Citations

Abstract Background: The functional importance of bone marrow adipocytes (BMA) is frequently overlooked even though they are critical components of the BM (bone marrow) microenvironment. BMA have been proposed to play a supportive role within the hematopoietic niche and to directly sustain hematopoietic stem cell (HSC) survival as well as to preferentially support leukemia cell survival and proliferation (Sabbah Cell Commun Signal 2023). Although significant ex-vivo data implicates direct and indirect crosstalk between BMA and neoplastic HSCs (Venti Front Endocrinol 2022), the possible role of BMA in myeloproliferative neoplasms and their dynamics following therapy have yet to be characterized. Adiponectin, an anti- inflammatory adipokine that maintains metabolic homeostasis through regulation of insulin sensitivity, lipid metabolism and pro-inflammatory signaling is low in MPN patients and increases with IFN-α therapy (Avcu Int J Hematol. 2006). IFN-α has also been implicated in inhibiting adipogenesis via JAK-STAT1 signaling (Lee Biochim Biophys Act. 2016). A single institutional study of IFN-α in patients with essential thrombocythemia (ET) and polycythemia vera (PV) confirmed the potential for BM histopathologic responses and a correlation with molecular responses (Masarova Exp Hematol Oncol 2017). The aim of this analysis was to characterize the change in BM cellularity and fat composition with pegylated IFN α-2a (Pegasys; PEG) and the relationship with both hematologic and molecular response from tissue collected in prospective, global clinical trials of PEG in patients with ET/PV. Methods: A total of 24 subjects from the phase 2 MPN-RC 111 (Yacoub Blood 2019) salvage PEG study and 16 subjects from the MPN-RC 112 (Mascarenhas Blood 2022) phase 3 study comparing PEG to HU with available clinical, BM H&E slides, laboratory and molecular data were included in this retrospective analysis of prospective clinical trial data. We assigned a semi-quantitative score for changes in cellularity, fat distribution, and megakaryocyte (MK) histo-topography for changes from baseline, at 12, 24 and 36 months when available. Changes in BMA content and para-trabecular distribution were assessed on whole slide digital images with machine learning models. BMA content was quantified with a QuPath pixel classifier that distinguished adipocytes from other marrow components (Bankhead Scientific Reports 2017). Para-trabecular adipocyte distribution was assessed by leveraging UNI2-h, a self-supervised Vision Transformer (ViT-H/14) model and successor to UNI (Mahmood Nature 2024). UNI2-h was pre-trained on 200 million image tiles from over 300,000 H&E and IHC slides. In this study, UNI2-h was adapted to distinguish between high and low para-trabecular adiposity using image tiles centered on trabeculae. Trabeculae with a surrounding layer of adipocytes were labeled as ‘high’ adiposity, while ‘low’ para-trabecular fat distribution was defined by the direct contact of cellular marrow with trabeculae, lacking surrounding adipocytes. Results: A total of 40 PEG-treated ET (n=18) and PV (n=22) patients were included in this analysis with a median age of 64 years (26-85), 77% JAK2V617F+, 23% CALRmut+, and 40% treatment-naïve. The median JAK2V617F variant allele fraction (VAF) was 26% (range 3-96%). A complete hematologic response (CHR) was obtained with PEG in 58%, 61% attained >20% reduction in driver VAF and 48% attained a >50% reduction in VAF (MR) within 24 months of baseline. We observed an increase in BMA content and notable increase in para-trabecular distribution (confirmed by morphology and ML, independently) in 93% and 53% of PEG treated patients attaining a MR versus only 31% and 6% who did not attain MR, respectively (P Value=0.0004). There was more notable improvement towards normalization of MK histo-topography and orderly erythropoiesis in MR (86.6%) than in non-MR (31.2%) (P value=0.001). Increase in BMA content, BMA para-trabecular distribution, or improvement in MK histo-topography were not associated with achievement of CHR or changes in CALR VAF in this small cohort. Cytokine correlation with BMA dynamics is currently ongoing and will be reported at the meeting. Conclusion: Treatment of MPN patients with IFN-α resulted in reproducible changes in BM cellularity including MK histo-topography, erythropoiesis, BMA number and distribution. Changes in BMA were closely associated with reduction in JAK2V617F VAF following PEG treatment.

