Kumar, Shaji

Abstract Although the human genome encodes a vast repertoire of noncoding RNAs that regulate gene expression, the noncoding genome remains underexplored due to technical challenges. Specifically, during transcriptomic sequencing data alignment, the overlap between noncoding and coding loci can create ambiguous read alignments that are subsequently discarded from downstream analysis. For this reason, most of the noncoding genome is excluded from standard genomic annotations used for sequencing alignment. To address this challenge and enable concurrent profiling of the coding and noncoding transcriptome, we systematically integrated standard coding (GENCODE) and noncoding (LncBook) genome annotations, preserving coding gene annotations and removing overlapping noncoding regions. The resulting integrated genome annotation expanded the number of annotated noncoding genes from 40,785 to 138,296 while preserving all coding genes and reducing ambiguous read assignment. To evaluate the utility of our integrated genome annotation for uncovering novel, biologically relevant noncoding RNAs (ncRNAs), we realigned CD138-positive bulk RNA-seq (N = 942) and CD138-negative single-cell RNA-seq (N = 478) data from the MMRF CoMMpass study, generating a comprehensive coding-noncoding atlas of the myeloma bone marrow microenvironment with noncoding genes representing 51% of highly variable genes and displaying significant cell type specificity. Tumor expression profiling based on this integrated profiling identified 15 clusters, including two enriched for amp(1q21) or t(4;14) and associated with shorter progression-free survival (PFS). Differential expression and systematic filtering yielded 19 candidate high-risk ncRNAs, including previously uncharacterized ENSG00000310209 , which was associated with poor PFS (HR = 1.141, P = 0.0025), increased IRF4 activity, Wnt pathway activation, CCL5 signaling, and the accumulation of anergic-like CD8+ T cells. These findings establish integrated coding-noncoding analysis as a strategic approach for discovering functional ncRNAs from transcriptomic sequencing data.

Abstract Background: The phase II and III GRIFFIN and PERSEUS studies evaluated DVRd vs. VRd in NDMM pts that were transplant eligible (TE). These studies included consolidation (cons) and dual agent maintenance (maint) with dara and len (DR). Little is known about the efficacy of DVRd in RW practice including frequency of bor use, use of cons, use of DR maint, and subsequent treatment after progression (PD) on DVRd. We aim to evaluate the RW efficacy of NDMM pts treated with DVRd across the tri-site Mayo Clinic Comprehensive Cancer (MCCC). Methods: We retrospectively analyzed the medical records of pts treated with DVRd between June 2018 and June 2024 at the MCCC. Outcomes were estimated using the Kaplan-Meier method. Results: 464 pts were included; 278 pts were male, and the median (m) age of MM diagnosis was 64 years (yr). 114 pts had ISS III, 205 pts had R-ISS III, 266 pts had high risk (HR) FISH, 80 pts had extramedullary disease, 165 pts had ultra HR disease (dz) (as per 2025 IMS/IMWG consensus), and 47 pts had renal insufficiency (RI) with creatinine >2 mg/dL. Starting len dose was 25mg in 356 pts, 15 mg in 40 pts and ≤10mg in 65 pts. 399 pts received bor 1x per week and 63 2x per week, 91 pts received 1-2 cycles of a different regimen prior to DVRd due to hospitalization (n=23), RI (n=38), poor performance status (n=6), other (n=34). 315 (67.9%) pts underwent autologous transplant (ASCT). The m number of induction cycles was 5; 4 for pts who underwent ASCT and 6 for pts who did not. The best ORR to induction for pts who underwent ASCT was 98% with 247 (79%) achieving ≥VGPR, and 82 (26%) achieving minimal residual disease negativity (MRD-) to at least 10-5. The best ORR for pts who did not undergo ASCT was 87%. For those who underwent ASCT, (96% with melphalan 200mg/m2), the ORR at day 100 was 97% with 56% achieving MRD-. At 1-yr post ASCT, 30% (93/312) were MRD-. 42 pts (13%) received post ASCT cons with DVRd for a m of 2 cycles. 281 pts received post ASCT maint including 107 (38%) len, 53 (19%) bor-len, 91 (32%) dara-len, 14 (5%) dara, 16 (6%) other. 