Citations

Abstract Recent studies have highlighted the important but pleiotropic role of IL-4 in response to chimeric antigen receptor T (CART) cell therapy. IL-4 was identified as a regulator of dysfunction in CD19-targeting CART cells with a CD28 costimulatory domain (CART19-28ζ) through a genome-wide CRISPR knockout screen as well as RNA and ATAC sequencing of baseline and exhausted healthy donor CART19-28ζ cells and pre-infusion CART19-28ζ cell products from responders and non-responders in the ZUMA-1 trial (Stewart et al, Nat Commun., 2024). However, interrogation of a single-cell atlas fromactivated pre-infusion CART cell products from patients with acute lymphoblastic leukemia revealed a beneficial role for IL-4 and other type 2 cytokines in the promotion of long-term response (Bai et al, Nature, 2024). In this report, we aim to further understand how IL-4 can be detrimental to CART cell therapy. To study the regulation of CART19-28ζ cells by IL-4, we performed RNA sequencing on CART19-28ζ cells that were stimulated with CD19+target cells in the presence of either 20 ng/mL hrIL-4 or diluent for 24 hours, one week, or two weeks in an in vitro model for exhaustion as previously described (Stewart et al, Nat Commun., 2024). We observed that hrIL-4 treatment drove the development of a distinct transcriptomic profile after chronic stimulation for one week (up genes = 3253 and down genes = 3645) or two weeks (up genes = 6435 and down genes = 6224) but not following 24 hours of activation (up genes = 0 and down genes = 0). Gene set enrichment analysis on the differentially expressed genes following two weeks of chronic stimulation showed that hrIL-4 treatment pushes CART cells to a more exhausted and less naïve phenotype (FDR = 0.015) and leads to a broad downregulation in cytokine signaling (FDR = 0.012). To investigate transcription factors associated with IL-4-induced CART cell dysfunction, we used BETA analysis with publicly available transcription factor binding sites for STAT6, GATA3, and EOMES and our differential expression data. EOMES (p = 0.039), but not STAT6 (p = 0.999) nor GATA3 (p = 0.999) significantly regulated the differentially expressed genes. In support of these findings, the addition of hrIL-4 also significantly upregulated EOMES expression after one (p < 0.0001) and two (p < 0.0001) weeks of chronic stimulation and downregulated the expression of TBX21 (p < 0.0001), a binding competitor of EOMES, following two weeks of chronic stimulation. To evaluate if EOMES is critical for IL-4-induced CART cell dysfunction, we treated either control or EOMES CRISPR knockdown CART cells with 20ng/mL hrIL-4 during chronic stimulation. EOMES knockdown reduced IL-4-induced CART19-28ζ cell dysfunction as seen by an increase in antigen-specific expansion (p = 0.046) and an increase in cytokine production including IL-2 (p < 0.0001), TNF-α (p = 0.006), and IFN-γ (p = 0.020). Having identified that EOMES is at least partially responsible for IL-4-induced CART cell dysfunction, we evaluated EOMES binding sites in human CART19-28ζ cells with CUT&RUN sequencing. Our analysis revealed EOMES binding at hypersensitivity site 2 (HS2) in the IL-4 locus which, in a previous study, was more accessible in both exhausted healthy donor CART19-28ζ cells and pre-infusion CART cell products from non-responders in the ZUMA-1 clinical trial (Stewart et al, Nat Commun., 2024). To determine how HS2 can impact CART cell functions, we generated CART19-28ζ cells from either wildtype (HS2+/+) or HS2-deleted (HS2-/-) murine T-cells and tested them in a syngeneic model of lymphoma generated by engrafting C57BL6 mice with luciferase+ TBL12 cells (1x106, tail vein injection on Day -3) following preconditioning (250mg/kg cyclophosphamide, intraperitoneal injection on Day -4). Following randomization of mice via tumor burden (n = 5 per group), mice were treated with either HS2+/+ or HS2-/- CART19-28ζ cells (1x106 cells, tail vein injection). In this model, HS2-/- CART cells showed enhanced expansion (p = 0.022), increased anti-tumor activity (p = 0.018), and improved overall survival (p = 0.003). Together, our study shows that IL-4 induces a distinct cellular fate in CART19-28ζ cells in the presence of chronic antigen-specific stimulation at least partially through the upregulation of EOMES. Further, the epigenetic regulation of CART cells by the IL-4 enhancer HS2 can significantly influence CART cell activity, and deletion of HS2 can improve CART cell therapy.

