Gertz, Morie A.

Abstract Background Smoldering multiple myeloma (SMM), an asymptomatic precursor of multiple myeloma (MM), carries a variable risk of progression to MM. There is little consensus on the efficacy or optimal timing of treatment in SMM. We systematically reviewed the landscape of all clinical trials in SMM. We compared the efficacy of treatment regimens studied in SMM to results from these regimens when used in newly diagnosed multiple myeloma (NDMM), to determine whether the data suggest deeper responses in SMM versus NDMM. Methods All prospective interventional clinical trials for SMM, including published studies, meeting abstracts, and unpublished trials listed on ClinicalTrials.gov up to April 1, 2023, were identified. Trial-related variables were captured, including treatment strategy and efficacy results. Relevant clinical endpoints were defined as overall survival (OS) and quality of life. Results Among 45 SMM trials identified, 38 (84.4%) assessed active myeloma drugs, while 7 (15.6%) studied bone-modifying agents alone. Of 18 randomized trials in SMM, only one (5.6%) had a primary endpoint of OS; the most common primary endpoint was progression-free survival (n = 7, 38.9%). Among 32 SMM trials with available results, 9 (28.1%) met their prespecified primary endpoint, of which 5 were single-arm studies. Six treatment regimens were tested in both SMM and NDMM; 5 regimens yielded a lower rate of very good partial response rate or better (≥VGPR) in SMM compared to the corresponding NDMM trial (32% vs 63%, 43% vs 53%, 40% vs 63%, 86% vs 89%, 92% vs 95%, and 94% vs 87%, respectively). Conclusion In this systematic review of all prospective interventional clinical trials in SMM, we found significant variability in trial design, including randomization status, primary endpoints, and types of intervention used. Despite the statistical limitations, comparison of treatment regimens revealed no compelling evidence that the treatment is more effective when introduced early in SMM compared to NDMM.

Abstract Aims We aim to determine if our previously validated, diagnostic artificial intelligence (AI) electrocardiogram (ECG) model is prognostic for survival among patients with cardiac amyloidosis (CA). Methods A total of 2533 patients with CA (1834 with light chain amyloidosis (AL), 530 with wild-type transthyretin amyloid protein (ATTRwt) and 169 with hereditary transthyretin amyloid (ATTRv)] were included. An amyloid AI ECG (A2E) score was calculated for each patient reflecting the likelihood of CA. CA stage was calculated using the European modification of the Mayo 2004 criteria for AL and Mayo stage for transthyretin amyloid (ATTR). Risk of death was modelled using Cox proportional hazards, and Kaplan–Meier was used to estimate survival. Results Median age of the cohort was 67 [inter-quartile ratio (IQR) 59, 74], and 71.6% were male. The median overall survival for the cohort was 35.6 months [95% confidence interval (CI) 32.3, 39.5]. For AL, ATTRwt and ATTRv, respectively, median survival was 22.9 (95% CI 19.2, 28.2), 47.2 (95% CI 43.4, 52.3) and 61.4 (95% CI 48.7, 75.9) months. On univariate analysis, an increasing A2E score was associated with more than a two-fold risk of all-cause death. On multivariable analysis, the A2E score retained its importance with a risk ratio of 2.0 (95% CI 1.58, 2.55) in the AL group and 2.7 (95% CI 1.81, 4.24) in the ATTR group. Conclusions Among patients with AL and ATTR amyloidosis, the A2E model helps to stratify risk of CA and adds another dimension of prognostication.

AbstractRenal AL amyloidosis can be complicated by end‐stage renal disease (ESRD) requiring renal replacement therapy (RRT). In this study, we describe the long‐term outcomes of renal AL amyloidosis patients undergoing autologous stem cell transplantation (ASCT) and assess the utility of the renal staging system. Retrospective study of renal AL patients (n = 697; Mayo Clinic, Boston University) who underwent ASCT between 2003 and 2020. Renal stage was assigned based on 24‐h proteinuria and estimated glomerular filtration rate measurements. Renal survival was defined as the time from ASCT until initiation of RRT, while patients who were not placed on RRT were censored at their last follow‐up. With a median follow‐up of 10.4 years, RRT was required in 149 patients (21%). The median time from ASCT to ESRD was 3.4 years, with late events of progression to ESRD seen >10 years from ASCT. Pre‐ASCT renal stage was significantly associated with the cumulative incidence of RRT: 3‐year RRT rate was 3%, 10%, and 37% for renal stages I, II, and III, respectively. However, in the 2012–2020 period subset, a significant decrease in ESRD risk was noted across all renal stages (3‐year RRT 0%, 5%, and 24%, respectively). In multivariate analysis, renal survival was independently associated with the pre‐ASCT renal stage, lambda isotype, bone marrow plasmacytosis ≥20%, post‐ASCT hematologic response, and year of ASCT. Long‐term outcomes of renal AL amyloidosis treated with ASCT are presented. Renal stage reliably predicts renal outcomes in patients with AL undergoing ASCT, despite a reduction in the proportion of patients progressing to RRT in recent years.

