% CI: 0.27, 0897) with p-value of 0.02). Out of the 104 patients induced with daratumumab, patients who had daratumumab added after the first induction cycle had longer diagnosis to ASCT time when compared with patients who take daratumumab starting from cycle 1 of induction (table 1). Median progression free survival (PFS) and overall survival (OS) was not reached in either group. Among populations of interest, there were 7, 2 African American (AA) and 5 white(W), 5 female (F) and 2 male patients, aged between 54 and 67 years, who had hemoglobin < 7.5 (range: 5.4 -7 g/dL) at diagnosis among the patients who had daratumumab containing induction regimen. All 7 of the patients had improvement in their hemoglobin post-induction and they remain in remission post-ASCT. Their hemoglobin trend is depicted on figure 1. There were 11 TE NDMM patients above age 70 (mean: 74, range: 71-77 years) who received daratumumab containing induction regimen. Although there was no statistically significant difference with the rest of the population, all patients had G3 infection within 30 days of ASCT, but no ICU admission or mortality with follow up of up to 39 months (average 18.45 months). We identified 10 patients with mean age of 53.8 years (range 45-65), 30% F, 40% AA, and 50% high-risk patients who had serum calcium >14 mg/dL. Only 1 patient had daratumumab containing induction regimen. Unfortunately, this patient died of disease progress 3 months after ASCT. Four other patients in this group also died between 3 and 54 months (mean: 18 months) from ASCT. Among 54 patients with creatinine > 2 at diagnosis, 8 patients, aged between 45 and 68 (mean = 58.37) years, mean creatinine of 4.95 (range 2.1-13.05) were induced with daratumumab containing regimen. Average creatinine dropped to 2.15 post-induction and 1.91 at 100 days post-ASCT. Three out of 8 died within 11months of ASCT (mean: 7 months) due to COVID infection in 1standard risk and disease progress in 2 high-risk patients. Conclusion: Inclusion of daratumumab at the onset of induction is associated with shorter time between diagnosis and ASCT. Longer follow up is warranted to determine difference in PFS and OS among patients with early and late incorporation of daratumumab containing induction regimen. Our study suggests that daratumumab containing induction regimen is safe and effective for TE NDMM of all ages, including those with severe anemia and creatinine > 2 mg/dL.

Safety and Efficacy of a Locally Produced Novel Anti-BCMA Chimeric Antigen Receptor T-Cell (CART) (HBI0101) for the Treatment of Relapsed and Refractory Multiple Myeloma

BACKGROUND: Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T-cell (CART) therapy shows remarkable efficacy in patients with relapsed and/or refractory (R/R) multiple myeloma (MM), with recent phase 3 studies showing clear advantage of idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel)over standard-of-care. However, access to these commercial CART products is a major barrier, and it is estimated that only around a quarter of eligible R/R MM patients will receive CART nowadays. HBI0101 is a novel second generation optimized anti-BCMA CART with 4-1BB co-stimulatory domain, that was developed in an academic setting, at Hadassah Medical Center and Bar-Ilan University. The phase Ia study evaluating HBI0101 (NCT04720313) demonstrated a manageable safety profile and an initial high efficacy (Asherie, Haematologica 2022). Here, we present the updated results of 50 patients receiving 800x10^6 CART cells in the NCT04720313 phases 1a-b / 2. METHODS: The phase 1a study with HBI0101 which first evaluated 20 R/R MM patients with ≥3 prior lines of therapy, including a PI, IMiD and anti-CD38 antibody, revealed a dose of 800x10^6 CART cells to be safe and effective. The phase Ib and phase 2 of the study evaluated this dose infusion in 43 additional patients. Inclusion criteria were relatively permissive with minimum creatinine clearance of 20ml/min, platelet count of 30x10 9/ml, left ventricular ejection fraction of 40%, and ECOG performance status of ≤2. Lymphodepletion included fludarabine 25mg/m 2 and cyclophosphamide 250mg/m 2 on days -5 to -3 before infusion (bendamustine 90mg/m 2 and on days -4 and -3 for patients with creatinine clearance <30ml/min). Planned manufacturing time was 10 days. RESULTS: Of 51 patients who underwent lymphocyte apheresis, 50 (98%) were treated with 800x10^6 CART cells; 7 patients in the phase Ia cohort and 43 in the phases 1b / 2 cohorts. HBI0101 production success rate was 100%, with manufacturing time of 10 days for all patients. The median age was 65y (range 40-84). The median number of prior lines was 4 (range 3-13) and most patients (47/50, 94%) were triple refractory to PI, IMiD and anti-CD38 antibody. Twenty patients (40%) were penta-refractory and 10 (20%) were refractory to the anti-BCMA antibody drug conjugate belantamab mafodotin. Forty-six patients (92%) were refractory to the last line of therapy. Twelve patients (24%) had high risk cytogenetics (t(4:14), t(14:16) or deletion 17p); 31 (62%) when 1q gain included. Sixteen patients (32%) had extramedullary involvement at study entry. Grade 3-4 hematological toxicities were common (anemia- 62%, thrombocytopenia- 54%, neutropenia- 98%, lymphopenia- 100%). Cytokine release syndrome (CRS) occurred in 48/50 (96%)- grade 1/2- 17 patients (82%); grade 3- 7 patients (14%). Tocilizumab was used in 40/48 patients with CRS (median of 1 dose, range 1-4) and corticosteroids in 8/48. Two cases of immune effector cell associated neurotoxicity syndrome (ICANS) were observed (grade 1 and 2). Two patients developed CART-associated hemophagocytic lymphohistiocytosis syndrome (HLH). No irreversible organ toxicities or treatment related deaths occurred. The overall response rate (ORR) was 45/50 (90%), including 29 patients (58%) with complete response (CR)/stringent CR, 10 (20%) with very good partial response and 6 (12%) with partial response. Thirty-five patients (70%) achieved minimal residual disease (MRD) negativity at day +30. At a median follow-up of 11.9 months (range: 0.6-19), the median progression-free survival was 10.6 months, and the median overall survival was not reached (Figure 1). Although the presence of extra-medullary disease and prior anti-BCMA therapy correlated with worse outcome, high response rates were still observed (ORR of 98%/75% for patients without/with extra-medullary disease, respectively, and 95%/75% for patients without/with prior anti-BCMA therapy, respectively). Updated results will be communicated at the presentation time. CONCLUSION: Our findings demonstrate the manageable safety and high efficacy profiles of HBI0101 also in high-risk patients. Fast production time enabled the timely treatment of 98% of apheresed patients. These favorable data are encouraging and support decentralization of CART production at an academic setting, ensuring a sufficient CART supply in the light of the increasing demand.

