Brexucabtagene-autoleucel (brexu-cel) produces high rates of measurable residual disease-negative (MRD-) complete response (CR) in adults with Philadelphia-chromosome positive (Ph+) acute lymphoblastic leukemia (ALL); however, subsequent relapses remain frequent. It is unclear whether maintenance with tyrosine kinase inhibitors (TKIs) can enhance remission durability. We evaluated outcomes among adults with relapsed/refractory Ph+ ALL who received commercial brexu-cel and achieved MRD- CR across 19 U.S. institutions. Considering TKI maintenance as a time-varying covariate, we analyzed outcomes based on receipt of subsequent TKI maintenance versus no maintenance. Patients receiving consolidative transplantation or non-TKI maintenance were excluded. Fifty-one patients were included: 20 received TKI maintenance and 31 received no maintenance. The use of TKI maintenance was associated with a significantly lower 1-year cumulative incidence of relapse (HR 0.12; 95% CI, 0.02-0.88; p=0.037) which translated into improved progression-free survival (PFS, HR 0.19; 95% CI, 0.04-0.85; p=0.029) and a trend towards improved overall survival (OS, HR 0.34; 95% CI, 0.07-1.62; p=0.18). There was no difference in non-relapse mortality (NRM, HR 0.83; 95% CI, 0.12-5.87; p=0.85). This real-world analysis supports the administration of TKI maintenance in Ph+ ALL following achievement of MRD- CR with brexu-cel as a strategy to improve PFS following chimeric antigen receptor T cell therapy.

Transplant-related morbidity remains a major barrier to broader application of allogeneic hematopoietic cell transplantation (HCT) in older adults. The frequency and importance of physical disabilities early after HCT have not been well-characterized. We sought to characterize the incidence and prognostic impact of physical disability complicating HCT in patients ≥60 years of age. We retrospectively analyzed 699 consecutive patients ≥60 years who underwent HCT at our institution. Physical disability post-HCT was defined as one or more of the following: (1) mobility dependence (requiring a person to assist walking); (2) delirium with loss of instrumental activities of daily living; (3) fall; or (4) intensive care unit admission. Disability-free Survival (DiFS) failure events included any of these disability events or death. The median age was 66 years; 20% were age ≥70 years. Melphalan-based conditioning was used in 85%, and 77% had matched donors. By day 30, 38% developed mobility dependence, 25% experienced delirium, 15% required intensive care unit care, and 5% experienced a fall. Day 30 DiFS was 57.2%, with a disability event preceding every death by day 30. One-year NRM landmarked at day 30 was 31.6% for patients with prior disability, versus 9.8% without (P < .001). In multivariable analysis, disability was independently associated with increased landmark NRM (Hazard Ratio [HR] = 2.70, 95% confidence interval [CI]: 2:03 to 3.60) and worse landmark overall survival (HR = 1.86, CI: 1.49 to 2.33), independent of acute graft-versus-host disease by day 30. Disability frequently complicates HCT in older adults and independently predicts higher NRM risk. Day 30 DiFS is a novel endpoint to quantify HCT morbidity and a potential target for trials to circumvent HCT-related complications.

CD19-directed therapy remains the mainstay treatment for relapsed/refractory B-cell acute lymphoblastic leukemia (ALL). However, treatment patterns and outcomes following CD19-negative (CD19-) relapse remain poorly defined. We retrospectively analyzed 65 adult patients with ALL who developed CD19-relapse after CD19-directed therapy. TP53 mutations and BCR::ABL1-like ALL were each identified in 27.7% (n = 18) of patients. Forty-six patients (70.8%) received one CD19-targeted therapy, whereas 19 patients (29.2%) received ≥ 2 prior to CD19-relapse. Overall, 60 patients (92.3%) received blinatumomab, and 23 (35.4%) received CAR T-cell therapy. The median time from the initiation of the most recent CD19-targeted therapy to CD19-relapse was 155 days (range, 13-1946). The median follow-up of the entire cohort was 32.7 months (IQR, 15.1-90.3). The median event-free and overall survival (EFS and OS) was 3.1 months (95% CI, 2.5-4.5) and 9.9 months (95% CI, 6.8-24.7), respectively. In multivariate analysis, receipt of ≥ 2 CD19-directed therapies was associated with both inferior EFS and OS, HR 2.17 (95% CI, 1.10-4.29; p = 0.03) and HR 3.05 (95% CI, 1.40-6.62; p = 0.005). The complete remission rate following first salvage therapy was 47.5% and 72.1% any time following CD19-relapse. Sixteen (34.8%) of 46 patients evaluated had subsequent CD19 re-expression, 5 of whom subsequently received CD19-directed therapy, and all 5 patients responded. Patients with ALL who develop CD19-relapse after CD19-directed therapy have poor outcomes and limited therapeutic options. However, since this study lacked a comparator cohort of patients with CD19-positive relapse, the independent prognostic impact of CD19 negativity could not be determined.

