Eapen, Mary

Abstract Introduction Elevated levels of fetal hemoglobin (HbF) ameliorate sickle cell disease (SCD) manifestations. BEAM-101 is an investigational cell therapy comprising ex vivo base-edited autologous CD34+ hematopoietic stem and progenitor cells (HSPCs) that directly target the HBG1/2 promoters to disrupt BCL11A binding, switching production from sickle (HbS) to majority anti-sickling HbF. We present ongoing data from the BEACON study (NCT05456880), a Phase 1/2, single-arm, open-label study evaluating a single dose of BEAM-101 in individuals with SCD and severe vaso-occlusive crises (sVOCs). Methods Eligible patients were aged 12–35 years with SCD and ≥4 sVOCs in the 2-year period prior to informed consent. After mobilization with weight-based or tiered fixed-dose plerixafor, autologous CD34+ HSPCs were collected by leukapheresis and genetically modified with an adenine base editor. Following conditioning with pharmacokinetically adjusted myeloablative busulfan (target cumulative AUC 80 hr*mg/L), patients received a single dose of BEAM-101 (≥3.0×106 viable CD34+ cells/kg). Patients were then monitored for neutrophil and platelet engraftment, adverse events (AEs), total Hb, Hb fractions, % F-cells, hemolysis markers, sVOCs, and additional protocol endpoints for up to 24 months. Results As of June 16, 2025, enrollment has been completed and 46 patients have initiated mobilization. Of the 26 patients who have received BEAM-101, mean duration of follow-up was 6.2 (range 1.0–18.7) months. Baseline demographics were: age 18–34 years, 24 βS/βS genotype, 21 self-reported Black/African American, and 11 female. One patient, who successfully engrafted and obtained stable HbF levels >60%, withdrew consent 5 months post-infusion. For the 26 treated patients, the median number of stem cell collection cycles was 1 (range 1–4); 18 (69.2%) required a single cycle, 4 required 2 cycles, and 4 required >2 cycles. Target cell dose was achieved with a median of 3 (1–12) collection days. Patients received a mean BEAM-101 dose of 8.4 (range 3.2–23.4) ×106 viable CD34+ cells/kg. By the data cut, patients achieved neutrophil (n=26) and platelet (n=24) engraftment at a median of 18 (12–30) days and 19 (11–50) days, respectively, with a median duration of 7 (4–17) days of neutropenia. Of the 24 evaluable patients, 9 (37.5%) achieved platelet engraftment without requiring platelet transfusion through the transplant process. No patients had ≥Grade 3 AEs or serious AEs related to BEAM-101. One patient died due to respiratory failure, assessed as likely related to busulfan conditioning, 4 months post-infusion as previously reported. Mean total Hb increased to 12.1 (range 9.0–14.7) g/dL by Month (M) 1 (n=24), 15.6 (11.9–18.6) g/dL by M6 (n=11), and was sustained through follow-up. Four patients had total Hb levels above the normal range beyond M6 without any associated clinical manifestations or need for therapeutic intervention. Erythropoietin levels trended towards normal in all patients, including those with elevated total Hb. Mean endogenous HbF (HbF/[HbF+HbS]) was >60% and HbS was <40% by M1, which was sustained through last follow-up. At M6, mean % F-cells were 99.2% (97.0–99.9; n=10) and mean HbF/F-cell was 20.8 (18.0–23.9; n=9) pg, exceeding the protective threshold of 10 pg against sickling. Peripheral blood editing was at a mean of 68.5% by M3 (n=16), 69.6% by M6 (n=10), and 72.8% by M12 (n=5). Hemolysis markers and sickling parameters normalized or improved for all patients. No patients experienced any investigator-reported sVOCs post-engraftment. Conclusions The BEAM-101 treatment process is characterized by a low number of mobilization and collection cycles and high editing efficiency, resulting in rapid neutrophil and platelet engraftment and robust pancellular HbF expression, with durability observed up to 18 months. Additionally, there is a corresponding reduction in HbS levels to <40%, and improvements or resolution of hemolysis parameters and anemia, along with resolution of investigator-reported sVOCs post-engraftment. The safety profile of the BEAM-101 treatment regimen is consistent with busulfan conditioning, autologous HSCT, and underlying SCD. These results demonstrate the potential for base editing of the HBG1/2 promoters as a safe and effective therapeutic modality for the treatment of SCD that also has the potential to minimize hospitalization and treatment process burden for patients, families, and sites.