Abstract We performed an international retrospective study on 283 patients with light chain (AL) amyloidosis to investigate the prognostic impact of cytogenetic abnormalities by fluorescence in situ hybridization, when treated with frontline daratumumab–based therapy. The cytogenetic subgroups of interest were t(11;14), gain/amp(1q) (hereafter, +1q), hyperdiploidy, deletion(13q), del(17p), and myeloma high-risk (HR) translocations (t[4;14], t[14;16], or t[14;20]). The end points of interest were rate of hematologic complete response (heme-CR), very good partial response (VGPR) or better, and hematologic event-free survival (heme-EFS). The incidence of abnormalities was as follows: t(11;14), 53.4%; deletion (13q), 28.9%; +1q, 22.3%; hyperdiploidy, 19.4%; HR translocations, 6.6%; and deletion(17p), 4.5%. The heme-CR rate by cytogenetic subgroups were as follows: t(11;14) vs no t(11;14), 45.2% vs 41.8% (P=0.597); del(13q) vs no del(13q), 46.8% vs 42.8% (P=0.594); +1q vs no +1q, 30.2% vs 47.9% (P=0.022); hyperdiploidy vs no hyperdiploidy, 39.5% vs 44.9% (P=0.541); HR translocations vs none, 45.5% vs 43.1% (P=0.877); and del(17p) vs no del(17p), 50.0% vs 42.9% (P=0.658), respectively. Similarly, +1q was the only subgroup with a significantly lower VGPR or better rate (64.2% vs 79.0%; P=0.033). At a median follow-up of 19.8 months, the median heme-EFS was 49.6 months (95% CI, 24.7-not reached [NR]), and the 2-year overall survival (OS) was 80.98% (95% CI, 75.6-85.4). The presence of +1q was significantly associated with worse heme-EFS on multivariate analysis (HR 2.06, 95% CI, 1.14-3.71; P=0.017). Notably, there was no adverse prognostic impact of t(11;14) on heme-EFS or OS. In conclusion, +1q is associated with worse outcome in the daratumumab-era. Clinical trials testing novel frontline immunotherapies should be enriched in +1q to further improve outcomes in this subgroup.

ImportanceKidney light chain (AL) amyloidosis is associated with a risk of progression to kidney replacement therapy (KRT) and death. Several studies have shown that a greater reduction in proteinuria following successful anticlonal therapy is associated with improved outcomes.ObjectiveTo validate graded kidney response criteria and their association with kidney and overall survival (OS).Design, Setting, and ParticipantsThis retrospective, multicenter cohort was conducted at 10 referral centers for amyloidosis from 2010 to 2015 and included patients with kidney AL amyloidosis that was evaluable for kidney response and who achieved at least hematologic partial response within 12 months of diagnosis. The median follow-up was 69 (54-88) months. Data analysis was conducted in 2023.ExposureFour kidney response categories based on the reduction in pretreatment 24-hour urine protein (24-hour UP) levels: complete response (kidCR, 24-hour UP ≤200 mg), very good partial response (kidVGPR, >60% reduction in 24-hour UP), partial response (kidPR, 31%-60% reduction), and no response (kidNR, ≤30% reduction). Kidney response was assessed at landmark points (6, 12, and 24 months) and best kidney response.Main Outcomes and MeasuresCumulative incidence of progression to KRT and OS.ResultsSeven-hundred and thirty-two patients (335 women [45.8%]) were included, with a median (IQR) age of 63 (55-69) years. The median (IQR) baseline 24-hour proteinuria and estimated glomerular filtration rate was 5.3 (2.8-8.5) g per 24 hours and 72 (48-92) mL/min/1.73m2, respectively. In a competing-risk analysis, the 5-year cumulative incidence rates of progression to KRT decreased with deeper kidney responses as early as 6 months from therapy initiation (11%, 12%, 2.1%, and 0% for kidNR, kidPR, kidVGPR, and kidCR, respectively; P = .002) and were maintained at 12 months and 24 months and best kidney response. Patients able to achieve kidCR/kidVGPR by 24 months and at best response had significantly better OS compared with kidPR/kidNR. Kidney progression, defined as a 25% or greater decrease in estimated glomerular filtration rate, was associated with cumulative incidence of progression to KRT and OS.Conclusions and RelevanceThe results of this cohort study suggest that graded kidney response criteria offers clinically and prognostically meaningful information for treating patients with kidney AL amyloidosis. The response criteria potentially inform kidney survival based on the depth of reduction in 24-hour proteinuria levels and demonstrate an OS advantage for those able to achieve kidCR/kidVGPR compared with kidPR/kidNR. Taken together, achievement of at least kidVGPR by 12 months is needed to ultimately improve kidney and patient survival.

