Kenderian, Saad S.

TRAIL is a TNF family ligand that trimerizes TRAIL-R1 (DR4) or TRAIL-R2 (DR5) to induce apoptosis, necroptosis, and/or NF-κB activation in receptor-bearing cells. We previously identified TRAILshort as a splice variant of TRAIL that lacks cysteine 230, cannot trimerize, and acts as a dominant-negative ligand that blocks TRAIL-mediated apoptosis. TRAILshort is expressed on cell surfaces and within extracellular vesicles, enabling it to confer TRAIL resistance to both producing and bystander cells. In this study, we showed that elevated TRAILshort levels were associated with chronic viral infections, cancer, and autoimmune diseases, suggesting a link to impaired immune regulation. Using unbiased phosphoproteomics and mechanistic studies, we demonstrated that TRAILshort binding to DR5 recruited and activated the phosphatase Src homology region 2 domain–containing phosphatase 1 (SHP-1), leading to zeta-chain-associated protein kinase 70 (ZAP-70) dephosphorylation, disruption of ZAP-70–CD3ζ interactions, and impaired T cell receptor signaling, thereby reducing T cell activation, proliferation, and cytokine production in response to antigen or CD3/CD28 ligation. Genetic or pharmacologic SHP-1 inhibition reverses these effects. In humanized mouse models, TRAILshort promoted the persistence of transformed mouse embryonic fibroblasts (MEFs) and L428 and antagonized CD19-directed CAR T cell activity, revealing TRAILshort as an immunomodulator of T cell function with therapeutic implications, including blocking TRAILshort to restore T cell immunity or delivering TRAILshort to enforce tolerance. TRAILshort, a variant of TRAIL, suppresses T cell function and immune responses in cancer and infectious diseases, highlighting its potential as a therapeutic target.

Patients in the liso-cel plus ibrutinib cohort of the phase 1/2, open-label TRANSCEND CLL 004 study had relapsed/refractory chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and received liso-cel (50×106 [dose level (DL)1] or 100×106 [DL2] chimeric antigen receptor-positive T cells) with concurrent ibrutinib from enrollment through 90 days after liso-cel infusion or longer per investigator discretion. Primary end point was complete response/remission (CR)/CR with incomplete marrow recovery (CRi) by investigator assessment. Among 56 patients who received ibrutinib plus liso-cel (DL1, n=5; DL2, n=51), median (range) age was 64.5 years (44‒77), 98% had high-risk cytogenetics, 55% had progression on Bruton tyrosine kinase inhibitor and venetoclax failure, and median (range) number of prior therapies was 5 (1‒13). Median (range) follow-up was 24.8 months (3.1‒51.8). At DL2, CR/CRi rate was 45% (95% confidence interval [CI], 31‒60) and overall response rate was 86% (95% CI, 74‒94). Median (95% CI) duration of response was not reached (NR; 28.7‒NR) for patients with CR/CRi and 41.4 months (23.3‒NR) for all responders. Median (95% CI) progression-free survival was 31.4 months (20.1‒NR). In DL1+DL2, most common grade ≥3 treatment-emergent adverse events (TEAE) were neutropenia (52%) and anemia (41%). Cytokine release syndrome was reported in 80% of patients (grade 3, 4%; no grade 4/5), and neurological events in 41% (grade 3/4, 11%; no grade 5). Ibrutinib-related TEAEs were reported in 68% of patients (grade 3/4, 43%; no grade 5). Liso-cel plus ibrutinib demonstrated notable efficacy in patients with relapsed/refractory CLL/SLL with predictable and manageable safety. Clinicaltrials.gov: NCT03331198; NCT03435796.

