Moreno, Eider

Background Clinical biomarkers are essential for optimizing CAR T-cell therapy in multiple myeloma (MM). Clinicians can anticipate patient responses by evaluating predictive biomarkers, particularly earlier during treatment, tailoring treatments to enhance efficacy and survival outcomes. Ferritin, a general inflammation marker, appears to be a promising predictor of clinical outcome in MM patients receiving therapy with CAR T-cells. Our goal was to evaluate this and other biomarkers in this patient population. Methods We retrospectively analyzed MM-patients treated with idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) at Mayo Clinic Arizona between September/2019 and November/2023. We evaluated the demographic characteristics, pre-infusion bone marrow samples, adverse events, mortality, and clinical response after CAR T-cell therapy infusion, and clinical laboratory data were interpreted using reference limits established by Mayo Clinic laboratories. Statistical calculations using parametric tests were performed, and survival curves were estimated using the Kaplan-Meier analysis and compared statistically using the log-rank test and Pearson's correlation. Results Forty patients with MM received CAR T cells, and 23 and 17 patients received cilta-cel and Ide-cel, respectively. The median age was 64 years [IQR 40-80], and 62.5% were male. All patients received inpatient CAR T-cell infusions; the median vein-to-vein was 54 days (IQR: 39-109), and the median length of hospital stay was ten days (IQR: 7-25). Cytokine release syndrome (CRS) was observed in 90% of patients (3% grade ≥3), while immune effector cell-associated neurotoxicity syndrome (ICANS) was observed in 23% of patients (3% grade ≥3). At day 90, the overall response rate (ORR) was 87.5%, with 21 patients (52.5%) having a complete response (CR), 9 (22.5%) with a very good partial response (VGPR), 5 (12.5%) had a partial response (PR), 1 (2.5%) had stable disease (SD), and 4 (10%) had progressive disease (PD). 35 patients was evaluated for minimal residual assessment (MRD) using flow cytometry cut-off 10-5. Of the total population eligible (PR, VGPR, and CR) for MRD evaluation, 97% were MRD negative. The median progression-free survival (PFS) was 13.5 months on ide-cel and has not been reached on cilta-cel. The mortality rate was 23.5% Ide-cel vs 8.6% with cilta-cel. In terms of PFS, we did not find any association with age, disease risk, number of previous lines of therapy, time from last treatment to CAR T-cell infusion, absolute lymphocyte counts at leukapheresis, % of plasma cells in bone marrow pre-infusion, vein-to-vein time, use of tocilizumab, or steroids for CRS/ICANS management. However, univariate analyses showed that a ferritin level <337 mcg/L at baseline pre-CAR T-cell infusion strongly correlated independently with improved PFS (median non-reached) compared with patients with ferritin levels >337 mcg/L that had a PFS of 13.50 months HR 0.2 (95% CI 0.07 - 0.83); p=0.0245. In addition, ferritin levels <337 mcg/L pre-infusion correlated with improved overall survival (OS) (median non-reached) compared with 22.23 months in patients with higher ferritin levels HR 0.2 (95% CI 0.02 - 0.53), p=0.0069. Conclusions In conclusion, our analysis shows that ferritin levels pre-CAR T-cell infusion are independent predictive biomarkers of PFS and OS in MM-patients regardless of the CAR T-cell product received. Our cohort of MM-patients treated with the two FDA-approved CAR T-cell products showed the expected PFS, OS, and adverse events. Moreover, our results showed no significant association between clinical response and age, risk stratification, number of previous therapy lines, or other evaluated factors with disease progression. Future prospective studies will help to validate these findings and explore the mechanisms associated with high ferritin levels and their potential implications in the heightened immune-activation state in patients that express high ferritin levels and their correlation with CAR T-cell efficacy.

Abstract Background Hypomagnesemia has been correlated with inferior outcomes in patients with large B cell lymphoma (LBCL) undergoing stem cell transplants. As T-cell and myeloid cell dysfunction have been associated with low magnesium conditions, we investigated whether serum magnesium (Mg) levels could predict clinical outcomes in LBCL patients who received chimeric antigen receptor T-cell therapy. Methods Patients with LBCL who received axi-cel under the ZUMA-1 trial or as FDA approved therapy at Mayo Clinic were examined. Serum samples were obtained at specified time points and cytokine analysis was performed. Single cell RNA sequencing was performed on peripheral blood mononuclear cells. The Student T-test, Kruskal Wallis, or Fisher's Exact Tests were used to compare differences in demographics across Mg levels. Survival curves were plotted using the Kaplan-Meier methodology and compared using the Wilcoxon test. Results We found that hypomagnesemia before lymphodepletion chemotherapy predicted for inferior progression-free and overall survival in the pivotal study ZUMA-1 (NCT02348216). These results were validated in an independent cohort of LBCL patients receiving axicabtagene ciloleucel (axi-cel) at Mayo Clinic. Hypomagnesemia correlated with increased inflammatory serum markers and cytokine levels including ferritin, IL-6, IL1Ra, IL-8, and MIP1a. scRNAseq analysis unveiled altered immune interactions between monocytes and T cells with a concordant immune suppressive transcriptome. Conclusions Hypomagnesemia at the time of CAR-T infusion associates with an unfavorable inflammatory profile and decreased response and survival in LBCL patients receiving axi-cel. These findings suggest a potentially actionable prognostic factor for patients with large cell lymphoma undergoing CAR-T.