Abstract Currently, the role of DNA methylation in the immunoglobulin M (IgM) monoclonal gammopathy disease spectrum remains poorly understood. In the present study, a multiomics prospective analysis was conducted integrating DNA methylation, RNA sequencing (RNA-seq), and whole-exome sequencing data in 34 subjects (23 with Waldenström macroglobulinemia [WM], 6 with IgM monoclonal gammopathy of undetermined significance [MGUS], and 5 normal controls). Analysis was focused on defining differences between IgM gammopathies (WM/IgM-MGUS) compared with controls, and specifically between WM and IgM-MGUS. Between groups, genome-wide DNA methylation analysis demonstrated a significant number of differentially methylated regions that were annotated according to genomic region. Next, integration of RNA-seq data was performed to identify potentially epigenetically deregulated pathways. We found that pathways involved in cell cycle, metabolism, cytokine/immune signaling, cytoskeleton, tumor microenvironment, and intracellular signaling were differentially activated and potentially epigenetically regulated. Importantly, there was a positive enrichment of the CXCR4 signaling pathway along with several interleukin (interleukin 6 [IL-6], IL-8, and IL-15) signaling pathways in WM compared with IgM-MGUS. Further assessment of known tumor suppressor genes and oncogenes uncovered differential promoter methylation of several targets with concordant change in gene expression, including CCND1 and CD79B. Overall, this report defines how aberrant DNA methylation in IgM gammopathies may play a critical role in the epigenetic control of oncogenesis and key cellular functions.

7558 Background: Survival in patients with multiple myeloma (MM) continues to improve with the newer therapies, but there is no clear evidence of a cure and patients continue to relapse. However, most patients have the most extended period without progression with their first-line therapy, and subsequent therapies often provide a shorter duration of response due to the use of drugs with overlapping mechanisms of action and, more importantly, a shorter first remission, pointing toward more aggressive disease biology. With newer immunotherapies being used at 1st relapse, this may change. We designed this study to explore the natural history of MM after the 1st relapse and define the predictors of outcome after the initial relapse. Methods: We identified all patients in the Mayo Clinic database diagnosed between Jan 2004-June 2019 who had had initial disease progression. The study cohort included 2005 patients. We explored the overall survival (OS) from the time of documented disease progression or the start of second-line treatment in patients who had not met IMWG criteria before second-line therapy. Front-line therapy was grouped into those with either an IMiD or PI, both IMiD and PI, daratumumab with IMiD and PI, and none of these agents. The IMiD and PI were always used with dexamethasone with or without an alkylator. Results: The median age was 63 (range 24-95) years and 60% were male. The median estimated follow-up from diagnosis for all patients was 86 mos. (95% CI; 82, 88) and the median time to progression from the start of therapy was 25 mos. (95% CI; 24, 26). The median OS from the first progression was 45 mos. (95% CI; 42, 50), 36 mos. for those diagnosed before 2009, and 52-53 mos. for those diagnosed later. On univariate analysis, age <70 at 1st relapse, RISS I, novel agents in initial therapy, CR in the first line, diagnosis after 2009, initial remission >18 mos, and initiation of therapy before IMWG progression were all associated with improved OS after 1st relapse (Table). On multivariate analysis, age <70, RISS I, initial remission >18 mos, and initiation of therapy before IMWG progression were all associated with improved OS after 1st relapse. Conclusions: The study provides an estimate of the outcomes and significant predictors of outcomes after 1st relapse in patients with MM. These factors should be taken into consideration when designing clinical trials in this patient population. In particular, these factors identify a high-risk group of patients not always identified by baseline characteristics and should be the focus of future trials. [Table: see text]

