Dispenzieri, Angela

Abstract Background: Waldenström Macroglobulinemia (WM) is an indolent B-cell lymphoplasmacytic lymphoma characterized by heterogeneous clinical behavior and variable progression patterns. While MYD88L265Pand CXCR4 mutations are frequently encountered, the broader genomic landscape underpinning disease evolution from smoldering WM (SWM) to active treatment naïve WM (TNWM), post-treatment remission WM (PTWM) and relapsed/refractory WM (RRWM) remains incompletely understood. To address this gap, we studied the mutational profile across the WM disease spectrum. Methods We performed whole exome sequencing (WES) on sorted (CD19 and/or CD138) bone marrow aspirates of patients across the spectrum of WM. Paired germline sequencing was performed using peripheral blood mononuclear cells (PBMCs). Unique molecular identifier-tagged reads were deduplicated using fgbio. WES data were processed through the Sarek pipeline. Any valid mutation from either caller, present on the index or in COSMIC was considered. Copy number variations (CNVs) were inferred via CNVkit and summarized at the gene and arm level (≥50% directional change). Mean tumor and germline coverages were 174X and 74X, respectively. Fisher's exact test was used for enrichment and hypergeometric test for overlap analyses. Results A total of 78 high-quality WM samples [15 SWM, 44 TNWM, 13 RRWM, 6 PTWM in remission (all with paired TNWM samples)] were sequenced. The mutational burden varied across disease states (median SWM=1.48 m/Mb, TNWM= 1.12 m/Mb, RRWM = 1.59 m/Mb; p=0.04). Density plots revealed bimodal VAF distributions, consistent with clonal and subclonal architectures in WM. Overall, 77% harbored a MYD88L265P mutation by WES. Among MYD88^WT^ patients, AS-PCR identified MYD88L265P in 4 (25%) not detected by WES, raising the overall mutation rate to 83%, plus one with a non-L265P variant. Low VAF (<10%) MYD88L265P mutations were seen in 6% of matched PBMCs. MYD88 copy number gain was seen in 2 (17%) MYD88WT TNWM patients. CXCR4 mutations were detected in 38% by WES (18% each frameshift and nonsense). Two (4%) CXCR4WT samples were positive by PCR, giving an overall rate of 40%. CXCR4 mutations were more frequent in RRWM (54%) vs TNWM (41%) and SWM (27%), though not statistically significant. Del(6q) and Del(17p) were noted in 16% (n=12) and 7% (n=5) of patient samples. All del(17p) events were noted in TNWM samples and in one paired post-treatment sample. Overall rate of del(17p) and TP53 mutation was 14% (n=11). RRWM was enriched in ARID1A alterations, a gene implicated in chromatin remodeling and plasma cell identity formation [38% (n=5) in RRWM vs. 11% (n=6) in TNWM and SWM], compared to TNWM and SWM p=0.03]. Alterations in NF-kB signaling gene MAP3K14 were more frequent in RRWM (31%, n=4) compared to the SWM/TNWM cohort [(7%), n=4; p=0.036). We noted an enrichment in the TP53 mutation rate in RRMW [n=3, 23%, OR 7.7] compared to TNWM and SWM cohorts [n=2, 4%), p=0.04]. Mutations in FUBP1 (p=0.03), an upstream regulator of MYC, and CARD11 (p=.043), a B-cell signaling scaffold protein were also more frequent in RRWM. Notably, none of the SWM patients harbored an ARID1A alteration (p=0.057), suggesting acquisition during progression. CNV analysis revealed that MAP3K14 amplifications were frequent in RRWM (n=3, 23%) compared to SWM/TNWM [n=2 (4%), p=0.043]. RRWM samples showed increased CD79B mutations (15%) and significant overlap with the C5/ABC diffuse large B-cell lymphoma (DLBCL) genomic cluster (Chapuy et al., Nat. Med. 2018; p=0.007). This overlap remained significant after excluding MYD88L265P (p=0.019), driven by CARD11, CD79B, and IGLL5, suggesting that a subset of RRWM may acquire an ABC DLBCL-like mutational profile. These findings warrant further investigation using transcriptional profiling. Conclusions This study provides a genomic map of WM evolution from precursor to relapse. Increasing somatic mutations and CNVs support stepwise progression. Enrichment of genes involved in chromatin remodeling and plasma cell identity formation (ARID1A), NF-kB or BCR signaling (CARD11, MAP3K14), and DNA damage repair (TP53) were noted at relapse, all of which have been shown to drive aggressive disease biology. Emergence of an ABC-like genotype in a proportion of RRWM indicates convergent evolution with aggressive lymphomas. Transcriptional studies are warranted to explore this further.