Abstract Philadelphia chromosome-like (Ph-like) B-cell acute lymphoblastic leukemia (B-ALL) represents a high-risk subtype characterized by therapy resistance and an adverse clinical profile similar to Ph+ ALL. Recent evidence highlights the growing significance of metabolic reprogramming in drug resistance in B-ALL. We have identified increased fructose transporter GLUT5 expression in Ph-like and Ph+ primary samples and cell lines compared to other B-ALL subsets. In this study, we aim to investigate the novel mechanistic roles of GLUT5 in pro-survival signaling and drug resistance in Ph-like B-ALL. Firstly, to study the role of GLUT5 and fructose availability in cell proliferation, Ph-like B-ALL cell lines (MHH-cALL4 and MUT5Z) stably expressing GLUT5 or empty vector control, were cultured in glucose- or fructose-rich standard media. GLUT5-overexpressing B-ALL cell lines in glucose- or fructose-rich media showed increased proliferation (quantified by CFSE) when compared to control in glucose-rich media. GLUT5-overexpressing cells showed increased colony formation in glucose- or fructose-rich media, while control cells showed the same effect only in fructose-rich media when compared to those in glucose-rich media, indicating that GLUT5-mediated fructose uptake provided a proliferation advantage. To gain better insights on the significance of GLUT5 expression in high-risk B-ALL, bulk RNA-Seq was performed on control or GLUT5-overexpressing Ph-like B-ALL cell lines in glucose- or fructose-rich media. Pro-survival signaling pathways (such as PI3K/AKT, MAPK, NFKB, HIF-α and others) were significantly upregulated in GLUT5-overexpressing cell lines in glucose- or fructose-rich and control cells in fructose-rich conditions (vs. control in glucose-rich condition). We confirmed increased expression of p-AKT/AKT, MYC and NFKB in GLUT5-overexpressing Ph-like B-ALL cell lines in glucose- or fructose-rich conditions by immunofluorescence and immunoblotting. Further, increased BCL-2 expression was observed in GLUT5-overexpressing Ph-like cell lines in fructose-rich conditions only, indicative of the potential role of GLUT5 and fructose availability in conferring venetoclax resistance. Consistent with this, GLUT5-overexpressing B-ALL cell lines treated with venetoclax in fructose-rich media showed significantly increased resistance vs. control. A combination of venetoclax with serine synthesis pathway (SSP) inhibitor partially reversed venetoclax resistance. This suggests that GLUT5 expression and fructose availability may divert glycolytic pathway intermediates to SSP as an alternative cell survival mechanism. In summary, GLUT5 may have clinically relevant role in high-risk B-ALL where it modulates pro-survival signaling and confers therapy resistance. Citation Format: Serene Xavier, Sonia Rodriguez, Zhaohui Gu, Lucy Ghoda, Stuart Blakemore, Lukas Frenzel, Alexey Danilov, Vinod Pullarkat. Overexpression of fructose transporter increases pro-survival signaling and confers venetoclax resistance in Ph-like B-cell acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1859.

