Szabó, Anikó

Abstract Background Hairy cell leukemia (HCL) is a rare, indolent B-cell malignancy accounting for ~1% of all lymphoid neoplasms. While purine analogs remain the standard first-line therapy, the increasing use of combination regimens and targeted agents has expanded the therapeutic landscape. Data on long-term outcomes in real-world practice remain limited. Methods This is a retrospective, multicenter cohort study. We included 104 patients aged ≥18 years with a diagnosis of HCL who had at least one oncology visit from January 1, 2010, to July 17, 2025. Patients diagnosed prior to 2010 were left-truncated to account for survivorship bias. Data were abstracted from electronic medical records. Key outcomes included treatment patterns, response rates, overall survival (OS), and progression-free survival (PFS). Results The median age at diagnosis was 56.9 years (range 32.1–83.8), and 80% were male. Most patients (77%) were diagnosed during or after 2010. The most frequent frontline therapies were cladribine (63%), cladribine with rituximab (12%), rituximab monotherapy (9.7%), vemurafenib-based regimens (7.7%), splenectomy with or without interferon (3.8%), interferon monotherapy (2.9%), and other (1.9%). The overall complete response (CR) rate to first-line therapy was 63%, with 15% achieving a partial response (PR) and 22% having stable or no response. For patients receiving cladribine with rituximab first-line (n = 12), 92% had a CR. For patients receiving cladribine monotherapy first-line (n = 65), 63% had a CR and 12% had a PR. For patients receiving rituximab monotherapy first-line (n = 10), 50% had a CR and 20% had a PR. For patients receiving vemurafenib-based regimens first-line (n = 8), 75% had a CR. Among the 39 patients who received second-line therapy, the most common regimens included cladribine (31%), rituximab (26%), cladribine plus rituximab (18%), and vemurafenib-based regimens (13%). The CR rate after second-line therapy was 72%. For patients receiving cladribine with rituximab second-line (n = 7), 86% had a CR and 14% had a PR. For patients receiving cladribine monotherapy second-line (n = 12), 67% had a CR. For patients receiving rituximab monotherapy second-line (n = 10), 80% had a CR and 10% had a PR. For patients receiving vemurafenib-based regimens second-line (n = 5), 40% had a CR and 20% had a PR. Among the 17 patients who received third-line therapy, the most common regimens included rituximab (41%), cladribine (18%), and vemurafenib-based regimens (18%). The CR rate after third-line therapy was 50%. For patients receiving rituximab monotherapy third-line (n = 7), 43% had a CR and 14% had a PR. For patients receiving cladribine monotherapy third-line (n = 3), 33% had a CR. For patients receiving vemurafenib-based regimens third-line (n = 3), 67% had a CR and 33% had a PR. Overall, treatment-related hospitalizations for first-line therapy occurred in 27% of patients. 50% of patients receiving first-line cladribine with rituximab had treatment-related hospitalizations. 25% of patients receiving first-line vemurafenib-based treatment had treatment-related hospitalizations. 23% of patients receiving first-line cladribine monotherapy had treatment-related hospitalizations. 20% of patients receiving first-line rituximab monotherapy had treatment-related hospitalizations. Overall, after a median follow-up of 6.6 years (range 0.1–46), estimated OS was 96.6% at 5 years, 85.7% at 10 years, and 80.3% at 15 years. The median OS was 24.5 years [95% CI: 18.3, not reached]. Estimated PFS was 95.1% at 1 year, 89.9% at 3 years, 74.8% at 5 years, and 50.8% at 10 years. Median PFS was 12.2 years [95% CI: 7.0, not reached]. Estimated OS for first-line cladribine monotherapy was 100% at 5 years and 86.5% at 10 years. Estimated OS for first-line vemurafenib-based treatment was 85.7% at 5 years and 85.7% at 10 years. Conclusions This large real-world cohort provides important insights into the long-term management of HCL. Cladribine-based regimens remain the predominant first-line approach, with high response rates and durable remissions. However, treatment-related toxicity is common. Outcomes in later lines remain favorable, particularly with re-treatment using purine analogs or combination regimens. These findings underscore the importance of individualized treatment planning and the continued need for real-world evidence to inform care in rare hematologic malignancies.

