Citations

7542 Background: Teclistamab, a novel bispecific monoclonal antibody targeting CD3 and BCMA, exhibits promising effects for patients with relapsed and refractory multiple myeloma (MM). However, rates of acute kidney injury (AKI) associated with this therapy remains inadequately characterized. Methods: This was a retrospective observational cohort study of patients with relapsed refractory MM who received teclistamab or Chimeric Antigen Receptor T-cell Therapy (CAR-T) therapy at Mayo Clinic between 12/1/2022-5/15/2023 and who were not in kidney failure at the time of treatment. The primary endpoint was incidence of AKI during follow-up; secondary endpoints included treatment and recovery from AKI. AKI was defined based on Kidney Disease Improving Global Outcomes criteria as an increase of serum creatinine levels > 1.5 times their baseline value after starting therapy. Cumulative incidences and Cox proportional hazard regression models were used to evaluate time to event data. Results: A total of 64 patients met inclusion criteria for the study (30 received CAR-T and 34 received teclistamab therapy). There were 14 AKI events occurring during follow-up (10 teclistamab [n = 6 stage 1, n = 3 stage 2 and n = 1 stage 3] and 4 CAR-T [n = 3 stage 1 and n = 1 stage 2]). Cumulative incidence estimates of AKI at 120 days after treatment were 32% (95% CI: 14%-47%) for teclistamab patients and 10% (95% CI: 0%-21%) for CAR-T patients. While patients receiving teclistamab were found to be at increased risk of an incident AKI event compared to patients receiving CAR-T therapy, results were not statistically significant (HR (95% CI): 3.38 (0.93-12.31), p = 0.065). Median time to development of AKI was 30 days (IQR 16, 73) in teclistamab and 59 days (IQR 9, 146) in CAR-T patients. Among the 10 patients in the teclistamab group with an AKI event, 4 (40%) had complete renal recovery and 4 (40%) had partial recovery, while among the 4 patients with CAR-T with an AKI event, 2 (50%) experienced complete renal recovery and 2 (50%) experienced partial recovery. Conclusions: Our study showed that almost one third of patients receiving teclistamab therapy for relapsed and refractory multiple myeloma experienced an incident AKI event during follow-up. This finding underscores the importance of monitoring for kidney function in these patients.

7529 Background: iAEs, such as cytokine release syndrome (CRS) and macrophage activation syndrome (MAS), can occur after infusion of chimeric antigen receptor T cell therapies such as ide-cel, but are typically low-grade and manageable with tocilizumab and corticosteroids. Although high-grade iAEs are rare with ide-cel, identification of patients at increased risk may improve management and remains an unmet need. Three composite biomarkers (multivariate models) of iAE risk were previously developed in a discovery cohort from the KarMMa and KarMMa-2 studies of ide-cel in RRMM (Mashadi-Hossein A, et al. J Clin Oncol 2023;41(16_suppl):e20005). Here, we validate these 3 prototype models for risk of developing high-grade iAEs after ide-cel infusion. Methods: Two models used pretreatment patient and routine clinical laboratory parameters; the third model also included change in 6 exploratory cytokines from baseline to 1 day following ide-cel infusion. To validate, each model was retrospectively applied to KarMMa-3 (NCT03651128) data in a blinded fashion, and sensitivity and specificity to identify grade ≥3 CRS and any-grade MAS were determined. Model performance thresholds used for sensitivity and specificity were 90% and 50%, respectively. Performance for identifying grade 2 CRS was also analyzed post hoc. Results: The first and simplest model comprised a manual algorithm with 7 features; it identified patients with grade ≥3 CRS or MAS with 85% sensitivity and 60% specificity. The second model comprised 19 routinely measured pretreatment features; it identified grade ≥3 CRS with 91% sensitivity and 59% specificity, and any-grade MAS with 60% sensitivity and 88% specificity. The third and most complex model comprised 7 pretreatment clinical features and 6 exploratory cytokines; it identified grade ≥3 CRS with 100% sensitivity and 51% specificity, and any-grade MAS with 100% sensitivity and 81% specificity. None of the models identified grade ≥2 CRS with passable sensitivity or specificity. Clustering analyses across all features showed that only a subset of grade 2 CRS cases was within the previously identified high-risk iAE cluster while the remaining grade 2 CRS cases were spread across other clusters. Conclusions: Two of the 3 composite biomarkers met validation criteria for grade ≥3 CRS risk. Criteria were not met for grade 2 CRS, suggesting these models are specific to higher-grade events and that grade 2 CRS represents a more heterogeneous group of patients. While high-grade iAEs are rare with ide-cel, these models may further optimize the robust benefit–risk profile that ide-cel has demonstrated by helping identify, prior to or shortly after infusion, patients most at risk for severe events. Clinical trial information: NCT03651128 .