Abstract Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL), accounting for approximately 30% of all NHL cases. DLBCL diagnosis relies on histologic examination, immunophenotyping, molecular and fluorescence in situ hybridization (FISH) analysis to differentiate it from similar NHL subtypes with overlapping morphological features, including more high-grade lymphomas like double-hit lymphoma. Because FISH is performed in a panel of single- or dual-target test format and analyzed through microscopy and manual image analysis, assessment of multiple target biomarkers can be cumbersome and expensive. As additional biomarkers for diagnosis, subtyping, prognosis, and therapeutic decision-making become available, target panels will become larger, posing additional challenges to clinical laboratories. Patients and Methods In this study, Hi-C sequencing of FFPE samples was performed to identify all genomic rearrangements by a single sequencing analysis for an unselected DLBCL case series of 159 patients, and the results were compared to FISH for the detection of clinically important variants. Results Hi-C sequencing showed superior performance compared to FISH: standard FISH for DLBCL includes testing for MYC, BCL2, and BCL6. Between FISH and Hi-C, these biomarkers were detected 105 times, of which, FISH detected 80/105 (76%) and Hi-C detected 102/105 (97%). The cohort included 4 double-hit lymphomas by FISH but Hi-C sequencing detected five. Besides DLBCL diagnostic biomarkers (MYC, BCL2, BCL6), many additional biomarkers were detected by Hi-C sequencing including variants not tested by FISH because the clinical suspicion was ambiguous and the relevant FISH probes were not used, and those not tested because the biomarkers were not thought to be common and, hence, left out of the FISH panel. In total, Hi-C sequencing detected additional biomarkers in 42 (26%) cases, including (1) variants targeted by FISH (i.e. MYC, BCL2, BCL6) but negative, (2) classification biomarkers for other lymphomas (CCND1, MALT, IRF4), and (3) those not tested because the biomarkers are not common and not included in the FISH panel. These additional biomarkers were supportive of suspected diagnosis of DLBCL versus double-hit lymphoma (24 cases), prompted reconsideration of a different diagnosis that may have led to different treatments (6 cases, e.g. mantle cell lymphoma), or biomarkers such as PDL1, ALK, and ATM which have implications for targeted therapies and/or inclusion in clinical trials (5 cases). Conclusion The Hi-C FFPE sequencing technology has the potential to improve the workflow of pathology labs for detection of a wide range of structural variants informing precision diagnosis and treatment for lymphomas.

Abstract Background: Undetectable minimal residual disease (uMRD) at the end of first-line (1L) treatment (tx) with 12-cycles (C) of venetoclax (ven) + obinutuzumab (obin) is associated with prolonged survival for patients (pts) with chronic lymphocytic leukemia (CLL, Al Sawaf et al. Blood 2024). We hypothesized that MRD may be used to guide ven tx duration for CLL pts treated with 1L ven + obin. Methods In this ongoing phase II, multicenter investigator-initiated study, pts receive ven + obin for 1L tx of CLL/small lymphocytic lymphoma (NCT04447768). Eligible pts have a CIRS score of ≤ 6 and require 1L tx per iwCLL 2018 criteria. Pts receive 6 x 28-day C of obin and initiate ven on C1D22. Ven duration is dependent on peripheral blood (PB) MRD status measured by ClonoSeq next generation sequencing. At C7, pts undergo MRD testing. Pts uMRD6 (<10-6 sensitivity) at both C7 and C9 dc ven after 9C and enter treatment free observation (TFO). Pts with detectable MRD6 (dMRD6) at C7 undergo repeat testing at C12; if uMRD5 (<10-5) pts dc ven after 12C. Pts dMRD5 at C12 continue ven for an additional 12C (24C total) prior to TFO. The primary study endpoint is 36-month PFS; the unpromising rate is set at 82% and will be tested by a nonparametric survival estimate (Kaplan-Meier) along with Greenwood's formula. RNA sequencing (RNAseq) was performed pre-tx on patient bone marrow (or PB if inaspirable) samples. Unsupervised clustering using machine learning (ML) based on consensus nonnegative matrix factorization was applied to the most variable genes to identify patient clusters. Clusters were then biologically characterized by gene signature scoring using xCell algorithm and assessed for association with uMRD6 at C7 using a Fisher exact test. Results Baseline characteristics of the 100 pts who initiated tx include: median age 58 (range 34-81); 71% male, 90% White, 3% Black and 2% Asian, 5% unknown; 49% IGHV unmutated, 16% TP53 mutation, 8% del17p (previously reported, Roeker et al. ASH 2024). 3 pts stopped tx prior to C7. 51 pts were uMRD6 at C7 and C9 and completed 9C ven. 46 pts were dMRD6 at C7; 6 pts stopped tx outside of meeting protocol requirements and are included in intention-to-treat (IIT) analyses. 32 pts were uMRD5 at C12 and dc ven after 12C. 8 pts were dMRD5 at C12: 5 continued ven per protocol (3 completed 24C ven, 2 ongoing tx as of 15 May 2025 data cut-off), 2 stopped ven outside of protocol requirements (included in ITT analyses), and 1 pt withdrew consent. At a median follow-up of 35 months, the 36-month PFS rate is 90% (95% CI: 84%, 97%). 36-month OS is 94% (95% CI: 89%, 99%). Landmark PFS analyses from EOT were performed for pts who dc ven after 9C due to uMRD6 (24-month PFS 92%, 95% CI: 85, 100%, n=51) and pts who dc ven after 12C due to uMRD5 (24-month PFS 96%, 95% CI: 89%, 100%, n=32). For pts dc ven after 9C due to uMRD6 (n=51), PB MRD at 12C after EOT was: 59% uMRD6, 12% uMRD5, 4% uMRD4, 8% dMRD4 and 18% unknown. For pts dc ven after 12C due to uMRD5 status (n=32), PB MRD at 12C following EOT was: 9% uMRD6, 31% uMRD5, 9% uMRD4, 25% dMRD4 and 25% unknown. Of the 5 pts with PD, 3 pts have had Richter Transformation to diffuse large B-cell lymphoma (all uMRD6 at C7 / 9). Two pts with PD have not met iwCLL tx criteria and remain in TFO. Five pts have died (suicide, West Nile encephalitis, COVID-19, complications of glioblastoma and RT DLBCL). Five C12 dMRD5 pts who continued ven have reached C18, with only 1 of 5 converting to uMRD5 in PB. However, all 5 maintained uMRD4 (<10-4). Of 3 pts that completed 24C ven (2 ongoing tx), 1 pt had deepening of response to uMRD5 at C24, and 2 pts had rising MRD on ven (dMRD4 at C24). To investigate patient heterogeneity at baseline and its relationship to uMRD, we clustered patient RNAseq samples into two clusters using artificial intelligence/ML based unsupervised clustering. The clusters associated with uMRD6 at C7 (Fisher exact test p=0.038), and patients in the cluster with significantly higher immunosuppressive cells such as T-regulatory cells and M2 macrophages were less likely to be uMRD6 at C7. Conclusions At a median follow-up of 35 months, the estimated 36-month PFS rate is 90%. RNAseq transcriptomic analyses identified that patients with enriched immunosuppressive cells were less likely to be uMRD6 at C7. Additional follow-up is required to confirm the durability of this MRD-guided ven + obin tx strategy.