Abstract Background The advent of T-cell redirecting bispecific antibodies (BsAb) therapies has led to deeper and durable responses in patients with RRMM. We sought to identify adverse prognostic factors for patients treated with BsAbs. We also explored whether the extent of the non-involved free light chain (niFLC) suppression could serve as a potential marker of T-cell engager activity, given the binding of BsAbs to both clonal and non-clonal plasma cells and the short half-life of serum FLCs. Methods We conducted a retrospective analysis of RRMM patients treated with BsAbs between 2022 and 2025 at Mayo Clinic. Baseline lymphocyte counts and ferritin levels were collected and analyzed both as continuous and dichotomized variables. niFLC was considered undetectable if it was below the quantification limit, while the magnitude of niFLC suppression was defined as the absolute difference between niFLC levels and the lower normal range threshold at the time of best response. In addition to standard statistical methods, interaction models were used to explore the potential effect modification of niFLC dynamics. Results A total of 158 patients were included (teclistamab, 73%; talquetamab, 15%; elranatamab, 12%). The median follow-up is 12 months (range 0 to 28 months). Median age is 71(range 65 to 77); 52% (n=85) were triple-class refractory (refractory to an IMiD, a PI, and CD38-antibody) and 37% (n=60) were penta-refractory. CAR-T therapy was previously administered in 28% (n = 46) patients, and 70% had undergone an autologous stem cell transplant. One or more high risk cytogenetic features including del(17p), gain(1q), amp(1q), del(1p), t(4;14), and t(14;16) were present in 57% (n = 90) of patients. Extramedullary disease was noted at the time of BsAb therapy in 44% of patients. Utilizing IMWG response criteria, 68% (n=107) achieved ≥partial response, and 64% (n=101) had ≥ very good partial response (VGPR) as best response following BsAb treatment. The median time to best response was 1.6 months (range 0.7 to 4.4). On multivariable analyses, baseline immunoparesis (HR 1.96; 95% CI, 1.08–3.58; p = 0.0274) and elevated ferritin levels (≥ 337 ng/mL) (HR 1.96; 95% CI, 1.24–3.09; p = 0.0041) were independent predictors of inferior progression-free survival (PFS). Lower baseline absolute lymphocyte count, analyzed as a continuous variable, was significantly associated with shorter PFS in the univariable analysis (HR 0.66; 95% CI, 0.44–0.98; p = 0.04), but not in the multivariable model (HR 0.75; 95% CI, 0.5–1.13; p = 0.166). Detectable niFLC at the time of best response was also significantly associated with inferior PFS (HR 1.80; 95% CI, 1.14–2.84; p = 0.0114). However, the magnitude of niFLC suppression did not show a statistically significant impact on PFS. The median PFS was 5 months in patients with high ferritin levels (≥ 337 ng/mL) and 21 months in those with lower ferritin (p = < 0.005). Similarly, PFS was 8 months in those with immunoparesis and not reached in those without baseline immunoparesis (p = 0.008). At the time of best response, detectable niFLC was associated with a trend toward shorter PFS (5 vs. 13 months), although the difference was not significant (p = 0.06). Logistic regression analysis supported these findings, with higher ferritin levels (OR 2.28; 95% CI: 1.09–4.96; p = 0.032) and the presence of baseline immunoparesis (OR 2.60; 95% CI: 1.18–6; p = 0.02) being significantly associated with higher likelihood of progression or death. Patients with deep reduction in niFLC achieved a VGPR or better. In contrast, those with detectable or higher-than-normal niFLC levels did worse in terms of response. Notably, niFLC became undetectable in 72% of patients with ≥VGPR (73/101), compared to 52% of those who did not achieve this level of response (30/57). Conclusion Among RRMM patients treated with BsAbs, baseline immunoparesis and elevated ferritin levels emerged as independent predictors of worse PFS. While failure to induce a deep reduction in niFLC at the time of best response suggests a tumor extrinsic mechanism of resistance, and it is also linked to inferior outcomes.