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]

7516 Background: Immune effector cell hemophagocytic lymphohistiocytosis IEC-HS is a complication of CAR T cell therapy (CART). This study aims to look at the outcomes of CART patients who develop IEC-HS. Methods: Patients who developed IEC-HS after receiving CART and patients who developed IEC-HS without (nonCART) between December 2020 and March 2022 were included. Results: The 20 CART patients were older than the 25 nonCART patients. Peak ferritin, fibrinogen, CRP, serum creatinine and transaminases were similar between the 2 group. CART patients had lower white blood cell count and platelets and bilirubin than the nonCART patients. CART patients were more like to have markedly elevated IL-6 levels (> 315 mg/ml), higher IL-18, higher MCP-1, and suppressed IL-1β and GMCSF than nonCART patients (Table). Treatment of IEC-HS included tocilizumab (n = 19), anakinra (n = 18) siltuximab (n = 4) and basiliximab (n = 4), dexamethasone (n = 18) methylprednisolone (n = 6), etoposide (n = 1) and ruxolitinib (n = 1). A significant response defined by a 90% reduction or normalization of the cytokine was observed with IL-10 and IFN-ϒ in 92.3% and 84.6% of the CART patients respectively. An intermediate response was noted with TNF, IL-6, MCP-1 and MIP-1 in 38.4%, 30.8% and 61.6% and 38.5% of the patients respectively. No patient had a significant response in IL-2Rα or IL-1β and only 7.7% had a significant response in IL-18. Of the 5 patients who had a MIP-1 response, 4 were on basiliximab +/- high flow continuous venovenous hemofiltration and the only patient that had an IL-18 response was on both modalities. The 100-day mortality after IEC-HS in the CART patients was 40% and was associated with higher peak and lower best ferritin but not the percentage reduction (Table). Higher TNF (90.3 pg/ml vs 37.2 pg/ml, p = 0.05), markedly elevated levels of IL-6 (92% vs 50%, p = 0.03) and IL-10 (33% vs 0%) and an IL-6 response (44.4% vs 0%) were associated with survival at day 100. IL-6 responders had lower peak ferritin vs IL-6 nonresponders (14066 mcg/L vs 45051 mcg/L, p = 0.08). Enterococcus faecium bacteremia developed in 75% of the nonsurvivors vs 16.6% of the 100-day survivors (p = 0.009). Survivors cleared the enterococcus bacteremia within days while nonsurvivors had protracted bacteremia. Conclusions: IEC-HS is devastating complication of CART. Anti-cytokine therapy can reduce some cytokines and ferritin but overimmunosuppression may lead infectious complication, in particular with E. faecium. Better biomarkers are needed to finetune immunosuppressive therapy in order to avoid over-immunosuppression. [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]