CIBMTR registry data shows that allogeneic HCT is being performed with increasing frequency in older patients. In this population, selecting a conditioning regimen that balances disease control while reducing non-relapse mortality (NRM) is critical to improving overall survival (OS). We retrospectively evaluated outcomes of 48 consecutive patients with AML, aged ≥ 70 years, who underwent allogeneic HCT at our center (2009 to 2019) using Flu/Mel conditioning and Tac/Siro-based GVHD prophylaxis. The primary objective of this retrospective analysis was to assess 5-year OS and identify clinical factors associated with survival.The median age at HCT was 71 years (range 70-78). Patients were transplanted in CR1 (62%), CR-2 (19%), or active disease (19%). Donor types were 8/8 HLA matched related (23%) or unrelated (77%). The median donor age was 31 years (range 19-77), and 17% of HCTs were from female donor to male recipient. A high/very-high Disease Risk Index (DRI) score was seen in 33% of patients, 44% of patients had an HCT-CI >2 and 21% had adverse risk features by ELN 2022 criteria. Peripheral blood stem cells were used as the graft source in all patients, and 75% of patients received a melphalan dose of 140 mg/m2.With a median follow-up duration of 7.0 years (range 5.1-10.7) among survivors, the 2 and 5-year OS rates were 77% (95% CI: 62-87%) and 65% (95% CI: 49-76%), respectively. Leukemia-free survival (LFS) at 2 and 5 years were 73% (95% CI: 58-83%) and 62% (95% CI: 47-74%), respectively. The relapse rate at 2 and 5 years were 10% (95% CI: 4-21%) at both time-points, and non-relapse mortality (NRM) was 10% (95% CI: 4-21%) at day 100 and 27% (95% CI: 15-40%) at 5 years. The cumulative incidence of Grade 2-4 and 3-4 acute GVHD at day +100 was 27% (95% CI: 15-40%) and 15% (95% CI: 6-26%), respectively. Cumulative incidence of chronic GVHD at 2 years was 65% (95% CI: 49-76%). Bone marrow CD3 chimerism > 95% at Day 30 was seen in 85% of patients.On Univariate analysis, 5-year was significantly corelated with remission status CR 1/2 versus active disease (70% vs 44%; p=0.014), secondary AML (80% vs 42%; p=0.027), prior Venetoclax use (72% vs 25%; p=0.003), and melphalan dose 140 mg/m2 vs 100 mg/m2 (75% vs 33%; p=0.018). These factors also showed significant differences in LFS and NRM, but not in relapse rate.In conclusion, our data suggests that allogeneic HCT using Flu/Mel conditioning and Tac/Siro GVHD prophylaxis in patients with AML results in promising 5-year OS with low relapse rates. This reduced intensity regimen remains an effective strategy for older AML patients undergoing allogeneic HCT from a matched donor.

The MAGIC Algorithm probability (MAP), based on serum ST2 and REG3α, predicts acute GVHD-related non-relapse mortality (NRM) as early as 7 days after HCT (Hartwell et al. JCI Insight 2017). We retrospectively analyzed day 7 MAP in 721 patients transplanted in 2021-2024 at City of Hope (Park et al. ASH Abstract 2464, 2025). Among them, 164 (23%) were high-risk (HR) and 557 (77%) were low-risk (LR) with detailed characteristics shown in Table 1. With a median follow-up of 18 months among survivors (n=539), HR patients had higher NRM compared to LR (29.8% vs. 9.5% at 1 year, p<0.001), higher NRM without prior acute GVHD (17.4% vs. 3.7% at 1 year, p<0.001), and lower overall survival (63.8% vs. 84.0% at 1 year, p<0.001), with no difference in relapse or acute GVHD incidence. In multivariable analysis, MAP remained independently associated with NRM (HR 3.4, 95% CI 2.4-5.0, p<0.001). Cause-specific mortality analysis demonstrated higher GVHD-related and non-GVHD-related deaths (primarily infection and organ dysfunction) among HR patients, supporting day 7 MAP as a marker of systemic tissue injury rather than GVHD alone.To identify clinical determinants of HR MAP, we further evaluated patient and HCT variables. Age, HCT-CI, KPS, disease type, conditioning regimen, donor type, and GVHD prophylaxis were significant in univariable analysis. In multivariable models, older age (each year: HR: 1.012 [1.000 - 1.024), p=0.047), HCT-CI ≥3 (HR: 1.941 [1.332 - 2.829], p<0.001), and unrelated donor (vs matched related) (HR: 2.246 [1.400 - 3.605], p=0.004) remained independently associated with HR MAP (Table 2). Regarding GVHD prophylaxis, PTCy or CNI+MTX, compared with tacrolimus/sirolimus (T/S), was not associated with higher HR MAP incidence, while ruxolitinib with T/S (mainly used in MF/MPN) and abatacept (primarily used in pediatric patients) were independently associated with lower incidence of HR MAP (HR: 0.232 [0.079 - 0.687], p=0.037). Because pre- HCT gut dysbiosis is associated with poor HCT outcomes, we examined pre-HCT broad-spectrum antibiotic exposure as a surrogate, which showed no association with HR MAP or clinical outcomes (NRM, acute GVHD).In summary, day 7 MAP is a strong, independent predictor of NRM irrespective of the development of acute GVHD. Our data suggest that the tissue vulnerability and resiliency in the organ function (represented by HCT-CI and age) and the magnitude of the initial allo-immune response as seen in matched unrelated donor compared with matched related donor, are key drivers of HR MAP. These findings provide insight into the complex nature of post-transplant NRM and warrant further effort to develop biomarker-guided preemptive strategies to mitigate the risk of GVHD-related NRM as well as non-GVHD-related NRM.