Abstract Introduction: Multiple myeloma (MM) accounts for nearly 20% of all hematologic cancers in the US and remains a substantial clinical burden, with patients (pts) requiring multiple lines of therapy (LOT). While advances such as BCMA-directed CAR T-cell therapy have improved outcomes, challenges persist, including disease relapse, treatment toxicities (CRS, ICANS, and non-ICANS neurotoxicities), and access. AZD0120 (formerly GC012F) is a first-in-class autologous BCMA/CD19 dual-targeting CAR T-cell therapy using the FasTCAR rapid manufacturing platform that preserves the naive and central memory T-cell phenotypes with marked in vivo proliferative capacity. Phase 1 investigator-initiated trials in China demonstrated deep, durable responses and a favorable safety profile following single-infusion AZD0120 in newly diagnosed and relapsed/refractory MM (RRMM) (Du J, et al. EHA 2024 and ASCO 2023). Here, we report for the first time preliminary phase 1b results from DURGA-1, an ongoing phase 1b/2 clinical trial evaluating the safety and efficacy of AZD0120 in pts with RRMM. Methods: This open-label, single-arm, US-based, multicenter study (NCT05850234) evaluated the safety/tolerability of 2 dose levels (DL) of AZD0120 in pts with RRMM along with preliminary efficacy. Eligible ptswere aged ≥18 y with RRMM (3+ prior LOT [pLOT] including a proteasome inhibitor, immunomodulatory drug, and anti-CD38 antibody), ECOG PS 0–1, and documented evidence of progressive disease. Exposure to BCMA-directed therapy ≥6 mo with best response of PR or better was permitted. Pts underwent lymphodepletion followed by a single infusion of AZD0120. Pts in DL1 received 1x105 cells/kg; DL2 received 3x105 cells/kg. Dose escalation and recommended phase 2 dose (RP2D) were determined by a safety review committee. Phase 1b primary objectives included safety/tolerability and RP2D determination; secondary objectives included efficacy, cellular kinetics (CK), and pharmacodynamics. Results: As of data cutoff (DCO) on 18 July 2025, a total of 25 pts received infusion of AZD0120 (n=12 DL1; n=13 DL2). The median age was 64 y (range 44–78), median pLOT was 4 (range 3–7), 72% were triple-class refractory, 20% had prior BCMA CAR T-cell therapy, 4% had prior teclistamab, 28% had high-risk cytogenetic features [del(13q), del(17p13), t(4;14), t(14;16), amp(1q)], and 8% had extramedullary plasmacytomas. The median time from apheresis to release was 14 d (range 10–30). Median time from apheresis to infusion was 28 d (range 19–44) with 5 pts receiving bridging therapy. Median follow-up was 1.4 mo (range 0–19.3). No dose-limiting toxicities were reported for either dose. The most common treatment-emergent AEs (TEAEs, any grade) were CRS (64%), neutrophil count decreased (56%), and anemia (32%). The most common grade ≥3 TEAEs were neutrophil count decreased (52%), lymphocyte count decreased (32%), and white blood cell count decreased (32%). CRS was reported in 75% of pts at DL1 (all grade 1) and 54% at DL2 (46% grade 1; 8% grade 2), with no cases of grade ≥3 CRS. Median time to CRS onset (DL1/DL2) was 9 d (range 2–11), with a median duration of 2 d (range 1–4); 12 pts (48%) received tocilizumab for CRS management and 12% received dexamethasone. No cases of ICANS, related non-ICANS neurotoxicity, IEC-colitis, or secondary primary malignancies have been reported. There have been no deaths. For efficacy-evaluable patients (n=15), ORR was 100% (33% sCR, 47% VGPR, 20% PR). CR rates in evaluable pts were 30% in DL1 (n=10) and 40% in DL2 (n=5); median time to response was 0.9 mo for both DLs (range 0.9–1.9 DL1; 0.6–1.8 DL2). All MRD-evaluable pts (n=5 DL1; n=3 DL2; DCO 01 July 2025) were MRD-negative by NGS at a sensitivity of 10-5. Three pts in DL1 with ≥12 mo follow-up maintained MRD negativity. Consistent with robust in vivo expansion, CK analysis from 16 evaluable pts (DCO 12 June 2025) demonstrated a median Tmax of 13 d post-infusion with a median Cmax of 85,266 copies/mg gDNA. Median persistence was 42 d (range 13–273). Updated clinical data with additional follow-up will be presented. Conclusion: Preliminary phase 1b results demonstrated AZD0120 was well tolerated, with a low incidence of serious AEs, no grade ≥3 CRS, and no ICANS. FasTCAR-manufactured AZD0120 had expectedin vivo expansion, which may have resulted in the predictable CRS profile. A single infusion of AZD0120 achieved early, deep responses with 100% MRD negativity from 4L+ triple-class‒exposed pts with RRMM.