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: Castleman disease (CD) is a heterogeneous group of lymphoproliferative disorders classified anatomically as unicentric (UCD), oligocentric (OligoCD), or multicentric (MCD). Human herpesvirus 8 (HHV-8)-negative MCD is referred to as idiopathic MCD (iMCD), which includes clinical subtypes with distinct phenotypes and treatment responses: TAFRO (thrombocytopenia, anasarca, fever, renal dysfunction and/or reticulin fibrosis, and organomegaly), idiopathic plasmacytic lymphadenopathy (IPL), and not otherwise specified (NOS). While UCD and iMCD, including TAFRO, have been more clearly defined, OligoCD and iMCD-IPL remain under-characterized, particularly in Western cohorts. This study aimed to validate the updated clinical classification of CD using a large institutional cohort by retrospectively reclassifying patients based on lymph node distribution and clinicopathologic criteria. We further examined whether OligoCD and IPL represent clinically and prognostically distinct entities compared to UCD or iMCD, and other iMCD subtypes. Methods: This study included 217 patients evaluated for CD at our institution between January 2004 and August 2024. All cases were reclassified based on the extent of lymph node involvement and iMCD subtype. UCD was defined as the involvement of a single lymph node region. OligoCD was defined as involvement of ≥2 contiguous lymph node stations without sufficient systemic symptoms to meet iMCD criteria. Patients with POEMS syndrome or HIV/HHV-8–associated CD, or lacking pathologic confirmation, were excluded. We evaluated clinical presentation, laboratory data, histopathology, treatment regimens, and outcomes. The primary endpoint was overall survival (OS), and the secondary endpoint was event-free survival (EFS), defined as time from first-line treatment to progression, change in therapy, or death. Survival outcomes were assessed using the log-rank test. Results: Among 217 CD patients, 123 (57%) had UCD, 43 (20%) had OligoCD, and 51 (23%) had iMCD. iMCD-defining symptoms were more common in iMCD compared to UCD and OligoCD. Among all, only fatigue and organomegaly were more common in OligoCD than in UCD. Laboratory values related to CD disease activities, including hemoglobin, serum creatinine, albumin, CRP, and plasma IL-6, showed significant differences in iMCD compared to UCD and OligoCD. No significant difference in the laboratory findings was observed between UCD and OligoCD, although patients with OligoCD had intermediate values between UCD and iMCD. With median follow-up of 4.0, 7.6, and 4.6 years for UCD, OligoCD, and iMCD, respectively, the 5-year OS was 99.0%, 97.7%, and 89.5% without differences among groups. Corresponding 2-year EFS rates were 95.2% for UCD, 68.0% for OligoCD, and 53.8% for iMCD. With OligoCD being the reference, UCD had a significantly lower hazard ratio (HR) of 0.20 (95% CI 0.10–0.41), and iMCD had a significantly higher HR of 2.0 (95% CI 1.1–3.6). Among OligoCD patients initially treated with surgery (40%), none required systemic therapy thereafter. Those treated with rituximab or glucocorticoid monotherapy required subsequent therapy in 50% and 43%, respectively. Within iMCD subtypes (TAFRO (n=16), IPL (n=9), and NOS (n=26)), the 5-year OS was 80.4%, 100%, and 91.0%, respectively, without significant differences among the subtypes. However, 1-year EFS rates were 40.2%, 100%, and 65.6%, respectively, with an HR of 4.3 (95% CI 1.2–15.2; p = 0.02) in TAFRO and 1.6 (95% CI 0.77–3.5) in NOS compared to IPL. Patients with IPL had a high rate of symptomatic improvement assessed by a physician of 89% with a longer time-to-next treatment. Conclusions: This extensive, retrospective cohort study supports the clinical relevance of updated CD subtype classification. As the present study spans two decades, it reflects evolving diagnostic criteria and therapeutic standards, including the 2014 FDA approval of siltuximab, the iMCD consensus criteria in 2017, with the addition of OligoCD and iIPL. The findings confirm the aggressive clinical nature of iMCD and suggest that OligoCD demonstrated intermediate features between UCD and iMCD, though closer to UCD in outcome. Also, the results reconfirmed that TAFRO is associated with severe symptomatic diseases, and validated that patients with IPL, even in the Western cohort, likely have favorable responses to treatment. Continued prospective efforts are warranted to confirm the clinical distinctions.