Safety and Efficacy Outcomes for Patients with High-Risk Multiple Myeloma Receiving Idecabtagene Vicleucel: The MD Anderson Experience

Background: There is a paucity of data regarding the impact of high-risk features on the efficacy and safety of B-cell maturation antigen (BCMA)-directed autologous chimeric antigen receptor (CAR)-T therapy in patients with multiple myeloma (MM). Methods: In this retrospective single-center study we included all MM patients who received idecabtagene vicleucel (ide-cel) between 12/2019-10/2022, either in the setting of a clinical trial (i.e. KarMMa-2 and KarMMa-3) or as a standard of care (SOC). We evaluated the impact of high-risk disease features on the efficacy and safety outcomes. Patients with high-risk MM (HRMM) were defined as having at least one of the following: high-risk cytogenetic abnormalities prior to CAR-T infusion (deletion 17p, translocation (t)(4:14), t(14:16) or 1q gain/amplification (1q+)), extramedullary disease (EMD), plasma cell leukemia and Revised International Staging System (R-ISS) stage 3. Minimal residual disease (MRD) was evaluated using 8-color next-generation flow cytometry (NGF), with a sensitivity of 1/10-5 cells (0.001%) based on the acquisition and analysis of at least 2 million events. Efficacy outcomes included response rates, progression free survival (PFS) and overall survival (OS). Safety outcomes included incidence/grade of cytokine release syndrome (CRS), Immune effector cell-associated neurotoxicity syndrome (ICANS), hematological toxicity and infections. Results: A total of 74 patients were included in our analysis, 49 received SOC ide-cel and 25 were treated on clinical trial. The median age was 65.3 (range 37.9-90.3) years, and 49 patients (66%) were male. Median number of previous lines of therapy was 6 (range 1-18). The HRMM group included 52 patients (70%), and the most prevalent high-risk features were high-risk cytogenetic abnormalities (43%, most often 1q+ (n=26, 81%), followed by del17p (n=17, 33%), t(4:14) (n=9, 17%) and t(14:16) (n=4, 8%)) and EMD (19%). Seventy five percent of patients who received SOC ide-cel had HRMM compared to 25% of those who received ide-cel on clinical trial (p=0.014). Compared to patients with standard-risk MM (SRMM), those with HRMM more often had disease refractory to proteasome inhibitors (p=0.042) or anti-CD38 antibodies (p=0.01), and more often received bridging therapy prior to CAR-T infusion (p=0.021). After bridging therapy, 43% of HRMM patients had progressive disease, compared to 20% of SRMM patients (p=0.21). Sixty seven percent of the entire cohort received prior BCMA-directed therapy before ide-cel, without a significant difference between the two risk groups (p=0.80) ( Table 1). For the entire cohort, overall response rate was 85%, and 51% achieved ≥CR at best response. There was no significant difference between the HRMM and SRMM groups in response rates or in rates of MRD negativity at day 30 and at 3/6/9 months after CAR-T infusion, yet fewer HRMM had MRD negativity at 12 months after CAR-T (50% vs. 100% of evaluable patients, p=0.019). The 6-months PFS for the HRMM group and the SRMM group was 64% and 81%, respectively (p=0.11) ( Figure 1A), and the 6-months OS was 80% and 90%, respectively (p=0.067) ( Figure 1B); Thirty-nine patients in the HRMM group developed CRS (83% of evaluable patients), including one grade 3 and one grade 5 CRS, compared to 15 (75%, p=0.65) in the SRMM group (all grade <3). Eight patients in the HRMM group developed ICANS (17%), including two grade 4 ICANS, compared to 3 (15%, p=0.93) in the SRMM group (all grade <3). We did not observe a difference in rates of neutropenia (p=0.63), anemia (p=0.75) or thrombocytopenia (p=0.53) by day 30, and also not in the rates of infection (p=0.16) between the two groups. In multivariate analysis on the entire cohort, receiving <4 prior lines of therapy (HR 0.06, 95% CI 0.004-0.71, p=0.026) and ECOG≤2 (HR 0.07, 95% CI 0.08-0.53, p=0.01) were associated with superior OS. Conclusions: Patients with HRMM receiving ide-cel had mostly comparable response rates compared to those with SRMM. HRMM patients had numerically worse PFS and OS compared to patients with SRMM, though not reaching statistical significance. Overall rates of CRS/ICANS were comparable between the two groups, yet only patients with HRMM had grade ≥3 of these complications. Patients who received ide-cel after less than four previous lines of therapy had better overall survival.

Outcomes of Triple Class Refractory Multiple Myeloma Patients: A Single Center Retrospective Study