ABSTRACT The recently published BLAST clinical risk model for chronic myelomonocytic leukemia (CMML) and its molecular version (BLAST‐Mol) differentiate low, intermediate, and high‐risk groups. The objective of the current retrospective study was to examine the survival impact of allogeneic stem cell transplant (ASCT) in a consecutive series of Mayo Clinic patients ( n = 775; 68% males, median age 71 years) with CMML, overall and adjusted for baseline BLAST/BLAST‐Mol risk categories. At a median follow‐up of 77 months, 151 (20%) patients underwent ASCT. Overall survival (OS) was longer in the ASCT compared to the non‐ASCT cohorts (median 77 vs. 28 months; p < 0.01). The significant difference in OS between the ASCT and non‐ASCT cohorts was retained after adjusting for BLAST clinical risk groups: high‐risk (median 50 vs. 14 months; p < 0.01), intermediate‐risk (81 vs. 28 months; p < 0.01), and low‐risk (111 vs. 65 months; p = 0.04), respectively. The same was mostly the case when OS comparison was adjusted for BLAST‐Mol with respective p values of < 0.01, < 0.01, and 0.08, respectively. Time‐dependent cox models confirmed the favorable survival impact of ASCT in the BLAST/BLAST‐Mol high‐ and intermediate‐risk groups. The current study highlights the benefit of ASCT for BLAST/BLAST‐Mol high‐ and intermediate‐risk groups in CMML and its potential to overcome the adverse impact of some high risk cytogenetic or molecular abnormalities. These observations support the early use of ASCT in CMML, ideally before BT and regardless of genetic characteristics.

Abstract Chimeric antigen receptor T (CAR T)-cell therapy is revolutionizing cancer treatment in hematologic malignancies, but challenges related to the tumor microenvironment have hindered CAR T success, especially in solid tumors. Myeloid cells in particular have been implicated in CAR T efficacy. In this review, we discuss the roles of myeloid cells in CAR T–associated toxicities, including cytokine release syndrome, immune effector cell–associated neurotoxicity syndrome, and immune effector cell–associated hemophagocytic lymphohistiocytosis–like syndrome, along with strategies to treat these toxicities by modulating myeloid cells. The review also explores myeloid cell–mediated suppression or enhancement of CAR T function. Finally, strategies used to target myeloid cells in combination with CAR T-cell therapy will be investigated.

Adoptive cell therapy (ACT) has shown remarkable success in the treatment of some malignancies, particularly leukemia. However, there are multiple factors that limit the durability of ACT in solid tumors, including dose-limiting toxicities, the immunosuppressive tumor microenvironment, and T-cell exhaustion. As the manufacture and preparation of adoptive T-cell therapies allows time and adequate conditions for ex vivo T-cell engineering, forward genetic screens can identify novel genetic targets that could improve their effectiveness. CRISPR is a commonly used functional genomics tool that has been successfully used to both enhance our understanding of mechanisms of resistance and to discover potential genetic edits to improve ACT. A complementary approach, Sleeping Beauty transposon mutagenesis provides additional opportunities to identify novel genetic edits without being constrained by the annotated human genome. Here, we summarize forward genetic screens and their tools to uncover strategies to enhance ACT. Complementary approaches can be combined and improved on to identify translatable genetic editing strategies through studies that accurately recapitulate disease-specific challenges.

