Citations

Black race and Hispanic ethnicity are associated with higher mortality in severe combined immunodeficiency (SCID) following hematopoietic cell transplantation (HCT), though mechanisms remain unclear. We evaluated 796 children with SCID who received nonsibling HCT between 1982 and 2020 using data from the Primary Immune Deficiency Treatment Consortium. Overall survival for Black (aHR 2.47, 95%CI 1.64, 3.71) and Asian/Pacific Islander patients (aHR 1.82, 95%CI 1.00, 3.30) was significantly lower compared with non-Hispanic White patients, while Hispanic patients had lower event-free survival (aHR 1.83, 95%CI 1.27, 2.63) compared with non-Hispanic White patients. Even after adjusting for age and infection, Black patients with SCID had more than twofold hazard of death compared with non-Hispanic White patients. NBS was associated with earlier diagnosis, reduced infection at HCT, and elimination of survival disparities between Black and non-Hispanic White patients. These findings suggest that universal, system-level interventions such as NBS can mitigate disparities in outcomes for children with SCID.

Background: Hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), and preterm delivery are associated with higher long-term cardiovascular, metabolic, and kidney disease risk. Their implications for living kidney donation remain uncertain. Methods: We conducted a retrospective cohort study of 498 female living kidney donors (2000–2017) from the Mayo Clinic Living Donor Program with documented pregnancy histories, pre-donation CT angiography, implantation kidney biopsy, and measured GFR. Donors with prior HDP (n=45), GDM (n=18), or preterm delivery (n=65) were compared with donors without adverse pregnancy outcomes (APO; n=385). Kidney morphometry, histology, and function were analyzed with adjustment for age at donation and first pregnancy, parity, and hypertension. Post-donation kidney outcomes were assessed using surveys and medical record review. Results: Donors with prior HDP and GDM had higher BMI at donation (+7.9% and +8.9%; p=0.006 and 0.04), whereas donors with preterm delivery had lower BMI (−4.8%; p=0.03) compared with donors with no APO. After adjustment, donors with HDP showed no differences in kidney volumes, biopsy features, or kidney function at donation or during follow-up. Donors with GDM had larger total and cortical kidney volumes (9.5–10%), less arterial luminal stenosis, and higher 5-year post-donation eGFR (+15%; p=0.03). Donors with preterm delivery had a lower risk of eGFR <45 mL/min/1.73 m 2 (HR 0.28; p=0.03). Conclusions: Prior adverse pregnancy outcomes were not associated with adverse kidney structure at donation or accelerated kidney function decline post-donation. These findings support that APO history alone should not preclude living kidney donation when other eligibility criteria are met.

Background Graft-versus-host disease (GVHD) remains a major determinant of morbidity and mortality following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Existing GVHD prediction models demonstrate modest discrimination and limited generalizability, and calibration drift across external populations is rarely characterized despite its essential role in the clinical interpretability of predicted probabilities. Objectives To develop and externally validate an explainable machine learning framework for predicting acute and chronic GVHD and associated overall survival in patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and myelodysplastic syndromes (MDS) undergoing allo-HSCT, and to systematically characterize calibration across heterogeneous external validation cohorts to inform deployment requirements. Study Design The model was developed on three publicly available registry-derived datasets (N = 2,509) and externally validated across six independent cohorts (N = 14,788) comprising adult and pediatric allo-HSCT recipients, including a regional Middle Eastern cohort (UAE and Jordan). A standardized preprocessing pipeline harmonized heterogeneous datasets. Gradient boosting models (CatBoost) were used for binary GVHD prediction; exploratory overall survival analysis used a Cox proportional hazards model with predicted acute GVHD risk as a covariate. Discrimination (AUROC with bootstrap 95% CI), calibration (logistic recalibration intercept and slope with analytical 95% CI), and feature importance (SHapley Additive exPlanations, SHAP) were assessed in training out-of-fold and all external cohorts. Results In internal validation, AUROC was 0.63 (95% CI 0.61–0.65) for acute GVHD and 0.72 (95% CI 0.70–0.74) for chronic GVHD. External validation demonstrated AUROC ranges of 0.51–0.57 (acute) and 0.54–0.64 (chronic), with consistent performance across disease subgroups despite substantial heterogeneity in transplant practices and feature availability. In exploratory survival analysis, the acute-GVHD-informed Cox model achieved a training-cohort C-index of 0.679 (95% CI 0.658–0.697); external C-indices ranged from 0.47–0.53. Calibration analysis identified systematic external risk overestimation (negative calibration intercept in 10 of 11 evaluable external cohort-target combinations) with heterogeneous slope drift requiring cohort-specific recalibration. Key predictors included recipient age, graft source, conditioning intensity, GVHD prophylaxis, and HLA match ratio. Conclusions An explainable, externally validated GVHD prediction framework was developed using heterogeneous registry-derived datasets, with systematic characterization of calibration drift across multiple external cohorts, an analysis rarely reported in prior GVHD prediction literature. Predictive performance was modest for acute GVHD and moderate for chronic GVHD, constrained by missing immunobiological variables and incomplete HLA characterization. Per-cohort recalibration is required before clinical deployment, with prospective validation and benchmarking against established GVHD risk scores identified as priority next steps.