BACKGROUND Despite recent advances in the treatment of multiple myeloma (MM), the disease remains incurable. Recent studies suggest that patients who are triple class refractory (TCR) to a proteasome inhibitor (PI), immunomodulatory agent (IMiD), and anti-CD38 monoclonal antibody (mAb) have especially poor outcomes with a median overall survival (OS) of less than 1 year. However, studies with these results have been conducted in large academic institutions. In this study, we retrospectively analyzed outcomes among MM patients with TCR MM in a single clinic specializing in the care of patients with MM. METHODS A retrospective chart review was conducted among patients with TCR MM who were treated in a single clinic specializing in the care of patients with this B-cell malignancy. From July 2003 to July 25, 2022, we determined these patients' progression-free survival (PFS), OS, cytogenetics, lines of prior therapy (LOT), and first treatment they received after they became TCR. Kaplan-Meier analysis was utilized to assess differences in PFS, OS from diagnosis, and OS from TCR status based on high-risk cytogenetics, defined as the presence of t(4;14), t(14;16), t(14;20), 1q gain, or deletion 17p, compared to those with standard-risk cytogenetics. Kaplan-Meier analysis was also used to compare PFS according to number of lines of prior LOT, time to TCR, and drug class used for the first treatment after becoming TCR. RESULTS TCR developed in 121 patients. The median time from diagnosis to development of TCR disease was 33.4 months (mo; range, 1.5-187 mo). Patients with a time to TCR status of > 33.4 months had a longer PFS (median 5.2 mo) compared with patients with a time to TCR status of < 33.4 mo (median 2.5 mo; p=0.0171). The median LOT these patients received was 7 (range, 3-26). The median LOT prior to becoming TCR was 3 (range: 2-12). The median PFS of patients from their first treatment following the development of TCR was 4.5 months; patients with < or > 3 LOT prior to becoming TCR had the same median PFS (4.5 mo). However, PFS was shorter for high-risk (median = 2.5 mo) than standard risk (median = 4.2 mo) TCR MM patients, but this did not reach statistical significance (p = 0.0633). The median OS from diagnosis of MM was 94.8 mo (range, 5.8 - 320.6 mo). Cytogenetic data was available for 65 patients (54%). Of these, 35 (54%) harbored high-risk cytogenetics. The median OS of TCR patients with high-risk cytogenetics from diagnosis was 98.2 mo and was not different from those with standard risk disease (74.2 mo; p = 0.704). Notably, the median OS of patients from the time of development of TCR was 25.5 mo (range, 1.5 - 186.8 mo); OS was shorter (median 18.7 mo) among those TCR patients with high-risk cytogenetics compared with that of standard risk (38.5 mo), but this was not significant (p = 0.1109). The first line of therapy administered following the development of TCR for the majority of patients (n= 108 [89%]) was retreatment with an IMID, PI, mAb, or a combination of agents from these drug classes. Thirteen patients (11%) were treated with a venetoclax- or alkylating agent-based combination therapy. In addition, all except 2 patients received steroids as part of their first treatment after developing TCR. The regimen with the longest PFS was the combination of a mAB and steroids (median 9.0 mo) but only 6 patients were treated with this combination. The shortest PFS was among those retreated with a PI and steroids (n = 15; median 2.4 mo). The use of an IMID with steroids was the most frequently used combination treatment (n=32) with a median PFS of 3.4 mo. CONCLUSION Despite being refractory to a PI, IMID, and mAb, TCR patients in our single-center retrospective study showed a median OS of more than 2 years (25.5 mo) from the development of TCR. This OS is the longest reported to date in this population of MM patients. Cytogenetic differences failed to predict both OS and PFS from the development of TCR. In addition, the number of prior lines of therapy did not predict PFS from their first treatment after showing TCR. The time to development of TCR, however, did predict OS as patients who took longer to become TCR had a longer median OS. The results of this study show that time to becoming TCR is a prognostic factor for this group of patients. Our study shows that OS is considerably longer for patients with TCR than has been previously reported.

Sequential Imaging with Diffusion-Weighted Whole-Body MRI (DW-MRI) and PET-CT Identifies Patients at High Risk of Relapse in Multiple Myeloma

Introduction: Although the vast majority of patients with newly diagnosed multiple myeloma (NDMM) achieve deep responses during first-line therapy, most of them face relapse over time. Focal lesions, which are seen in up to 80% of NDMM, play a crucial role in MM evolution and can act as reservoirs for relapse disease. As a consequence, the combination of imaging- and minimal residual disease (MRD) negativity has been defined as a new response category. However, the dynamics and location of focal lesions during the treatment course remains poorly characterized and the answer to what imaging modality should be used to visualize focal residual disease remains elusive. In this study, we employed two techniques, PET-CT and DW-MRI, at multiple pre-defined time points to longitudinally track resistant lesions and investigate the combined prognostic value of these imaging modalities with other prognostic markers. Methods: We included 170 NDMM patients who were diagnosed between the years of 2010-2015 to ensure sufficient median follow-up time, which was 10 years. Median age of the study cohort was 60 years (range: 34-76), 104 were male (61%), and 31 patients (18%) had high-risk according to gene-expression profiles. All patients underwent PET-CT and DW-MRI evaluation at three pre-defined timepoints: baseline, post autologous stem-cell transplantation (ASCT) and at relapse. Minimal residual disease testing (MRD) by 8 color flow cytometry at a sensitivity level of 10 -5 post ASCT was available for 70 patients. Results: At baseline, 144/170 patients (85%) presented with focal lesions. Both imaging modalities, PET-CT and DW-MRI, showed positive results in 116 patients (68%). However, 21 patients (12%) had focal lesions detectable only by DW-MRI, while 7 patients (4%) showed focal lesions solely in PET-CT. After ASCT, only 12 patients had PET-CT positive lesions, whereas DW-MRI detected focal lesions in 53 patients, indicating a much higher detection rate with DW-MRI. Overall, 55 out of 170 patients (32%) showed residual lesions at this time point. The 26 patients w/o focal lesions in both PET-CT and DW-MRI at baseline remained negative post ASCT. Except for one patient, focal lesions after ASCT were persistent from initial diagnosis. Of note, two-thirds of the patients had residual focal lesions in the humeri and/or femora, which is surprising given that myeloma is considered a disease of the axial skeleton. Next, we correlated the presence of residual lesions with baseline patient characteristics, including age, gender, stage, and cytogenetic risk factors. Compared to patients w/o residual lesions, PET-positive patients showed an enrichment of rISS stage III (7 vs 50%, p<0.001) and deletion 17p (10 vs 33%, p=0.04). In contrast, patients who were DW-MRI positive only showed no significant association with any of the investigated variables. Both PET- and DW-MRI positive lesions post ASCT were associated with poor PFS (median 1.5 and 2.4 years, respectively vs. 9.4 years in imaging-negative patients, p<0.001) and OS (median 3.7 and 5.7 years, respectively vs. 11.3 years, p<0.001). Importantly, in a multivariate model the adverse prognostic effect of residual lesions was independent of baseline risk factors. To increase the power of the following combined imaging/MRD analysis, we defined an “Imaging+” group, which included the patients with PET+ and/or DW-MRI+ focal lesions. Among the 20 patients who achieved MRD-negative and imaging-negative status, an excellent PFS was observed, with only three events occurring in an 8-year follow-up. Residual lesions despite MRD negativity were only seen in two patients, and one of them progressed after 1.5 years. Dismal PFS was seen for double-positive patients (median 1.4 years), significantly worse compared to patients with MRD positivity only (8.9 years). Conclusion: Taken together, DW-MRI captures more patients with prognostically relevant residual focal lesions compared to PET-CT and should therefore be considered as a preferable imaging modality post ASCT. The high number of residual lesions in the extremities suggests a role of humeri and femora as reservoirs for treatment-resistant cells, deserving further investigation. For patients with MRD and imaging double positivity post ASCT, prognosis is dismal and alternate therapeutic approaches should be considered.