4545 Background: The treatment landscape of front-line nccRCC has evolved with recent trials demonstrating the efficacy of combination systemic therapy. However, the efficacy of treatment after combination therapy is unknown. This study evaluates the efficacy of VEGF-based regimens in nccRCC patients (pts) previously treated with combination regimens. Methods: ORACLE is a real-world, multi-center, retrospective database that includes nccRCC patients that received combination systemic therapies (IO+IO, IO+VEGF and VEGF+ mTOR) in any line. Subsequent treatments were categorized as VEGF only regimens (cabozantinib vs other VEGF), IO+ VEGF and VEGF+ mTOR. The primary endpoint was objective response rate (ORR) assessed by investigator review using RECIST 1.1. Secondary endpoints included disease control rate (DCR), defined as the proportion of patients achieving complete or partial responses or stable disease, time to treatment progression (TTP), calculated from the date of VEGF-based initiation to progression or last follow-up using the Kaplan-Meier method. Differences between groups were estimated with the log-rank test, and categorical outcomes were compared with the chi-square test. Results: 105 pts who received VEGF – based regimens after combination therapy were included in the analysis. Baseline characteristics: median age: 59years, 71 % male, 58% white, 25% black, 87% ECOG 0-2. IMDC-risk categories included:21% favorable, 59% intermediate and 20% poor risk. Histology included papillary (40%), unclassified (32%), chromophobe (16%) and other rare subtypes (12%). Prior combination therapies included IO+IO: 62%, IO+ VEGF: 34% and VEGF+ mTORi:4%. 70% pts received combination therapy in the first line setting while the remainder received combination therapy in a second or later line. Outcomes with subsequent treatments are described in Table1. IMDC risk score correlated with TTP. Conclusions: Modest antitumor activity was observed with VEGF- based approaches in combination therapy refractory nccRCC. Optimal management of nccRCC remains an unmet need. Outcomes of nccRCC patients by treatment and histologic type. Outcomes per Treatment n ORR (%) DCR (%) mTTP (mo.) Cabozantinib 56 18 47 3.6 VEGF/mTOR 19 16 42 9.3 IO+VEGF 17 29 47 5.6 Other VEGF 13 15 46 5.5 Outcomes per Histology Papillary 42 19 43 6.5 Unclassified 33 21 42 6.1 Chromophobe 17 29 59 8.9 Other * 13 0 46 NR

Background Polyclonal autologous T cells that are epigenetically reprogrammed through mTOR inhibition and IFN-α polarization (RAPA-201) represent a novel approach to the adoptive T cell therapy of cancer. Ex vivo inhibition of mTOR results causes a shift towards T central memory (TCM) whereas ex vivo IFN-α promotes type I cytokines, with each of these functions known to enhance the adoptive T cell therapy of cancer. Rapamycin-resistant T cells polarized for a type II cytokine phenotype were previously evaluated in the allogeneic transplantation context. Methods The clinical trial (NCT04176380) evaluated RAPA-201 therapy in combination with fludarabine-sparing low-dose host conditioning for the treatment of patients with relapsed, refractory multiple myeloma (RRMM). Results From December 2020 to December 2022, 14 patients with RRMM received a median of three RAPA-201 infusions (median dose, 80×106 cells). RAPA-201 drug products (DPs) were: polyclonal; enriched for TCM cells; reduced for immune checkpoint expression, including PD1, CD73, and LAIR1; and preferentially secreted Th1 cytokines. The median chemotherapy dose administered per cycle was 1,817 mg total for cyclophosphamide (range, 1,100–2,200) and 2.35 mg/M2 for pentostatin (range, 0–16). Nine of 14 patients (64%) achieved disease remission, with eight partial responses and one stringent complete response. Median progression-free survival was 6.0 months (range, 2.1 to>16.8 months). There were no toxicities of any grade attributable to RAPA-201, including no cytokine release syndrome and no immune effector cell-associated neurotoxicity syndrome. Only 4 of 14 patients (29%) had a serious adverse event (≥ grade 3) of any attribution. Conclusions Consistent with our hypothesis, ex vivo manufacturing using mTOR inhibition and IFN-α polarization consistently yielded a novel RAPA-201 DP that possessed a desirable phenotype relative to cytokine phenotype, memory status, and checkpoint expression. RAPA-201 recipients had preservation of T cell counts and Th1 cytokine secretion yet had increased T cell receptor clonality that associates with antitumor responses in the setting of monoclonal antibody checkpoint therapy. RAPA-201 therapy overcomes previous barriers to effective autologous polyclonal T-cell therapy, as it is feasible to manufacture, exquisitely safe to administer, and mediates remission in patients with RRMM. Trial registration number ClinicalTrials.gov: NCT04176380.