Abstract Introduction AL amyloidosis is a rare disorder caused by amyloid fibrils produced by clonal plasma cells, leading to serious organ dysfunction. Cardiac involvement is a major risk factor for poor survival. CD38-binding Daratumumab (D) targets plasma cells and, with bortezomib, cyclophosphamide and dexamethasone (VCd) is the only approved regimen for newly diagnosed AL amyloidosis. The ANDROMEDA phase 3 study showed significant improvements in hematologic responses, major organ deterioration progression free survival and overall survival, compared with VCd alone. The AQUARIUS study (NCT05250973) evaluated cardiac safety of different D-VCd schedules and potential cardiac toxicity mitigation strategies. Methods This multicenter, open-label, phase 2 study enrolled 151 newly diagnosed AL amyloidosis patients at 37 sites in 10 countries. Patients enrolled in either Cohort 1 (n=120, cardiac involvement [Mayo 2004 stage II/IIIA], randomized 2:1 to receive D + immediate VCd or D + deferred VCd) or Cohort 2 (n=31, racial or ethnic minorities with ≥1 any organ involvement, treated with D + immediate VCd). Immediate VCd began on Cycle 1, deferred VCd on Cycle 4. The primary safety endpoint was the incidence of cardiac treatment emergent adverse events (TEAEs). Cardiac assessments included HS TroponinT, NT-proBNP, echocardiogram (ECHO), ECG, NYHA, and the 6-minute walk test (6MWT). Clinical cardiac signs and symptoms (S&S) were assessed at baseline and monthly. Selected, clinically relevant grade ≥3 and/or serious cardiac TEAEs were defined as Major Cardiac TEAE and were assessed by an independent adjudication committee for causality. Patients were followed for 12 treatment cycles or 12 months from first dose (if treatment discontinued prior to 12 cycles). Results 142 patients from both cohorts had cardiac involvement and received at least one dose of D + immediate VCd (n=103) or D + deferred VCd (n=39). Baseline characteristics were balanced between the two groups, including Mayo 2004 stage (IIIa: immediate VCd, 35.0%; deferred VCd, 35.9%; II: immediate VCd, 62.1%; deferred VCd, 53.8%). Treatment duration (median: 10.4 months) and proportion completing ≥10 cycles (79% vs 85%) were similar. Serious cardiac TEAEs occurred at similar rates across groups (immediate VCd, 7.8%; deferred VCd, 7.7%). The most common serious cardiac TEAE (MedDRA term) was cardiac failure (immediate VCd, 5.8%; deferred VCd, 2.6%). Two deaths occurred within 60 days of first study treatment, both were in the immediate VCd group, cardiac-related and unrelated to treatment. The immediate VCd group had fewer cardiac TEAEs overall (48.5% vs 61.5%) but experienced them more frequently during Cycles 1-3 than deferred VCd (35.9% vs 28.2%). This trend reversed for Cycles 4-6 (immediate VCd, 17.7%; deferred VCd, 28.9%). Cardiac TEAEs were low for both groups for Cycles 7-9 (immediate VCd, 9.3%; deferred VCd, 12.1%) and Cycles 10-12 (immediate VCd, 7.4%; deferred VCd, 12.1%). Levels of NT-proBNP, HS troponin T, the 6MWT, and overall cardiac S&S improved similarly for both treatment groups. Rate of cardiac TEAEs of any grade was similar for Mayo stage III patients in the two groups (immediate VCd, 73.0%; deferred VCd, 68.8%) whereas for Mayo stage II patients the incidence was higher in the deferred group (35.9% vs 57.1%). Twenty