Abstract Early-phase clinical trials of BTK degraders in relapsed/refractory CLL have shown response rates of over 80%, including in patients with BTK mutations that confer resistance to conventional BTK inhibitors (BTKi). The molecular basis of resistance to BTK degraders is unknown and, given the promise of this class of drugs, would hold implications for therapy sequencing and the design of next-generation BTK degraders. To this end we identified five patients at Memorial Sloan Kettering who developed progressive disease while being treated on the phase 1 trials of zelebrudomide (NCT04830137, 4 patients) or bexobrutideg (NCT05131022, 1 patient). In two patients, one treated with zelebrudomide and the other with bexobrutideg, a pre-existing BTK A428D mutation had expanded at progression, rising from &lt;1.5% at the start of treatment to &gt;25%. In both cases, the increase in frequency of BTK A428D coincided with the loss of BTK degradation in peripheral blood B cells. No mutation in cereblon, the ligase utilized by these BTK degraders, was detected. To validate these clinical findings we generated wild-type and BTK A428D knock-in single-cell clones in TMD8 and HBL1 cells. BTK A428D conferred resistance to BTKi, including ibrutinib, acalabrutinib, zanubrutinib, and pirtobrutinib, as well as the clinical-stage BTK degraders zelebrudomide, bexobrutideg, BGB-16673, and AbbVie-1 (Compound 1, WO 2023183811). BTK A428D’s pan-resistance is unique compared to previously studied BTKi resistance mutations which remain susceptible to at least one BTKi and all clinical-stage BTK degraders tested. To understand how BTK A428D confers pan-resistance to BTKi and BTK degraders we conducted surface plasmon resonance studies which demonstrated that BTKi and all four clinical-stage BTK degraders tested are unable to bind BTK A428D. We next solved the crystal structure of apo BTK A428D to 1.8Å, which revealed that the mutant aspartate, which is larger and negatively charged compared to the wild-type alanine, sterically blocks BTKi and degraders from accessing residues in the hinge region of the kinase that are required for drug binding. We next asked why BTK A428D, despite conferring pan-resistance, has only been detected in 1.1% of patients treated with BTK inhibitors. Intriguingly, we noted that in one of our index patients, the frequency of BTK A428D declined and became undetectable after the withdrawal of zelebrudomide, suggesting a fitness defect. To assess this hypothesis, we compared the proliferation rates of five TMD8 wild-type and five BTK A428D single-cell clones; the BTK A428D clones grew more slowly and were consistently outcompeted in mixing studies. In summary, low-frequency BTK A428D mutations can expand under the selection pressure of BTK degraders and confer clinical resistance by preventing drug binding. The mutation, however, is outcompeted in the absence of BTK-targeted therapies. These findings provide rationale for the investigation of combination therapies and the development of next-generation BTK degraders capable of circumventing BTK A428D. Citation Format: Quinlan Sievers, Hao Lu, Allison Cool, Stefan Grajewski, Tim Kong, Mark Noviski, Xiaoli Mi, Emel Ficici, Ratul Mukerji, James Iuliano, Jordan Ye, Mateo Sanchez Garcia de los Rios, Hugo Bousquet, Sarah Whelan, May Tan, Christopher Phelps, Jahan Raman, Ryan Notti, Lizbeth Mendoza Navarrete, Samantha Sekeres, Eria Lamkin, Eduardo Bravo, Mark Ewalt, Prioty Islam, Anthony Mato, Lindsey Roeker, Justin Taylor, Meghan Thompson, Gwenn Hansen, Omar Abdel-Wahab. BTK A428D is a recurrent pan-resistance mutation to BTK degraders in clinical trials [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr PR004.