Abstract Chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable response rates in relapsed/refractory aggressive B-cell non-Hodgkin's lymphoma. However, durable remissions occur in only 40% of treated patients, highlighting mechanisms of therapeutic resistance and immune escape. While cytotoxicity is principally executed by CAR T-cells, monocytes shape CAR-T cell efficacy and orchestrate cytokine-driven immunity. In this study, we defined distinct metabolic profiles of T-cell and monocyte subsets based on clinical response. Single-cell RNA sequencing (scRNA-seq) and T-cell receptor sequencing (scTCR-seq) were performed on peripheral blood mononuclear cells at three timepoints: before lymphodepletion (BL), at peak CAR-T expansion (PK), and one-month post-infusion (M1). Data were processed with CellRanger v7.0.1 and analyzed with the immunopipe pipeline (Wang et al., 2025). Seurat v4.3.0 was utilized for unsupervised hierarchical clustering analysis; subsets identified included classical monocytes (CM), intermediate monocytes (IM), non-classical monocytes (NM), and monocytic myeloid derived suppressor cells (mMDSC). Metabolic profiles were compared across patients achieving ≥6-month complete remission (CR, n=16), primary refractory disease (PD1, n=4), or relapsed after a prior response (PD2, n=12). A total of 107035 T cells and 129981 monocytes from 77 serial samples in 32 patients were analyzed. CR patients had a higher T-cell:monocyte ratio than PD1/PD2 at all time points, especially at BL and PK (BL 1.2 vs 0.4, p=0.011; PK 1.3 vs 0.3, p=0.027). Clinical responses were compared with metabolic pathway analysis and identified oxidative phosphorylation (OXPHOS) as the dominant pathway. OXPHOS was consistently enriched in PD cohorts across T-cell subsets, particularly in PD1 vs CR at BL (mucosal-associated invariant T-cell (MAIT) and T peripheral memory (Tpm)), and at PK (CD4/CD8 memory precursor effector cells (MPEC) and activated MPECs (MPECa), CD4 T-helper 1 proliferating (Th1p), CD4 Th2 activated (Th2a), regulatory T-cell (Treg), CD8 naive senescent (CD8NS), CD8 T effector memory (Tem) tumor recirculating (TR), CD8 Tpm, CD8 T resident memory (Trm) TR and MAIT Tpm). By M1, OXPHOS enrichment in CD4/CD8MPECa, CD4Th2a, CD8NS, CD8TemTR reversed, now predominant in CR although CD8Tpm and CD8TrmTR remained enriched in PD1. In the monocyte subsets at BL, PD2 showed OXPHOS enrichment in CD163+ monocytes (mono), IM IL1, mMDSC SIRPA, mMDSC TGFβ, and CM IL6 subsets compared to PD1 and CR, while PD1 showed OXPHOS enrichment in IM CD38, CM TGFβ, and mMDSC HIF1A vs CR and PD2. This persisted at PK. By M1, the pattern reversed and mirrored that of T-cells, with CR patients showing OXPHOS enrichment in CD163+mono, CM IL6, CM TGFβ, IM CD38, mMDSC HIF1A, mMDSC SIRPA and mMDSC TGFβ, and additionally in CM EMT, CM p53, NM, NM CD36 vs PD1/PD2. Glycolysis/gluconeogenesis (GLY) was also enriched across subsets. In T-cells, PD1 vs CR showed GLY enrichment in CD4Th2a, CD8Tpm, CD8Tpm proliferating and MAIT Tpm at PK. In monocytes, GLY was enriched in PD1/2 vs CR at BL (CD163+mono, CM IL6) and PK (CD163+mono, IM CD18, mMDSC SIRPA). By M1, GLY metabolism was enriched in CR vs PD1/PD2 in CD163+mono, CM IL6, mMDSC SIRPA. Additional GLY enriched subsets at CR vs PD1 included CM, CM p53, EMT, IM CD38, IM IL1, mMDSC HIF1A, NM, NM CD36. Inositol phosphate metabolism (IP) was predominantly enriched in PD2 vs CR at BL (CD8NS, CD8Tcm, CD8Tpm activated), PK (CD4Th2, CD8NS, CD8Tem TR, CD8Tpm proliferating, γδT Tem) and M1 (CD4/CD8 MPECa, CD4 Th1/Th2, CD8NS, CD8Tpm, CD8 Tpm proliferating, Treg and MAIT Tpm). Notably, Treg was the only T-cell subset enriched for IP at PK in CR vs PD1/PD2. Additionally, the TCA cycle was enriched in PD1 Tregs and Th2 cells at BL and PK vs CR/PD2. A higher T-cell:monocyte ratio in CR vs PD1/PD2 supports prior evidence that elevated pre-lymphodepletion lymphocyte:monocyte ratios predict better outcomes. We identified distinct metabolic signatures in T-cells and monocytes between CR and PD1/PD2. OXPHOS enrichment in T-cells and monocytes at M1 in CR patients may reflect oxidative programming as a hallmark of sustained anti-tumor immunity. Conversely, GLY enrichment in PD1 T-cells at PK may reflect short-lived effector states lacking persistence. Overall, these findings highlight metabolic profiling as a promising predictive biomarker and therapeutic programming target to enhance CAR T-cell outcomes.