patients (Immediate VCd, 13; deferred VCd, 7) experienced 30 Major Cardiac TEAEs (selected grade ≥3 and/or serious). Adjudicators attributed 28 events primarily to amyloid cardiomyopathy and 2 events primarily to treatment. These 20 patients had higher baseline Mayo stage (IIIa: 70% vs 29.5%) than the remaining patients (n=122), higher baseline median NT-proBNP (4862 ng/L vs 1723 ng/L) and overall S&S score (7.5 vs 4.0). Several ECHO measures were worse at baseline in these 20 patients (notably, median GLS: -8.8% vs -13.7% and E prime lateral: 4.4 cm/s vs 6.1 cm/s) as was 6MWT (median distance: 319 m vs 363 m). Complete Response (CR) rates were similar in both groups: immediate VCd, 62.1%; deferred VCd, 59.0%. Median time to CR was 64 days for the immediate VCd group and 113 days for the deferred VCd group. Conclusion The D-VCd regimen (immediate or deferred) had a manageable safety profile consistent with previous studies. Cardiac TEAEs were similar between regimens, and their emergence correlated with the start of VCd. Major cardiac events were associated with underlying disease and baseline risk factors that are quantifiable and monitorable.

Abstract Background B-cell maturation antigen (BCMA)-targeting immunotherapies represent a promising class of treatment for the management of immunoglobulin light chain (AL) amyloidosis, a disease that is related to clonal plasma cells. Etentamig is a 2nd generation, off-the-shelf, fully human BMCA X CD3 bispecific antibody with bivalent BCMA domain and low CD3 affinity that targets both BCMA-expressing plasma cells and CD3-expressing T cells. Etentamig monotherapy is being studied in multiple myeloma (MM) in an ongoing phase 3 study (NCT06158841). Here, we report the first safety and efficacy results from M24-209, an open-label phase 1/2 study evaluating etentamig monotherapy in patients (pts) with relapsed/refractory (RR) AL amyloidosis from dose level 1 (DL1). Methods The phase 1 dose escalation (ESC) portion of the study (NCT06158854) with etentamig enrolled pts with RR AL amyloidosis with ≥1 prior lines of therapy (LOT), including a proteasome inhibitor and an anti-CD38 monoclonal antibody with no prior BCMA exposure. Eligible pts were required to have a difference in involved and uninvolved serum free light chain (dFLC) of ≥50 mg/L, and pts with Mayo Clinic 2004 cardiac risk stage IIIb with NT-proBNP ≥8500 pg/ml were excluded. Three dose groups were explored in dose ESC (etentamig dose levels [DL] 1, 2, and 3). In all cohorts, pts will receive up to 24 cycles of treatment and will be followed until disease progression. In dose ESC, the primary objectives are to determine safety/tolerability, pharmacokinetic/pharmacodynamic, and recommended phase 2 dose. The secondary objectives include evaluation of efficacy as measured by hematologic response and organ response. Responses are investigator assessed per consensus guidelines (Comenzo, et al. Leukemia. 2012. 26[11]:2317-25; Palladini G, et al. Amyloid. 