Curcumin Enhances Ibrutinib Induced Killing Effect Against TP53-Mutated Chronic Lymphocytic Leukemia Cells in Vitro

Introduction TP53 mutation and del (17p) are the most important poor prognostic factors in patients with Chronic Lymphocytic Leukemia (CLL).Patients with deletion 17p or TP53 mutations tend to have lower response rates to standard first-line chemoimmunotherapy and a more aggressive clinical course(Stilgenbauer et. al. Blood 2014). RESONATE-2 study long-term follow-up showing that ibrutinib continues to demonstrate significant and durable clinical benefit in older patients, including those with TP53 mutation(Barr et. al. Blood Adv 2022).However, CLL bearing del(17p) showed inferior OS and time to next treatment compared to non-del(17p)(Mato et. al. Haematologica 2022). A significant proportion of patients treated with single-agent ibrutinib experienced CLL progression.BTK and/or PLCG2 mutations were present in 80.0% of patients progressing with CLL, confirming prior reports on the high prevalence of these mutations in patients with ibrutinib-resistant CLL(Ahn et. al. Blood 2017). Curcumin is a bioactive natural polyphenol compound extracted from the Curcuma longa(Zingiberaceae plant). Curcumin has anti-tumor effect and can induce apoptosis and inhibit the proliferation of a series of tumor cells(Willenbacher et. al. Int J Mol Sci 2019). Curcumin may limit the development of therapy-related toxicity and reduce the financial burden of treatment.In this study, we found that Curcumin inhibits TP53-mutated CLL cells, and eliciting a strong synergistic cytotoxic effect in combination with ibrutinib. Methods The inhibitory effect of ibrutinib combined with curcumin on the proliferation of TP53-mutated Chronic Lymphocytic Leukemia cells was detected by CCK8, and the apoptosis of TP53-mutated CLL cells induced by ibrutinib combined with curcumin was detected by flow cytometry;The differences of gene and signal pathway expression among different treatment groups were analyzed by RNA-seq ;Using Western blot technology to verify the expression of related pathway proteins and explore the mechanism of curcumin increasing the killing effect of ibrutinib against TP53-mutated Chronic Lymphocytic Leukemia cells. Results The CCK8 results showed that the IC50 of ibrutinib for 24 hours was 40.61±2.35μM, while the IC50 of curcumin for 24 hours was 26.6±0.94μM. The IC50 of ibrutinib for 48 h was 14.6 ±0.8307μM, and the IC50 of curcumin for 48 h was 15.7±2.53μM.Cell inhibition of various group for 48h is shown in Figure 1.The CI of ibrutinib combined with curcumin at 24 hours and 48 hours was calculated by CompuSyn software. The results showed that the CI values of ibrutinib combined with curcumin were less than 1 at 24 h and 48 h, suggesting that ibrutinib combined with curcumin has a synergistic killing effect on CLL cells with TP53 mutation;Flow cytometry showed that the IC50 of ibrutinib for 24 hours was 67.20±2.86μM, while the IC50 of curcumin for 24 hours was 144±6.6 μM. The CI value of ibrutinib combined with curcumin was less than 1 at 24 h, suggesting that ibrutinib combined with curcumin has a synergistic promoting apoptosis on CLL cells with TP53 mutation;RNA-seq analysis and KEGG analysis of down-regulated genes of combination group compared with the control group were mainly enrich in PI3K/AKT, Cytokine-Cytokine Recptor signal pathway and so on;4.The results of Western blot showed that the protein expression levels of P65PI3K and p53 in the single drug group and the combination group were down-regulated in varying degrees, especially in the combination group（Figure 2). Conclusion Ibrutinib combined with curcumin has synergistic killing effect on TP53- mutated CLL cells;Curcumin increases the killing effect of ibrutinib on TP53-mutated CLL cells by inhibiting PI3K and NFκB pathway, and degrading p53mt protein.

Tailor: Interventional Study Evaluating Physician's Choice of Ibrutinib Monotherapy or Ibrutinib-Venetoclax Combination Using Dose Modifications and Alternate Dosing Approaches in Patients with Untreated Chronic Lymphocytic Leukemia