Abstract Introduction: Older adults (OAs) with classic Hodgkin lymphoma (cHL) have inferior survival compared with younger patients (pts). NAVD has been widely adopted in clinical practice for frontline (1L) treatment of OAs with advanced stage cHL based on the subset analysis of S1826 study (Rutherford et al, JCO 2025) showing a 1-year progression-free survival (PFS) of 93% and 1-year overall survival (OS) of 95% after NAVD (n = 50) which remained durable on longer-term follow up. Another phase 2 study (Torka et al, JCO 2025) showed that NAVD is a highly effective and well-tolerated 1L regimen in OAs with cHL (n=40) across a wide range of geriatric impairments. Adverse events (AEs) and efficacy have not been reported in OAs treated with NAVD outside of a clinical trial. Hence, we sought to evaluate safety profile and efficacy outcomes of OAs with cHL treated with 1L NAVD in a real-world setting (RWS). Methods This is a multicenter retrospective cohort study of adults (≥18 years) with cHL treated with 1L NAVD between 2023 and 2025 at 20 US academic sites. Baseline characteristics and outcomes of pts ≥60 years were evaluated as a pre-planned subset analysis. The safety evaluable cohort received at least 1 cycle of NAVD and included pts who had not yet completed treatment. The efficacy evaluable cohort had completed 6 cycles of treatment including end of treatment (EOT) PET-CT and included pts who intended to complete treatment but died or discontinued due to progressive disease or AEs. The primary endpoint was EOT overall response rate (ORR). Secondary endpoints included EOT complete response rate (CRR), PFS and OS. PFS and OS were analyzed using the Kaplan Meier method. Results Among 311 pts, 81 were OAs (26%). Median age of the OA cohort was 70 (range 60-88) yrs, 65% male, 84% Caucasian, 71% nodular sclerosis subtype, 58% stage 4 disease, 59% B symptoms, 14% bulky disease (>7.5 cm), 69% extranodal sites, 41% EBV positive, 54% hypoalbuminemia, 49% IPS ≥ 4 and10% had an autoimmune disease. G-CSF was given in 81% pts. All 81 pts were evaluable for safety; 74% experienced a grade 3+ (≥G3) AE, 54% had ≥G3 hematological AE, 48% had ≥G3 neutropenia, 17% had febrile neutropenia. Infection rate was 28% with 10% ≥G3, neuropathy rate was 23% with 4% ≥G3. One infusion reaction was noted. Treatment related hospitalizations rate was 23% with median duration of 7 (range 1-16) days. There were 24 immune related AEs (IrAE) (30%) of which 5 were ≥G3. Most common IrAE was hypothyroidism (n=5), followed by inflammatory arthritis (n=4), pneumonitis (n=2, ≥G3, n=1), hepatitis (n=2, both ≥G3), adrenal insufficiency (n=2, ≥G3, n=1), colitis (n=2), and rash (n=2). One patient each had autoimmune neutropenia, sarcoidosis of lung/skin and myocarditis (≥G3). Overall, 15% pts required steroids with resolution of IrAEs in 56% cases, 30% (n=7) pts required continued therapy (levothyroxine in 4 pts, steroids in 3 pts, medical tx for heart failure in 1 pt). Treatment was interrupted in 22%, reduced in 22%, and discontinued in 23% pts. Nivolumab was discontinued in 14% pts. Among all pts (n=81), 81% had an interim PET-CT after 2-4 cycles. The ORR and CR rate at interim PET-CT were 100% and 81%, respectively. In the efficacy evaluable pts (n=52; 24 still on therapy), the EOT ORR and CRR were 93.2% and 84% in OAs compared to 96.8% and 91.7% in pts <60yrs, respectively. At a median follow up of 10.2 mo (range 0.27-28.52), the 1-yr PFS was 90.6% (95% CI: 82.7%-99.3%) in OAs and 95.5% (95% CI: 91.6%- 99.6%) in pts <60 yrs (p=0.044). 1-yr OS was 97.5% (95% CI: 94.1-100%) and not evaluable in pts <60yrs (p=0.017). None of the baseline features were predictive of response, additional analysis to understand impact on AEs and survival is ongoing. Among the 5 pts with progression/relapse, 4 were primary refractory. 4 pts received 2nd line (2L) therapy.79 pts are alive at data cut off, 2 deaths occurred- 1 infection-related and other unknown; both after the 1st cycle. Conclusions In this largest RWS cohort of OAs treated with NAVD we showed comparable response rates, AEs and 1-year survival outcomes to those in the pivotal S1826 trial. Notably, rates of ≥G3 AEs including infections, neuropathy and IrAEs remained low and manageable. Although survival significantly improved with NAVD compared to historical data, outcomes of OAs remained inferior compared to pts <60 yrs. Our data reinforces the use of NAVD as the preferred 1L option for OAs with advanced stage cHL.

Abstract Background: MyeloMATCH is an NCI-sponsored initiative for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) employing a Master Screening and Reassessment Protocol (MSRP) to assign patients (pts) to a pt and disease biology-specific clinical trial. Several trials evaluating initial therapies are currently open, while subsequent trials dedicated to eradicating measurable residual disease during consolidation and including stem cell transplant are being developed. A pt enrolled at diagnosis may be followed longitudinally and be eligible for trials in sequential tiers throughout the treatment course. We report key data concerning the first cohort of pts enrolled on the MSRP. Methods: After pts with suspected AML or MDS consent for the MSRP, blood and marrow are sent to the myeloMATCH Molecular Diagnostics Network (MDNet) of central CLIA labs operating under a single Investigational Device Exemption to rapidly define molecular, cytogenetic, and immunophenotypic characteristics. These data are catalogued by a bioinformatics team (MATCHBox) and reviewed daily to assign participants