7520 Background: There are 2 CAR-T products and 3 bispecific antibodies (BsAbs) that are FDA-approved for patients (pts) with relapsed, refractory multiple myeloma (MM). Clinical trials experience to date suggests that clinical response of BsAb is less impacted after CAR-T therapy. We examined the outcome of pts who received BsAb in standard-of-care (SOC) practice at Mayo Clinic Rochester. Methods: Retrospective analysis of MM patients who received FDA-approved BsAb at Mayo Clinic, Rochester between 12/2022- 1/2024. IMWG criteria was used for clinical response. Results: Sixty-two patients received BsAbs: 77% (48/62) received teclistamab, and 23% (14/62) received talquetamab. Median age was 62 years (range: 33-81), 60% (37/62) were males, and 45% (28/62) received prior CAR-T. Patients who had prior CAR-T therapy had more prior lines of therapy compared to those who did not. Overall, ORR to teclistamab was 61%, which is comparable to previous studies and other real-world reports. ORR and ≥CR rates were comparable between patients with and without prior CAR-T (Table). Of the 28 pts who received CAR-T before BsAbs, 61% (17/28) received idecabtagene vicleucel, 10% (3/28) were ciltacabtagene autoleucel, and 29% (8/28) on clinical trial. We then compared outcome of BsAb between pts who had relapsed from CAR-T within 1 year (n=21, median PFS: 8.84 months (range, 1.12, 10.84)) or after 1 year (n=7, median PFS: 16.62 months (range, 13.30, 36.20)). At the time of BsAb infusion, pts with who relapsed < 1 year vs ≥1 year post CAR-T had comparable blood counts, ALC, M-protein and involved FLC levels, CRP, ferritin and LDH. BsAb CR/sCR rate was significantly higher in pts with disease relapse ≥1 year compared to <1 year post CAR-T (57% vs 14%, p=0.02). Conclusions: Irrespective of prior CAR-T exposure, BsAb have clinical activity in SOC practice in pts with MM. Our preliminary data suggest that responses to BsAbs are better in pts with late compared to early relapse post CAR-T. Longer follow-up is needed to understand the duration of response. Larger, multi-center studies with longer follow-up will help identify factors that impact BsAb response post CAR-T.[Table: see text]

7515 Background: BCMA directed CAR T cells, antibody drug conjugates (ADCs), and T cell engagers (TCEs) each have distinct strengths and weaknesses. While these agents have shown unprecedented response rates and survival outcomes, no head-head comparisons exist. We assessed the relative efficacy of different BCMA-therapies in relapsed myeloma, with a focus on high-risk subgroups. Methods: Retrospective study of MM patients treated at Mayo Clinic with commercial or investigational BCMA targeted therapies between April 2018-June 2023. Results: 385 patients (ADC=59, TCE=134, CAR T=192) with a median follow up of 20-months. The median time from diagnosis was 6.1 years. The table shows disease, and treatment characteristics. Amongst ADCs and TCEs recipients, the median treatment duration was 1.9 and 3.5 months respectively, disease progression (64% and 79%) and intolerance (22% and 10%) were the most common reasons for discontinuation. The overall response rates were 27, 50, and 86% for ADCs, TCEs and CAR T, respectively. Compared to ADCs, CAR T was associated with improved PFS (adjusted HRPFS=0.29, 95%CI=0.20-0.43) and OS (aHROS=0.28, 95%CI=0.18-0.44) when adjusting for age, R-ISS, double hit high risk cytogenetic abnormalities (HRCAs), extramedullary disease (EMD, excluding paraskeletal plasmacytomas), triple class refractoriness, and the number of lines of therapy (LOTs) received in the preceding 1 year. Likewise compared to ADCs, TCEs were associated with superior PFS (aHRPFS=0.59, 95%CI=0.40-0.86) and OS (aHROS=0.60, 95%CI=0.39-0.93). Amongst patients with plasma cell leukemia (PCL) or EMD at the time of BCMA therapy (n=123), median PFS was poor irrespective of the therapeutic class at 1.3, 1.7 and 6.1 months for ADCs, TCEs and CAR T, respectively. Equally, for patients previously treated with BCMA therapy (n=58), median PFS was poor regardless of class at 1.9, 2.4 and 3 months for ADCs, TCEs and CAR T, respectively. Of 229 relapses the mode of relapse was known in 192 cases (84%), with 101 (52%) having EMD at relapse. Conclusions: While contingent on myriad other factors, patients able to receive BCMA-directed CAR T therapy experience superior survival compared to ADC and TCEs. EMD, PCL and BCMA-exposed populations are recalcitrant to BCMA-directed immunotherapy, and EMD is a common means of relapse. [Table: see text]