Abstract Background: Integrin αE (CD103) has been thought to mediate gut-homing Treg retention during GVHD by facilitating E-cadherin interaction on intestinal epithelial cells. However, only a small percentage of natural Tregs express CD103 in peripheral blood (PB). To leverage this mechanism and potentially enhance Treg therapeutic efficacy, we hypothesized that Tregs overexpressing CD103 (CD103high) would show improved gut-homing and GVHD mitigation. Methods: Murine CD4 Tregs were isolated from C57BL/6 (B6) mice via flow sorting and were retrovirally transduced with murine CD103 or truncated epidermal growth factor receptor as a control. Transduced Tregs were then tested in a murine acute GVHD model (B6 → BALB/c). Mouse organs, including small intestine (SI), colon, spleen, PB, axillary (aLN) and mesentric lymph nodes (mLN) were harvested on day 10 post-transplant and analyzed by flow cytometry, multiplex cytokine assay, histopathology, and single-cell RNA sequencing (scRNA-seq). Ex vivo expanded Tregs were subjected to 13C-glucose tracing assay to evaluate glycolytic flux, TCA cycle, and lipid biosynthesis. Results: Despite comparable FoxP3 expression at the end of ex vivo expansion, CD103high Tregs had significantly higher in vitro suppression compared to control Tregs (54% vs. 33% at Treg:Tcon ratio of 1:8, p=0.004). Upon re-stimulation, CD103high Tregs demonstrated increased proliferation compared to control Tregs (3.8 vs 2.8 fold expansion, p <0.0001). Bulk RNA seq on ex vivo expanded CD103high showed upregulation of immuneregulatory and metabolic programs including GTPase signaling and oxidative stress control. These transcriptomic changes suggest that CD103 intrinsically promotes a regulatory phenotype, stress tolerance and metabolic fitness. In vivo, CD103highTregs significantly decreased the severity and mortality of GVHD, compared to control Tregs, as measured by clinical scores, weight loss, and survival (50% vs 0% on day +60, p<0.0001 for three independent experiments combined; n = 24/group). Day 20 histopathology revealed significantly improved colitis scores in mice treated with CD103high Tregs vs controls (9.5 vs. 14.6, p=0.02). While these findings could be partially attributed to CD103 gut-homing function, we observed that CD103high Treg absolute number and frequency were higher not only in the the GI organs and mLN, but also in the spleen, PB, and aLN with similar distribution ratios across different organs (~5-fold higher). In vivo CFSE suppression assay, where CFSE labeled donor T cells were cotransferred with Tregs into B6 Rag1ko mice, demonstrated enhanced suppressive function of CD103high Tregs in the spleen (p=0.02), an effect that could not be accounted for by the conventional gut-homing mechanism attributed to CD103. Plasma cytokine analysis showed significantly elevated IL-10 levels in mice treated with CD103high Tregs (p<0.0001), consistent with increased Treg number and frequency. 13C-glucose tracing assay showed lower palmitate levels in CD103high Tregs, indicating lower de novo lipid synthesis, while glycolysis and TCA cycle tracing were similar. Day 10 scRNA-seq on colon samples revealed seven distinct immune clusters. The neutrophil cluster was absent in CD103high Treg group, suggesting reduced inflammation. Donor-derived dendritic cells (DCs) upregulated genes such as Cstb, and Slamf7, while pro-inflammatory genes including Cd52 and Cd74 were downregulated. STAT5 signaling was upregulated, indicating reprograming of myeloid cells toward an immunoregulatory state. Colon epithelial cells from CD103high Treg-treated mice displayed enhanced stress tolerance, with increased oxidative phosphorylation, fatty acid metabolism, and epithelial repair pathways. CellChat analysis revealed that CD103high Tregs reshaped the intestinal communication landscape, with DCs acting as key signaling hubs through interactions such as Ccl6–Ccr2 and Lgals3–Cd44. Enhanced DC-to-DC and DC-to-T cell communication suggest that CD103high Tregs promote a tolerogenic DC network that modulates downstream immune responses and supports epithelial recovery. Conclusion: Tregs overexpressing CD103 via retroviral transduction significantly improve overall survival and GVHD clinical scores in a murine transplant model. CD103High Tregs orchestrate broad remodeling of cell-cell communication across immune and stromal compartments, promoting an immunoregulatory microenvironment that underlies their protective effects in GVHD.