Fetal hemoglobin (HbF) is anti-sickling and elevated HbF ameliorates sickle cell disease (SCD) manifestations. BEAM-101 is an investigational cell therapy comprised of autologous CD34+ hematopoietic stem and progenitor cells (HSPCs) that are base edited ex vivo to introduce naturally occurring A-to-G substitutions into the promoters of the HBG1/2 genes that encode γ-globin to disrupt BCL11A transcriptional repressor binding sites, leading to increased HbF production. We previously demonstrated in pre-clinical studies that base editing potently induced HbF (>60%) and proportionately reduced sickle hemoglobin (HbS) (<40%) without relying on double-stranded DNA breaks. We present initial data from BEACON (NCT05456880), a Phase 1/2, single-arm, open-label study evaluating the safety and efficacy of a single dose of BEAM-101 in patients with SCD with severe vaso-occlusive crises (VOCs). Patients 18-35 years diagnosed with SCD and ≥4 severe VOCs in the 2-year period prior to screening per trial criteria were eligible. After plerixafor mobilization, autologous CD34+ HSPCs were collected by leukapheresis/isolation and genetically modified with an adenine base editor. After myeloablative conditioning with pharmacokinetically adjusted busulfan, patients received a single infusion of BEAM-101 (≥3.0 × 106 viable CD34+ cells/kg) and are monitored for neutrophil and platelet engraftment, adverse events (AEs), total hemoglobin (Hb), Hb fractions, % F-cells, hemolysis markers, peripheral blood editing, and VOCs for 24 months. As of July 2, 2024, >20 patients are enrolled and BEAM-101 has been manufactured for 8 patients, of whom 6 patients have been dosed. One patient not included in this analysis discontinued during the mobilization/collection period prior to BEAM-101 treatment for non-medical reasons. Baseline demographics were as follows: 5/6 patients βS/βS, 1/6 patients βS/β0, all self-reported Black/African American, 50% female, aged 19-27 years. Of the 6 patients, half (n=3) required only a single mobilization cycle and the other half required 2. Patients received a mean BEAM-101 dose of 11.9 × 106 (5.2-23.4) viable CD34+ cells/kg. Excepting safety data that include all patients dosed (n=6), the following data are from patients dosed with ≥1 month of follow up (n=4; 6, 5, 2, and 1 month[s] post-treatment, each). All 4 patients with ≥1 month of follow up achieved neutrophil and platelet engraftment at a median of 17 (15-19) and 20 (11-34) days, respectively. One patient died due to respiratory failure, likely related to busulfan conditioning, 4 months after infusion. In all patients dosed (n=6), there have been no ≥Grade 3 AEs or serious AEs related to BEAM-101. Using the central laboratory data, patients' total Hb increased from baseline (mean 9.3 [7.9-10.9] g/dL) to 17.9, 18.2, 11.0, and 11.8 g/dL at last time point (LTP) available for P1, P2, P3, and P4, respectively. No signs/symptoms or interventions were undertaken for high total Hb. All patients achieved >60% HbF of non-transfused Hb (total Hb − HbA) at Month (M) 1 and sustained this elevation to the LTP available. By M1, HbS% in non-transfused blood dropped to ≤36% in all 4 patients and was sustained through LTP. In total blood, % F-cells were 99.6% in P1 at M6, 94.4% in P2 at M4, 52.0% in P3 at M2, and 13.3% in P4 at M1 with all patients having >19 pg HbF/F-cell at LTP available. Peripheral blood editing in nucleated cells, measured in P1 (at M6) and P2 (at M3), was 69.9% and 76.1%, respectively. Markers of hemolysis (lactate dehydrogenase, indirect bilirubin, haptoglobin, and reticulocyte counts) have normalized or improved for all patients. No VOCs have been reported by investigators following BEAM-101 treatment. These initial data show a safety profile for BEAM-101 consistent with busulfan conditioning and autologous HSCT. Treatment with BEAM-101 resulted in rapid engraftment, improvement in hemolysis markers, and marked improvement of anemia in all 4 dosed patients. We observed rapid and robust HbF induction consistent with pre-clinical data by M1 (>60%) and corresponding HbS reduction (≤36%) in non-transfused blood in all post-treatment assessments. No VOCs were reported by investigators post-treatment. These initial data support base editing of the HBG1/2 promoters as an effective therapeutic modality for the treatment of SCD and will continue to be investigated in the ongoing BEACON study. Updated data to be presented.