Abstract BACKGROUND Early disease progression within 24 months following chemoimmunotherapy (CIT) is an established adverse prognostic factor for overall survival (OS) in patients (pts) with indolent non-Hodgkin lymphomas. Initially reported in pts with follicular lymphoma, progression of disease (PD) within 24 months in pts with CLL treated with CIT (occurring in ~1-out-of-4 pts) is also associated with inferior OS. The prognostic utility of early event status in pts with CLL treated with targeted therapies is unknown. Recently, we reported worse than expected outcomes with BCL2 inhibitor (BCL2i) treatments in an international cohort of pts with covalent BTK inhibitor (BTKi)-resistant, CIT-naïve CLL. We hypothesize that early disease progression on first-line (1L) targeted agent treatment will identify additional pts with high-risk disease beyond conventional prognostics in the current era. METHODS We identified pts in the Mayo Clinic CLL Database with the following 1L treatments a) BTKi (+/- anti-CD20 monoclonal antibody [CD20mAb]); b) BCL2i + CD20mAb; c) BTKi + BCL2i +/- CD20mAb. PD was defined by a) new or progressive lymphadenopathy or splenomegaly; and/or b) ≥ 50% increase from nadir absolute lymphocyte count (ALC) with persistent (&gt;2 months), and otherwise unexplained ALC ≥ 10x109/L; and/or c) Richter transformation. Logistic regression model evaluated association between clinical factors and POD36 status. OS in pts with PD within 36 months of 1L start (POD36) was evaluated and compared to those without early PD (non-POD36) with analyses: a) starting from time of PD (POD36) and starting from 3 years after 1L initiation (non-POD36); and b) Kaplan-Meier landmark analysis amongst pts alive 3 years post 1L initiation. Cox regression analyses compared a) OS from POD36 by groups and b) OS from 1L treatment with POD36 as a time-dependent covariate. RESULTS A total of 787 pts with CLL initiated 1L targeted therapy (n=538 [68%] BTKi +/- CD20mAb; n=151 [19%] BCL2i + CD20mAb; n=98 [13%] BTKi + BCL2i +/- CD20mAb. The median age at 1L start was 67 years (range 26-92 years), and 67% of pts were male. Among pts with complete CLL-IPI data (n=519), 44% and 15% had high- and very high-risk CLL-IPI risk scores, respectively. Specific pre-1L treatment disease characteristics included TP53 disruption (del17p or TP53 mutation) in 120/639 (19%), del11q in 103/634 (16%), unmutated IGHV in 406/591 (69%), complex karyotype (≥3 clonal structural or numerical abnormalities on karyotype) in 70/273 (26%), and positive CD49d expression in 229/449 (46%). The median pre-treatment beta-2-microglobulin level was 3.3 mcg/mL (range 1.2-24.4 mcg/mL). The median follow-up from 1L start was 50 months (95% CI 46-54 months). 496 pts met criteria for defining POD36 status; 72 (15%) had PD, and 424 did not. TP53 disruption (OR 2.9; 95% CI 1.5-5.7, P=0.001) was associated with POD36 on univariate analysis; complex karyotype, unmutated IGHV status, elevated serum lactate dehydrogenase level, age, sex, and inclusion of CD20mAb were not associated with POD36 status. Median OS from the time of determination of POD36 status was not reached. OS was significantly shorter after POD36 compared to non-POD36 pts (HR 3.5; 95%CI 2.1-6.0, P&lt;0.0001), with 4-year OS estimates of 65% and 88%, respectively. When assessed by landmark analysis at the 3-year timepoint following 1L start (n=50 POD36), OS was also shorter in pts with POD36 compared to non-POD36 pts (HR 3.5; 95%CI 1.8-6.8, P=0.0002). In the overall cohort (n=787), when evaluating OS from 1L treatment with POD36 as a time-dependent covariate, POD36 status was associated with an increased risk of death (HR 4.3; 95% CI 2.6-7.1, P&lt;0.0001) on univariable analysis; and remained an independent marker of shorter OS in multivariable analyses after adjusting for age, sex, TP53 disruption status, and IGHV status (HR 4.2; 95% CI 2.1-8.4, P&lt;0.0001). CONCLUSIONMost pts achieved durable CLL disease control with 1L targeted treatments, and early PD occurs much less frequently than previously reported with CIT. However, among pts who receive 1L targeted therapies for CLL, PD within 36 months is associated with a ~4-fold higher risk of death. These results, if validated in larger data sets, will provide a practical measure for identifying a high-risk subgroup of pts in need of novel treatment strategies in future trials.