61(13%) pts had change in treatment, due to change to second line therapy (35; 55%), discontinuation (d/c) of len (11; 17%), d/c of dara (3; 5%), d/c of bor (15; 23%), d/c of dex (0; 0%). The m follow-up time for all pts was 26 months (mo) (17-39). The m PFS of pts who underwent ASCT was not reached (NR), and was 57 mo (52-NA) for pts who did not undergo ASCT. For pts who underwent ASCT, the PFS at 24mo for pts who did not have HR FISH was 93% (88-99%) compared to 80% (73-88%) for pts with HR FISH (p=0.12) and 77% (68-87%) for pts with ultra-HR dz (p=0.013).The PFS at 24mo of pts with RI who underwent ASCT was 81% (66-98%) compared to 86% (82-92%) for those without RI, p=0.57. The PFS at 24mo of pts with RI who did not undergo ASCT was 53% (28-100%) compared to 64% (55-75%) for those without RI, p=0.42. The ORR and MRD- rate for pts who received once-weekly bor was 94% and 24%, compared to 94% and 27% for pts who received 2x weekly bor (p=0.85, p=0.93). For pts who underwent ASCT, the PFS at 24mo for pts who received len maint was 91% vs. 83% for pts who receive dual agent maint (DR or VR) (p=0.25), although pts who got dual agent maint were more likely to have HR FISH than pts who received len maint (p<0.001). The PFS at 24mo for pts that received post-ASCT cons was 91% compared to 85% for those that did not (p=0.53); pts who got post-ASCT cons were more likely to have HR FISH (p=0.07). For pts that underwent ASCT, the 3 yr PFS rate is 85% and the 3 yrs OS rate is 96%. For pts that did not undergo ASCT the 3 yrs PFS rate is 60% and the 3 yr OS rate is 85%. 55 pts had functional HR (FHR) MM (relapse within 18 mo) and m PFS for FHR pts who underwent ASCT was 15 mo (11-NA), while m PFS was NR for pts without FHR MM (p<0.001). 79 pts relapsed after 1st line DVRd. The most common 2nd line therapies (tx) were dara-carfilzomib (K)-D, dara-pomalidomide(P)-D, KPD, and other. The m follow-up time from 2nd line tx was 10 mo, the best ORR to 2nd line tx was 76%, and the m PFS with 2nd line tx was 18 mo (7-NA). Conclusion: In this RW analysis, the efficacy and survival outcomes of NDMM pts treated with DVRd was comparable to that reported in the PERSEUS and GRIFFIN trials, although MRD- rates appear lower. DR maint and post-ASCT cons use was not common and was used more frequently in pts with HR FISH. Pts can be effectively salvaged following PD on front-line DVRd with available tx.

Abstract Introduction: Patients (pts) with soft tissue plasmacytomas noncontiguous with bone (true extramedullary disease [EMD]) have poor outcomes with standard therapies shown by low overall response rates (ORRs), which are not durable. Talquetamab (Tal; anti-GPRC5D×CD3) and teclistamab (Tec; anti-BCMA×CD3) are first-in-class bispecific antibodies (BsAbs) approved as monotherapies for triple-class exposed (TCE) relapsed/refractory multiple myeloma (RRMM). Primary analysis from the RedirecTT-1 (NCT04586426) dedicated phase 2 EMD cohort (March 2025 data cut; median follow-up [mFU] 12.6 mo) showed Tal + Tec elicited an ORR of 78.9% (assessed by independent review committee) and a 12-mo progression-free survival (PFS) of 61.0%. Here, we report updated efficacy, using investigator assessment, and safety results from the phase 2 RedirecTT-1 EMD cohort with Tal + Tec. Importantly, we report EMD location and a novel analysis of tumor burden as a prognostic indicator of ORR. Methods: Pts had TCE RRMM and true EMD defined as ≥1 nonradiated soft tissue plasmacytoma noncontiguous with bone ≥2 cm in 1 dimension (with or without paramedullary plasmacytomas). Nonsecretory/oligosecretory disease was permitted. Prior CAR-T and non-BCMA/-GPRC5D BsAb therapies were permitted. Pts received Tal 0.8 mg/kg + Tec 3.0 mg/kg Q2W, preceded by step-up doses, with a permitted switch to monthly dosing at investigator's discretion after cycle 6 or after cycle 4 with confirmed ≥VGPR. Response was assessed per IMWG; EMD response was assessed by PET-CT or MRI whole-body scans. Tumor burden was assessed by total EMD tumor volume. Results: As of July 2025, 90 pts received Tal + Tec, with a median follow-up of 16.3 mo (range 0.5–23.7). Baseline characteristics were as previously reported; 39% had nonsecretory/oligosecretory disease, 20% had prior anti-BCMA CAR-T therapy, and 9% had prior BsAb therapy (all anti-FcRH5). The median number of plasmacytomas was 2 (range 1–7); 17 (18.9%), 29 (32.2%), and 74 (82.2%) pts, respectively, had ≥1 nodal, organ, or soft tissue EMD, while 11 (12.2%) also had ≥1 additional paramedullary plasmacytoma. Of 268 EMDs across all pts, 95 (35.4%) were nodal EMD, 77 (28.7%) were organ EMD (most commonly liver), and 64 (23.9%) were soft tissue EMD; 32 (11.9%) were paramedullary. Baseline EMD tumor volume was <25 cm2in 43 (47.8%) pts, 25–50 cm2 in 21 (23.3%) pts, and >50 cm2 in 26 (28.9%) pts. Per investigator assessment, ORR (95% CI) was 77.8% (67.8–85.9); 50.0% had a ≥CR. Median duration of response (DOR) was not estimable (NE; 12-mo DOR rate, 60.1%), 12-mo PFS was 55.6%, and median overall survival (OS) was NE (12-mo OS rate 73.8%). ORR was 90.7% (77.9–97.4; ≥CR 60.5%) in pts with EMD tumor volume <25 cm2, 66.7% (43.0–85.4; ≥CR 52.4%) for 25–50 cm2, and 65.4% (44.3–82.8; ≥CR 30.8%) for >50 cm2. Common adverse events (AEs) included CRS (77.8%; no grade [gr] 3/4) and neutropenia (72.2%; gr 3/4 62.2%). Taste changes (78.9%), non-rash skin AEs (68.9%), and nail AEs (55.6%) were all gr 1/2, and rash AEs (30.0%) were mostly gr 1/2. ICANS occurred