Aims Reliable assessment of joint stiffness is essential for studying arthrofibrosis in preclinical animal models. This study presents a new dedicated biomechanics device for measuring knee stiffness in mouse, rat, and rabbit models of arthrofibrosis, with the aim of validating its performance and comparing it to a previously validated device. Methods The new system integrates a torque load cell, stepper motor, and absolute encoder in a through-hole, unified configuration for precise continuous torque-angle measurement, with custom limb brackets ensuring species-specific alignment at the joint’s centre of rotation. To validate this device and compare it to a previously validated device, arthrofibrosis was induced using established models of extra-articular immobilization in mice and intra-articular violation with immobilization in rats and rabbits, followed by defined remobilization periods. Torque-angle curves were recorded ex vivo across species-specific torque ranges, and measurement variability between the new and a previous validated device was statistically compared using Brown-Forsythe’s test. Results The onset of hyperextension in contralateral limbs occurred at mean angles of 152.4° (mice), 154.4° (rats), and 152.8° (rabbits), and at maximum torque, mean flexion angles were 79.2°, 87.3°, and 140.5°, respectively. No significant differences in measurement variability were observed between devices across all species. Conclusion These findings demonstrate that our new device provides reproducible torque-angle data while maintaining the statistical robustness of the previous device and offering improved mechanical design and operational standardization. By enabling standardized, cross-species joint stiffness quantification, this platform improves cross-study comparability and strengthens the translational reliability of preclinical arthrofibrosis research. Cite this article: Bone Joint Res 2026;15(6):716–725.

e24088 Background: Chemotherapy-induced nausea and vomiting (CINV) significantly affects treatment tolerance and quality of life. ASCO guidelines recommend a NK-1 receptor antagonist with a 5-HT3 receptor antagonist and corticosteroid for patients receiving highly emetogenic chemotherapy (HEC). Olanzapine has emerged as an alternative antiemetic, with evidence suggesting noninferiority in triple regimens. Given its favorable cost profile, we performed a pooled analysis comparing olanzapine- versus aprepitant-based triple antiemetic regimens for CINV prevention. Methods: This PRISMA-compliant review was prospectively registered in PROSPERO (CRD420261284983). Five databases were systematically searched to identify studies comparing olanzapine (OLZ) versus aprepitant (APR) based triple antiemetic regimens. The primary endpoint was complete response (CR) for prophylaxis of chemotherapy-induced nausea and vomiting (CINV) in adult patients receiving HEC. Statistical analyses were performed in R (version 2025.05.0+496; Posit). Results: 13 studies were included in the final synthesis, comprising 1,557 patients (OLZ: n = 779; APR: n = 788). CR was comparable between groups (RR 1.02, 95% CI 0.95–1.09; I² = 55.8%). Exclusion of Mehta et al. (2017) reduced heterogeneity to zero (I² = 0%). In the acute phase ( < 24 h), CR was also similar between OLZ and APR (RR 1.09, 95% CI 0.98–1.20; I² = 82.7%); however, OLZ demonstrated superior CR in the 10-mg dose subgroup (RR 1.08, 95% CI 1.03–1.14; I² = 74%). For delayed-phase CR (24-120 h), the pooled effect estimate was RR 1.11 (95% CI 0.98–1.27; I² = 84.3%). Control of nausea was significantly improved in the OLZ group compared with APR (RR 1.19, 95% CI 1.01–1.40; I² = 72.8%), particularly in anthracycline–cyclophosphamide–based regimens (RR 1.30, 95% CI 1.09–1.54; I² = 62.9%) and the 10-mg OLZ dose subgroup (RR 1.22, 95% CI 1.01–1.49; I² = 75.2%). Nausea control was also superior in both the acute phase (RR 1.13, 95% CI 1.01–1.27; I² = 76.5%) and the delayed phase (RR 1.31, 95% CI 1.05–1.65; I² = 93.3%). Control of vomiting was comparable between OLZ and APR (RR 0.99, 95% CI 0.92–1.07; I² = 0%), with no significant differences observed in the acute ( < 24 h) phase (RR 1.03, 95% CI 0.97–1.10; I² = 49%) or the delayed (24–120 h) phase (RR 1.00, 95% CI 0.97–1.04; I² = 0%). Conclusions: OLZ-based triple antiemetic regimens provide comparable CR and vomiting control to APR, with superior nausea control, particularly in anthracycline–cyclophosphamide regimens and at the 10-mg dose.