2021 [Epub];28[1]:1-2). Results As of 17 July 2025, all DLs in dose ESC have been fully enrolled, and 12 pts have been treated with etentamig at DL1. Due to short follow-up, this initial report only includes data from DL1, with further follow-up data from ESC to be included at the time of presentation. Median duration of follow up in DL1 was 9.4 months (8.3–13.8) with 83% of pts continuing treatment. Median age for pts was 72 years (range, 56–85 years). Median number of prior LOT was 2 (range, 1–6), and median time from initial diagnosis was 3.6 years. Thirty-three percent have received a prior stem cell transplant and 50% previously received the regimen of daratumumab with cyclophosphamide, bortezomib, and dexamethasone in combination. Median dFLC at study baseline was 110. 5 mg/L (range, 56.6–617.5). At baseline, 83% of pts had cardiac involvement, 25% had renal involvement, and 8% had hepatic involvement. Eighty-three percent of pts had lambda AL amyloidosis. Treatment-emergent adverse events were reported in 100% (42% Grade ≥3) of pts at DL1. Cytokine release syndrome (CRS) occurred in 2 pts (17%, all Grade 1), with no instances of any grade immune effector cell-associated neurotoxicity syndrome (ICANS). CRS occurring after the first dose had median time to onset of 6.8 hours (range, 6.7–6.9). Grade ≥3 infections occurred in 1 pt (8%, all Grade 3). Grade ≥3 neutropenia also occurred in 1 pt (8%, all Grade 3), and no Grade ≥3 events of thrombocytopenia or anemia occurred. No Grade 5 events have occurred. Within the dose ESC DL1 cohort, the overall hematologic response rate was 100%, with all pts achieving ≥VGPR and 83% of pts achieving complete response (CR). The median time to CR was 0.9 months (0.3–9.3). The median duration of response has not yet been reached and 100% of pts remain in their best overall response by investigator assessment. To date, no pts have experienced hematologic progression on study. Cardiac response was observed in 30% of evaluable pts. Renal response was seen in 67% of evaluable pts. Conclusions In the DL1 cohort, etentamig showed a manageable safety profile in AL amyloidosis with low incidence and severity of CRS, no ICANS, and limited Grade ≥3 cytopenia events. Deep and rapid hematologic responses were observed with 100% ≥VGPR rate and 83% hematologic CR rate. Additional dose-level data will be presented at the time of the meeting. All pts remain in ongoing follow-up and evaluation, and the study will begin the dose expansion (EXP) portion after dose selection.

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: Systemic AL amyloidosis is an incurable disorder caused by misfolded light chain fibrils. Survival is determined by the extent of cardiac involvement and response to therapy. Mayo 2012 (stage I-IV) and European modified Mayo 2004 (stage I-IIIB) prognostic scores were developed in a historic treatment era, prior to widespread bortezomib and daratumumab use. These no longer discriminate those with the poorest outcomes. We presented a new model sub-stratifying IIIB into a high risk, ‘IIIC’ group, incorporating longitudinal strain (LS) to the European modified score (IIIC: LS >-9% + NT-proBNP >8500ng/L + high-sensitivity troponin T [hs-TnT] >50ng/L) in the bortezomib-era (2015-2019) last year (Khwaja et al, ASH 2024). Here, we present an independent external validation of the IIIC model in the modern treatment era. Methods: The ‘IIIC model’ was derived from a large real-world cohort of adults from the UK National Amyloidosis Centre (2015-2019). Performance was externally validated across Europe (Greece, Italy, Netherlands, Switzerland), USA (2015-2024) and UK (2020-2024). Survival estimates were