to an available trial based on pt and disease features. A Tier Advancement Pathway (TAP) allows standard of care therapy with potential for assignment to subsequent myeloMATCH trials. Since activation in May 2024, 550 patients age≥18 were enrolled on the MSRP from 76 institutions: 48 Academic, 14 NCORP, 11 community, 3 VA. There are currently 4 open randomized AML trials (≥age 60 or unfit with mutant FLT3, ≥age 60 IDH2 mutant AML, fit age<60 ELN 2017 intermediate-risk AML, fit age<60 ELN 2017 adverse risk) and 1 MDS trial(IDH2 mutant). Patients not eligible for an open protocol were assigned to TAP. Results: Of the 550 pts consented, 491 completed screening assays; 49 had no or incomplete samples; 10 withdrew before completed analysis. Median cytogenetic turnaround time (TAT) was 69 hours (91% within 72 hours), and median Next Generation Sequencing (NGS) TAT from receipt was 49 hours (95% within 72 hours). Seventy-six pts (of 491 with assay data) were not assigned due to non-AML or non-MDS diagnoses, the most common being: B-ALL [n=11], MPN [9], benign marrow [9], APML [7], and MPAL [6]. The AML/MDS verified cohort was 415 pts, 366 (89.2%) patients with AML (45% age <60) and 49 (11.8%) with MDS. The median age at screening was 63 years (range:18-95) and 186 (45%) were female. Eighty-two percent identified as White, 7.5% Black, 3% Asian, 7% unknown, and 9% as Hispanic. The most frequent mutations in the AML pts were NPM1 (24.0%), DNMT3A (22.7%), TET2 (19.9%), NRAS (18.0%), FLT3 (18.0% ITD, TKD 7.1%), TP53 (14.5%), and CEBPA (8.7%); IDH1/2 mutation rates were 8.2% and 13.7%, respectively. Co-mutations include FLT3/NPM1 (9.8%), NPM1/IDH2 (4.4%), IDH1/2 and any RAS (3.8%). Karyotypes were normal in 40.4%, complex 20.8%, inv(16) 6.0%, MLL/KMT2A 4.6% and t(8;21) 1.9%. 29% had favorable risk disease, 29% intermediate, and 42% adverse (ELN 2017). In MDS, mutations included: TP53 (36.7%), RUNX1 (20.4%) ASXL1 (20.4%), TET2 (18.4%), spliceosome mutations (SRSF2, SF3B1, U2AF1 and ZRSR2, 28.6%) andIDH1/2 in 4.1% and 6.1%, respectively. Karyotypes were normal in 24.5%; complex in 40.8%. By IPSS-R, 2.4% were low, 73.8% intermediate, 2.4% high, and 21.4% very high risk. 82/415 (20%) pts were assigned to initial therapy protocol, with an increase in assignment rate to 44% in the most recent two months. 71/415 pts (16%) were enrolled in one of the MyeloMATCH studies. Three-hundred forty-four pts (80%) were assigned and enrolled to TAP (296 AML, 48 MDS) for potential assignment to subsequent tier trials. In the TAP AML pts, 99 (33%) have completed initial treatment, including intensive chemotherapy (IC) in 62% of pts and hypomethylating agents/venetoclax (HMA/VEN) in 38%. In pts <60 years of age, 87% received IC v. 13% with HMA/VEN, in >60 34% IC v. 66% HMA/VEN and in age 60-75 42% IC v. 58% HMA/Ven. Conclusion: MyeloMATCH has screened over 500 pts from academic and community sites in the US and Canada in 14 months, meeting the TAT goal of sample acquisition to results of <72 hours. Assignment to treatment protocols has substantially increased recently. As additional trials open (12 in development) we expect the percentage of pts enrolled on MSRP who go on to therapeutic trials will markedly increase, thereby allowing a personalized medicine approach for a broad group of US and Canadian adult pts with AML and MDS.

Abstract Chimeric antigen receptor T (CART) cell therapy has shown unprecedented success in the treatment of hematological malignancies. However, the immunosuppressive tumor microenvironment of both solid and liquid tumors is a major barrier for CART efficacy. Immunosuppressive myeloid cells inhibit CART efficacy. Colony-stimulating factor 1 receptor (CSF1R) promotes macrophage proliferation, survival, and anti-inflammatory response and is upregulated on myeloid cells in many cancers, making CSF1R an appealing therapeutic target. We aimed to test the interactions between CSF1R, myeloid cells, and CART response, and to study CSF1R targeting in the context of CART cell therapy. We utilized CD19-targeted CART cell therapy (CART19) in lymphoma preclinical models and thyroid-stimulating hormone receptor (TSHR)-targeting CART cell therapy (TSHR-CART) in thyroid cancer models. We first measured CSF1R expression on myeloid cells in vitro. Suppressive myeloid cells, polarized from healthy donor monocytes using an anaplastic thyroid cancer (ATC) cell line, 8505c, or mantle cell lymphoma cell line, JeKo-1, significantly upregulate CSF1R (p=0.0002) compared to media control. After polarization, myeloid cells significantly inhibit TSHR-CART and CART19 antigen-specific proliferation compared to freshly isolated monocytes (p=0.012, p<0.01, respectively) indicating that suppressive myeloid cells contribute to CART failure in multiple tumor types. We then performed single cell RNA sequencing on peripheral blood taken at baseline from patients with mantle cell lymphoma treated with CART19. We found a significant increase of CSF1R on monocyte subsets in CART19 non-responders vs responders (padj=0.0037). Next, we determined the impact of CSF1R blockade on CART cell therapy in vivo. Using lymphoma models, B6 mice were engrafted with the luciferase+ CD19+ murine lymphoma cell line TBL-12 (1x106 cells i.v. 1 day after 250 mg/kg cyclophosphamide). Tumor burden was significantly reduced after 7 days of treatment with low dose CART19 (0.5x106 i.v.) + anti-mouse CSF1R antibody (16mg/kg i.p. twice weekly) vs CART19 + IgG control (p=0.0146). We then tested the impact of CSF1R blockade in mice experiencing tumor relapse. After TBL-12 