in 11 (12.2%) pts (gr 3, 1.1%; gr 4, 1.1%). Infections occurred in 72 (80.0%) pts (gr 3/4 40.0%), most commonly upper respiratory tract infection (26.7%; gr 3/4 5.6%); IVIG was highly recommended to prevent and manage hypogammaglobulinemia and infection. Ten (11.1%) pts discontinued Tal + Tec due to treatment-emergent AEs (4 pts due to infections and 6 due to gr 5 AEs). Two pts discontinued Tal only due to AEs. In total, 11 (12.2%) pts had gr 5 AEs (6 due to infections), 6 of which were deemed to be drug related by investigators. Data will be updated with an additional 4 mo of follow-up for the presentation. Conclusions: With longer follow-up in pts with TCE RRMM with true EMD regardless of baseline tumor characteristics, Tal + Tec efficacy exceeded all approved therapies, including T-cell redirecting and cellular therapies, noting limitations of cross-study comparisons. Lower total EMD tumor volume was associated with a higher ORR but low pt numbers in each group and lack of statistical testing limits robust interpretation. The safety profile of Tal + Tec was generally consistent with each monotherapy; AEs were not exacerbated with the combination. These data continue to highlight the clinical benefit of the novel combination of Tal + Tec in pts with true EMD, a population with high disease burden and significant unmet need.

Abstract Background The prognostic relevance of fluorescence in-situ hybridization (FISH) abnormalities is well-established in multiple myeloma (MM), where high-risk (HR) abnormalities are associated with poor survival. In AL amyloidosis, however, the cytogenetic landscape and its implications might be different. For example, t(11;14), common in AL amyloidosis, has historically been linked to inferior outcomes in the pre-daratumumab era. HR FISH abnormalities are less common and less well-defined in this setting, underscoring the need to evaluate their significance in this disease. Methods We retrospectively analyzed 698 newly diagnosed AL amyloidosis patients seen at Mayo Clinic, Rochester, between 2012–2021 who had baseline FISH testing. HR FISH was defined as del(17p)/monosomy 17, t(4;14), t(14;16) or t(14;20). Baseline characteristics and treatment patterns were compared between the HR and the standard-risk (SR) groups. Staging used the Mayo 2004 system with European modification. Hematologic responses were assessed at 2 and 6 months, and cardiac/renal responses at 3, 6, 12, and 24 months per consensus criteria. Overall response rate (ORR) for hematologic and organ responses included patients who achieved partial response (PR), very good partial response (VGPR), and complete response (CR). Overall survival (OS) was estimated via Kaplan-Meier; comparisons used log-rank testing. Cox regression was used for univariate and multivariable analyses. Results Among 698 patients, 73 (10.4%) had HR FISH. The most common HR abnormality was t(14;16) (n=34, 4.9%), followed by del(17p)/monosomy 17 (n=21, 3%), and t(4;14)/t(14;20) (n=12 each, 1.7%). Across the cohort, t(11;14) was most frequent (51.3%), followed by del(13q) (36.2%), hyperdiploidy/tetraploidy (26.3%), and 1q gain/amp (23.6%). Compared to SR group, HR FISH group had fewer males (43% vs. 69%, p<0.0001), with no difference in age (62.5 vs. 65, p=0.44), cardiac (73% each, p=1) or renal involvement (52% vs. 54%, p=0.71). More HR patients had early cardiac stage (69% vs. 55.9%, p=0.04). Both groups were predominantly lambda isotype (82% vs. 74%, p=0.15), with similar baseline dFLC (21.6 vs. 28.4 mg/dL; p=0.81). Intact immunoglobulin secretion was more common in the HR group (68% vs. 45%, p=0.004). The HR group more often underwent advanced bone imaging (44% vs. 29%, p = 0.015) and had a higher incidence of lytic lesions or fractures (27% vs. 15%, p = 0.046). Use of bortezomib-based therapy, primarily CyBorD, was similar between the groups (67% each). Daratumumab-based therapy (16% vs. 11%, p=0.25) and autologous stem cell transplantation (ASCT) (33% vs. 25%, p=0.16) were numerically higher in the HR group, though not statistically significant. Post-ASCT maintenance was more frequent in the HR group (17% vs. 7%, p=0.006). At 2 months, hematologic ORR was higher in the HR group (90% vs. 72%, p=0.007), with higher ≥VGPR (67% vs. 32%, p<0.0001) and CR rates (24% vs. 8%, p=0.0004). At 6 months, the HR group maintained higher ≥VGPR (89% vs. 71%, p=0.008) and CR rates (41% vs. 26%, p=0.04), with no difference in ORR (98% vs. 92%, p=0.18). Cardiac responses at 6 months favored the HR group (VGPR or better: 29% vs. 12%, p=0.013; CR: 13% vs. 3%, p=0.007). At 12 months, cardiac ≥VGPR remained higher (50% vs. 29%, p=0.01), though CR was not significantly different (18% vs. 9%, p=0.1). Renal ≥VGPR at 6 months was more common in the HR group (47% vs. 22%, p=0.004), but not renal CR (9% vs. 7%, p=0.95). At 12 months, renal ≥VGPR remained higher in HR (61% vs. 40%, p=0.004). With a median follow-up of 87 months, median OS was not reached in HR (95% CI: 72.6–NR) vs. 88.9 months (95% CI: 72.8–110.5) in SR (p=0.03). In multivariable analysis, age ≥65 (HR 1.56, p=0.0001) and >2 organ involvement (HR 1.46, p=0.002) were associated with worse OS, while ASCT (HR 0.35, p<0.0001) and cardiac stage I/II (HR 0.48, p<0.0001) predicted better OS. HR FISH was not independently associated with OS (HR 0.74, p=0.14). Conclusions HR FISH abnormalities in AL amyloidosis are not independently associated with OS, unlike in MM. Patients with HR FISH abnormalities more often presented with earlier cardiac stage and demonstrated deeper hematologic and organ responses than patients with SR FISH abnormalities. This study underscores how clonal characteristics can potentially aid in more personalized treatment approaches for patients.

Abstract Background Multiple myeloma, the second most common hematologic malignancy, has witnessed incremental progress in its management over the past decade underscored by substantial improvement in patient outcomes, although it remains largely incurable. Due to its relapsing-remitting course with current therapies, patients experience considerable burden, particularly with the use of parenteral regimens that are administered on a continuous basis. As such, exploration of newer oral, finite-duration therapeutic options may be of benefit. Selinexor, an oral selective exportin (XPO)-1 inhibitor has an established synergistic activity with other antimyeloma therapies, including immunomodulatory drugs and proteasome inhibitors. In combination with dexamethasone, selinexor is currently approved at 80 mg twice a week dose, and in combination with bortezomib plus dexamethasone, it is approved at 100 mg once weekly dose for patients with relapsed and/or refractory multiple myeloma (RRMM). Herein, we present the results of Arm B of the 2-arm SCOPE trial that examined an all-oral regimen of selinexor, pomalidomide and low-dose dexamethasone (SPd) regimen for RRMM. Methods The SCOPE trial is an investigator-initiated, single arm, phase 2 study that assessed the efficacy and safety of selinexor (S), 60 mg orally (PO) weekly, pomalidomide (P), 4 mg PO, days 1-21 and dexamethasone (d), 40 mg PO, weekly in 28-day cycles given for a fixed duration (total 18 cycles ) in patients who were exposed to up to 2 prior lines of antimyeloma therapy, at least one of which included both a proteasome inhibitor and the immunomodulatory agent, lenalidomide. Olanzapine, along with a 5-HT3 antagonist comprised the mandatory anti-emetic prophylactic regimen. The trial's primary endpoint was overall response rate (ORR), based on confirmed response, and the key secondary endpoints were progression-free survival (PFS), duration of response (DOR), overall survival (OS), and safety of SPd. The International Myeloma Working Group (IMWG) 2016 criteria were used for response assessment in addition to reporting of the minor response. The distribution of PFS and OS was estimated using the Kaplan Meier method. Toxicity was graded using the Common Terminology Criteria for Adverse Events (CTCAE), version 5. Results At the data cutoff date (May 28, 2025), 28 of 29 enrolled patients with RRMM were evaluable. The median age at study entry was 67.5 years (range: 65-72 years). SPd was used as the first salvage regimen in 21% of patients, and the remaining 79% of patients had previously received 2 lines of therapy at study entry. All patients had previously been exposed to a proteasome inhibitor and an immunomodulatory agent, and 32% were dual refractory. Notably, 64% of patients had previously been exposed to the anti-CD38 monoclonal antibody, daratumumab, and 11% of patients were daratumumab-refractory. The median follow-up was 23.9 months (range: 2.9-38.8 months). The patients had received a median of 9 cycles of SPd (range:1-18 cycles), and at data cutoff, 36% of patients had completed all the planned 18 cycles of SPd. The ORR was 61% (95% CI:41-78) and the rate of measurable residual disease (MRD)-negative complete response (CR) was 21%, CR 11%, very good partial response (VGPR) 18%, partial response (PR) 11% as the best response achieved. Additionally, 7% and 25% of patients had attained a minor response (MR) and stable disease (SD), respectively. The median PFS was 24 months [95% CI: 7.1– not-estimable (NE)] months, and the median DOR was not reached (NR). 2-year OS rate was 93%. The toxicity associated discontinuation rate was 7%, and no grade (Gd) 5 events or unexpected toxicities were encountered during treatment. Gd 3 or higher hematologic toxicities occurred in 43% [Gd 3/4 anemia (11%/0%), thrombocytopenia (14%/0%), neutropenia (25%/7%), lymphopenia (4%/4%)]. Gd 3+ non-hematologic toxicities occurred in 46% [Gd 3 /4 (%) infections (21%/0%), fatigue (4%/0%), nausea (7%/0%) and anorexia (0%/7%). No patients experienced Gd 3 or 4 diarrhea, vomiting or weight loss. Additional data will be presented at the meeting. Conclusion Weekly selinexor in combination with pomalidomide and dexamethasone is an effective and safe, all-oral regimen for patients with RRMM who are previously exposed to a proteasome inhibitor and lenalidomide. SPd regimen is currently being examined in an ongoing phase 3 randomized controlled trial.