e16435 Background: Peritoneal metastasis in pancreatic ductal adenocarcinoma (PDAC) is historically associated with a dismal prognosis and limited response to systemic therapy alone. The role of locoregional therapy remains controversial. This study evaluated the survival impact and safety of HIPEC, with or without cytoreductive surgery (CRS), compared to standard-of-care systemic therapy in patients with peritoneal metastatic PDAC. Methods: We conducted a comparative analysis of 130 patients with peritoneal metastatic PDAC, comprising a study cohort treated with HIPEC (n = 33) and a control group treated with systemic chemotherapy alone (Non-HIPEC, n = 97). HIPEC patients received induction chemotherapy (predominantly FOLFIRINOX) followed by HIPEC ± CRS. Co-primary endpoints included 12 months survival, and 6 months progression free survival (PFS). Secondary endpoints evaluated Overall Survival (OS ), safety of CRS, and impact of germline mutation status on survival. Study was approved under IRB protocol 25-008762. Results: The 12-month OS rate was significantly higher in the HIPEC group compared to the chemotherapy-only control group (100% vs. 52.6%, P < 0.001). The 6-month PFS rate in the HIPEC group was 63.0% vs. 47.94 in-only control group (P < 0.001). For secondary endpoints, the HIPEC group demonstrated a significantly longer median OS of 33.0 months vs. 17.0 months for controls (P < 0.001). Within the HIPEC cohort, the addition of CRS (n = 25) significantly improved outcomes compared to HIPEC alone (n = 8): median OS improved from 21.5 to 36.0 months (P = 0.03). Germline testing was performed in 61% of HIPEC patients and 48% of controls, identifying pathogenic mutations in 25% and 17%, respectively. Identified pathogenic mutations in both groups included ATM (n = 4), MUTYH (n = 2), BRCA2 (n = 1), CHEK2 (n = 1), PALB2 (n = 1), and KIT (n = 1). In the control group, specific mutations drove divergent outcomes; ATM median OS: 23.5 months vs. MUTYH : 8.0 months (P = 0.04). Conversely, in the HIPEC+CRS cohort, survival was excellent regardless of genetic profile: mutation carriers achieved a median OS of 33.0 months compared to 31.0 months in wild-type patients (P = 0.85). Despite a 34.8% postoperative complication rate in the HIPEC group, there was no perioperative mortality. Conclusions: In selected patients with peritoneal metastatic PDAC, HIPEC provides a substantial survival advantage over systemic therapy alone, achieving a 100% 12-month survival rate and more than doubling the median overall survival. Importantly, germline mutation status did not preclude survival benefit, with mutation carriers deriving equal efficacy from the multimodal approach. These findings support HIPEC+CRS as a highly effective strategy that may overcome adverse biologic drivers.