Abstract BackgroundAlternative splicing (AS) is a fundamental process in eukaryotes contributing to the diversity of mRNA isoforms with variable ratios of intron/exon. SF3B1 is a pivotal protein of the spliceosome machinery. Mutations in the SF3B1 gene have prognostic value in Chronic Lymphocytic Leukemia (CLL). Our previous studies have shown that SF3B1 inhibition with macrolides induces apoptosis specifically in CLL compared with normal cells. SF3B1 inhibition is associated with a widespread increase in intron retention (IR) on most transcripts, suggesting that IR can be used as a marker of spliceosome inhibition in CLL cells. However, it is unknown how the activity of SF3B1 contributes to the spliceosome activity and the poor clinical prognosis in CLL.MethodsTo better understand this process, we performed a comprehensive analysis to quantify the abundance of individual exonic and intronic mapped reads on annotated RNA-Seq transcripts derived from the B cells of 98 CLL patients and nine healthy volunteers (Normal B cells – NBC). We calculated ratios for intron and exon abundance for each transcript and use this as a measure of intron retention (IR) and a surrogate for alternative splicing (AS).ResultsWe found that 66% of CLL B-cells transcripts had significant IR elevation compared to NBC and that transcripts with high IR were associated with low expression levels and mRNA downregulation. The IR increase in CLL B-cells was independent of prognostic factors such as IgVH or SF3B1 mutations. Transcripts with the highest IR levels belonged to biological pathways associated with gene expression and RNA splicing. Also, we observed a >2-fold increase of active pSF3B1 in CLL B-cells compared to NBC. Additionally, when the CLL-B cells were treated with macrolides (pladienolide-B), a significant decrease in pSF3B1, but not total SF3B1 protein was observed. ConclusionsOur findings suggest that IR/ARS is increased in CLL and that this process is associated with SF3B1 phosphorylation and susceptibility to SF3B1 inhibitors. These data provide additional support to the relevance of AS in carcinogenesis and evidence of pSF3B1 participation in this process.

e14516 Background: IEC are arguably the most promising therapy in oncology, and FDA approvals for CAR T cells are a testament to their real potential. This has led to a great growth of clinical trials (CT), making the evaluation of their associated data increasingly challenging. To facilitate this process, we performed a systematic review of ClinicalTrials.gov focused on IEC therapies in oncology. We performed an analysis of the CT data and forecast trends for 2025. Methods: CT registries were retrieved from ClinicalTrials.gov with a systematic search query. We included CT registered between 1993-2020, which used IEC-based therapies in oncology. Statistical analysis using descriptive and inferential methods allowed us to identify trends and establish forecasts. Results: We identified 938 registrations of IEC-CTs in oncology, and 51% of those were active. The most common IEC type was CAR T (51%), followed by NK (15%), TCR T (8%), TIL (8%), and CIK (3%). 69% of IEC-CTs were aimed at a specific target vs. 31% that lack that specificity. The number of annual CAR T-CTs continue to increase, and we forecast 320 registrations during 2025. Since 2018, the number of CTs using unmodified T cells and TIL has increased (largely due to metastatic melanoma studies). NK cells CTs represent 8% of all registrations, and by 2025 we anticipate that >150 NK-based CTs will be registered per year, a number similar to CAR T-CTs registered during 2020. IEC-CTs based on allogeneic sources represent 18% of all registrations and are expected to grow 2.5 fold in the next 5 years. In solid tumors, the most common IEC-CTs are based on Non-CAR studies, while in hem-malignancies 76% of CTs are CAR T. Only one solid tumor, CAR T-CT, has reached phase 2/3, while 7 CIK-CTs were used to target various organ tumors. Conclusions: IEC-CTs continue to grow exponentially and represent an active field of clinical research in oncology. Allogeneic and NK-CTs increase rapidly and are among the most promising IEC-CTs. A rising proportion of CTs in solid tumors are using CIK and TIL rather than CAR T-cells, which are more popular for treating hem-malignancies. This is a direct reflection of the challenges associated with CAR T infiltration and persistence in solid tumors. Our analyses indicate that annual IEC-CTs registrations will double by 2025. We anticipate the increase in cellular therapy options will demand an organized response, including adequate logistical planning and policy implementation in response to the landscape changes in clinical oncology during the upcoming years.[Table: see text]