Abstract Introduction: Suboptimal response to therapy, early disease relapse, and limited long-term survival remain critical challenges in a substantial number of patients with multiple myeloma (MM). While cross-sectional imaging studies are commonly obtained in clinical practice, only limited information is currently incorporated into risk stratification efforts and clinical decision making. Here, we investigate the use of novel image-based biomarkers to identify patients at high risk for adverse outcomes. Methods: We obtained the pretreatment 18F-FDG PET/CT scans of patients with newly diagnosed MM with available clinical and laboratory data seen at Mayo Clinic between 2006 and 2022. In this analysis, we included 637 patients with detectable metabolic tumor volume on their pretreatment scan. The native DICOM images were pre-processed and subjected to automated image segmentation using nnU-Net (nnU-Net v1.0, inference using a pre-trained hematologic malignancies model). Limitations of this automated segmentation approach include heterogeneity introduced by varying image quality, technical variability in PET reconstruction, and potential inclusion of non-neoplastic FDG-avid lesions in segmented regions. PyRadiomics was used to extract quantitative radiomics features for clinical prediction modeling. We evaluated the predictive power of tumor size-, shape-, and texture-related radiomics features for identifying high-risk disease (advanced ISS stage at diagnosis, the presence of high-risk FISH abnormalities, failure to achieve a stringent complete response [sCR] to first-line therapy by IWMG criteria, and early mortality). All radiomics features were quantile-normalized for downstream modeling. Forward and backward feature selection as well as testing for multicollinearity were used to remove redundant features. Results: Median age at diagnosis of the 637 myeloma patients was 64 years (range 22–90), and 387 patients (61%) were male. After a median follow-up of 4.4 years (95% CI 0.2–11.7), median overall survival (OS) was 7.3 years (95% CI 6.3–8.3). Increased total tumor volume (upper tertile vs lower tertiles), measured by the total tumor surface area, was associated with advanced ISS stage (III vs I+II; OR 1.73, 95% CI 1.24–2.42, p=0.001, n=637). Increased tumor density (dichotomized at the median), measured by the median gray level intensity (OR 1.93, 95% CI 1.94–3.12, p=0.007, n=303), and decreased tumor heterogeneity (lower tertile vs upper tertiles), measured by the variability of gray-level intensities (OR 1.88, 95% CI 1.49–3.12, p=0.012, n=303), were associated with the presence of high-risk cytogenetics. Both increased total tumor volume (4.9% increase per tertile, 95% CI 2.2–7.6, p<0.001, n=600) and tumor density (8.9% increase per tertile, 95% CI 4.5–13.3, p<0.001, n=600) were independently associated with more extensive bone marrow involvement at diagnosis. Increased tumor heterogeneity (upper tertiles vs lower tertile), as measured by rapid changes of gray level intensities, was associated with failure to achieve a stringent complete response to first-line therapy (OR 0.50, 95% CI 0.30–0.82, p=0.006, n=351). Increased tumor volume was associated with shorter OS (HR 1.35 per tertile, 95% CI 1.11–1.63, p=0.002, n=301), independent of age, sex, ISS stage, and the presence of high-risk cytogenetics. A simple additive score consisting of tertiles of total tumor volume, ISS stage, and plasma cell labeling index ≥2% identified patients at risk of mortality within 3 years of diagnosis (OR 2.00, 95% CI 1.40–2.85, p<0.001, n=126), with moderate discrimination (AUC=0.71). Sensitivity analysis demonstrated total tumor volume and texture as most predictive of overall survival in a random forest survival model (C-index 0.712, 95% CI 0.649–0.775) and tumor texture as most predictive of response to therapy in a random forest classification model (C-index 0.693, 95% CI 0.607–0.779). Conclusions: Automated image segmentation and radiomics feature extraction from 18F-FDG PET/CT scans produces biomarkers that capture disease stage, burden, and risk in newly diagnosed MM. Total tumor volume and heterogeneity are strongly associated with important disease characteristics and can be used to identify patients at high risk for therapeutic resistance, early mortality, and inferior long-term outcomes.