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disease characterized by complement-mediated hemolysis with or without overt hemoglobinuria and is associated with bone marrow failure (BMF). PNH can be classified into 3 subcategories: classical (hemolytic) PNH, PNH with underlying BMF, and subclinical PNH. The optimal approach for patients with underlying BMF or subclinical PNH is not clearly defined. In addition, recommendations for screening and monitoring nonclassical patients are dated. A modified Delphi panel consisting of 10 hematologists and hematologist-oncologists evaluated 414 patient scenarios on 2 separate occasions and participated in a moderated in-person meeting. Consensus statements were developed based on the second round of ratings. After the meeting, the panel agreed on 90% of the ratings and made recommendations on when to screen patients for a PNH clone, when to initiate complement inhibitor treatment, and when to reevaluate patients with a PNH clone who are not yet on treatment. For example, it is appropriate to initiate complement inhibition in patients with a PNH clone size ≥10% who had a recent thrombotic event with laboratory evidence of hemolysis. Further evidence is required to improve recommendations for patients with small (<10%) PNH clone sizes.

The JAK-STAT signaling pathway regulates cytokine and growth factor production and signaling, hence, influencing immune recovery after allogeneic HCT. We have previously reported results of our phase 2a clinical trial (NCT04339101) showing that peri-HCT administration of Itacitinib (Ita), a selective JAK1 inhibitor, in combination with tacrolimus (Tac) / sirolimus (Siro) GVHD prophylaxis in matched donor reduced intensity HCT setting, is safe and associated with 100% engraftment, a low cumulative incidence of GVHD, and promising 1-year GVHD-free relapse-free survival of 54% [Ali et al, Blood (2024) 144 (Supplement 1)]. Here, we report the pharmacokinetics/pharmacodynamics of Ita and its impact on immune reconstitution in patients enrolled in this trial.GVHD prophylaxis was Ita (200 mg/day – from day -3 pre-HCT until day +100), with Tac/Siro (target levels: 5-10ng/ml for both). Ita exposure was assessed from day -3 to day +5. T cell subsets were monitored on days +35 and +100. Serum cytokine level was measured at pre-HCT, days +14 and +28.Ita at 200 mg/day dose resulted in variable systemic exposure, with average trough concentration of 12.5 nM (IQR: 7.3-23.0) (Fig 1A) and AUC0-12 at 2145 nM*h (IQR: 1440-2926). The average trough concentrations for Tac and Siro were less variable mainly due to therapeutic drug monitoring (TDM): 8.83 ng/ml (IQR: 7.65-10.2) and 7.06 ng/ml (IQR: 5.15-8.5), respectively (Fig 1B). When stratified by Ita trough levels, patients with higher-than-median Ita concentrations (24.5 nM; IQR: 16.8–33.7) also exhibited higher Siro trough levels (Fig 1C), likely due to shared metabolic pathway involving Cytochrome P450 3A4.The absolute number of T cell subsets on day +35 averaged 61.6/µL (IQR: 30.8–131) for CD4⁺, 21.3/µL (IQR: 10.1–39.7) for CD8⁺, increasing by day +100 to 94.5/µL (IQR: 51.9–153) and 37.8/µL (IQR: 21.5–75.9), respectively. Regulatory T cells (Treg) counts were 3.91/µL (IQR: 1.95–7.54) on day +35 and 3.31/µL (IQR: 1.74–6.42) on day +100.Patients who developed grade 2–4 acute GVHD had Treg counts of 1.22/µL (IQR: 1.1–2.3) at day +35 and 5.7/µL (IQR: 2.1–7.0) at day +100 (Fig 1D). Ita trough levels and AUC demonstrated a negative correlation with Treg counts (Fig 1E). These patients also had modest elevations in GVHD biomarkers (HGF, Reg3A, TNF-R1) on day 14 but not on day 28 (Fig 1F). While Ita trough centration did not significantly correlate with GVHD biomarkers (Fig 1G), Ita AUC showed a positive correlation with HGF, IL-6, and ST2 levels.In conclusion, oral administration of Ita during the peri-HCT period showed substantial interindividual variability in drug exposure and possible interaction with Siro. Interestingly, the higher Ita levels (trough and/or AUC) were associated with lower number of Treg and higher levels of GVHD biomarkers, suggesting that further optimization of Ita dosing and TDM may lead to further improvement of HCT outcomes.