generated from diagnosis to death or last follow-up using the Kaplan-Meier method and groups compared using Cox regression (using Stata v18). Stage IIIB and IIIC were defined as follows IIIB: LS <-9%, NT-proBNP >8500ng/L, hs-TnT >50ng/L and IIIC: LS >-9%, NT-proBNP >8500ng/L, hs-TnT >50ng/L, respectively. Stage I, II and IIIa were defined as previously described in the European modification of Mayo 2004 staging system. Results: 2493 patients were analysed from 2015-2024 (derivation, n=573; validation: Europe, n=374, USA n=458, UK, n=1088). In the derivation cohort, LS ≥-9% and standard cardiac biomarkers (NT-proBNP 332ng/L and 8500ng/L and hs-TnT>50ng/L) were selected as independent prognostic factors in a multivariable model. In the European and UK validation cohort (n=1462), median age at diagnosis was 67 years (range 35-95) with 1014 (69%) cardiac and 869 (60%) renal involvement. Median difference in involved and uninvolved free light chain (dFLC) was 181 mg/L (range 0-24933), NT-proBNP 1911ng/L (range 42-70000), hs-TnT 45ng/L (range 3-1221) and LS -14.7% (range -3- -28). In the US cohort median NT-proBNP was 1764 (range 13-71000) and hs-TnT 44 (6-687). Applying the new model staging, the patient stages were across Europe and UK were stage I: 224 (15%), II: 627 (43%), IIIA: 396 (27%), IIIB: 139 (10%) and IIIC: 76 (5%), respectively. 592 (41%) were treated with first-line daratumumab-based regimens. In the US dataset stage I: 103 (22%), II: 176 (38%), IIIA: 131 (29%), IIIB: 48 (10%) and IIIC: 16 (3%), respectively. 234 (51%) were treated with first-line daratumumab-based regimens. At a median follow-up of 30 months (95% CI 28-32) in the European and UK validation cohort, estimated median overall survival (OS) was not reached and 2-year OS was 74% (95% CI 72-77). Median survival for stages I-II, IIIA, IIIB and IIIC were not reached (NR), 67, 31 and 10 months, respectively (p<0.001). Hazard ratios for stage II, IIIA, IIIB, IIIC were 2.01 (95% CI 1.32-3.07), 3.51 (95% CI 2.31-5.35), 5.67 (95% CI 3.60-8.91) and 11.12 (95% CI 6.93-17.87), respectively (p<0.001). This was confirmed in the US cohort with a median survival for respective stages were NR, NR, NR, 8 and 2 months (p<0.001). External validation in the European and UK cohorts exhibited good predictive performance: 12-month calibration slope was 1.00 (95% CI 0.81-1.20, p=0.98), Harrel's C was 0.90 (95% CI 0.76-1.00), Royston's D 1.07, R2D 0.21 (95% CI 0.15-0.28). In 1462 patients with dataset available, stage IIIC discriminated the poorest outcome despite a greater proportion treated with first-line daratumumab v IIIB in the validation cohort (59% v 40%, p=0.008). 12-month OS for IIIC v IIIB was 44% (95% CI 32-55) v 69% (95% CI 60-76), specificity for 12-month OS 97% v 92% and diagnostic odds ratio 6.62 v 2.36. Conclusions: This study validates the new staging system from stage I-IIIC with robust identification of an ultra-poor prognostic group (Stage IIIC) in a contemporarily treated patient cohort. Despite novel therapies, the OS remains <12 month in the IIIC group and also poor in stage IIIB with median OS 31 months compared to a median of >5 years for all other stages. This staging system can be considered as a new standard of care for risk stratification of AL amyloidosis. Novel approaches are required for patients with advanced risk.