7508 Background: Idecabtagene vicleucel (Ide-cel) has demonstrated excellent efficacy in patients with relapsed/refractory multiple myeloma (RRMM). However, outcomes in patients with extramedullary disease (EMD) remain to be better characterized. Methods: We included patients from 11 US academic centers, who were evaluated for EMD and were infused with ide-cel between May 2021 and April 2023. Patients with soft tissue or visceral lesions non-contiguous from bony lesions were classified as having true EMD, with paraskeletal disease classified as non-EMD. Disease responses were evaluated using the IMWG criteria. Time-to-event analyses were performed from the date of ide-cel infusion. Results: Among 351 patients with RRMM treated with ide-cel, 84 (24%) had EMD prior to infusion. Median follow-up for the entire cohort was 18.2 months (95% CI: 17-19.3). Baseline characteristics at ide-cel infusion for EMD and non-EMD cohorts are depicted in the table. For the EMD and non-EMD cohorts, the Day 30 objective response rates (ORR) were 58% vs. 69% (p=0.1), Day 30 ≥complete response rates were 16% vs 24% (p=0.11), the Day 90 ORR were 52% vs 82% (p<0.001), and best ORR were 58% vs 82%, respectively. The median progression-free survival (PFS) was 5.3 months (95% CI: 4.1-6.9) for the EMD cohort vs. 11.1 months (95% CI: 9.2-12.6; p<0.0001) for the non-EMD cohort. The median duration of response for EMD among day 30 responders was 6.4 months (95% CI: 5.1-8.4). In a multivariable analysis, EMD was an independent predictor of inferior PFS [hazard ratio 1.8 (95% CI: 1.2-2.5), p<0.001] after adjusting for ECOG status, revised ISS stage, penta-drug refractoriness, elevated ferritin, prior BCMA-directed therapy and use of bridging therapy. Pattern of progression in the EMD cohort (n=68/84) included EMD site only (21%), hematologic only (22%), or both (57%), with comparable PFS for type of progression (p=0.19). The median overall survival (OS) was 14.8 months [95% CI: 9-Not reached (NR)] for EMD and 26.9 months [95% CI: 26.3 vs NR, p=0.006)] for the non-EMD group. Rates of Grade ≥2 cytokine release syndrome or neurotoxicity syndrome were comparable between the two cohorts. Conclusions: Patients with EMD demonstrate significantly inferior Day 90 ORR and presence of EMD is an independent risk factor for inferior PFS. [Table: see text]

7038 Background: While chimeric antigen receptor T-cell (CAR-T) therapy has transformed treatment for hematological malignancies, severe (≥ grade 3,Gr 3, CTCAE) cytopenias post CAR-T and therapy related myeloid neoplasms (t-MN) are particularly difficult to manage. Survival after diagnosis of t-MN is dismal. Management of ≥Gr 3 cytopenias that do not recover by month 3 after CAR-T require frequent monitoring and transfusion support. Growth factor and thrombopoietin mimetics have variable success, with stem cell boost emerging as having more consistent success. Evaluation for CAR-T eligibility, prior to leukapheresis, is the critical timepoint where factors identified at this time could inform risks and benefits of CAR-T versus alternative treatment and for consideration of stem cell collection in patients who may benefit from stem cell boost to treat severe cytopenia post CAR-T. Methods: We conducted a retrospective analysis comparing clinical data of patients (pts) with lymphoma (NHL) and multiple myeloma (MM) treated with FDA-approved and investigational CAR-T between 01/2016 – 06/2022 at Mayo Clinic. Prolonged cytopenias were defined as hemoglobin (Hg)<8 g/dL, absolute neutrophil count (ANC)<0.5 x 109/L, and/or platelet count (PLT)<50 x 109/L at 3 months after CAR-T. Pts with progressive disease were excluded from cytopenia analysis. Logistic regression to identify factors correlated with cytopenia and t-MN. Results: Among the 186 pts who received CAR-T, 42 (22%) patients developed severe cytopenia (26/102, 25%, in NHL; 16/84, 19% in MM); 15/186 (8%) had more than 1 concurrent cytopenia. Univariate analysis identified that baseline ferritin and CAR-HEMATOTOX score correlated with cytopenia. Multivariate analysis showed that advanced age (≥ 65 years) (HR 2.69, 95%CI 1.17 – 6.40, P = 0.02) and thrombocytopenia (HR 4.01, 95%CI 1.77 – 9.34, P = 0.001) were associated with severe cytopenia. Twenty (10.7%) patients [8 (40%) males] developed t-MN at a median of 9.5 months (IQR 4.8 – 19.3 months) after CAR-T (14/102, 13% in NHL; 6/84, 7% in MM). Univariate analysis identified ferritin and CAR-HEMATOTOX score correlated with t-NM. Multivariate logistic regression showed advanced age (HR 5.03; 95%CI 1.59-18.7, P= 0.009), hemoglobin ≤ 10 g/dl (HR 3.63, 95%CI 1.04-13.30, P = 0.04), and thrombocytopenia (HR 4.06, 95%CI 1.32-14.2, P 0.02) are significantly associated with development of post-CART t-MN. Conclusions: Advanced age, anemia and thrombocytopenia at the time of evaluation for CAR-T eligibility, prior to leukapheresis, are associated with the development of post-treatment severe cytopenia and t-MN. Larger, multi-center studies are needed to validate these findings.