e14545 Background: Durable antitumor immunity depends on the maintenance of stem-like CD8⁺ T cells capable of sustaining long-term effector responses. Oncolytic viruses (OVs) are potent immunomodulatory agents that reshape the tumor microenvironment and augment antitumor immunity. We hypothesized that platinum-based chemotherapy alters tumor-intrinsic type I interferon (IFN-I) signaling in a manner that can be functionally restored by OV therapy, thereby promoting the generation and persistence of stem-like CD8⁺ T cells. Methods: Tumor cells treated with platinum chemotherapy were evaluated in vitro for changes in IFN-I pathway activity, OV replication, and markers of immunogenic cell death (ICD). Syngeneic mouse tumor models were used to assess antitumor efficacy and immune remodeling following combination therapy. Tumor-infiltrating lymphocytes were analyzed by single-cell RNA sequencing and multiparameter flow cytometry to define CD8⁺ T-cell states and functional programs. Guided by these preclinical findings, a clinical trial combining XELOX, PD-1 blockade, and OV therapy was initiated (ChiCTR2500107607). Results: Platinum chemotherapy significantly suppressed tumor-intrinsic IFN-I signaling, while OV therapy restored antiviral responses, enhanced viral replication, and increased ICD in vitro. In vivo, the combination strategy resulted in superior tumor control and profound remodeling of the tumor immune microenvironment. The most pronounced immunologic effect was observed within the stem-like CD8⁺ T-cell compartment. Combination therapy induced a distinct population of TCF7⁺ ISG15^high NFATC1^low AP-1^low CD8⁺ T cells, characterized by restrained activation, enhanced persistence, and reduced propensity toward terminal exhaustion. In IRF7-deficient tumors, this stem-like CD8⁺ T-cell population failed to emerge and antitumor efficacy was significantly diminished, indicating that moderate tumor-intrinsic IFN-I signaling is required for this immune state. Conclusions: Tumor-intrinsic type I interferon signaling is a critical determinant of synergy between platinum chemotherapy and oncolytic virotherapy, enabling the maintenance of durable stem-like CD8⁺ T-cell immunity. These findings establish a mechanistic rationale for combining platinum chemotherapy, oncolytic viruses, and immune checkpoint blockade and support ongoing clinical translation. Clinical trial information: ChiCTR2500107607.

9558 Background: Ipilimumab 3 mg/kg plus nivolumab 1 mg/kg (Ipi3+Nivo1) is the standard immunotherapy regimen for metastatic melanoma with brain metastases (MBM) but is associated with significant immune-related toxicity, particularly neurologic toxicity. Ipilimumab 1 mg/kg plus nivolumab 3 mg/kg (Ipi1+Nivo3) has demonstrated improved tolerability in extracranial melanoma, though comparative data in MBM are limited. We compared efficacy and toxicity of these dosing strategies in a multisite real-world cohort. Methods: We retrospectively identified patients with MBM treated with ipilimumab plus nivolumab across three Mayo Clinic sites between 2016 and 2024. Patients were classified by induction dosing as Ipi1+Nivo3 or Ipi3+Nivo1. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan–Meier method and compared using log-rank tests. Best overall response (BOR) and toxicity outcomes were summarized descriptively. Results: Among 147 patients (Ipi1+Nivo3 n=32; Ipi3+Nivo1 n=115), 144 were evaluable for survival. Median age was higher in the Ipi1+Nivo3 group (69.5 vs 66.0 years); males predominated in both groups (71.9% vs 61.7%), and the cohort was predominantly White (>96%). Most patients had ECOG 0–1 in both groups (84.4% in Ipi1+ Nivo3 and 90.4% in Ipi3+Nivo1). BRAF mutation status was balanced between regimens, with approximately half of patients harboring BRAF-mutant disease (51.6% vs 53.2%). Median OS was 18.5 months (95% CI, 5.7–54.7) with Ipi1+Nivo3 versus 10.6 months (95% CI, 6.5–19.1) with Ipi3+Nivo1 (log-rank p=0.25). Two-year OS was 45.9% and 35.0%, and five-year OS was 24.5% and 19.2%, respectively. Median PFS was 7.3 months (95% CI, 1.8–10.9) versus 2.8 months (95% CI, 2.1–4.4) (log-rank p=0.16). BOR was available for 138 patients; objective response rates were 35.5% and 31.8%, respectively. 