Background: Ibrutinib is a first-in-class Bruton's tyrosine kinase inhibitor (BTKi) that has changed the treatment paradigm for patients with chronic lymphocytic leukemia (CLL) with durable responses and improved overall survival (OS). In the pivotal Phase 3 GLOW and Phase 2 CAPTIVATE trials, fixed-duration combination of ibrutinib-venetoclax (I+V) resulted in deep and sustained clinical responses, and a broadly manageable safety profile in patients with CLL. Several factors including genetic features, disease status, comorbidities, patient preferences, and safety profiles contribute to selection of the optimal therapeutic option for patients with CLL in the first-line setting. Adverse events (AEs), such as atrial fibrillation, bleeding, and hypertension, have been seen with the BTKi therapeutic class.Long-term clinical and real-world experience with ibrutinib has led to specific guidance regarding AE management, which has been included in the updated ibrutinib prescribing information (US PI, May 2022; EU SmPC, April 2023). Retrospective evidence, including post-hoc analyses of clinical trial data, demonstrates that dose reduction of ibrutinib mitigates recurrence or worsening of AEs while preserving efficacy. Thus, these findings together support the rationale to prospectively evaluate the impact of regimen and dosing flexibility of ibrutinib in patients with untreated CLL. Aim: The key objective of the TAILOR study (NCT05963074) is to assess the efficacy and safety of I+V and ibrutinib monotherapy regimens with both a proactive and reactive dose adjustment in patients with untreated CLL. Methods: TAILOR is a phase 2, two-arm, four-cohort interventional study designed to provide physicians the choice of ibrutinib monotherapy or I+V combination therapy for previously untreated patients with CLL and prospectively evaluate proactive and reactive dose adjustment approaches. Eligible patients will have previously untreated active CLL, needing therapy as per iwCLL 2018 criteria. Key exclusion criteria include significant active or history of cardiovascular disease, uncontrolled hypertension, and ECOG performance status > 2. Patients will be randomized after selection of regimen: I+V fixed-duration regimen (2 cohorts, 80 patients in each cohort) or ibrutinib monotherapy (2 cohorts, 80 patients in each cohort), as per physician's choice. Patients in the I+V arm will receive ibrutinib 420 mg QD as lead-in for 3 cycles plus 12 cycles of either ibrutinib 420 mg QD (Cohort 1a) or 280 mg QD (Cohort 1b) in combination with venetoclax, which will be initiated in cycle 4 with dose ramp-up per label over 5 weeks (20, 50, 100, 200, and 400 mg/day) and continued at 400 mg/day dose from cycle 5 onward. In addition, patients with deletion 17p and/or mutated TP53 will receive optional ibrutinib maintenance. Patients in the ibrutinib monotherapy arm will receive ibrutinib 420 mg QD (Cohort 2a) or 420 mg QD for 3 cycles, then 280 mg QD (Cohort 2b) until progressive disease or unacceptable toxicity ( Figure). All cohorts will follow the dose modification guidance as per protocol based on the US PI/ EU SmPC. The primary endpoint is best overall response rate as assessed by investigators and compared with historic controls. Secondary endpoints include: complete response rate, duration of response, PFS, and OS; undetectable minimal residual disease rate (I+V cohorts only); safety (AEs, discontinuation due to AEs, adherence rates); and patient reported outcomes. The study is currently recruiting patients.

Management Patterns and Outcomes for Multiple Myeloma Patients with High-Risk Cytogenetics at an Urban Safety Net Hospital

Background: Over the past decade, there have been tremendous advancements and drug approvals for multiple myeloma (MM). This is especially true with the advent of therapies such as chimeric antigen T-cell receptor therapy (CART). As a result, patients with MM are living longer; with many patients living a decade or longer. However, there is still a small subset of patients with high-risk disease that unfortunately continue to do poorly. High-risk disease based on cytogenetics is defined by disease specific biologic features such as t(4;14), del17p, t(14;16), t(14;20), and gain of 1q. Patients with such features tend not to respond as well to induction therapies and autologous stem cell transplantation as those with standard risk cytogenetics. Here we report a retrospective cohort of patients with high-risk cytogenetics to evaluate patient characteristics, management patterns, and outcomes in an urban safety net hospital. Methods: We performed a retrospective chart review of all patients aged 18 years or older who presented to Harbor-UCLA Medical Center between 2008-2022 with the diagnosis of MM. Patients were included if they were 18 years or older, had MM based on IMWG criteria, and had high risk cytogenetics defined as having one or more of the following abnormalities: t(4;14), del17p, t(14;16), t(14;20), and gain of 1q. Data collected included demographics, induction regimens, transplant status, response, consolidation therapy, progression free survival (PFS) on first line therapy, and overall survival (OS). Results: We identified 28 MM patients with high-risk cytogenetics. The median age at diagnosis was 65, and the cohort was 79% Hispanic, 10% Asian, 7% African American, and 4% Caucasian. 54% of patients were female and 46% were male. Cytogenetic abnormalities were prevalent in the following order: deletion 17p (50%), gain of 1q (29%), t(4;14) (18%), t(14;16) (3%). The most used induction regimen was cyclophosphamide, bortezomib, and dexamethasone (CyBorD) (71%) followed by revlimid, velcade, and dexamethasone (RVD) (25%). Only 32% of patients received autologous stem cell transplantation. The most common drug used in the maintenance setting was velcade (50%). The median PFS for first line treatment in patients with high-risk cytogenetics was 14 months (18.1 months average). The median OS was 29 months (average 37.6 months). Conclusion: In this high-risk patient population, with few resources available, we found that the majority of patients were treated with CyBorD, primarily due to kidney disease or inability to access revlimid upfront. In addition, the majority of patients did not receive autologous stem cell transplantation, which is considered standard of care for upfront management of MM, especially in patients with high-risk cytogenetics. Our centers median PFS for first line treatment was 14 months, which was significantly lower compared to other published data with reported PFS of around 37 months. In addition, our median OS of 29 months was also lower compared to reported OS at other centers of around 60 months. This is most likely due to the low utilization of RVD upfront and transplantation, among other comorbidities that are unique to our population. Further research is needed to characterize real world outcomes and elucidate mechanisms of disparity.