6006 Background: IMPT has unique biologic and physical properties compared with IMRT, limits radiation dose beyond the targeted tumor volumes, and is a novel de-intensification strategy for the management of head and neck tumors. This study was designed to compare the outcomes for patients with OPC after chemoradiation therapy (CRT) with IMRT vs IMPT. Methods: This is a multi-center, randomized, phase III non-inferiority OPC trial Stage III/IV (AJCC 7th) squamous cell carcinoma stratified patients by human papillomavirus status, smoking status, and receipt of induction chemotherapy (IC). The primary endpoint was the rate of progression-free survival (PFS) rate at 3 years, where progression was defined as disease recurrence or death. Under the null hypothesis, H0: r ≥ 1.535 established the margin for non-inferiority of IMPT. Secondary endpoints include overall survival (OS), treatment-related malnutrition, and gastrostomy-tube dependence. Analyses were conducted on intent-to-treat (ITT; n=440), per-protocol (PP; n=296), and as-treated (AT; n=397) populations. Results: Patients (n=440) were randomized to undergo IMRT(n=219) or IMPT (n=221) at 21 institutions. The median age was 61 years and HPV/p16 was positive in 95%. IC was the initial treatment in 13% of patients. All patients were treated with CRT to 70 Gy in 33 fx with bilateral neck treatment, and post-CRT surgical lymph node dissection occurred in 8%. The median follow-up was 3.14 years. In the ITT analysis, the hazard ratio (HR) for disease progression or death at 3 y was 0.87 (95%CI 0.56,1.35); p=0.006 and the corresponding HR for death (OS) was 0.63 (95%CI 0.36-1.10) suggesting a protective affect with IMPT. In PP analysis, the PFS HR was 0.85 (95%CI 0.52,1.38); p=0.009 and HR for death (OS) was 0.60 (95%CI 0.32-1.12). In the AT analysis, PFS HR was 0.88 (95%CI 0.56,1.37); p=0.007 and the corresponding HR for death (OS) was 0.70 (95%CI 0.40-1.22). For each analysis above, the null hypothesis was rejected and IMPT was non-inferior to IMRT. PP gastrostomy-tube dependence decreased with IMPT vs. IMRT from 42% to 28% (p=0.019), and more IMPT patients sustained their nutrition with end of treatment weight loss < 5% from baseline: 24% vs 14% (p=0.037). Conclusions: IMPT is non-inferior to IMRT and has emerged as a standard of care CRT approach for OPC that reduces malnutrition and gastrostomy-tube dependence. Clinical trial information: NCT01893307 .