Abstract Background Central nervous system involvement in multiple myeloma (CNS-MM) is a rare but highly aggressive manifestation. Limited data exists regarding its incidence, biology, treatment patterns, and outcomes. A deeper understanding of the features unique to CNS-MM will help inform risk stratification and management strategies. Methods We conducted a retrospective study of CNS-MM patients at our institution between January 2000 and December 2023. We identified 305 MM patients with pathology-proven extramedullary disease (EMD). CNS involvement was defined as the presence of parenchymal (brain or spine) or leptomeningeal involvement by MM. Univariate analysis was performed to compare the clinical characteristics between EMD patients with and without CNS-MM. Results Out of 305 patients with EMD, we identified 22 patients with CNS-MM. Common symptoms prompting evaluation of CNS-MM were headaches (32%), numbness or tingling (32%), weakness (27%), confusion (23%), falls (23%), and visual disturbances (14%). Among these patients, 17 (77%) had detectable disease in cerebrospinal fluid (CSF), 12 (55%) in the brain parenchyma, 4 (18%) in the spinal cord parenchyma and 6 (27%) in the leptomeninges. Of the CNS-MM patients, the median age at diagnosis of MM was 58.3 years and the median time to CNS-MM involvement was 16.2 months, with 3 (14%) patients having CNS involvement at diagnosis. The predictors of CNS-MM development were high-risk cytogenetics (OR 2.9, p=0.04) and presence of additional visceral organ involvement outside of the CNS (OR 3.4, p=0.03). EMD was multifocal in 20 CNS-MM patients (83%) and visceral organ involvement [most commonly lymphadenopathy (27%), solid organ (18%) and pleural fluid (14%)] was present in 14 (64%) of these patients, compared to 54% in EMD patients without CNS-MM. High-risk cytogenetics [del(17p), 1q gain/amplification, t(4;14), t(14;16), t(14;20)] were seen in 16 (73%) patients, most commonly 1q gain or amplification (40%), t(4;14) (23%), and del(17p) (18%). Five (23%) exhibited a double-hit profile. In comparison, 113 (40%) EMD patients without CNS-MM had high risk cytogenetics. The median overall survival (OS) from diagnosis of CNS-MM was 6 months (95%CI:1.26-36) compared to 15.6 months (95%CI: 12-18) from diagnosis of EMD in EMD patients without CNS-MM (p=0.05). Median OS from diagnosis of MM in the CNS-MM cohort was 36 months (95%CI: 22.8-NA) compared to 55.2 months (95%CI: 45.6-68.4) in EMD patients without CNS-MM (P=0.11). When excluding CAR-T or bispecific therapy recipients, median OS from diagnosis of MM for CNS-MM was 22 months versus 48 months in EMD patients without CNS-MM (P=0.02). Overall response rate in our CNS-MM cohort with first treatment for EMD was 32% compared to 48% in EMD patients without CNS-MM (p=0.04). In patients with CNS-MM, median progression-free survival (PFS) from CNS-MM diagnosis was 3.3 months (95%CI: 0.8-12) versus 3.9 months (95%CI: 3-5.1) in EMD patients without CNS involvement (p=0.2). Six (27%) CNS-MM patients received CAR-T; 3 received cilta-cel, 2 received ide-cel and one received a BCMA CAR-T on trial. Bispecific therapy was used in 4 (18%) patients, with 2 receiving Teclistamab and 2 Talquetamab. Three (14%) CNS-MM patients received both CAR-T and bispecific therapy. The median PFS on CAR-T therapy was 10.5 (95%CI: 5.6-NA) months and 12.7 (95%CI: 10.2-NA) months on bispecific therapy. The median OS from diagnosis of CNS-MM for patients who received CAR-T or bispecific therapy was 36 months (95%CI: 14.0-NA), compared to 1.2 months (95%CI: 0-14.4) for those who did not (p=0.002). Six (27%) patients with CNS-MM, all of whom had CSF involvement of disease, received intrathecal therapy; methotrexate in 3, cytarabine in 2, and one receiving both. Two of these patients demonstrated improvement in cerebrospinal fluid findings following intrathecal chemotherapy, in conjunction with other therapies. Patients who received intrathecal chemotherapy had a median OS measured from development of EMD of 10.8 (95%CI: 3.6-NA) months, compared to 15 months (95%CI: 4.8-NA) in those without IT chemotherapy (p=0.59). Conclusion Central nervous system involvement in MM is relatively uncommon and associated with dismal outcomes. High-risk cytogenetics and involvement of other visceral sites are associated with a higher risk of CNS involvement. Intrathecal therapy offers limited value and immune effector therapies represent efficacious options for treatment.