Abstract Background We performed a prospective study evaluating a baseline GA battery and clinical outcomes in fit older adults (age ≥60 years) with AML and normal cardiac and renal function in the recent E-A NCTN E2906 phase 3 study. A patient-reported outcomes (PRO) assessment of Depression, Activities of Daily Living (ADL), Cognitive Function, Social Support (SS) domains, and comorbidity was performed at study registration to evaluate the prevalence of vulnerabilities and their impact on overall survival (OS) and 30-day induction mortality rates (IM) in this cohort selected for fitness to receive IC. Methods E2906 study design and results have been presented previously [n=727, age ≥60 years, randomized 1:1 to ‘standard 7&3‘ & high dose cytarabine (Arm A) vs. single agent clofarabine (CLO, Arm B), as remission induction (Step 1) and consolidation (Step 2)]. There was no difference in composite complete remission (CCR, 50%) or IM (8.5%), and CLO was inferior for OS. A baseline GA was a key secondary protocol objective, offered to all patients, and n=532 (73%) participated. We assessed Geriatric Depression Scale (GDS, none vs. any depressive symptoms, n=524); cognitive screen using Mini-Mental Exam Section (MMES, score 8/8 vs. <8, n=516); ADL & Instrumental ADL (iADL), (need for assistances vs. not n=526); a Medical Outcomes Study SS Survey (MOS-SS, measured as per unit increase, n=527); a Comorbidity survey ( ≤4 vs. ≥5 patient-reported comorbidities, n=530), patient-reported prescription medications use (PM, 0-3 vs. ≥4, n=519); and a survey of Sexual Desire (n=491) and Sexual Activity (n=477) within 4 weeks of AML diagnosis. Association of GA domains with OS, IM, and achievement of CCR was evaluated using the Chi-squared, Fisher's exact, and Wilcoxon rank sum test. Survival analysis was performed using the Cox proportional hazards models, adjusted for treatment arm. All p-values are 2-sided. Results The median age among those participating in GA battery was 67 yrs (range 60-85), including 38% age ≥70. There were 42% females, and ECOG performance status was 0 (28%), 1 (54%), 2 (16%), or 3 (2%). Central Cytogenetic review was classified (ELN2017) as Favorable (3%), Intermediate (66%), and Adverse (31%) risk. There was a notable rate of GA scores outside ‘normal’ clinical cutoff, including Depression (GDS 31%), cognitive and functional impairment [MMSE (37%), ADL (25%) and iADL (32%)], ≥5 Comorbidities (23%), and ≥4 PM's (44%). 81% & 76%, respectively, reported no sexual activity and low/none sexual desire. MOS-SS tended to be high in this cohort [mean (SD) score 87 (17)]. We observed a significant association of GA domains with OS & IM. For OS, absence of depressive symptoms [GDS, Hazard Ratio (HR) 0.79, 95% confidence Intervals (CI) 0.64-0.97, p=0.025)], MMES 8/8 (HR 0.78, 95%CI 0.64-0.96, p=0.016), requiring no assistance with ADLs (HR 0.65, 95%CI 0.52-0.82, p<0.001) and iADLs (HR 0.69, 95%CI 0.57-0.85, p<0.001), and ≤4 Comorbidities (HR 0.68, 95%CI 0.54-0.84, p=0.001) were significant for superior OS; use of ≥4 PM's was associated with inferior OS (HR 1.32, 95%CI 1.09-1.61, p=0.005). There was no association of sexual activity/desire, BMI ≥30 kg/m2, or MOS-SS with OS. IM was significantly higher among those with any depression symptoms (GDS, p=0.005), any ADL (p=0.010) or iADL (p=0.013) impairment, ≥5 comorbidities (p=0.037) and ≥4 PM's (p=0.001); there was no association with MOS-SS or MMES. There was no significant association of GA scores with cytogenetic risk group or with CCR rates. Only ADL independence (p=0.048), and possibly Comorbidity ≤4 (p=0.071), were associated with proceeding to Step 2. Conclusions In this large prospective cohort of fit older adults with AML selected to receive IC, we observed high rates of PRO-assessed GA vulnerability, which was significantly associated with inferior OS and higher IM rates, and (for ADL impairment) lower rates of proceeding to consolidation therapy. This suggests that functional and cognitive impairments are prevalent and can significantly impact outcome even in fit older adults. Despite potential long-term OS advantages of IC previously observed in E2906, efforts to systematically recognize those at higher risk based on GA PROs are needed to help identify patients who may be more appropriate for study of lower intensity treatment options to mitigate impact on IM and OS. SImilarly we plan to evaluate the potential benefit of GA-driven supportive care to improve patients' outcomes.