Deletion 1p at Time of Diagnosis of Multiple Myeloma Portends Inferior Outcomes

Background: Multiple myeloma (MM) is associated with several cytogenetic abnormalities (CA) that influence the disease course, response to treatment and survival. Trisomies and immunoglobulin H chain translocations are primary CA while del(17p), gain(1q), del(1p) and others are secondary CA. Gain (3 copies) and amplification (>3 copies) 1q have been recognized as adverse prognostic markers and incorporated into the second revision of the International Staging System (R2-ISS). However, the role of del(1p) is less well defined, especially in the era of modern myeloma therapeutics. We aimed to analyze the outcomes of newly diagnosed MM (NDMM) patients (pts) with chromosome 1 abnormalities, mainly del 1p, treated with autologous hematopoietic cell transplant (AHCT) consolidation at The Ohio State University. Methods: We identified and reviewed the medical records of all NDMM pts who were treated with AHCT from 1/1/2015-2/13/2019 (n=511). High-risk cytogenetics (HRC) was defined by the presence of del(17p), t(4;14), or t(14;16) similar to R-ISS; standard-risk cytogenetics (SRC) were defined as the absence of HRC. Modified HR cytogenetics (mHRC) included gain/amp 1q and/or t(14;20) in addition to HRC, while ultra high-risk (uHRC) included 2 or more mHRC risk factors. Results: The baseline pt characteristics are presented in Table 1. Of 511 pts transplanted, 453 had cytogenetic data from diagnosis. SRC were seen in 353 pts (77.9%), while 100 (22.1%) had HRC, 156 (34.4%) had mHRC, and 43 (9.5%) had uHRC. Thirty-two (7.1%) pts had del(1p) while 105 (23.2%) had gain 1q and 30 (6.6%) had amp 1q. As expected, compared to SRC pts, pts with HRC, mHRC and uHRC had higher risk of relapse or death. Patients with gain and amp 1q had inferior outcomes in terms of PFS (HR 1.35; 95% CI 1.06-1.73, p=0.016), TTNT (HR 1.84; 95% CI 1.40-2.42, p<0.001) and OS (HR 1.47; 95% CI 1.06-2.02, p=0.02), consistent with published literature. The median PFS, TTNT and OS from AHCT in pts with gain/amp 1q was 3.17 years (y), 3.95y and 7.13y, respectively, compared to 4.01y, 7.60y and 8.21y in pts without gain/amp 1q. Pts with del(1p) had inferior PFS (median 2.43y versus 3.98y; HR 1.75; 95% CI 1.16-2.64, p=0.008), TTNT (median 2.72y versus 6.17y; HR 1.96; 95% CI 1.22-3.14, p=0.005) and OS (median 4.11y versus 8.38y; HR 2.19; 95% CI 1.34-3.58, p=0.002) from AHCT compared to those without del(1p). (Figure 1). Conclusions: In this cohort of NDMM pts that underwent AHCT, del(1p) at diagnosis was an independent predictor of shorter PFS, TTNT and OS. Despite advances in induction regimens, AHCT consolidation and maintenance therapy, del(1p) continues to portend inferior outcomes. Larger analyses are needed to validate the prognostic value of del(1p) and investigate its role in predicting outcomes in MM.

BCMA CAR-T-Cell Therapy in Combination with Long-Term Pomalidomide Is a Safe and Effective Treatment for Relapsed/Refractory Multiple Myeloma

Background: B-cell maturation antigen (BCMA)-targeted chimeric antigen receptor T-cell (CAR-T-cell) therapy has exhibited remarkable efficacy in refractory or relapsed multiple myeloma (R/R MM), but recurrence and rapid progression of disease are still observed in some cases within a short time after treatment. Long-term pomalidomide therapy, which potentiates T-cell functionality and has direct antimyeloma effects, might enhance the efficacy of BCMA CAR-T-cell therapy. Here, we present the efficacy of this combination regimen for R/R MM. Methods: We performed a single-center prospective clinical study that was registered with the Chinese Clinical Trial Registration Center (ChiCTR2000036350). Patients with relpased or refractory multiple myeloma receiving BCMA CAR-T cell infusion were randomized to receive long-term pomalidomide treatment (4 mg/day) one month after infusion. The primary endpoint is overall survival (OS) in R/R MM with long-term pomalidomide administration compared to those without pomalidomide therapy after CAR T-cell infusion. The secondary endpoints include time to progression (TTP) and therapeutic response. Also, the copy numbers of CAR were assessed after infusion. Results: A total of 14 R/R MM patients who received BCMA CAT T-cell therapy, were included in this study. The median age of the enrolled R/R MM patients was 59.5 years (44-71). Five patients had high-risk cytogenetic abnormalities (IGH rearrangement, 1q21 amplification, and P53 deletion) at the time of initial diagnosis. In addition, high-risk genetic alterations were newly detected in patient 2 during first-line therapy. All patients had previously received 3 to 6 lines of treatment with proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), or anti-CD38 monoclonal antibodies. As shown in Figure 1, all patients had demonstrated progressive disease prior to CAR T-cell infusion. The objective response rate (ORR) of BCMA-CART was 100%. Three months following CAR-T-cell infusion, of the 6 patients receiving pomalidomide, all patients (6/6) achieved VGPR (very good partial response) or CR (complete response）, while only 5 patients (5/8) who did not receive pomalidomide treatment achieved VGPR or better. At a median follow-up of 19.7 months, for the 8 patients who did not receive pomalidomide administration, the median TTP (time to progression) was 4.5 (1-14) months, while the TTP was not reached in patients who received long-term pomalidomide treatment. Moreover, the dynamic abundance of circulating BCMA CAR-T cells was monitored as shown in Figure 2. In patients who received pomalidomide treatment after CAR-T-cell therapy, the CAR copy numbers of circulating CAR-T cells peaked 8 to 10 days after CAR-T-cell infusion, with a peak copy number of up to 10 6. In addition, BCMA CAR-T cells persisted (>1*10 3 copies/µg DNA) for 3 months in vivo. Without pomalidomide administration, BCMA CAR-T cells persisted for up to 2.5 months in the peripheral circulation (results not shown). Conclusion: Our results confirm the efficacy of the long-term oral pomalidomide administration (4 mg/day) after BCMA CAR T-cell infusion in patients with R/R MM. Notably, this combination regieme reduced the recurrence rate and prolonged progression-free survival for R/R MM patients, providing a promising option for treating R/R MM. In addition, oral administration of pomalidomide did not significantly prolong the persistence of BCMA CAR T-cells in vivo. However, data from studies with larger sample sizes are required to draw valid conclusions.