engraftment, mice were treated with anti-mouse CSF1R or IgG control antibody followed two days later with high dose CART19 (1x106 i.v.) to induce remission. Mice were re-challenged with TBL-12 14 days later. Mice treated with anti-mouse CSF1R antibody showed increased tumor control and significantly higher survival (p=0.0416). Using thyroid cancer models, first we identified high macrophage infiltration in biopsy specimens of patients with ATC compared to normal thyroid tissue and benign thyroid tumors through immunohistochemistry (IHC) of patient samples (p<0.01, p<0.0001, respectively). To test if macrophages are associated with CART failure in ATC, NSG mice were subcutaneously engrafted with 1x106 TSHR+ THJ529 tumors, an ATC cell line derived from patient biopsy samples from the Mayo Clinic thyroid cancer biobank, followed by i.v. treatment with 1x107 TSHR-CART or untransduced T cell control (UTD). IHC staining of tumor tissue collected at experimental endpoints revealed a dose-dependent, significant infiltration of human CD3+ T cells into the tumors which inversely correlated with murine F4/80+ myeloid cell and murine YM-1+ M2 macrophage infiltration. This led us to hypothesize that myeloid cell targeting with CSF1R blockade can improve TSHR-CART efficacy. We utilized the same ATC model described above to test CSF1R targeting. When TSHR+ THJ529 tumors reached approximately 100 mm3, mice were randomized by tumor volume and treated with CSF1R inhibitor PLX5622 (600mg/kg) or vehicle control, followed by either UTD or TSHR-CART cells 5x106 i.v. Mice treated with TSHR-CART + PLX5622 showed significantly improved tumor control vs TSHR-CART + vehicle control (p<0.0001) or UTD + PLX5622 (p<0.0001). Together, our results highlight immunosuppressive myeloid cells which express CSF1R as a major cell type limiting CART efficacy in both solid and liquid tumors. We also identified a strategy to overcome myeloid-mediated suppression of CART cells by targeting CSF1R with antibody or small molecule inhibitors.

Abstract Introduction Persistent symptom burden in classic myeloproliferative neoplasms (MPNs) i.e., polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis (MF) is linked to shorter survival, more thromboembolic events and impaired quality of life. Identifying demographic, clinical, laboratory, and treatment-related predictors of symptom improvement can inform risk-adapted care and guide supportive interventions. Methods Patients with PV, ET, and MF were identified through a retrospective chart review. Total symptom scores (TSS) and scores of individual symptoms were recorded at the time of first TSS assessment. Demographic (age, sex, race, ethnicity), seasonal (summer: April–September; winter: October–March), clinical (time since diagnosis, depression, obesity, spleen size), treatment-related (phlebotomy, hydroxyurea, interferon-alpha, anagrelide, JAK inhibitors, antidepressants) and laboratory (complete blood counts, serum chemistry) factors were captured at the baseline. Symptom improvement was defined as a ≥50% TSS reduction from baseline. Cumulative incidence analyses, accounting for death as a competing risk, were performed to estimate the probability and timing of symptom improvement. Multicollinearity was assessed using variance inflation factors (VIFs). Highly correlated (VIF ≥5) features and features with ≥15% missing observations were excluded. Multivariable Fine-Gray hazards regression was performed to identify predictors of symptom improvement. Sub-distribution hazard ratios (sHR) with 95% confidence intervals (CI) were computed with p-values <0.05, indicating a statistically significant association with symptom improvement. Results A total of 532 patients (PV: 195, ET: 180, MF: 157) were identified between 2019 and 2024. The median age was 65 (IQR: 57-74) for PV, 65 (52-75) for ET, and 69 (63-75) for MF. Most patients were White (PV: 178, ET: 164, MF: 145) and female (PV: 99, ET: 134, MF: 84). Fatigue was the most frequently reported symptom (PV: 161, ET: 155, MF: 136) whereas weight loss was the least reported (PV: 9, ET: 12, MF: 26). Baseline TSS was highest in MF (median: 15; IQR: 7-27) followed by PV (13; 6-25) and ET (13; 5-23). Symptom improvement was observed in 89 (46%) PV, 71 (39%) ET, and 44 (28%) MF patients. Among those who improved, the cumulative incidence of symptom improvement reached 100% by 55 months in PV, 53 months in ET, and 58 months in MF. At 6, 12, and 24 months, cumulative symptom improvement was 22%, 34%, and 57% in PV; 15%, 25%, and 43% in ET; and 19%, 28%, and 39% in MF. Median time to improvement was not reached in any group. Death before symptom improvement was observed in 5 (3%) PV, 6 (3%) ET, and 37 (24%) MF patients. Multivariable regression analyses in PV identified higher baseline TSS (sHR: 1.02; 95%CI: 1.01-1.03) as associated with symptom improvement (p = 0.02). In ET, lower white blood cell count (sHR: 0.89; 95%CI: 0.81-0.98) and less time since diagnosis (0.99; 0.98-0.99) were associated with symptom improvement (p = 0.02). In MF, more months since diagnosis (sHR: 1.01 95%CI: 1.01-1.01) was associated with symptom improvement (p = 0.01). Conclusions Symptom trajectories differed across MPN subtypes. In PV, a higher baseline symptom burden; in ET, a lower white blood cell count and more recent diagnosis and in MF, a longer disease duration were associated with symptom improvement. These readily available parameters may help inform supportive strategies, tailor response expectations, and identify patients for symptom-directed interventions or clinical trials.