Abstract Introduction: Indolent systemic mastocytosis (ISM) is a clonal mast cell disease driven by the KIT D816V mutation in ~95% of cases and is associated with symptoms of mast cell activation and tissue infiltration. It can cause chronic, debilitating symptoms − including life-threatening anaphylaxis and impaired bone health. While historically most patients have relied on symptom-directed best supportive care (BSC) therapies, avapritinib is used as a new standard of care targeting KIT D816V, the primary driver for SM. Avapritinib is an oral, potent, selective KIT D816V inhibitor, and the first and only approved targeted therapy for adult patients with ISM in the USA and the EU. Approval was based on results from the phase 2 PIONEER trial. Here, we present the findings from ~3.5-year long-term follow-up. Methods: Adults with centrally confirmed ISM and uncontrolled moderate-to-severe symptoms who completed the randomized dose-finding (Part 1), or randomized, double-blind, placebo-controlled (Part 2) portions of PIONEER (NCT03731260) rolled over to the open-label, long-term extension (Part 3). This cumulative analysis includes patients who initiated avapritinib at the recommended dose of 25 mg once daily (QD) in either Parts 1, 2, or 3. All patients received BSC. Per investigator discretion and based on disease burden, dose titration up to 50 mg QD of avapritinib was permitted in Part 3. Long-term efficacy was assessed by measuring changes in symptoms and QoL, using the ISM-Symptom Assessment Form (ISM-SAF; ©2018 Blueprint Medicines, a Sanofi Company) and the Mastocytosis Quality-of-Life Questionnaire (MC-QoL). Safety was also assessed. Results: Overall, 226 patients initiated avapritinib 25mg QD across Parts 1, 2, and 3. This longer-term analysis is inclusive of 65 patients who dose titrated from 25 mg to 50 mg QD in Part 3. Median (range) treatment duration was 40.0 months (0.7‒67.2) as of February 21, 2025. Longer-term efficacy data with ~3.5 years of follow-up demonstrated sustained disease-related symptom improvements. The mean change (standard deviation [SD]) in total symptom score (TSS, per ISM-SAF), was −19.80 (19.81) at Week 144 (Month 33) and −20.43 (20.57) at Week 168 (Month 39) from a baseline of 48.08 (19.47). Additionally, avapritinib-treated patients demonstrated durable improvement in their most severe symptoms (mean change [SD] from baseline of −3.35 [3.02] at Month 33 and −3.47 [3.19] at Month 39) per ISM-SAF. Sustained responses were observed across all individual symptom domains (0–30) with mean changes (SD) at Month 33 and Month 39 of −3.77 (5.52) and −3.84 (6.05) for the gastrointestinal domain, −8.21 (7.70) and −8.20 (7.85) for the skin domain, and −4.66 (6.24) and −4.87 (6.51) for the neurocognitive domain. The mean percent change (SD) in MC-QoL was −34.67 (40.16) at Month 33 and −40.72 (33.24) at Month 39 from a baseline of 54.24 (18.32). Treatment with avapritinib was well tolerated, and its safety profile was similar to the previously reported placebo-controlled portion. Most treatment-related adverse events (TRAEs) were Grades 1–2, and 7% of patients experienced Grade ≥3 TRAEs of which diarrhea, neutrophil count decrease, and weight increase occurred in >1 patient. No Grade ≥3 TRAEs of increase in transaminases were observed. Edema (peripheral and periorbital), the most frequently reported TRAE, was mostly Grade 1 and occurred most frequently during the first 3–4 months of treatment. Three patients (1%) experienced serious adverse events assessed as treatment related. However, none led to treatment discontinuation and no trends were observed. After approximately 3.5 years of follow-up, low rates of treatment discontinuations (n=7, 3%) due to TRAEs were observed. Conclusion: Longer follow-up of patients with ISM treated on the PIONEER trial, including some on avapritinib for up to 5 years, demonstrates that prolonged avapritinib therapy continues to be effective and well tolerated. Additional prospective analyses will be needed to determine effects of selective KIT D816V-inhibition on anaphylaxis. These data support a favorable benefit-risk profile of avapritinib as a chronic treatment for adult patients with ISM.

Abstract B cell maturation antigen (BCMA)-targeted chimeric antigen receptor T (CART) cell therapies have emerged as a potentially curative treatment for multiple myeloma (MM). However, 50-70% of patients relapse within 3 years. The MM tumor microenvironment (TME) is highly immunosuppressive with an abundance of bone marrow (BM) cancer-associated fibroblasts (CAFs), which contribute to BCMA-CART cell failure. Therapeutic targeting of BM-CAFs has been beset by 1) an incomplete understanding of CAF interactions with CART cells and other BM cells and 2) toxicity risks due to prolonged depletion of healthy fibroblasts and inefficient drug delivery to the BM. To elucidate how BM-CAFs drive BCMA-CART resistance, we performed single cell RNA sequencing (scRNAseq) of baseline BM aspirates from responders (R, n = 6) and non-responders (NR, n = 6) to BCMA-CART cell therapy. NR BMs were enriched for inhibitory CAFs (iCAFs) that highly express fibroblast activation protein (FAP). Spatial analyses of BM cells revealed greater iCAF-iCAF and iCAF-inhibitory macrophage interactions in NR. These findings suggest that FAP+ iCAFs in NR are abundant in the BM and exhibit significant interactions with immunosuppressive macrophages. Next, we sought to validate our scRNAseq data in preclinical models. Xenograft mice were intravenously (IV) engrafted with luciferase+ (luc+) BCMA+ OPM2 cells and/or patient-derived (pd) BM-CAFs (1x106 each). Following engraftment, mice received 1x106 BCMA-CART cells (IV). BCMA-CART cells eradicated tumors in mice engrafted with OPM2 cells, but not in mice engrafted with pdBM-CAFs and OPM2 cells (p<0.01). In NSG and humanized mice (NSG mice engrafted with human CD34+ cells in the first 48 hours of life), tumor growth was significantly accelerated in the presence of pdBM-CAFs (NSG: p<0.01; humanized: p<0.001). BCMA-CART, OPM2, and pdBM-CAF co-cultures also showed significant increases in immunosuppressive cytokines including IL-1Rα, IL-4 and IL-10 and inhibited CART cell proliferation compared to co-cultures without pdBM-CAFs (IL-1Rα, IL-10: p<0.01; IL-4: p<0.001; proliferation: p<0.05). To overcome CAF-mediated CART dysfunction, we engineered BCMA-CART cells