Importance Neurological manifestations during acute SARS-CoV-2–related multisystem inflammatory syndrome in children (MIS-C) are common in hospitalized patients younger than 18 years and may increase risk of new neurocognitive or functional morbidity. Objective To assess the association of severe neurological manifestations during a SARS-CoV-2–related hospital admission with new neurocognitive or functional morbidities at discharge. Design, Setting, and Participants This prospective cohort study from 46 centers in 10 countries included patients younger than 18 years who were hospitalized for acute SARS-CoV-2 or MIS-C between January 2, 2020, and July 31, 2021. Exposure Severe neurological manifestations, which included acute encephalopathy, seizures or status epilepticus, meningitis or encephalitis, sympathetic storming or dysautonomia, cardiac arrest, coma, delirium, and stroke. Main Outcomes and Measures The primary outcome was new neurocognitive (based on the Pediatric Cerebral Performance Category scale) and/or functional (based on the Functional Status Scale) morbidity at hospital discharge. Multivariable logistic regression analyses were performed to examine the association of severe neurological manifestations with new morbidity in each SARS-CoV-2–related condition. Results Overall, 3568 patients younger than 18 years (median age, 8 years [IQR, 1-14 years]; 54.3% male) were included in this study. Most (2980 [83.5%]) had acute SARS-CoV-2; the remainder (588 [16.5%]) had MIS-C. Among the patients with acute SARS-CoV-2, 536 (18.0%) had a severe neurological manifestation during hospitalization, as did 146 patients with MIS-C (24.8%). Among survivors with acute SARS-CoV-2, those with severe neurological manifestations were more likely to have new neurocognitive or functional morbidity at hospital discharge compared with those without severe neurological manifestations (27.7% [n = 142] vs 14.6% [n = 356]; P &amp;lt; .001). For survivors with MIS-C, 28.0% (n = 39) with severe neurological manifestations had new neurocognitive and/or functional morbidity at hospital discharge compared with 15.5% (n = 68) of those without severe neurological manifestations ( P = .002). When adjusting for risk factors in those with severe neurological manifestations, both patients with acute SARS-CoV-2 (odds ratio, 1.85 [95% CI, 1.27-2.70]; P = .001) and those with MIS-C (odds ratio, 2.18 [95% CI, 1.22-3.89]; P = .009) had higher odds of having new neurocognitive and/or functional morbidity at hospital discharge. Conclusions and Relevance The results of this study suggest that children and adolescents with acute SARS-CoV-2 or MIS-C and severe neurological manifestations may be at high risk for long-term impairment and may benefit from screening and early intervention to assist recovery.

IntroductionAlzheimer's disease (AD) is a neurodegenerative disease with neurogenic fiber tangles caused by amyloid-β protein plaques and tau protein hyperphosphorylation as the pathological manifestations. This study was based on multi-omics to investigate the mechanisms and immune characterization of AD.Material and methodsBased on bulk RNA-seq (GSE122063 and GSE97760), we screened potential biomarkers for AD by differential expression analysis and machine learning algorithms. Then, we elaborated the expression characteristics and immune functions of the above biomarkers by scRNA-seq (single-cell RNA sequencing) data analysis (GSM4996463 and GSM4996462) and immune infiltration analysis.ResultsFive biomarkers (RBM3, GOLGA8A, ALS2, FSD2, and LOC100287628) were identified using machine learning algorithms. Single-cell analysis revealed distinct expression patterns of these biomarkers in astrocytes from AD samples compared to normal samples. Additionally, three key biomarkers were selected based on interaction networks, and the diagnostic models indicated high diagnostic efficacy for these biomarkers. Based on immune infiltration and correlation analyses, RBM3, GOLGA8A, and ALS2 were all highly correlated with CD8 T cell content in the immune microenvironment of AD.ConclusionsThe biomarkers identified in this study demonstrate significant diagnostic potential for AD. Notably, the downregulation of RBM3 in astrocytes and the decreased presence of CD8 T cells infiltrating brain tissue are potential risk factors for AD.