Abstract Background/rationale Primary myelofibrosis (PMF) and post-polycythemia vera/essential thrombocythemia (Post-PV/ET MF) (collectively termed MF) are chronic hematopoietic malignancies with progressive bone marrow collagen fibrosis, peripheral cytopenias, extramedullary hematopoiesis, splenomegaly, debilitating constitutional symptoms and heightened risk of transformation to acute leukemia. The only currently approved therapies for MF are JAK inhibitors (JAKi) which can provide significant improvements in splenomegaly and systemic symptoms but do not fundamentally change the pathogenesis of the disease. As a result, additional non-JAKi therapies for patients with MF after JAKi failure represent an important translational focus. Reparixin is a novel, potent and specific inhibitor of the chemokine CXCL8 (IL)-8. IL-8 is a member of a class of cytokines involved in leukocyte recruitment and activation in tissues. There are two known types of CXCL8 receptors – CXCR1 and CXCR2, which are expressed in neutrophils (Baggiolini M, Adv Immunol 1994). IL-8/CXCR1/2 signaling has been shown to be a key mediator of inflammatory signaling in MF patients. Hematopoietic stem/progenitor cells from patients with MF are enriched for a CXCL8/CXCR2 gene signature and display enhanced proliferation and fitness in response to an exogenous CXCL8 ligand in vitro. Genetic deletion or a small molecule inhibitor of CXCR2 in MF mouse adoptive transfer models ameliorates fibrosis, extends overall survival and improves hematologic parameters (Dunbar A, Blood 2023). This pre-clinical data validates targeting this pathway in clinical investigations. Study design This is an open-label, phase II study assessing the efficacy, safety, and tolerability of reparixin in patients with Dynamic International Prognostic Scoring System (DIPSS) intermediate-2, or high-risk PMF, post ET/PV MF either after prior treatment with, or those who are ineligible for treatment with a JAKi. Patients will receive oral reparixin 1200 mg three times daily on a four-week cycle for a core study period of 24 weeks. Patients who achieve at least clinical improvement (CI) or stable disease (SD) with one grade improvement in bone marrow fibrosis by International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) criteria at the Cycle 7 response assessment may continue receiving reparixin until loss of response, disease progression, unacceptable toxicity, patients/physician withdrawal, or termination of study by sponsor. The study monitors both efficacy and toxicity using a Bayesian Optimal Phase 2 (BOP2) design. If response is observed in at least one patient out of 10 and safety is confirmed at the interim analysis, the trial will proceed to full enrollment of 26 patients. If more than three responses are observed in the total cohort, then a signal of activity is confirmed. Primary Objective: To estimate the efficacy of reparixin treatment in DIPSS intermediate-2 or high-risk subjects with PMF, post PV-MF, or post ET-MF. Secondary Objectives: To assess the efficacy of reparixin as determined by response assessment using IWG-MRT/ELN criteria at the end of Cycle 6 and Cycle 12. To assess the change in bone marrow fibrosis grade at the end of Cycle 6 and Cycle 12 with reparixin. To assess the safety of reparixin as measured by the adverse event profile of Common Terminology Criteria for Adverse Events v5.0. To assess spleen volume reduction by imaging after Cycle 6 and Cycle 12 as compared to baseline spleen volume. Key Exploratory Objectives: To evaluate changes in quality of life and patient-reported outcomes To conduct correlative studies to measure biomarkers of reparixin activity, such as Vascular Endothelial Growth Factor (VEGF) levels, bone marrow microvessel density, megakaryocyte number and peripheral blood CD34+ cell number, and patients with and without IL-8 secretion. Key inclusion criteria: Have a pathologically confirmed diagnosis of PMF, post-ET-MF, or post-PV-MF as per the WHO diagnostic criteria with intermediate-2 or higher risk disease by DIPSS Be refractory/resistant to or intolerant of/inappropriate for JAKi therapy Have adequate liver and kidney function Platelet count ≥ 25 x 109/L Bone marrow and peripheral blood blast count < 10% ANC ≥ 1000 mm3. MPN Research Consortium (MPN-RC) 120 is currently enrolling patients through the MPN-RC clinical sites throughout the United States. Clinical Trial Identifier NCT05835466

Abstract Background: Despite recent therapeutic advances in AS cHL, PET-adaptive chemotherapy-based regimens remain a first-line treatment option, especially for patients (pts) without access to novel agents. Most PET-adaptive regiments start with either 2 cycles of escBEACOPP (escBEACOPP2) or ABVD (ABVD2) prior to interim PET assessment (iPET), followed by treatment de-escalation or intensification by iPET result. There have been no direct comparisons of escBEACOPP2 vs ABVD2 PET-adaptive regimens. Additionally, the AS-Hodgkin Lymphoma International Prognostication Index (A-HIPI) score (Rodday JCO 2023) has not been fully explored in escBEACOPP2 regimens. Therefore, we utilized multiple analytic approaches to compare outcomes of PET-adaptive escBEACOPP2 and ABVD2 regimens, while adjusting for and assessing the effect of the baseline A-HIPI score. Methods: Through the global HoLISTIC Consortium (www.hodgkinconsortium.com), we obtained individual patient data from 4 AS clinical trials of newly diagnosed cHL pts treated with PET-adaptive escBEACOPP2 (AHL2011) or ABVD2 (SWOG0816, RATHL, HD0607) regimens. Pts were restricted to age 18 to 65 years (y), stage IIB-IV, and PET-adapted treatment arms. Positive iPET was based on Deauville score >3. Treatment effects of escBEACOPP2 vs ABVD2 (reference) on 5y progression-free survival (PFS) and overall survival (OS) were first evaluated using Cox models. Importantly, baseline disease risk was adjusted for using the 5y PFS or OS A-HIPI score (including