Abstract Background Etentamig is a second-generation B-cell maturation antigen (BCMA) x CD3 bispecific antibody that has shown promising efficacy and a favorable safety profile in heavily pretreated patients with relapsed/refractory multiple myeloma (RRMM). Etentamig possesses a unique combination of 2 high-affinity BCMA binding domains, coupled to a low-affinity CD3 binding domain that have been shown to reduce the negative impact of soluble BCMA (sBCMA), decrease risk for cytokine release syndrome (CRS), and drive sustained T-cell activation with reduced immune exhaustion in preclinical models of MM (Blood 2023;142 [suppl 1]:4666). Here, we describe correlative biomarker analyses from Phase 1 (NCT03933735) and Phase 1b (NCT05650632) clinical trials of etentamig in RRMM designed to assess the impact of sBCMA on clinical response and pharmacodynamic changes in proinflammatory cytokines, and T-cell redistribution, activation, proliferation, and exhaustion. Methods Peripheral blood and serum samples from patients with RRMM enrolled in Phase 1 and Phase 1b open-label studies who received etentamig monotherapy were collected at baseline, on treatment, and at disease progression. The Phase 1b study consisted of dose-optimization (DO) and dose-expansion (DE) phases. During DO, patients received a single step-up dose (SUD) of intravenous etentamig (2 or 4 mg) on Cycle (C) 1 Day (D) 1, followed by the target dose of 60 mg on D4. In DE, based on DO findings, patients received the recommended etentamig SUD (2 mg) on C1D1, followed by 60 mg on D4 with modified dexamethasone predosing. Samples were analyzed by flow cytometry for immune cell populations, Luminex® for cytokines, and electrochemiluminescence for sBCMA. Peripheral blood mononuclear cells and bone marrow mononuclear cells (BMMC) at baseline and on-treatment were subjected to single-cell Cellular Indexing of Transcriptomes and Epitopes sequencing (scCITEseq) and single-cell T-cell receptors (scTCR) / B-cell receptors clonality analyses. Results While baseline serum sBCMA levels did not correlate with clinical response to etentamig at the selected dose level of 60 mg every 4 weeks (Q4W) with 2 mg SUD, a reduction in sBCMA levels over time was associated with best International Myeloma Working Group response. Etentamig treatment led to a rapid and transient increase of proinflammatory cytokines and promoted T-cell redistribution, activation, and proliferation. Maximum reduction in peak levels of CRS-related cytokines, including (interleukin [IL]-6, IL-8, IL-10, tumor necrosis factor–a), were observed in DE compared with DO and 60 mg Q4W without SUD. Peak induction levels of proinflammatory cytokines during C1 correlated with occurrence of CRS (≥Grade [G] 1) as well as clinical response across dose levels. A modified dexamethasone premedication schedule of 2 mg/60 mg Q4W cohort for C1 resulted in significantly reduced baseline levels of IL-6 and key macrophage-associated cytokine/chemokines (eg, monocyte chemoattractant protein-1 and macrophage inflammatory protein-3 beta). Incidence of CRS was lowest in the 2 mg/60 mg Q4W cohort (26% G1, 4% G2, 0% ≥G3). Higher T-cell to myeloma cell ratio in BMMCs at baseline correlated with better response to etentamig. scCITEseq and scTCR analysis revealed that at baseline, responders also had greater CD8+ T-cell cytotoxic activities, increased TCR clonality, and elevated inflammatory signatures in T-cells from both peripheral blood and bone marrow. Etentamig at a dosage of 60 mg Q4W resulted in significant clonal expansion of CD8+ effector T-cells and enhanced gene expression signatures related to activation and cytotoxicity in both CD8+ T effector and natural killer cells. Along treatment cycles, responders maintained their T-cell fitness, high clonality, and low T-cell exhaustion levels. Frequency of baseline CD4+ or CD8+ T-cell exhaustion (programmed cell death receptor 1+/ T cell immunoglobulin and mucin-domain containing-3 +) did not impact clinical response at optimal dose level of 2 mg/60 mg Q4W etentamig. Conclusions Responses to etentamig were independent of baseline sBCMA levels and resulted in rapid and transient proinflammatory cytokine production that promoted robust T-cell redistribution, activation, and proliferation indicating that the optimal dose of etentamig (2 mg/60 mg Q4W) maximizes its clinical potential as a convenient, safe, and effective therapy for MM.