Background It remains unclear whether prior chimeric antigen receptor (CAR) T-cell therapy is associated with an increased risk of graft-versus-host disease (GVHD) or non-relapse mortality (NRM) following allogeneic hematopoietic cell transplantation (HCT). Objective We evaluated the incidence of NRM, acute GVHD, and chronic GVHD in patients who underwent HCT following CAR T-cell therapy compared with matched controls who did not receive CAR T-cell therapy prior to HCT. Study Design We conducted a retrospective propensity-score matched case (prior CAR T recipients)-control (no CAR T prior to HCT) study to describe the impact of prior CAR T treatment on HCT outcomes. Results Day-100 NRM in the case vs control groups were 6.2% vs 8.6% (p=0.82). Day-100 CI of grades II-IV and III-IV acute GVHD in the case vs control groups were 43.1% vs 44.8% (p=0.83) and 20.0% vs 12.1% (p=0.099), respectively. The 1-year CI of any and moderate/severe chronic GVHD in the case vs control groups were 43.8% vs 42.3% (p=0.87) and 28.1% vs 20.3% (p=0.23), respectively. Overall and GVHD/relapse-free survival were not statistically significantly different after adjusting for DRI, p=0.094 and p=0.14, respectively. The cumulative incidence of relapse and disease-free survival were not statistically significantly different. Patients who had less than 3 months between CAR T and HCT had improved graft-vs-host disease/relapse-free survival (GRFS), 40% vs 24.4% at 1-year (p=0.032), owing to reduced grade III-IV acute GVHD, 5% vs 26.7% at 100-days (p=0.030). Conclusion . Prior CAR T-cell therapy was not associated with an increased risk of GVHD or NRM, suggesting that CAR T-cell therapy can be administered without adversely affecting subsequent HCT outcomes.

Abstract Patients with paroxysmal nocturnal hemoglobinuria (PNH) on anti‐C5 often experience extravascular hemolysis with anemia. Iptacopan, the first oral proximal complement inhibitor targeting factor B, has shown efficacy and safety in PNH patients. APPULSE‐PNH (NCT05630001), a phase 3b, single‑arm, open‐label trial, enrolled adult patients with PNH and hemoglobin ≥10 g/dL on stable anti‐C5 for ≥6 months. Patients switched to iptacopan monotherapy (200 mg twice daily; 24 weeks). Primary endpoint: mean hemoglobin change from baseline across four visits (Days 126–168). At baseline, 57.7% of patients had elevated absolute reticulocyte counts (ARCs; above ULN = 123 × 109/L) and 50% had C3 deposition on red blood cells (RBCs) >10%, indicative of extravascular hemolysis. There was a statistically significant increase in hemoglobin during the trial; adjusted mean change from baseline (95% CI) was +2.0 g/dL (1.7–2.3) overall, and in patients with baseline hemoglobin <12 g/dL and ≥12 g/dL, +2.4 (2.0–2.7) and +1.4 (1.0–1.8), respectively. Patients maintained transfusion independence, 92.7% with hemoglobin ≥12 g/dL. Adjusted mean change from baseline (95% CI) in lactate dehydrogenase and ARC were −1.3% (−6.6 to 4.3) and −89.2 × 109/L (−95.5 to −82.9), respectively. Mean (SD) proportion of C3d+ PNH RBCs, assessed by flow cytometry, decreased from 11.0% (8.6) to 0.2% (0.7) at Day 168. No patients had breakthrough hemolysis or major adverse vascular events. FACIT‐Fatigue and treatment satisfaction scores improved by Days 84 and 168. Safety showed consistency with previous iptacopan PNH trials. Iptacopan improved hematologic outcomes in PNH patients with hemoglobin ≥10 g/dL on anti‐C5, maintaining control of intravascular hemolysis and resolving extravascular hemolysis.