stage, sex, age, bulk, lymphocyte count, albumin, white blood cell count), where higher scores indicate higher predicted risk (scale 1-100). The A-HIPI was modeled per 1 standard deviation (SD) increase. Our multistate model (MSM) comprised 4 health states: diagnosis, sustained remission at 1yr, treatment failure, and death from any cause. Pts all started in the diagnosis state and transitioned to other states without return to prior states. We assessed the impact of treatment on transitions (except binary sustained remission at 1y) that involved ≥5 pts per treatment group, adjusting for A-HIPI for all transitions. All effects are reported as adjusted hazard ratios (aHRs) with 95% confidence intervals (CI). Results: 2,381 AS cHL pts were included (n=372 for escBEACOPP2, n=2009 for ABVD2). For escBEACOPP2 and ABVD2 groups (median follow-up 60 and 56 months), respectively, the mean baseline A-HIPI scores (i.e., predicted 5y PFS event rate) were 25.1 (SD=6.3) and 22.9 (SD=6.5), the rates of positive iPET were 11.3% and 17.0%, 5y PFS was 87.0% and 79.5%, and 5y OS was 96.3% and 94.6%. In Cox models, escBEACOPP2 was associated with significantly improved PFS compared to ABVD2 (aHR=0.54, 95% CI=0.39-0.73); the aHR for OS was 0.67 (95% CI=0.37-1.19). Notably, higher risk A-HIPI score was associated with significantly worse PFS (aHR=1.42, 95% CI=1.31-1.54) and OS (aHR=1.60, 95% CI=1.47-1.76), independent of treatment. In the MSM, the effect of escBEACOPP2 compared to ABVD2 regimens was modeled in 3 transitions with adjustment for A-HIPI score: those treated with escBEACOPP2 had lower likelihood of treatment failure with (aHR=0.38, 95% CI=0.22-0.66) or without (aHR=0.61, 95% CI=0.40-0.92) sustained remission at 1y; the aHR for treatment failure to death was 0.55 (95% CI=0.25-1.22). Higher risk baseline A-HIPI score was associated with higher likelihood of treatment failure and death without sustained remission at 1y (aHR=1.43, 95% CI=1.28-1.61 and aHR=2.50, 95% CI=1.80-3.49, respectively). Furthermore, higher risk baseline A-HIPI score was associated with higher likelihood of treatment failure after achieving sustained remission at 1y (aHR=1.29, 95% CI=1.12-1.48) as well as death after treatment failure (aHR=1.54, 95% CI=1.27-1.86). Conclusions: Comparing newly diagnosed adult AS cHL PET-adaptive regimens with adjustment for baseline A-HIPI score, we found pts treated with escBEACOPP2 on AHL2011 had improved PFS versus pooled pt data from 3 ABVD2 trials. Using MSM, we further demonstrated that escBEACOPP2 was associated with a lower likelihood of treatment failure with or without achieving sustained remission at 1yr. In addition, baseline A-HIPI score was associated with PFS and OS, which was independent of treatment. Finally, higher baseline A-HIPI scores maintained prognostic impact throughout the disease course, including increased risk of treatment failure for pts in remission at 1yr and death after treatment failure.

Abstract Background: A randomized multicenter trial (BMT CTN 1703) demonstrated that after reduced intensity conditioning HCT, PT-Cy-based GVHD prophylaxis led to significant reductions in acute and chronic GVHD, but was associated with significantly more Grade 2 (moderate) infections and similar overall survival vs Tac/MTX. A linked mechanistic study (BMT CTN 1801) found that PT-Cy led to pan-T cell depletion and reduced T cell receptor (TCR) repertoire diversity vs Tac/MTX. To discover the molecular mechanisms driving the association of PT-Cy with increased infections, we examined pathogen-specific T cell reconstitution in BMT CTN 1801 patients (n=165 PT-Cy, n=159 Tac/MTX). Methods: We performed deep TCR sequencing on 2,369 blood samples collected pre-HCT (recipient baseline) and on Days +7, 14, 28, 63, 100, 180, 270, 365, 730, and from the graft infusion product. We then applied a novel set of TCR classifiers (Adaptive Biotechnologies) capable of identifying pathogen-specific clones associated with CMV, EBV, SARS-CoV-2, HSV-1, HSV-2, parvovirus, RSV, influenza A, rhinovirus, adenovirus, HHV-6B, norovirus and Toxoplasma. Single-cell (sc) TCR/RNA-sequencing on a sample subset (n=26) was performed to determine the phenotype of pathogen-specific T cells. Results. By linking scRNA-seq with pathogen-specific TCR barcoding, we identified CD4 and CD8 memory T cells as their predominant T cell reservoir. We found that the total number of pathogen-specific singleton TCRs was significantly lower with PT-Cy, starting early post-HCT and persisting through 2 years. For example, at Day +14, PT-Cy patients had 7.8-fold fewer pathogen-specific singleton TCRs vs Tac/MTX (mean of 6.9 vs 54.1, p<0.001). Consistent differences between PT-Cy and Tac/MTX were observed for TCRs specific for each pathogen individually. Patients who developed Grade 3 (severe) viral infections had significantly fewer pathogen-specific singleton TCRs at Day +14 compared to those who had no viral infections (mean of 4.0 vs 32.5, p=0.03). Leveraging intrinsic TCR barcoding of the HCT infusion (“graft”) and of the patient's baseline samples (“recipient”), we could assign the graft/recipient origin of the pathogen-specific cells with high fidelity. This analysis revealed pronounced differences in the origin of pathogen-specific T cells with PT-Cy vs Tac/MTX, especially prior to Day +100. The absolute number of pathogen-specific TCRs originating from the graft was significantly higher with Tac/MTX vs PT-Cy. This difference was observed from day +7 through 6 months post-HCT, with up to 7.1-fold more graft-derived pathogen-specific TCRs in Tac/MTX vs PT-Cy (p<0.001 at each timepoint before day +100). Within patients who received Tac/MTX, the balance of graft vs recipient pathogen-specific clones significantly favored graft clones (for example, a mean of 14.9 graft vs 8.6 recipient pathogen-specific TCRs at Day+14, p=0.02). By contrast, with PT-Cy, in addition to having substantially fewer