Abstract Cyclin D1, encoded by CCND1, is a cell cycle regulator, overexpressed in ~15% of multiple myeloma (MM) cases via CCND1::IGH super-enhancer juxtaposition through t(11;14). Cyclin D1 also plays a non-canonical role in transcriptional regulation, but in t(11;14) MM its function in gene regulation remains undefined. We investigated the global transcriptional and epigenomic consequences of CCND1overexpression in t(11;14) MM. To define a CCND1 signature, RNA-seq from two independent primary MM patient cohorts, CoMMpass and Mayo, was utilized to compare high CCND1 t(11;14) cases (≥300 transcripts-per-million [TPM], n=271) vs. low CCND1 hyperdiploid cases (<30 TPM, n=233). Two CCND1 knockout (KO) clones in t(11;14) MM U266B1 were also generated by CRISPR/Cas9, introducing a frameshift insertion (A) after chr11:69641478 (hg38) in exon 1. ATAC-seq and ChIP-seq (H3K4me3, H3K4me1, and H3K27ac) were performed in duplicates, and RNA-seq in triplicates in U266B1 wild-type (WT) and KO. Libraries were sequenced on Illumina NextSeq 2000 (2x51 bp for ChIP/ATAC, 2x150 bp for RNA-seq). Reads were mapped to hg38 by BWA (ChIP/ATAC) or STAR (RNA-seq), peaks called by MACS2 (FDR< 0.01), peak and gene raw counts estimated by featureCounts. Differential peaks (fold-change ≥1.5) and differentially expressed genes (fold-change ≥2) were identified by edgeR (FDR<0.05), including peaks detected in ≥2 samples and genes with TPM ≥0.1 in ≥1 sample. Interactions between promoters and distal regulatory regions were identified using publicly available chromatin interaction data in blood cell types. Pathway analysis was performed using Enrichr. Co-immunoprecipitation was performed in t(11;14) KMS12BM cells. Differential analysis comparing CCND1-high t(11;14) and CCND1-low MM cases in the two patient cohorts identified 21 upregulated and 21 downregulated genes associated with CCND1 expression which were also captured in the wild-typevs. CCND1 KO U266 cells. Enriched pathways (p<0.05) included Notch signaling, early/late estrogen response, epithelial-mesenchymal transition and reduced mitotic spindle and myogenesis. Dysregulated genes included those related to apoptosis, ubiquitin-proteosome, extracellular matrix, adhesion, and immune response, demonstrating a broader role for cyclin D1 in MM beyond cell cycle control. To explore the epigenomic basis of this transcriptional regulation, for each of the 42 differentially expressed genes we examined the changes of histone marks and chromatin accessibility in promoter and the interacting distal regulatory regions in the U266 KO model. Ten of the 21 genes upregulated in CCND1-high (downloaded in KO; e.g., argininosuccinate synthase 1 [ASS1], PMAIP1, MYEOV, CCR7, and DTX1) and 12 of the 21 genes downregulated in CCND1-high (upregulated in KO; e.g., UACA, RASAL2, PTPRZ1, PPT2, and IL23R) showed concordant changes in histone marks and/or chromatin accessibility, predominantly in distal regulatory regions, suggesting a chromatin-mediated mechanism of gene regulation by cyclin D1. The most prominent changes involved H3K27ac, a mark defining active enhancers. As H3K27ac is deposited by histone acetyltransferases CBP, we tested for the possible cyclin D1-CBP interaction. Co-IP confirmed this interaction, suggesting a role for this complex in chromatin remodeling and transcriptional control in t(11;14) MM. One gene notably upregulated in association with CCND1 is ASS1, which encodes a urea cycle enzyme responsible for endogenous arginine synthesis. Metabolomic studies demonstrated KO cells had elevated aspartate and citrulline and lowered arginine and ornithine compared to WT cells (p<0.01) demonstrating impaired urea cycle function. Further, KO cells displayed significantly reduced ASS1 protein expression, cell growth and S-phase entry compared to WT cells in arginine-replete conditions, with both WT and KO cell types further inhibited by arginine depletion (p<0.05). Together, a cyclin D1-associated gene signature was identified supporting its role in t(11;14) MM beyond the CDK4/6 mediated cell cycle control, including a role in metabolic plasticity and survival under arginine depleted conditions. These findings highlight cyclin D1 as a therapeutic vulnerability and open new avenues for personalized treatment strategies.