It remains unclear whether prior chimeric antigen receptor (CAR) T-cell therapy is associated with an increased risk of graft-versus-host disease (GVHD) or nonrelapse mortality (NRM) following allogeneic hematopoietic cell transplantation (HCT). We evaluated the incidence of NRM, acute GVHD, and chronic GVHD in patients who underwent HCT following CAR T-cell therapy compared with matched controls who did not receive CAR T-cell therapy prior to HCT. We conducted a retrospective propensity-score matched case (prior CAR T recipients)-control (no CAR T prior to HCT) study to describe the impact of prior CAR T treatment on HCT outcomes. Day-100 NRM in the case versus control groups were 6.2% versus 8.6% (P = .82). Day-100 CI of grades II to IV and III to IV acute GVHD in the case versus control groups were 43.1% versus 44.8% (P = .83) and 20.0% versus 12.1% (P = .099), respectively. The 1-year CI of any and moderate/severe chronic GVHD in the case versus control groups were 43.8% versus 42.3% (P = .87) and 28.1% versus 20.3% (P = .23), respectively. Overall and GVHD/relapse-free survival were not statistically significantly different after adjusting for DRI, P = .094 and P = .14, respectively. The cumulative incidence of relapse and disease-free survival were not statistically significantly different. Patients who had less than 3 months between CAR T and HCT had improved graft-versus-host disease/relapse-free survival (GRFS), 40% versus 24.4% at 1-year (P = .032), owing to reduced grade III to IV acute GVHD, 5% versus 26.7% at 100-d (P = .030). Prior CAR T-cell therapy was not associated with an increased risk of GVHD or NRM, suggesting that CAR T-cell therapy can be administered without adversely affecting subsequent HCT outcomes.

Cluster of differrentiation 19 (CD19)-directed therapies have significantly improved outcomes in B-cell malignancies; however, relapse driven by antigen escape remains a major clinical challenge, underscoring the need for alternative therapeutic targets. The B-cell activating factor receptor (BAFF-R), a key regulator of B-cell survival, is highly expressed in mature B-cell neoplasms, but its relevance in B-lymphoblastic leukaemia (B-ALL) remains unclear. We assessed BAFF-R expression in diagnostic and relapsed fresh B-ALL samples using multi-parameter flow cytometry. BAFF-R was consistently expressed in most cases, albeit at lower levels than in mature B cells, and expression was retained in the majority of CD19-negative relapses following CD19-directed therapy. Notably, tumor protein p53 (TP53) alterations were significantly enriched in CD19-negative immune escape disease (68.8% vs. 21.7%; p = 0.0006; OR = 7.9), yet BAFF-R expression remained preserved in this high-risk group. These findings establish BAFF-R as a stable immunotherapeutic target in B-ALL, including in CD19-negative and TP53-altered relapsed disease, and underscore its relevance amid ongoing early-phase clinical trials of BAFF-R-directed chimeric antigen receptor (CAR) T-cell therapy.

BACKGROUND:Total marrow and lymphoid irradiation delivers augmented doses of radiation to the bone marrow and lymph nodes while maintaining low doses to vital organs. We aimed to assess the effectiveness of combining total marrow and lymphoid irradiation (2000 cGy to bone marrow and lymph nodes) with high-dose cyclophosphamide and etoposide as a conditioning regimen before allogeneic haematopoietic cell transplantation (HCT) in patients with relapsed or refractory acute leukaemia. METHODS:This single-centre, open-label, phase 2 trial with an initial six-patient safety lead-in, conducted in the USA, enrolled patients aged between 16 and 60 years with relapsed or refractory acute myeloid leukaemia or acute lymphoblastic leukaemia. Total marrow and lymphoid irradiation was given on days -9 to -5, etoposide 60 mg/kg on day -4, and cyclophosphamide 100 mg/kg on day -2. Bone marrow or peripheral blood stem cells from sibling or matched or one allele mismatched unrelated donors were infused on day 0. Graft versus host disease prophylaxis consisted of tacrolimus and sirolimus. The primary endpoint for the initial safety lead-in segment was toxicity and for the phase 2 study was 2-year progression-free survival. All patients who began treatment were included in the analysis. This trial is registered with ClinicalTrials.gov, NCT02094794, and is closed to accrual. FINDINGS:Between May 9, 2014, and Mar 5, 2024, 107 patients were enrolled and screened for eligibility. One did not meet eligibility criteria (uncontrolled cytomegalovirus). 106 received conditioning radiation and HCT per protocol. Median follow-up was 1·8 years (IQR 0·6-3·0) for all patients and 3·1 years (2·1-4·9) for patients who were alive at last contact. None of the six patients in the safety lead-in experienced unacceptable toxicity. 49 (46%) of 106 patients were female and 57 (54%) were male. 72 (68%) of patients were White and 22 (21%) were Asian or Pacific Islander. The 2-year estimate of progression-free survival in all patients was 34% (95% CI 25-43%). The most common grade 3-4 adverse events were cytopenias 96 (91%), metabolic disorders 83 (78%), oral mucositis 45 (42%), diarrhoea 25 (24%), nausea 21 (20%), and palmar-plantar erythrodysesthesia syndrome 11 (10%). One patient died of sinusoidal obstruction syndrome attributed to the conditioning regimen. INTERPRETATION:Adverse events were few, probably due to organ sparing by total marrow and lymphoid irradiation. Total marrow and lymphoid irradiation 2000 cGy could be safely delivered in combination with high-dose etoposide and cyclophosphamide. The regimen was associated with encouraging 2-year progression-free survival rates. FUNDING:National Institutes of Health and Accuray.

Abstract: Relapse after allogeneic hematopoietic cell transplantation (alloHCT) remains a challenge for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), and salvage therapy in this setting is not standardized. Given the efficacy of hypomethylating agents and venetoclax (HMA-VEN) in the frontline and relapsed settings, we evaluated the use of this therapy for post-alloHCT relapse. Eighty-three patients with AML (n = 69) or MDS (n = 14) who relapsed after alloHCT were included in this retrospective analysis. The median time to relapse after alloHCT was 7.0 months. Most patients (55%) had prior VEN exposure, and 28% of these patients had previously experienced treatment failure with a VEN-based regimen. HMA-VEN treatment-emergent toxicities were predominantly neutropenia and thrombocytopenia; however, the 30-day mortality was only 3.6%. There were 3 deaths within 30 days because of infectious complications. HMA-VEN led to a complete response (CR) or CR with incomplete hematological recovery in 48% of the patients, with 58% of these patients achieving minimal residual disease negativity. In multivariable analysis, European LeukemiaNet 2024 genetic risk stratification was a predictor of survival outcome. Additionally, prior VEN failure was not a predictor of overall survival. In conclusion, HMA-VEN provides an efficacious and well-tolerated option for post-alloHCT AML or MDS relapse regardless of their prior therapy and may allow responders to undergo a second alloHCT with curative intent.

Dietary interventions may improve gut microbial diversity and HCT prognosis. Lysozyme, an antimicrobial protein highly expressed in human milk, supports the establishment of a healthy gut microbiota. Maga et al., at UC Davis developed the Artemis line of transgenic goats producing milk with human lysozyme (hLZ), which showed improve clinical outcomes, intestinal mucosa integrity, and gut microbiota in piglets with E. coli-induced severe diarrhea.In our ongoing pilot trial (NCT03531281) with the primary objective to evaluate the safety/feasibility of hLZ consumption, 41 evaluable patients (pts; median age=61 years; range: 22-78 years) with ALL (n=14), AML (n=8), or MPN or MDS (n=19) have been enrolled. The trial included a safety lead-in segment (SLI; n=6) followed by a randomized segment with pts receiving standard HCT care alone (SOC; n=17) or SOC+hLZ (n=18). Grafts were PBSC (n=40) or bone marrow (n=1) from matched related (n=11) or unrelated (n=30) donors. All SLI pts received myeloablative conditioning (FTBI), but most randomized pts (80%) received reduced intensity conditioning. GVHD prophylaxis was tacrolimus/sirolimus.Data from the SLI showed the feasible hLZ volume for consumption in the randomized segment is 450ml daily from admission to HCT and 300ml daily from HCT to discharge. These doses correspond to 2-3x naturally produced lysozyme in saliva in healthy individuals. There were no hLZ-related serious adverse events. Overall AEs were similar in the SLI, SOC and hLZ arms. Blood stream infections occurred in 4 pts by day 100 (SLI n=1, SOC n=2, hLZ n=1). Grade 3-4 infections occurred in 4 pts in SOC vs 1 in hLZ (p=0.18).At a median follow-up duration of 11.4 months (range 0.2-25.5) for surviving pts, all pts engrafted; median of 14 days to neutrophil recovery. In the randomized segment, day 180 non-relapse mortality (NRM) was 0% in the hLZ and 12% in the SOC arm (p=0.16). One-year overall survival (OS) was 90% for hLZ and 88% for SOC. Cumulative incidence of G3-4 aGVHD was 6% (95%CI: 0.4-26%) in SOC and 0% in hLZ pts. Lower GI GVHD was seen in 3 pts (SOC=1, hLZ=2).Shotgun metagenome sequencing analysis of stool samples showed a trend for better preservation of gut microbial diversity in hLZ pts at day 14 post-HCT vs. SOC pts, particularly among those who developed aGVHD. Some pathobionts such as E. coli (day 30, 100) Prevotella (Admit – day 100), Klebsiella (day 30,100), Staphylococcus (day 30) and Enterococcus (day 14) were more enriched in SOC vs hLZ pts. The dominance of antimicrobial resistance (AMR) genes by group and aGVHD changes over time, with SOC aGVHD+ exhibiting the greatest domination of select AMR genes.Our preliminary data establishes the safety & feasibility of hLZ in HCT pts. While survival outcomes were similar between hLZ and SOC in this interim analysis, we observed promising low rates of G3-4 infections, G3-4 aGVHD, and NRM, associated with reduced disruption of microbial communities.

We report a phase 1 study assessing safety and efficacy of CD19 chimeric antigen receptor (CAR) T cells as definitive consolidation in older adults (≥55 years) with B-cell acute lymphoblastic leukemia (B-ALL) in first complete remission (CR1) (ClinicalTrials.gov identifier: NCT05707273). Eighteen patients received lymphodepletion followed by infusion of memory-enriched CD19 CAR T cells. The median age was 64 years, and all patients were measurable residual disease (MRD)-negative pre-lymphodepletion. There were no dose limiting toxicities, grade ≥2 cytokine release syndrome or any grade immune effector cell-associated neurotoxicity syndrome. Estimated 18-month event-free and overall survival were 84% and 100%, respectively. CAR T cells expanded in blood and cerebrospinal fluid despite patients' MRD-negative status. Comparing clinical samples from patients with relapsed/refractory (R/R) B-ALL from our historical trial (NCT02146924) and patients in CR1, we found that the blood and CAR T cell products from R/R patients were hyper-inflammatory and hyper-immunometabolic, respectively. First line CAR T cell therapy was safe, well-tolerated, and potentially extended remission in patients in MRD-negative CR1. These findings support further investigation of early use of CAR T cell therapy for B-ALL.

Patients with B-cell acute lymphoblastic leukemia (B-ALL) and high disease burden (DB; ≥5% marrow blasts and/or extramedullary disease) before lymphodepletion (LD) experience inferior survival and increased toxicity following CD19-directed chimeric antigen receptor T-cell (CAR T) therapy. Bridging therapy (BT) administered between leukapheresis (LA) and LD is frequently used to reduce DB, yet the impact of successful cytoreduction on CAR T outcomes remains unclear. We retrospectively reviewed 154 patients with B-ALL treated with CD19-directed CAR T therapy at City of Hope between 2014 and 2024 who underwent disease assessments both pre-LA and pre-LD. High DB pre-LA were classified as high-to-low (H-L) if cytoreduction was achieved prior to LD or high-to-high (H-H) if DB remained elevated. Outcomes included cytokine release syndrome (CRS), immune effector cell–associated neurotoxicity syndrome (ICANS), leukemia-free survival (LFS), and overall survival (OS). Among 124 patients with high DB pre-LA, 117 received BT, and 23% (n=28) achieved cytoreduction. Two-year LFS was significantly improved in H-L versus H-H patients (56.3% vs. 34.8%, p=0.04) with similar rates of grade ≥3 CRS and ICANS. Among BT modalities, only tyrosine kinase inhibitor (TKI)-based therapy increased the odds of cytoreduction (OR=3.77, p=0.03), but no individual BT type was independently associated with improved survival. Successful cytoreduction prior to CAR T infusion, rather than BT type, was associated with superior LFS. Optimizing individualized BT strategies to achieve effective cytoreduction while minimizing treatment-related toxicity may further improve outcomes in high-DB B-ALL.

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is a high-risk subtype of B-cell ALL associated with poor response to induction chemotherapy, suboptimal measurable residual disease (MRD) clearance, and inferior survival outcomes compared to non-Phlike subtypes. We retrospectively analyzed 140 consecutive adult patients with Ph-like ALL treated at our institution. The median age was 33.5 years, and the majority harbored CRLF2 rearrangements (85%). IKZF1plus deletion and JAK mutations were identified in 26% and 37% of patients, respectively. The majority (75%) received pediatric-inspired regimens (PIR), which were associated with higher complete remission (CR) rates (p=0.034), reduced risk of relapse (p.