pathogen-specific TCRs overall, the proportion of these TCRs was not significantly different between graft and recipient clones (mean of 2.1 graft vs 3.3 recipient pathogen-specific TCRs at Day+14, p=0.42). These data uncover that, in addition to the reduction in pathogen-specific T cells with PT-Cy, there was a relative skewing of the anti-microbial T cell reservoir towards recipient cells that persisted after conditioning. Conclusions: PT-Cy led to in vivo T cell depletion across all T cell subsets, which prominently included clones tracked from the allograft itself into the HCT recipient, with a relative sparing of recipient T cell clones that survived transplant conditioning. While the mechanism for relative sparing of recipient cells has not yet been determined, these conditioning-exposed cells may be less proliferative than newly infused graft T cells. The depletion of graft T cells included CD4 and CD8 memory cells specific for infections, which may have contributed to relative deficits in protective immunity against infection in patients receiving PT-Cy. Importantly, these data suggest that with PT-Cy, persisting recipient TCRs may play a key role in preserving anti-infectious immunity. Taken together, these results provide a mechanistic basis for key post-transplant clinical outcomes of the landmark BMT CTN 1703 study. They also underscore the importance of recipient immune status with PT-Cy, creating the opportunity for targeted infection risk assessment in these patients.

Abstract Introduction: Brexucabtagene autoleucel (Brexu-cel) is a CD19-targeted chimeric antigen receptor (CAR-)T cell therapy approved for treatment of relapsed/refractory (r/r) B-ALL. Brexu-cel's approval was founded on data from the ZUMA-3 trial, in which 78 patients (pts) were treated at the pivotal dose of 1x10e6 CAR-T cells/kg, resulting in a complete remission (CR) rate of 73%. Three-year follow-up from ZUMA-3 demonstrated median relapse-free and overall survival (RFS/OS) of 11.6 and 25.6 months (mos) for all treated pts. Amongst responders, the median OS was 60.4 mos for those who did not receive a subsequent allogeneic hematopoietic cell transplant (HCT) (n=43), but only 36.3 months for those who did (n=14). This has led some to conclude that HCT may not be beneficial following brexu-cel therapy for r/r B-ALL; however, it must be noted that 29 (37%) of the pts treated on ZUMA-3 received brexu-cel for post-HCT relapse. T cells collected from individuals who relapse in the post-HCT setting are largely of donor origin, making the CAR-T product comparable to a genetically modified donor lymphocyte infusion (DLI). The immunology at play in this scenario may be different from that in which CAR-T cells are of truly autologous origin. Methods: The Real-World Outcomes Collaborative for CAR-T in ALL (ROCCA) consortium database includes pt characteristics and outcomes of brexu-cel therapy given as standard-of-care across 41 US institutions. We identified pts who achieved an MRD negative (neg) CR by either flow cytometry (minimum sensitivity 10e-4) or NGS following brexu-cel for r/r Ph neg B-ALL and categorized them into three groups with regard to use of HCT: Never HCT, Pre-CAR HCT, or Post-CAR HCT. Pts who received second HCT following brexu-cel for post-HCT relapse (n=9) were excluded. Pt/disease characteristics, RFS, and OS were assessed for each group, landmarked at 73 days after brexu-cel infusion (the median time to consolidative allogeneic HCT). Results: In the ROCCA database we identified 165 pts who achieved MRD neg CR following brexu-cel, amongst whom 69 never underwent HCT, 49 were transplanted pre-CAR (ie, brexu-cel served as a genetically modified DLI), and 47 underwent post-CAR consolidative HCT while in CR. The median follow-up is 373 days. The median age was higher in the Never HCT group (49, range 19-83) in comparison with the Pre-CAR HCT (40, 24-72) and Post-CAR HCT (34, 18-70) groups. Thirty-five percent were >60yo in the Never HCT group vs 20% in the Pre-CAR HCT and 9% in the Post-CAR HCT groups. Ph-like disease was present in 38%, 29%, and 43% of the Never HCT, Pre-CAR HCT, and Post-CAR HCT groups, respectively (p=0.35). No significant differences were observed in pre-apheresis bone marrow blasts, presence of CNS disease at apheresis, prior blinatumomab or inotuzumab treatment, or use of bridging therapy across the groups, though there was a higher prevalence of non-CNS extramedullary disease in the Pre- and Post-CAR HCT groups (32, 39%) vs the Never HCT group (13%) (p=0.004). A minority of pts in all groups were deemed to be in MRD neg CR prior to apheresis (6-20%). Median RFS was 260 days in the Never HCT group and not reached in the Pre- and Post-CAR HCT groups (p=0.002), with respective 1-yr RFS of 38%, 64%, and 67%. Median OS was not reached in any group and was similar for all at 1-yr at 68-79% (p=0.13). Characteristics of those in the Never HCT group who were least likely to relapse included age >60 (OR 0.22, CI 0.07-0.73 vs age 18-39, p=0.024) and those with non-Ph-like B-ALL (OR 0.33, CI 0.12-0.94, vs Ph-like, p=0.037) in univariate analyses. Conclusions: Real-world data regarding outcomes following brexu-cel therapy allow evaluation of the role for consolidative allogeneic HCT, which remains one of the most important unresolved questions in the use of CAR-T therapy for r/r B-ALL. This analysis demonstrates that a first consolidative HCT after achieving MRD neg CR with brexu-cel is associated with a significant decrease in relapse. Additionally, use of brexu-cel for post-HCT relapse is also associated with a significantly lower risk of relapse compared with those who never received an allogeneic HCT. With the current duration of followup, OS is not significantly different across the three groups. These data suggest there is a benefit for relapse-free survival in pts receiving an allogeneic HCT at some point in the course of treatment for r/r Ph neg B-ALL.