Impact of Typical and Atypical Complex Karyotype Subgroups on Outcome of AML Patients Undergoing Allogeneic Stem Cell Transplantation

Introduction Acute myeloid leukemia (AML) with a complex karyotype (CKT) confers an adverse prognosis, even within the subgroup of patients (pts) with adverse risk according to European LeukemiaNet 2022 (ELN22) risk stratification. Mrózek et al. further characterized CKT pts according to distinct mechanisms of leukemogenesis into balanced (presence of ≥1 balanced rearrangement), and unbalanced CKT (CKT ub, exclusively unbalanced cytogenetic abnormalities). Considering the high incidence of deletions (del) of 5q, 7q, and 17p in CKT, CKT ub were further divided in typical CKT ub (with latter abnormalities present), and atypical CKT ub (with exclusively other abnormalities). In the context of consolidating chemotherapy, typical CKT ub was associated with shorter event-free survival (EFS) and overall survival (OS) compared to atypical CKT ub. However, we lack data in the context of allogeneic hematopoietic stem cell transplantation (HSCT) which remains the preferred treatment in eligible pts. Here we aimed to investigate this classification in CKT AML pts consolidated by HSCT. Methods We analyzed 263 pts with AML who were classified as ELN22 adverse risk and underwent an allogeneic HSCT. 105 had a CKT, while 158 fulfilled other ELN22 adverse risk criteria. Of the pts harboring a CKT, median age at HSCT was 61 (range 20 - 76) years. Remission status at HSCT was first complete remission with or without count recovery (CR/CRi, 62%) or refractory AML (38%). Conditioning intensity according to EBMT criteria were myeloablative (19%), reduced intensity (31%) or non-myeloablative (50%). Donors were matched related (16%), haploidentical (2%) or matched (65%) or mismatch unrelated (17%).Cytogenetic analyses at diagnosis were performed using standard techniques of banding and in situ hybridization. Pretreatment genomic DNA was screened for genes recurrently mutated in myeloid malignancies using next generation sequencing. Median follow-up alive was 1.3 years. Results Pts with a CKT had a significantly shorter EFS ( P<.01) and OS ( P<.01) than other ELN22 adverse risk pts. Of all pts harboring a CKT, 17% had a balanced CKT, and 83% a CKT ub. Among CKT ub, 85% were classified as typical (67% with del(5q), 49% with del(7q), 26% with del(17p), Figure 1). Comparing typical and atypical CKT ub, pts with typical CKT ub more often had a monosomal karyotype ( P<.01), had more cytogenetic abnormalities (in typical CKT ub median 8 [range 3-39] vs atypical CKT ub median 6 [range 3-9], P=.04), more often TP53 mutations ( P=.02), less often RUNX1 mutations ( P=.03) and a lower LDH at diagnosis ( P=.03). They also had a higher expression of the leukemic stem cell markers CD34+/CD38- ( P=.01) and GPR56 ( P<.01). However, after allogeneic HSCT, EFS ( P=.50) and OS ( P=.50) did not differ between pts with typical and atypical CKT ub (Figure 2). Next, we looked for other adverse prognostic factors within CKT pts receiving HSCT, which in univariate analyses were the presence of a del(5q) (EFS P<.01 and OS P=.03), a del(17p) (EFS P=.10 and OS P=.02), the presence of ≥5 vs <5 cytogenetic aberrations (EFS P=.03 and OS P=.06), a concomitant TP53 mutation (EFS P=.01 and OS P=.01), and a higher age at HSCT (≥60 years, EFS P=.04 and OS P=.08). In contrast, neither the presence of a del(7q) nor a monosomal karyotype impacted EFS or OS within pts with a CKT. In multivariate analyses for CKT pts, the presence of ≥ 5 cytogenetic aberrations (Hazard Ratio. [HR] 1.7, 95% Confidence Interval [CI] 1.0-3.0, P=.05), higher age at HSCT (HR 1.6, 95% Ci 1.1-2.5, P=.02), and no CR/CRi at HSCT (HR 1.7, 95% CI 1.1-2.7, P=.01) were adverse factors for EFS, while the presence of a del(17p) (HR 2.0, 95% CI 1.2-3.4, P=.01), higher age at HSCT (HR 1.8, 95% CI 1.1-3.0, P=.02), and no CR/CRi at HSCT (HR 1.8, 95% CI 1.1-2.9, P=.02) were adverse factors for OS. Conclusion The presence of a CKT retains its negative prognostic impact after HSCT and differentiates within the ELN22 adverse risk group. However, in contrast to chemotherapy consolidation alone, the subgroup of pts harboring a typical CKT ub did not perform worse than pts with an atypical CKT ub, indicating a potential immune-mediated beneficial effect of HSCT. Within pts with a CKT receiving HSCT, we identified additional prognostic factors including the presence of ≥5 cytogenetic aberrations. These pts are in urgent need for novel post HSCT approaches.

Mosaic Chromosomal Alterations and Monoclonal B-Cell Lymphocytosis: Relationship and Risk of Hematologic Malignancies