6591 Background: BMT CTN 1101 was a Phase III randomized controlled trial evaluating the comparative effectiveness of unrelated umbilical cord blood (UCB) versus HLA-haploidentical related donor bone marrow (haplo-BM) cell sources for hematopoietic cell transplantation (HCT) in patients with high-risk hematologic malignancies (leukemias, lymphomas). We report results of an economic evaluation conducted as part of the clinical trial. Methods: 368 patients (90% of planned accrual) enrolled from 33 centers in the U.S. were randomly assigned to unrelated UCB (n=186) or haplo-BM (n=182) transplant. Healthcare utilization and costs were estimated using propensity-score matched cohorts of BMT patients in the OptumLabs Data Warehouse for trial participants <65 years, and Medicare claims for trial participants ≥65 years. Cost-effectiveness was calculated from payer perspectives (commercial, Medicare) over a 20-year time horizon from time of transplant. Weibull models (best fit based on AIC/BIC) were used to extrapolate survival from 5-year trial follow-up data. Trial participant surveys (EQ-5D) were used to derive health state utilities for estimating Quality-Adjusted Life Years (QALYs). One-way and probabilistic sensitivity analyses were conducted to assess uncertainty in results. Outcomes were discounted at 3% annually. Results: At 5-year follow-up, overall survival was 42% for haplo-BM versus 36% for UCB (P=.06). Over a 20-year time horizon, haplo-BM is expected to be more effective and more costly for <65 year-olds and in ≥65 year-olds it is expected to be more effective and less costly. In one-way uncertainty analyses, for persons <65, the cost/QALY result was most sensitive to life years and health state utilities. For persons ≥65, life years were more influential than costs and health state utilities. Using probabilistic sensitivity analysis, for persons <65 there was a 43% chance that haplo-BM was cost-effective using a willingness to pay threshold of $150k/QALY and 52% at a $200K/QALY threshold. Conclusions: Results from a large national clinical trial indicate that compared to UCB, haplo-BM was moderately cost-effective for patients aged <65 years, and less costly and more effective for persons ≥65 years. Haplo-BM is a fair value choice for commercially insured patients with high-risk leukemia and lymphoma who require HCT. For Medicare enrollees, haplo-BM is a preferred choice when considering costs and outcomes. [Table: see text]

Abstract BACKGROUND: Our group recently reported on the results of Blood and Marrow Transplant (BMT) Clinical Trials Network (CTN) 1101 a randomized comparison between double umbilical cord blood (dUCB) and haploidentical bone marrow (haplo) with post-transplant cyclophosphamide (ptCy) in the nonmyeloablative setting that showed similar progression free survival (PFS) between the two treatment groups, but lower non-relapse mortality (NRM) and better of overall survival (OS) in the haplo arm. In this secondary analysis we sought to investigate if transplant center experience with haplo and or cord blood HCT had an impact on outcomes. PATIENTS AND METHODS: All patient randomized in BMT CTN 1101 were included. In order to determine the transplant center experience with either haplo or dUCB we queried the Center for International Blood and Marrow Transplant Research (CIBMTR) for number of transplants with each platform in the year prior to initiation of the study. Centers were then grouped as dUCB center (&gt; 10 dUCB, n=117, 10 centers), Haplo center (&gt;10 haplo and ≤10 dUCB, n=110, 2 centers), and ≤10 haplo and ≤10 dUCB HCTs (other center, n=140, 21 centers). Further analysis considered the alternative cut-off for haplo (&gt; 5 vs ≤ 5) experience, and considered the outcomes based on the donor experience vs. others (e.g. dUCB &gt; 10 vs. ≤ 10; haplo &gt; 5 vs. ≤ 5). RESULTS: The effect of center experience on HCT outcomes shown in Figure, below . After adjusting for age, Karnofsky performance score and, disease risk index we found that there was no difference in outcomes between haplo and dUCB for centers that were experienced with dUCB or had limited to no experience with either dUCB or haplo. In contrast, in centers that were primarily experienced with haplo had better outcomes with this donor type, as compared to dUCB. The higher risk of treatment failure (relapse or death) and overall mortality in dUCB in haplo experienced centers was driven by significantly higher risk of relapse. We then considered the transplant experience with each of the donor types separately. In transplant centers that had performed &gt; 10 dUCB, there were similar outcomes for recipients of both dUCB and haplo. Similarly, centers that had ≤ 5 haplo HCTs had no difference in outcomes between donor types suggesting an overlap with centers that had performed &gt; 10 dUCB HCTs. Overall mortality was higher among dUCB recipients in centers that had performed ≤ 10 dUCB. Notably, the hazard ratio of