Abstract Background: Chronic graft-versus-host disease (cGVHD) is a leading cause of non-relapse mortality following allogeneic hematopoietic cell transplantation (allo-HCT). Further investigation is needed to understand cGVHD risk, diagnostic features, and outcomes. Patient-reported outcomes (PROs) are important for characterizing the direct and indirect impact of cGVHD on patients, caregivers, and the healthcare system. THRIVE (NCT05919511) is a prospective, longitudinal observational study of patients at risk for cGVHD to describe the clinical course, burden, and practice patterns for cGVHD. THRIVE uses a novel app-based platform designed for rigorous collection of PROs related to symptoms, quality of life, and indirect costs to the healthcare system. We report preliminary patient demographics and clinical characteristics at study enrollment. Methods: THRIVE includes adults aged ≥18 years in the United States who were enrolled 90–180 days after allo-HCT. Follow-up is for 36 months at intervals determined by clinician standard practice; a virtual site is available for patients who return to community sites for follow-up. Presence or absence of GVHD symptoms, cGVHD therapies when applicable, and adverse events are captured in medical records at clinical visits every ~3 months. In all, 13 PROs are assessed (Cutaneous GVHD Questionnaire [CuGQ], General Anxiety Disorder [GAD-7], Lee Total Symptom Scale [TSS; 7-day], modified Frenchay Activities Index [mFAI], modified Patient-Generated Subjective Global Assessment [mPG-SGA], Oral Health Impact Profile [OHIP-14], Ocular Surface Disease Index [OSDI-12], Patient Health Questionnaire [PHQ-9], Patient-Reported Baseline Data [PRBD], Patient-Reported Caregiver Assessment [PRCA], Patient-Reported Economic, Income, and Insurance Data [PREIID], Patient-Reported Outcomes Measurement Information System–Sexual Function [PROMIS-SF], and Pulmonary GVHD Questionnaire [PulmGQ]). Patients are randomized to sequence groups to complete rotating sets of 4–5 PRO measures via digital platform, monthly (Year 1) then every 2 months (Years 2–3). Recruitment is ongoing (target, 1500 patients). Results: This interim report includes the first 340 patients enrolled in THRIVE (data cutoff: June 17, 2025) at 22 sites across the United States since August 1, 2023. Median (range) age was 60.5 (19–83) years (>70 years, n=60 [18%]). Most patients were male (n=190, 56%), White (n=276, 81%), and had college/graduate education (n=219, 64%). Underlying disease was malignant in 328 (96%) patients; most common malignancies requiring allo-HCT were acute myeloid leukemia (n=129, 38%), myelodysplastic syndrome (n=50, 15%), and acute lymphocytic leukemia (n=37, 11%). Most patients (n=212, 62%) were in complete remission at time of allo-HCT, 282 (83%) enrolled after their first allo-HCT, and median (range) time from allo-HCT to enrollment was 111 (77–211) days. Transplant source was most commonly peripheral blood stem cells (n=272, 80%) from unrelated (n=229, 67%) donors, of whom 169 (50%) were male. Overall, 188 (55%) patients had human leukocyte antigen identical HCT, 72 (21%) had mismatched HCT, and 55 (16%) had haploidentical HCT. Conditioning regimens were myeloablative for 177 (34%) patients, reduced intensity for 164 (48%), and non-myeloablative for 16 (5%). At data cutoff, 296 (87%) patients were continuing in THRIVE; 18/44 (41%) patients who discontinued were alive at discontinuation. There were 107 patients (31%) who developed acute GVHD before enrollment (grade I, n=52; grade II, n=35; grade III, n=9; grade IV, n=0; missing/unknown, n=11); 85 (79%) received systemic treatment for acute GVHD. Overall, 28 (8%) patients had cGVHD at enrollment (mild, n=25; moderate/severe, n=3). Organs affected by cGVHD were skin (n=13), eyes (n=4), and gastrointestinal tract (n=3). Conclusions: THRIVE aims to report on clinical practice for managing risk and treatment of cGVHD after allo-HCT in a prospective cohort of ~1500 patients in the United States for ≤3 years. Although real-world assessment of PROs can be associated with challenges including willingness to participate in an observational study and the collection of data without routine clinical visits, the virtual hybrid design is intended to improve patient access and facilitate data collection. In the 22 months since initiation, 340 patients have been enrolled at 22 sites, and the discontinuation rate is low.