Abstract Background Measurable residual disease (MRD) negativity post- autologous stem cell transplantation (ASCT) in newly diagnosed multiple myeloma (MM) is associated with favorable outcomes and may overcome the adverse impact of high-risk cytogenetic abnormalities (HRCAs). However, as the definition of high risk evolves and MRD emerges as a key endpoint, understanding its prognostic value within individual HRCAs is critical for treatment guidance. Methods We retrospectively included patients with NDMM that underwent an ASCT between September 19, 2016, and October 19, 2023, and achieved MRD negativity on Day 100 post ASCT. The MRD testing was conducted using multiparameter flow cytometry with a sensitivity of 2x10. HRCAs were defined as del(17p), 1q21+ gain or amplification (1q21+), t(4;14), t(14;16), t(14;20) and del(1p) and rest were considered standard risk (SRCA). Patients were grouped by the number of HRCAs (0, 1, ≥2). An adaptation of the recently proposed International Myeloma Society (IMS)/International Myeloma Working Group (IMWG) classification for high-risk disease (TP53 mutation unavailable) was also used. Progression-free survival (PFS), measured from stem-cell infusion to progression or death, was estimated using Kaplan–Meier methodology and compared using log-rank test. Results We identified 386 patients with MRD negativity post ASCT, of which 381 had cytogenetic data available for analysis. The median follow-up for the study cohort was 47.3 months (95% CI: 43.2-50). The median age at the time of ASCT was 65.7 (25.4-79.2) years and 58.3% patients were males. A total of 49% (n=189) patients had standard-risk cytogenetics, 31.4 % (n=121) harbored 1 HRCA, 15.3% (n=59) patients had two HRCAs and 3.1% (n=12) had 3 HRCAs. The individual HRCA by their prevalence were: 1q21+ in 35.5%(n=137), del(17p) in 14.3% (n=55), t(4;14) in 10.9% (n=42), t(14;16) in 5.4% (n=21), del(1p) in 4.2% (n=16), and t(14;20) in 1.04% (n=4) of patients. The most common double-hit lesions were1q21+ gain and/or amplification co-occurring with t(4;14) (33.9%, n=20) and del(17p) with 1q21+ (18.6%, n=11). Despite universal MRD negativity at Day 100, several HRCAs remained prognostically significant for PFS. Patients with del(17p) had worse 3-year PFS (71%) than those without (81%) [hazard ratio (HR)=1.85, 95% CI 1.11–3.07, p = 0.0172], though 3-year OS did not significantly differ at data cutoff (80% vs. 92%, p=0.1176). Presence of 1q21+ was associated with an inferior 3-year PFS (73%) compared to those without [84%, HR: 1.96 (95% CI: 1.25–3.06), p=0.0026], while 3-year OS was similar (88% vs. 91%, HR:1.33 p=0.36). Isolated 1q21+ had inferior PFS with comparable OS when compared to SRCA [3-year PFS of 82% vs. 88% respectively (HR:1.97, p=0.0177)]; 3-year OS was 91% vs. 94% (HR:1.38, p=0.44)]. Among 1q21+ patients, those with co-occurring HRCAs had a 3-year PFS of 66% vs. 81% for isolated 1q21+ (HR: 1.47, p=0.21). Patients with t(4;14) had worse 3-year PFS (64%) vs. 82% in non t(4;14) [HR 2.11(95% CI: 1.21-3.67) p=0.0064], and 3-year OS of 82% compared to 91% [HR 2.14 (95% CI: 1.02–4.49), p=0.038]. Isolated t(4;14) showed a 3-year PFS of 59% vs. 87% in standard-risk (p=0.06), and 3-year OS of 90% vs. 93% [HR 3.29, 95% CI 0.95–11.33, p = 0.06]. The presence of t(14;16), t(14;20), and del(1p) did not significantly affect 3-year PFS (all p>0.1), likely due to small subsets. When patients were grouped by the number of HRCAs, PFS declined with increasing cytogenetic complexity. Compared to standard risk, the 3-year PFS was 77% for 1 HRCA vs [HR = 2.11 (95% CI: 1.29–3.46), p = 0.0027], 67% for ≥2 HRCA [HR = 2.64 (95% CI: 1.53–4.57), p = 0.0005]. Maintenance therapy was used in 98% of patients. Patients with HRCAs received a doublet maintenance compared to SRCA (p<0.0001), even in MRD negative disease post ASCT. Conclusion In patients with certain HRCA, achievement of MRD negativity post-ASCT does not overcome the adverse impact of HRCA on PFS. In our cohort, patients with del(17p), t(4;14), or 1q21+ continued to exhibit significantly shorter PFS despite achieving MRD-negative status. These findings underscore the need for ongoing risk-adapted strategies even in patients with MM who attain MRD-negative state. The OS estimates are immature at this time.