Abstract Introduction: Pirtobrutinib, a highly selective non-covalent BTK inhibitor, demonstrated encouraging efficacy in Richter transformation (RT) of chronic lymphocytic leukemia (CLL) in the BRUIN trial (Wierda et al, Lancet Haematology, 2024). However, a control arm was not included in this phase 1/2 trial, and how pirtobrutinib compares to usual care is unknown. To address this gap of knowledge, we sought to compare efficacy outcomes in BRUIN to that in a control cohort consisting of RT patients treated with usual care at Mayo Clinic. Methods: The study was approved by the Mayo Clinic IRB. Patient-level data from BRUIN (n=79; investigator-assessed) were obtained from the study sponsor. Patients with histologically confirmed RT (large B-cell lymphoma) who received at least one line of therapy (n=230) were identified from the Mayo Clinic CLL Database. Multivariable logistic regression was employed to calculate propensity scores for baseline covariates (ie, age at RT treatment line, number of prior lines of CLL treatment [truncated at 3], number of prior lines of RT treatment [truncated at 3], and LDH). For each Mayo patient, propensity scores for each line of RT therapy were calculated, and the line with the highest propensity score was chosen as the index RT treatment line. Using the inverse probability treatment weighting (IPTW) methodology, individual weights were computed, and standardized mean differences (SMDs) were examined for each of the unadjusted and weighted baseline covariates to ensure that balance was obtained between BRUIN cases and Mayo controls. Overall survival (OS; the primary endpoint) and progression-free survival (PFS) were analyzed using unweighted and weighted Cox proportional hazards models. Unweighted and weighted overall response rates (ORRs) and complete response (CR) rates were analyzed using logistic regression. Results: The final analysis dataset contained 79 BRUIN cases (median age 67 [range 26-95], 66% male) and 204 Mayo controls (median age 69 [range 30-89], 74% male). The BRUIN cohort had more patients with ECOG PS ≥1 (61% vs 40%, p=0.001) and elevated LDH (81% vs 63%, p=0.003) than the Mayo cohort. The proportion of patients with TP53 aberration was not statistically different in both cohorts (57% vs. 44%, p=0.15). The index line of RT treatment in the Mayo cohort included chemoimmunotherapy (n=167, 80%) and novel agent-based therapy (eg, cBTKi, venetoclax, PI3Ki, immune checkpoint inhibitor, etc; n=42, 20%). Median lines of prior CLL therapy were 2 (IQR 1-4) vs 1 (IQR 0-3) in the BRUIN and Mayo cohorts, respectively; median lines of prior RT therapy were 2 (IQR 1-2) vs 0 (IQR 0-2). The SMDs of the weighted baseline factors met pre-determined criteria (-0.25≤SMD≤0.25), indicating that balance between the two cohorts was achieved. The median follow-up was 18.3 months (range 0.7-32.9) in the BRUIN cohort and 122.8 months (range 0-280.2) in the Mayo cohort. The unweighted median OS was 12.5 months (95% CI 7.0-20.6) in the BRUIN cohort and 5.7 months (95% CI 3.9-10.7) in the Mayo cohort. The unweighted HR was 0.76 (95% CI 0.54-1.07, p=0.12). After IPTW, the weighted HR was 0.63 (95% CI 0.50-0.78, p&lt;0.001), significantly favoring the BRUIN cohort. The unweighted median PFS was 3.6 months (95% CI 2.8-5.1) in the BRUIN cohort and 3.1 months (95% CI 2.5-4.3) in the Mayo cohort. The unweighted HR was 0.98 (95%CI 0.72-1.34, p=0.92). After IPTW, the weighted HR was 0.78 (95% CI 0.64-0.95, p=0.01), again favoring the BRUIN cohort. Response was evaluable/available in 69 patients in BRUIN and 182 patients in Mayo cohort. The unweighted ORR was 58% vs 53% in BRUIN and Mayo cohorts, respectively (OR=0.83, 95% CI 0.47-1.45, p=0.51), and the CR rate was 16% vs 36% (OR=2.94, 95% CI 1.43-5.88, p=0.003). After IPTW, the weighted OR was 0.65 (95% CI 0.45-0.93, p=0.02) for ORR, favoring the BRUIN cohort, and 1.89 (95%CI 1.23-2.86, p=0.02) for CR rate, favoring the Mayo cohort. Conclusions: This individual patient-level IPTW-based analysis demonstrated that single agent pirtobrutinib is associated with improved OS, PFS, and ORR compared to usual care in patients with RT. These results support the choice of pirtobrutinib over traditional therapies for RT. Although these results are encouraging, the durability of response to pirtobrutinib remains suboptimal. Ongoing trials and other future research will evaluate the efficacy of pirtobrutinib in combination with other treatments in this setting.