to secrete molecules to target BM FAP+ iCAFs and remodel the MM-TME (STriKEs). We designed two BCMA-CART-STriKE strategies: 1) a tri-specific composed of IL-15, anti-FAP, and anti-CD16 molecules to activate innate immune cells to kill CAFs and 2) bi-specific anti-FAP, anti-SIRPα molecules linked to an antibody Fc region (Fc fusion) targeting the CD47/SIRPα axis to induce phagocytosis of FAP+ iCAFs. We hypothesized that BCMA-CART-STriKEs would surmount CAF-mediated immunosuppression without toxicity. We generated BCMA-CART-STriKEs from healthy human donor T cells. CAR expression, STriKE secretion, and binding were confirmed via flow cytometry. Co-cultures of BCMA-CART-STriKEs, donor-matched macrophages, OPM2 cells or BCMA+ MM1S cells, and pdBM-CAFs showed significantly higher OPM2 or MM1S killing (p<0.001), immune cell activation (p<0.01), and phagocytosis (p<0.05), compared to control BCMA-CART cells secreting IL-15 or Fc fusions targeting only FAP or only SIRPα. Next, we assessed BCMA-CART-STriKE efficacy in vivo. NOD-SCID-γ-/- (NSG) mice received 1x106 pdBM-CAFs and 1x106 luc+ OPM2 or luc+ MM1S cells via IV or subcutaneous (SQ) injection. Mice were randomized after confirming tumor engraftment (via bioluminescence imaging for IV or tumor caliper for SQ) and received IV treatment with 1x106 BCMA-CART-STriKEs (or controls) and 5x105 donor-matched macrophages or CD16+ immune cells. BCMA-CART-STriKE-treated mice achieved total tumor clearance. Treatment with BCMA-CART cells secreting IL-15 led to lethal weight loss despite tumor clearance while BCMA-CART cells secreting Fc fusions targeting only FAP or SIRPα failed to eradicate tumors. Lastly, we assessed the potential toxicities of BCMA-CART-STriKEs in humanized mice engrafted with OPM2 cells and pdBM-CAFs (1x106 each). CART cells expressing BCMA and FAP CARs (BCMA-FAP CART) served as a control. BCMA-FAP CART treatment resulted in significant toxicity and weight loss while BCMA-CART-STriKE treatment did not (p<0.01). In summary, we have identified iCAF interactions with immunosuppressive immune cells as key contributors to BCMA-CART cell failure and designed novel BCMA-CART-STriKEs that overcome this failure in MM preclinical models. These findings support the translation of BCMA-CART-STriKEs to a phase I clinical trial.

Abstract Background: Intravenous (IV) isatuximab plus pomalidomide and dexamethasone (Isa-Pd) is approved for treatment in patients with relapsed/refractory multiple myeloma (RRMM) based on the ICARIA-MM study. Subcutaneous (SC) administration of Isa offers potential advantages such as shorter administration duration and greater patient comfort compared with IV routes. Isa SC via an on-body injector (OBI), an investigational wearable bolus injector, demonstrated safety and efficacy in a Phase 1b study in patients with RRMM. The IRAKLIA trial (NCT05405166) was the first Phase 3 trial evaluating the non-inferiority of Isa-Pd SC via an OBI vs Isa-Pd IV in patients with RRMM. Here, we report the findings of the IRAKLIA trial in the East Asian subgroup with RRMM. Methods: This global, multicenter, open-label study enrolledpatients aged ≥18 years with RRMM who had received ≥1 prior line of therapy (LOT) including lenalidomide and a proteasome inhibitor (PI). Patients were randomized 1:1 to Isa SC (1400 mg) or Isa IV (10 mg/kg) weekly in Cycle (C)1, then every 2 weeks in addition to P (4 mg orally daily, Day [D]1-21) and d (40 mg orally [20 mg if age ≥75 years] weekly). Treatment was administered in 4-week cycles and continued until disease progression, unacceptable toxicity, or patient withdrawal. Co-primary endpoints included overall response rate (ORR) and observed Isa concentration before dosing (Ctrough) at steady state (predose at C6D1). Key secondary endpoints included rate of very good partial response or better (≥VGPR), Ctroughlevel Cycle 2 Day 1 (C2D1), infusion reaction incidence, and patient satisfaction rate based on the patient experience and satisfaction questionnaire (PESQ) at C5D15. Results: The East Asian subgroup consisted of 105 patients from China (Mainland, n=82 and Taiwan, n=1) and Japan(n=22) (SC, n=50; IV, n=55). Baseline characteristics of the East Asian subgroup were generally balanced between the two arms and generally comparable to the overall global population (median age 62 years; median 2 prior LOT; 29.5% high-risk cytogenetics; 82.9% refractory to lenalidomide; 7.6% prior exposure to daratumumab). After a median of 13.0 months follow-up, ORR in the SC and IV arm was 74.0% and 70.9%, respectively (relative risk [95% CI] = 1.044 [0.815 – 1.335]). The mean (SD) of Ctroughat C6D1 was 502 (232) µg/mL for SC arm and 282 (123) µg/mL for IV arm. The geometric mean ratio (90% CI) comparing SC to IV for Ctrough at steady state was 1.756 (1.346 – 2.290). The ≥VGPR rates were 58.0% for SC and 50.9% for IV (relative risk [95% CI] = 1.139 [0.798 – 1.631]). The mean(SD) of C2D1 Ctroughlevel was 420 (161) µg/mL for the SC arm and 262 (111) µg/mL for IV arm. The geometric mean ratio (90% CI) comparing SC to IV for Ctrough at C2D1 was 1.673 (1.321 to 2.120). The infusion reaction incidence was 0% and 21.8% for SC and IV, respectively. Grade ≥3treatment-emergent adverse events were observed in 82.0% and 87.3% of patients in the SC and IV arms, respectively. Treatment discontinuation rates were 6% for the SC arm and 12.7% for the IV arm. Injection site reactions (ISRs) occurred in 4% (2/50) of patients in the SC arm and in 0.21% (2/964) of SC injections (all Grade 1), with 99.3% of SC injections completed successfully. Isa SC patients expressed higher satisfaction with their injection method, with 64.0% of patients reporting “satisfied” or “very satisfied” vs 52.7% of Isa IV patients (odds ratio [95% CI] = 1.594 [0.728 – 3.489]). Conclusions: The efficacy, safety and pharmacokinetic results between Isa SC vs IV + Pd in the East Asian population from the IRAKLIA study were consistent with the results of the overall global population, in which non-inferiority of ORR, Ctrough at C6D1, ≥VGPR and Ctrough at C2D1 was demonstrated and statistically significantly fewer infusion reactions and higher patient satisfaction were also noted for SC vs IV. These results support the potential use of Isa SC delivered via OBI in East Asian patients and demonstrate the potential of this delivery method to improve patient experience and practice efficiency.