3–5 adverse events occurred in 24.1% of Ipi1+Nivo3 versus 30.5% of Ipi3+Nivo1 patients. Hospitalizations were less frequent (16.7% vs 36.1%), and neurologic adverse events occurred only with Ipi3+Nivo1 (11.9% vs 0%). Conclusions: In this multisite real-world MBM cohort, Ipi1+Nivo3 demonstrated comparable efficacy, numerically longer survival, and a more favorable toxicity profile compared with standard Ipi3+Nivo1. Notably, no neurologic toxicity was observed with the Ipi1+Nivo3 regimen. These findings support further prospective evaluation of lower dose ipilimumab strategies. Response and survival outcomes. Outcome Ipi1 + Nivo3 Ipi3 + Nivo1 Complete response (CR) 2 / 31 (6.5%) 8 / 107 (7.5%) Partial response (PR) 9 / 31 (29.0%) 26 / 107 (24.3%) Objective response rate (ORR = CR+PR) 11 / 31 (35.5%) 34 / 107 (31.8%) Disease control rate (DCR = CR+PR+SD) 18 / 31 (58.1%) 51 / 107 (47.7%) Median PFS, months (95% CI) 7.3 (1.8–10.9) 2.8 (2.1–4.4) 2-year PFS 27.6% 22.3% Median OS, months (95% CI) 18.5 (5.7–54.7) 10.6 (6.5–19.1) 2-year OS 45.9% 35.0% 5-year OS 24.5% 19.2%

9021 Background: An escape room is a team-based activity in which participants collaborate to solve puzzles within a fixed time limit and escape. Prior studies demonstrate high learner satisfaction and improved teamwork and communication with medical education escape rooms. To date, no published reports describe an escape room designed specifically for hematology/oncology (hem/onc) fellows. As part of Hem/Onc Curriculum, we designed and implemented a hem/onc-focused escape room and evaluated learner satisfaction and perceived learning impact. Methods: The escape room was designed using evidence-based learning science principles (Table 1). Teams worked to solve sequential puzzles, centered on a patient case, addressing key hem/onc concepts, including transfusion medicine, peripheral blood smears, lymphoma classification, and coagulation disorders. Each solved puzzle revealed additional patient laboratory and pathology data. Successful completion required teams to diagnose the patient and select appropriate treatment. Following the activity, teams participated in a facilitator-led debrief focused on team dynamics, communication, and problem solving. Teams observed each other and shared feedback. A larger group debrief co-led by chief fellows and faculty reviewed learning objectives and key takeaways. Learner outcomes were assessed using a post-activity survey evaluating satisfaction, engagement, and impact on learning. Results: Eighteen learners participated, including 14 hem/onc fellows, 1 APP hem/onc fellow, and 3 internal medicine residents. Three of four teams escaped within 1 hour (mean completion time, 52 minutes). All participants provided positive verbal feedback. Fifteen learners completed the post-activity survey, and all respondents reported satisfaction with the activity and would recommend it for future fellows. One-word descriptors included “engaging,” “fun,” and “challenging.” Most respondents (93.3%) agreed that the activity reinforced key hem/onc concepts and improved confidence in clinical problem-solving. All learners felt the activity supported learning, and 93.3% reported that collaboration enhanced the learning experience. Participants identified team-based problem solving, clinical application, and interactive puzzles as the most effective components. Conclusions: A hem/onc escape room resulted in high learner satisfaction and reinforced hem/onc knowledge and clinical problem-solving. This feasible, fun, and innovative activity complements traditional fellowship education by leveraging adult learning principles through gamified, team-based learning and should be incorporated into training programs’ curriculum. Learning science principles applied in a hem/onc escape room. Active Learning Belonging Contrasting Cases Debriefing Deliberate Practice Elaboration Generation Listening and Sharing Reward Worked Examples