Background: Acute promyelocytic leukemia (APL) is one of the most treatable leukemias in the current era, with cure rates upwards of 90%. Early mortality due to coagulopathies often seen at diagnosis is a major driver of adverse outcomes. Prompt initiation of all-trans retinoic acid (ATRA) is crucial for suspected APL, as it is known to reverse these coagulopathies. Chemotherapy-free protocols consisting of arsenic trioxide (ATO) and ATRA have become the standard of care for low-risk APL with high cure rates and reduced hematologic toxicities. For high-risk disease, there are multiple treatment options that have not been compared. Since APL is rare, there is a lack of real-world data for this disease. This retrospective review aimed to assess the outcomes of APL patients (pts) across multiple institutions and to examine the most common induction regimens, characteristics linked to early (30-day) mortality, and supportive care strategies. Methods: This retrospective study involved 9 institutions in the US and was conducted through the Consortium on Myeloid Malignancies and Neoplastic Diseases (COMMAND). Data included pts admitted from 8/5/2006 through 2/3/2024 with a confirmed diagnosis of APL. Each institution received a data-collection form and contributed data on APL pts from presentation to last follow-up. Key data categories included patient demographics, presenting laboratory and molecular data, treatment regimen, supportive care, and patient outcomes. Results: Data for 412 pts were identified with a median age of 51 (range 17-90) and 49% were female. Cardiovascular comorbidities were present in 44% of pts and 16% had a known pulmonary comorbidity. At presentation 109 (27%) had high risk-disease, defined as a white blood cell count (WBC) greater than 10 x 109/L. A FLT3 mutation was seen in 50% of tested pts, WT1 (22%), KRAS (3.6%), and NRAS (6.5%). The median WBC at presentation was 2 x 109/L (range: 0-166 x 109/L) and the median platelet count was 27 x 109/L (range: 2.0-315 109/L). Twenty-six percent presented with grade 2+ thrombosis, bleeding, or both. A higher percentage of pts with high-risk vs. low-risk disease presented with grade 2+ thrombosis, bleeding, or both (43% vs. 20%), DIC (60% vs. 36%), and mutated FLT3 (81% vs. 37%). The majority of pts received a chemotherapy-free induction regimen consisting of ATRA plus ATO. It was determined that 36 (8.7%) pts received induction with intermittent ATO plus ATRA (Burnett AK, Lancet Oncol 2015), 276 (67%) received daily ATO plus ATRA (Ravandi F, J Clin Oncol 2009 and Lo Coco, NEJM 2013), and 70 (17%) received a regimen inclusive of an anthracycline plus ATRA. Eleven pts did not start an induction regimen other than single-agent ATRA due to early death, while 19 had their regimen classified as “other” because they did not follow a conventional induction path. In total, 295/358 (82%) received ATRA within 24 hours of admission. At least 1 dose of gemtuzumab ozogamicin was given to 58 (14%) pts, of which 35 (60%) were considered high risk. The incidence of differentiation syndrome (DS) was 37% (n=154). Among the 243 pts who received steroid prophylaxis, 30% developed DS, compared to 52% of those who did not receive prophylaxis. Among the 360 pts with at least 1 available PCR result after starting induction, 94% achieved PCR-negativity. The 30-day mortality rate was 6.6%. On univariate analysis, presenting variables associated with a higher 30-day mortality include older age, diabetes, cardiovascular comorbidities, thrombosis or bleeding, DIC, eGFR < 60, elevated total bilirubin and D-dimer levels, and high-risk disease. The median overall survival (OS) of the cohort was not reached, and the 5- and 10-year OS was 88% (95% CI: 84-91%) and 79% (95% CI: 72-87%) respectively. The cumulative incidence of relapse at 3 years was 2.7% (95% CI: 1.4 - 5.1%), with no additional relapses observed. The incidence of CNS relapse at 3 years was 0.9% (95% CI: 0.3% - 2.8%), with 2 of the 4 pts classified as high-risk. Conclusion: This is the largest real-world evidence data collection in the US evaluating the outcome of pts with APL in the current era, inclusive of ATO as front-line induction. Outcomes for this disease remain extremely positive, with low 30-day mortality rates noted in this study along with durable OS rates and low incidence of relapse. Additional information on outcomes, safety, and supportive care will be presented at the meeting.

Summary Chimeric antigen receptor T‐cell (CAR‐T) therapy and bispecific T‐cell engagers (BsAb) have emerged as promising immunotherapeutic modalities in patients with relapsed and/or refractory multiple myeloma (RRMM). However, there is limited data on the safety and efficacy of CAR‐T and BsAb therapies in MM patients with a prior history of allogeneic transplantation (allo‐HCT). Thirty‐three MM patients with prior allo‐HCT received CAR‐T ( n = 24) or BsAb ( n = 9) therapy. CAR‐T therapy demonstrated an ORR of 92% (67% ≥ CR), and 73% were MRD negative. BsAb therapy resulted in an ORR of 44% (44% ≥ CR) and 44% MRD negative. Safety analysis showed grade ≥3 AEs in 92% of CAR‐T and 56% of BsAb patients. Cytokine release syndrome (CRS) occurred in 83% of CAR‐T and 78% of BsAb recipients, while immune effector cell‐associated neurotoxicity syndrome (ICANS) was observed in three CAR‐T patients. Infections of grade ≥3 were reported in 50% of CAR‐T and 44% of BsAb recipients. No exacerbation of graft‐versus‐host disease occurred except in one BsAb recipient. CAR‐T and BsAb therapies appear to be feasible, safe and provide deep and durable responses in MM patients with prior allo‐HCT.

Introduction Secondary central nervous system (CNS) involvement develops in 2-10% of large B-cell lymphoma (LBCL) cases. Current treatment approaches for relapsed or refractory CNS disease generally do not provide durable responses. Limited data suggest efficacy and feasibility of CAR-T therapy in SCNSL. We report here the largest multicenter retrospective analysis of the safety and efficacy of CD19-directed CAR-T therapy in SCNSL patients. Methods This study included SCNSL patients who received commercial CD19-directed CAR-T therapy at 9 academic institutions in the United States between 2016 and 2022. SCNSL was defined as history of parenchymal and/or leptomeningeal/cerebrospinal fluid (CSF) involvement by lymphoma at any time prior to receiving CAR-T therapy. Systemic response was assessed using the Lugano criteria while CNS response was assessed as per International PCNSL Collaborative Group criteria. Kaplan-Meier curves were generated for progression-free survival (PFS) and overall survival (OS) for entire cohort, as well as subsets of patients with and without active CNS disease at the time of CAR-T infusion. Results Ninety patients were included in the analysis, with baseline characteristics shown in Table 1. CAR-T products utilized include axicabtagene ciloleucel (n= 38, 42%), tisagenlecleucel (n=37, 41%) and lisocabtagene maraleucel (n= 15, 14%). Fludarabine/cyclophosphamide was used as lymphodepletion in 84 patients (93%). 28 patients received CNS directed radiation therapy (RT) prior to CAR-T infusion (31%) within a median time of 28.5 days (range 5 - 906) from last day of RT. Amongst all patients at the time of CAR-T infusion 82 (91.1%) had active CNS and/or systemic involvement while 8 (8.9%) had no evidence of disease; 68 (75.5%) had active CNS involvement while 22 (24.5%) had a prior history of CNS involvement but no active at the time of CAR-T infusion. ( Table 1) Median follow up all patients was 0.5 year (range 0.01 - 4.7). 71 patients (79%) developed cytokine release syndrome (CRS; median time to onset 3 days) with 3.3% patients developing Grade 3-4. Immune effector cell-associated neurotoxicity syndrome (ICANS; median time to onset 5 days) was reported in 55 patients (61%), with 28.8% developing Grade 3-4. No patients died due to CRS or ICANS. At 1-month post CAR-T, 80 patients were evaluable for CNS response and 71 patients in the entire cohort were evaluable for systemic response. Similarly, at 3-months these numbers were 66 and 60, respectively. Objective response rates (ORR) were 75% and 80% at 1-month for CNS and systemic disease respectively, while corresponding ORRs at 3-months were 68% and 76.7%. At 1- and 3-months timepoint 36 (45%) and 33 (50%) patients, respectively achieved CNS complete remission (CR), while 44 (62%) and 42 (70%) patients respectively achieved systemic CR. 1- and 2-year PFS for entire cohort were 25% (95%Cl 15% - 34%) and 16% (95%Cl 8.5% - 28%) respectively, while 1- and 2-year OS were 46% (95%Cl 36% - 59%) and 31% (95%Cl 22% - 46%). Non-relapse mortality (NRM) were 4.6% (95%CI, 1.8% -12%) and 7.2% (95%CI 2.9% - 18%) at 1- and 2-year. Cumulative incidence of relapse at 1- and 2-year were 73% (95%Cl 63% - 83%) and 77% (95%Cl 68% - 88%), respectively. ORRs for CNS response in patients with active CNS disease at 1-month and 3-month interval were 71% (n=45) and 60% (n=31). Similarly, ORR for systemic response with active CNS disease at 1-month and 3-month interval were 85% (n=43) and 74.3% (n=32).The 2-year PFS for patients with and without active CNS disease at CAR-T infusion were 12% (95%Cl 5.4% - 27%) and 28% (95%Cl 12% - 65%) respectively, with a corresponding OS of 25% (95%Cl 15% - 41%) and 58% (95%Cl 37% - 91%). ( Figure 1) The 2-year NRM rates for patients with and without active CNS disease at CAR-T infusion were 4.6% (95%Cl 1.5% - 14%) and 14% (95%Cl 3.6% - 53%) respectively, while the cumulative incidence of relapse in similar order were 83% (95%Cl 73% - 95%) and 58% (95%Cl 39% - 88%). Conclusion In this largest known case series to date, CAR-T therapy appeared safe and feasible in patients with SCNSL, but is associated with high rates of treatment failure, particularly in patients with active CNS disease at CAR-T infusion. This warrants further study of optimal CNS-directed treatment strategies prior to CAR-T, development of novel cellular therapy platforms or consideration of post CAR-T maintenance therapy in these high-risk patients.

Background: Outcomes of adults with relapsed/refractory T-cell acute lymphoblastic leukemia (T-ALL) has remained poor. CD38 is a transmembrane glycoprotein that is highly expressed in T-ALL and is potentially targetable with CD38 blocking agents [Naik J et al. Haematologica 2019, Bride KL et al. Blood 2018, Tembhare et al. J Immunother Cancer 2020]. XmAb18968 is a novel CD38-CD3 bi-specific T-cell engager with Fc domain modified to minimize Fcγ receptor binding and non-selective T-cell activation resulting in reduced cytokine release without compromising target cell killing. We designed a phase I clinical trial to assess the safety and tolerability of XmAb18968 in patients with T-ALL. Methods: We conducted a multicenter, open label, phase I dose escalation study of XmAb18968 (NCT05038644). Patients aged ≥18 years with relapsed/refractory T-ALL or T-lymphoblastic lymphoma (T-LBL), ECOG PS 0-2 and adequate organ function were eligible. Major exclusion criteria are hematopoietic cell transplantation within 6 months of enrollment, prior therapy with daratumumab in the last 6 months and active acute graft-versus-host disease. Dose escalation was conducted using 3+3 design, and 4 separate dose levels were studied [0.8mg, 1mg, 1.3mg, 1.5mg]. XmAb18968 was administered intravenously on days 1, 8, 15, 22 on a 28-day cycle. During cycle 1 alone, day 1 dose was fractionated and administered over 2 days to minimize the risk of significant cytokine release syndrome (CRS). Treatment was continued until progression or unacceptable toxicity. The primary objective was to determine the safety and dose limiting toxicity (DLT) and secondary objective was to determine the preliminary efficacy. Correlative studies included pharmacokinetics, characterizing changes in serum cytokines and phenotypic expression of activated T-cells and leukemic cells, correlation of the phenotypic expression with changes in transcriptome at the single-cell level, proteomics evaluation of cytokine secretion at the single-cell level and correlation of response with N-glycan profiling, quantitative site-occupancy, and direct glycopeptide analysis. Results: Four patients with relapsed/refractory T-ALL have been enrolled so far at dose level 1 (0.8mg) with 3 of them being evaluable for response (one patient came off study before DLT period). Median age was 62 years (34-74), all response evaluable patients had early T-precursor ALL (ETP-ALL), and one patient (25%) was previously treated with allogeneic HCT, CD7 CAR-T therapy and daratumumab. Grade 3 or higher adverse events are summarized in Table 1. CRS grades 1 was noted in 25% of patients, no grade ≥3 CRS or neurotoxicity (any grade) was seen. Of the 3 evaluable total patients, 2 patients had achieved complete response (CR) after 1 cycle of therapy (one patient had prior allogeneic HCT, CD7 CAR-T therapy and daratumumab) (Table 2). The two responders remain on treatment. Conclusions: XmAb18968, a novel CD-38 bispecific antibody appears safe and is showing response at the starting dose level in T-ALL. The study is currently enrolling additional patients with T-ALL. Updated analysis with additional patients and details on correlative studies examining mechanisms of therapeutic efficacy will be reported at the main meeting.

Background: Outcomes of adults with relapsed/refractory acute myeloid leukemia (RR-AML) have remained poor. CD38 is a transmembrane glycoprotein that is highly expressed in AML and is potentially targetable with CD38 blocking agents [Naik J et al. Haematologica 2019, Tembhare et al. J Immunother Cancer 2020]. XmAb18968 is a novel CD38-CD3 bi-specific T-cell engager with Fc domain modified to minimize Fcγ receptor binding and non-selective T-cell activation resulting in reduced cytokine release without compromising target cell killing. We designed a phase I clinical trial to assess the safety and tolerability of XmAb18968 in patients with RR-AML. Methods: We conducted a multicenter, open label, phase I dose escalation study of XmAb18968 (NCT05038644). Patients aged ≥18 years with relapsed/refractory AML, ECOG PS 0-2 and adequate organ function were eligible. Major exclusion criteria are hematopoietic cell transplantation within 6 months of enrollment, active acute graft-versus-host disease, and acute promyelocytic leukemia. Dose escalation was conducted using 3+3 design and 4 separate dose levels were studied [0.8mg, 1mg, 1.3mg, 1.5mg]. XmAb18968 was administered intravenously on days 1, 8, 15, 22 on a 28-day cycle. During cycle 1 alone, day 1 dose was fractionated and administered over 2 days to minimize the risk of significant cytokine release syndrome (CRS). Treatment was continued until progression or unacceptable toxicity. The primary objective was to determine the safety and dose limiting toxicity (DLT) and secondary objective was to determine the preliminary efficacy. Measurable residual disease (MRD) status was assessed using multicolor flow cytometry with 0.01% sensitivity. Correlative studies included pharmacokinetics, characterizing changes in serum cytokines and phenotypic expression of activated T-cells and leukemic cells, correlation of the phenotypic expression with changes in transcriptome at the single-cell level, proteomics evaluation of cytokine secretion at the single-cell level and correlation of response with N-glycan profiling, quantitative site-occupancy, and direct glycopeptide analysis. Results: Thirteen patients with RR-AML were enrolled, 12 of whom were evaluable (1 patient came off study before DLT period). Median age was 63 years (45-77), 77% with adverse risk disease, 38% with secondary AML, and received median two (range 2-7) prior lines of therapy. Twelve of 13 patients (92%) were previously treated with venetoclax based regimen and 31% had prior allogeneic HCT. Adverse risk mutations included TP53 (31%), RUNX1 (23%), and ASXL1 (15%). Grade 3 or higher adverse events included anemia (8%), neutropenia (15%), and thrombocytopenia (23%) (Table 1). CRS grades 1-2 were noted in 62% of patients, no grade ≥3 CRS or neurotoxicity (any grade) was seen. There was no dose limiting toxicity (DLT). Of the 12 evaluable total patients, clinically meaningful response was noted in two patients who were MRD positive by flow cytometry prior to study entry and achieved MRD negative CR (Table 2). These two patients who achieved MRD negative CR subsequently proceeded to allogeneic HCT. Median time to response was 1 cycle. Median OS of the cohort was 6.2 months (1.8-NR). Conclusions: XmAb18968 is safe and well tolerated in patients with RR-AML. Dose escalation yielded MRD negative CR in RR-AML patients who were MRD positive at study entry. Details on correlative studies examining mechanisms of therapeutic efficacy and resistance will be reported in the main meeting.