Background: Monoclonal B-cell lymphocytosis (MBL) is a precursor condition to chronic lymphocytic leukemia (CLL) characterized by the presence of circulating monoclonal B-cell populations in the peripheral blood of otherwise healthy individuals. MBL increases risk of several adverse clinical outcomes, including development of hematological malignancies. Mosaic chromosomal alterations (mCAs) are a form of clonal hematopoiesis which affect large segments of DNA and include gains, losses, and copy number neutral loss of heterozygosity events. mCAs can be detected from SNP-array genotyping. Prior work has suggested mCAs as a potent risk factor for hematological malignancies. However, the nature of the relationship between mCAs and MBL is unknown. We sought to determine 1) the association between mCAs and MBL and 2) their combined effect on risk of hematological malignancies, in a large, prospectively collected, and well-annotated cohort of individuals with known MBL, mCA, and clinical outcomes. Methods: We examined the prevalence of mCA in a cohort of individuals from the Mayo Clinic Biobank who were screened for MBL using a sensitive eight-color flow cytometry assay. We classified MBL by the size of the clone relative to total B-cells, with high count (HC) defined as those individuals who had a percent clonal B-cell count ≥85% out of total B-cell count and low-count (LC) otherwise. Autosomal mCAs were detected from whole blood DNA collected at the time of MBL screening using a SNP-array-based assay. The MoChA pipeline was used to identify mCA events. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CIs). To examine incident hematological cancers, we identified and validated all hematological cancers through medical record abstraction using the International Statistical Classification of Diseases codes. Cox regression was used to calculate hazard ratios (HR) and 95% CIs, stratified by MBL status or autosomal mCA status. All models were adjusted for age and sex. Results: We evaluated the prevalence of autosomal mCA in 3,764 individuals (792 individuals with MBL of whom 64 had HC-MBL and 2,972 without MBL). The prevalence of autosomal mCA was 7.7% ( n=288) with a median mCA cell fraction of 0.09 (range 0.01-1). Among those with and without MBL overall, the prevalence of mCA was 15.5% ( n=123) and 5.6% ( n=165), respectively (Figure 1). Compared to those without an autosomal mCA, individuals with an autosomal mCA were 2.4-fold more likely to have MBL (95% CI 1.9-3.2; P =2.0x10 -11; Figure 1). CLL-associated mCA (i.e., those commonly altered in CLL including trisomy 12 and deletion of 6q, 11q, 13q, and 17p) were present in 42 individuals, of whom 38 (90.5%) had MBL overall and 30 (71.4%) individuals had HC-MBL. Compared to those without a CLL-associated mCA, individuals with a CLL-associated mCA were 539.39-fold more likely to have HC-MBL (95% CI 190.3-1975.9; P <2.0x10 -16) and 6.7-fold more likely to have LC-MBL (95% CI 2.0-26.5; P =0.0031; Figure 1). Next, we evaluated the relationship between MBL and mCA with risk of developing a hematologic malignancy in 3,009 individuals with follow-up data (median 10 years). Forty-one individuals developed an incident hematological malignancy (68.3% lymphoid). When we evaluated the effect of autosomal mCA stratified by MBL status we observed elevated but non-significant risk of hematological malignancies (Figure 2). When we evaluated the effect of MBL stratified by autosomal mCA status we observed elevated and significant increased risk of developing a hematological malignancy (Figure 2). Conclusions: We found that the presence of an autosomal mCA is highly associated with having MBL. In particular, >90% of CLL-associated mCA carriers had MBL with ~7- and ~540-fold increased association for LC- and HC-MBL, respectively. These results suggest that almost all individuals in large biobanks with CLL-associated mCAs have undiagnosed MBL. However, not all individuals with MBL have an mCA. When evaluating risk of hematological malignancies, we found autosomal mCAs had >2-fold elevated but non-significant effects when stratified by MBL status while MBL remained a significant risk factor regardless of autosomal mCA status. Collectively these results support that MBL remains an important risk factor and suggests that mCAs hold potential to identify a subgroup of individuals at greater risk of developing a hematological malignancy.

Impact of Prior Lines of Therapy before Autologous Hematopoietic Cell Transplant on Survival in Standard Risk Multiple Myeloma

Introduction: Patients with standard risk (SR) multiple myeloma (MM), as defined by the absence of high risk cytogenetic abnormalities including immunoglobulin heavy chain (IGH) gene translocations such as t(4;14), t(14;16), t(14;20), deletion of (17p), or gain/amplification(1q), have favorable prognosis and respond well to standard of care induction with plasma-cell directed therapy followed by AHCT consolida-tion and lenalidomide (LEN)-based maintenance. Despite this, it has been noted that a significant proportion of SRMM patients may suffer from early relapse after AHCT, and could potentially benefit form mitigation strategies. The aims of this study were to assess the impact of prior lines of therapy on post-AHCT outcomes in SR MM patients, and then evaluate the role of an augmented LEN-based maintenance regimen in those who did not achieve a complete response (CR) post transplant. Methods: All MM patients who underwent AHCT at our institutions between January 2011 and January 2021 were retrospectively reviewed. Electronic medical charts were searched to collect data on baseline demographic characteristics, disease status, fluorescent in situ hybridization (FISH) cytogenetic studies, blood and bone marrow studies, number of lines of treatments pre-AHCT, as well as maintenance therapy post-transplant. Responses were according to the International Myeloma Working Group (IMWG) criteria. Kaplan Meier method was used for event free survival (EFS) assessment. Results: A total of 293 SR MM patients were included in this analysis, of whom 188, 63, 32 and 10 received 1, 2, 3, and ≥4 lines of therapy pre-AHCT. Despite having comparable CR rates pre-AHCT (28% vs 19% vs 22% vs 10%, respectively; p=0.3), patients with ≥4 prior lines of therapy experienced significantly worse outcomes as determined by shorter mediant EFS of 8.4 months vs 54.5, 55.9 and 21.7 months (P<0.0001) for the 1, 2, and 3 pre-AHCT lines of therapy groups, respectively ( Figure 1A). We then focused on the subgroup of SR MM patients (n=100) who did not achieve a hematologic CR at day-100 post-AHCT. Among them 87 were placed on LEN-monotherapy, and 13 on LEN-based combination maintenance therapy post-AHCT. Of note, none was LEN-refractory. Both the LEN-monotherapy and combination groups had comparable baseline patients and disease characteristics including age (60.5 vs 56 years, p=0.07), time from diagnosis to transplant (≥12 months in 24% vs 30.8%, p=0.7), hematopoietic cell transplantation-specific comorbidity index (HCT-CI) score ( ≥3 in 44% vs 30.8%, p=0.5), male representation (59% vs 69%, p=0.6), white ethnicity (82 vs 77%, p=0.7), international scoring system stages (p=0.9), pre-AHCT number of lines of therapy (p=0.8), and pre-AHCT bone marrow plasma cell percentage (≥10% in 9.5% vs 7.7%, p=0.9), respectively. Kaplan-Meier survival analysis showed a significantly shorter median estimated EFS for the LEN monotherapy group at 38.1 months vs 68.6 months (p=0.03) for the LEN combination maintenance group ( Figure 1B). Conclusion: SR MM constitute heterogenous group of patients with variable outcomes post-AHCT. Those with heavily pretreated disease, that have received four or more lines or therapy, tend to have worse outcomes post transplant, therefore, should be considered for alternative approaches such as chimeric antigen receptor T cell therapies or bispecific agents. For patients who undergo AHCT but do not achieve a CR, LEN-combination maintenance should be strongly considered especially in the setting of relapsed-refractory disease.