Abstract Marginal zone lymphoma (MZL) is an uncommon non-Hodgkin B-cell lymphoma accounting for 7-10% of lymphoma diagnoses. Extranodal MZL (EMZL) of mucosa-associated lymphoid tissue (MALT) is the most common subtype (61%) of MZL. While the mutational landscape, chromosomal aberrations and transcriptome of nodal and splenic MZL have been extensively evaluated, the mutational landscape of EMZL has only been evaluated in a small number of patients and mainly by targeted sequencing. Consequently, the comprehensive genomic landscape of EMZL remains largely uncharacterized. Herein, we performed whole exome sequencing followed by targeted sequencing of potential tumor driver genes, copy number and/or RNA transcriptome analyses in 165 patients with pretreatment EMZL tumors involving 16 anatomic locations. All samples were collected and underwent expert review as part of the Atlas of Blood Cancer Genomes consortium. The most common anatomic locations were ocular adnexa (OAMZL) (n=35), gastric (n=25, including 6 positive for Helicobacter pylori), salivary glands (n=25), and lungs (n=24). Using common criteria for variant mutation calling and significant focal copy number (CN), we identified 1218 variants (1030 missense and 188 truncation mutations) across 174 genes and 2837 CN focal alterations (1614 copy gains and 1223 copy number losses). Of these genes, 44 and 11 were mutated in >5% and >10% of specimens, respectively. We detected variants identified previously by targeted sequencing in EMZL from different locations (e.g. TNFAIP3 (A20) (12%), TBL1XR1 (13%), SPEN (10%), CARD11 (7%), TET2 (7%) and CREBBP (6%)). We detected mutations in KLF2 (10 mutations in 8 EMZL patients) and PTPRD (7 mutations in 7 EMZL patients) that were previously suggested to be specific for splenic and nodal MZL, respectively. We also detected variants not previously reported in EMZL, including a transcriptional factor ZEB2, LRP1B,and others. The most frequently mutated gene in our study (25% of tumors) was IGLL5. Some mutations were limited to specific locations (e.g. ZEB2 mutations seen exclusively in gastric and salivary gland EMZL), while most were observed across all anatomic locations. There was no association between specific mutations and clonal IGHV, in contrast to previous reports. Using Enrichr tool, we observed enrichment of mutations in genes belonging to the B cell receptor activation, NOTCH signaling, Wnt-beta catenin signaling, NF-kB signaling , PI3K AKT signaling, DNA repair and other pathways. Chromosomal and copy number changes were also commonly observed including previously reported trisomy of chromosomes 3 and 18. Combining DNA mutations and CN alterations, the number of genetic lesions per tumor sample in the 174 mutated genes ranged from 0 to 95, with an average load of 17 lesions per case. RNA sequencing was successful in 159 EMZL tumors from 16 distinct anatomic locations. Unsupervised clustering using all genes with a median log2-normalized gene expression value greater than 5 and a standard deviation greater than 1 (1323 genes) demonstrated that the majority of gastric EMZL with and without H. pylori infections clustered together on 2 dendrograms as did most of the samples of OAMZL. Since the clustering could be forced by organ-specific and not tumor-specific gene expression, we next focused on the expression of the 345 genes from the LM22 matrix that passed our transcriptomic row filtering. Unsupervised clustering resulted in clustering of most gastric EMZL irrespective of H. pylori positivity together in the same dendrogram branch, accompanied by few additional EMZL from other anatomic locations. Most of the EMZL samples from other locations did not show preferential co-clustering together. On comparison of gene expression between gastric and OAMZL, there was enrichment of the B-cell receptor signaling pathway, B-cell activation, B-cell naïve and B-cell memory cells, B-cell proliferation and NF-kB signaling in the latter. Immune microenvironment analysis showed a statistically significant increase in resting mast cells and decrease in M1 macrophages in gastric EMZL and increase in regulatory T cells in salivary EMZL. The broad genomic studies reported here underscore the biological similarity of EMZL across anatomical sites with the potential exceptions of gastric EMZL (regardless of H. Pylori status). These data provide valuable genomic and transcriptomic resources to inform future diagnostic and therapeutic strategies.