non-relapse mortality favored haplo in all four donor experience type of transplant center, albeit not statistically significant. CONCLUSION: Except for dUCB recipients in centers with &lt; 10 dUCB/year had worse overall mortality, primarily driven by relapse, the transplant center experience in the year prior to the initiation of BMT CTN 1101 had limited impact on the outcomes of this randomized clinical trial. Figure 1 Figure 1. Disclosures Brunstein: NANT: Research Funding; FATE: Research Funding; GamidaCell: Research Funding; BlueRock: Research Funding; AlloVir: Consultancy. Costa: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria. Cutler: Deciphera: Consultancy; Cimeio: Consultancy; Editas: Consultancy; Kadmon: Consultancy; Pfizer: Consultancy; Mallinckrodt: Consultancy; CareDx: Consultancy; Incyte: Consultancy; Omeros: Consultancy; Syndax: Consultancy; Mesoblast: Consultancy; Jazz: Consultancy. Horowitz: Sobi: Research Funding; Regeneron: Research Funding; Orca Biosystems: Research Funding; Tscan: Research Funding; Xenikos: Research Funding; Miltenyi Biotech: Research Funding; Stemcyte: Research Funding; Medac: Research Funding; Vor Biopharma: Research Funding; Kite/Gilead: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Kiadis: Research Funding; Seattle Genetics: Research Funding; Mesoblast: Research Funding; GlaxoSmithKline: Research Funding; Sanofi: Research Funding; Pfizer, Inc: Research Funding; Omeros: Research Funding; Magenta: Consultancy, Research Funding; Jazz Pharmaceuticals: Research Funding; Vertex: Research Funding; Genentech: Research Funding; Takeda: Research Funding; Novartis: Research Funding; Shire: Research Funding; Gamida Cell: Research Funding; Daiicho Sankyo: Research Funding; CSL Behring: Research Funding; Chimerix: Research Funding; Bristol-Myers Squibb: Research Funding; bluebird bio: Research Funding; Astellas: Research Funding; Amgen: Research Funding; Allovir: Consultancy; Actinium: Research Funding. Horwitz: Gamida Cell: Research Funding. McGuirk: Novartis: Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; EcoR1 Capital: Consultancy; Pluristem Therapeutics: Research Funding; Novartis: Research Funding; Bellicum Pharmaceuticals: Research Funding; Astelllas Pharma: Research Funding; Gamida Cell: Research Funding; Fresenius Biotech: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau. Rezvani: US Department of Justice: Consultancy; Kaleido: Other: One-time scientific advisory board; Nohla Therapeutics: Other: One-time scientific advisory board; Pharmacyclics-Abbvie: Research Funding. Rybka: Spark Therapeutics: Consultancy; Merck: Consultancy. Vasu: Kiadis, Inc.: Research Funding; Boehringer Ingelheim: Other: Travel support; Seattle Genetics: Other: travel support; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees.

PURPOSETo compare the outcomes of patients with Hodgkin or non-Hodgkin lymphoma undergoing nonmyeloablative haploidentical or unrelated cord blood (UCB) hematopoietic cell transplantation.PATIENTS AND METHODSWe retrospectively studied 740 patients with Hodgkin lymphoma (n = 283, 38%) and non-Hodgkin lymphoma (n = 457, 62%) age 18-75 years who received transplantations from 2009 to 2016. Data were reported to the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation, Eurocord, or Center for International Blood and Marrow Transplant Research. Of the 526 patients who received haploidentical transplantation, 68% received bone marrow and 32% received peripheral blood. All patients received a uniform transplantation conditioning regimen (2 Gy of total-body irradiation, cyclophosphamide, and fludarabine) and graft-versus-host disease prophylaxis (calcineurin inhibitor and mycophenolate). In addition, patients who received a haploidentical transplantation received posttransplantation cyclophosphamide.RESULTSCompared with haploidentical bone marrow and peripheral-blood transplantations and adjusted for age, lymphoma subtype, and disease status, survival was lower after UCB transplantation (hazard ratio [HR], 1.55; P = .001; and HR, 1.59; P = .005, respectively). Similarly, progression-free survival was lower after UCB transplantations compared with haploidentical bone marrow and peripheral-blood transplantations (HR, 1.44; P = .002; and HR, 1.86; P < .0001), respectively. The 4-year overall and progression-free survival rates after UCB transplantation were 49% and 36%, respectively, compared with 58% and 46% after haploidentical bone marrow transplantation and 59% and 52% after peripheral-blood transplantation, respectively. Lower survival was attributed to higher transplantation-related mortality after UCB transplantation compared with haploidentical bone marrow and peripheral-blood transplantation (HR, 1.91; P = .0001; and HR, 2.27; P = .0002, respectively).CONCLUSIONWhen considering HLA-mismatched transplantation for Hodgkin or non-Hodgkin lymphoma, the data support haploidentical related donor transplantation over UCB transplantation.

Abstract Abstract 3009FN2 Objective: To determine toxicity and efficacy of adding fludarabine (FLU) to a regimen of total body irradiation (TBI), anti-thymocyte globulin (ATG) and cyclophosphamide (CY), with de-escalation of the CY dose. The goal is to minimize CY-related toxicities while preserving (or improving) engraftment and survival in patients with SAA receiving an unrelated donor marrow transplant. Patients and Methods: Since May 2006, the Blood and Marrow Transplant Clinical Trials Network (BMT CTN), sponsored by the NHLBI and NCI, has conducted a prospective Phase I/II clinical trial of unrelated donor marrow transplantation in SAA (BMT CTN 0301). Patients with SAA are eligible if they are < 65 years, have adequate organ function, and have an available unrelated marrow donor matched 7 of 8 HLA-A, B, C, DRB1 loci. Patients with Fanconi anemia and other marrow failure syndromes are excluded. All patients receive TBI 200 cGy, ATG (either thymoglobulin: 3 mg/kg IV or ATGAM 30 mg/kg IV daily × 3, days –4 to –2), FLU (30 mg/m2 IV daily × 4, days –5 to –2). The Phase I portion of the trial sequentially tested four CY dose levels: 150 mg/kg (administered days –4 to –2); 100 mg/kg (days –3 to –2); 50 mg/kg (day –2); and, 0 mg/kg, and allowed enrollment of up to six patients at each CY dose level unless toxicity or graft failure boundaries were crossed. In the Phase II portion of the trial, patients enroll onto the optimal CY dose level, which is chosen using adaptive Bayesian criteria to rank desirability of the CY doses. All patients are followed for two years after transplantation. Early stopping guidelines are used to monitor for graft failure and early transplant-related mortality through day 100. Results: Twenty-one patients accrued to the Phase I portion of the trial. CY dose level 0 mg/kg was closed after all three enrolled patients developed secondary graft failure. All received a second allograft. One patient remains alive at 23 months after the first transplantation. The other two died from adult respiratory distress syndrome (ARDS) at 114 days after the first transplant and idiopathic pneumonia at 200 days after the first transplant. Review of Phase I results for the other three dose levels suggested CY dose 150 mg/kg as the optimal dose level for Phase II testing. However, after an additional eight patients were treated at this dose, the level was closed to further accrual because of excess toxicity. Seven of the 14 patients receiving 150 mg/kg of CY (and 7 of the last 8 enrolled) died. Causes of death were cardiac/pulmonary/multi-organ failure (n=4), ARDS (n=2), and parainfluenza virus type 3 pneumonia (n=1). Bayesian evaluation of the two remaining dose levels indicates very similar desirability scores and accrual continues at both the CY 100 mg/kg and 50 mg/kg levels. As of July 15, 2011, a total of 61 patients have been enrolled, 17 on the two closed levels, 33 on the 100 mg/kg level and 11 on the 50 mg/kg level. Conclusions: Early analysis of this trial, made necessary by these unexpected severe adverse events, revealed two important findings among patients receiving low-dose TBI, ATG, and FLU at the doses outlined: 1) CY dose 0 mg/kg is associated with higher than expected graft failure; and, 2) CY dose 150 mg/kg is associated with excess transplant-related toxicity. Neither CY dose level should be tested further in the context of the regimen used in this trial. To date, the two intermediate CY dose levels (100 mg/kg and 50 mg/kg) have not crossed the graft failure or fatality stopping boundaries and accrual is in progress. Disclosures: Pulsipher: Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees.