Citations

Abstract RATIONALE: Hypereosinophilic syndrome (HES) is a group of rare diseases characterized by persistent hypereosinophilia causing organ damage/dysfunction. Idiopathic and lymphocytic HES (I-HES/L-HES) subgroups exclude clonal and reactive HES. We evaluated real-world clinical outcomes of patients with I-HES/L-HES. METHODS: This retrospective observational cohort study of patients with I-HES/L-HES collected data from the TriNetX Linked Network of de-identified Electronic Health Records plus Claims in the US. Patients had a HES diagnosis (ICD-10-CM: D72.11) between 10/01/2020–09/12/2023, with ≥12 months continuous enrollment before their first HES diagnosis record (index date [ID]). Patients with myeloproliferative/reactive HES, or a diagnosis of eosinophilic granulomatosis with polyangiitis after HES diagnosis, were excluded. Baseline was defined as 12 months prior to ID. Year 1 was defined as 12 months after ID. Patients were followed up until either 09/12/2023, disenrollment from insurance, death, or 24 months after ID, whichever came first. Clinical response was defined as ≥3 months without HES symptoms and a blood eosinophil (bEOS) count ≤750 cells/µL. Complete hematological remission was defined as a bEOS count ≤500 cells/µL. Partial remission was defined as a bEOS count <50% of baseline value, but >500 cells/µL. Kaplan-Meier curves estimated time to first HES flare and hematological remission. Analyses were descriptive. RESULTS: At ID, patients with I-HES/L-HES (N=110) had a mean (standard deviation [SD]) age of 43.8 (21.3) years; 66 (60.0%) were male, 58 (52.7%) were White and 30 (27.3%) were Black or African American. Mean (SD) follow-up was 15.1 (7.7) months. Median (95% confidence interval [CI]) time from ID to first flare (n=47) was 18.0 (11.0, not estimated) months (Table 1). Median (95% CI) time to first complete or partial hematological remission (n=52) was 15.3 (10.8, 21.6) months. The proportion of patients with a definite or probable HES flare was lower at Year 1 (10/69 [14.5%]) versus baseline (40/110 [36.4%]). Few patients achieved clinical response at baseline (10/110 [9.1%]) and Year 1 (5/69 [7.2%]). Among patients with bEOS data, mean (SD) bEOS count was 2235.3 (4351.7) cells/µL at baseline (n=51) and 833.6 (1396.0) cells/µL at Year 1 (n=11). The proportion of patients with a bEOS count <500 cells/µL was 20/51 (39.2%) at baseline and 7/11 (63.6%) at Year 1. CONCLUSION: Despite a reduced proportion of patients experiencing flares within a year after diagnosis, many did not experience hematological remission or clinical response by Year 1; suggesting high disease burden with existing treatment and the need for novel therapies to better manage I-HES/L-HES.

We have developed a cost-effective method to study the fate of stents, particularly flow diverter stents placed in the abdominal aorta, in a rat model. This technique utilizes (caudal) tail artery access,1–5 thereby avoiding the need for surgical exposure of the femoral or carotid arteries and reducing procedural invasiveness,6 7 aligning with the principles of refinement and reduction in animal research.7 This approach may be particularly beneficial for studies requiring multiple or iterative vascular access. The use of ultrasound guidance further reduces costs and infrastructure requirements by eliminating the need for specialized angiography suites.8 This makes this technique accessible to a broader range of research settings, promoting wider adoption and collaboration in the field of endovascular research. A detailed demonstration of this method is provided in the accompanying educational video (video 1). Video 1 -Technical video describing the tail artery access and flow diverter deployment using ultrasound guidance.

Abstract Purpose: Recent advances have seen the development of targeted therapeutics against the receptor tyrosine kinase (RTK)/RAS/MAPK pathway, which, when aberrantly activated, drives the malignant transformation of many cancer indications. However, the efficacy of inhibitors targeting single molecules is dampened by pathway feedback activation and acquired drug resistance. We seek to evaluate the application of JAB-3312 (sitneprotafib), a potent inhibitor of SHP2, in RTK/RAS/MAPK pathway–targeted combination therapies. Furthermore, SHP2 plays a vital role in PD-1–mediated immunosuppression. The rational combination of JAB-3312 with PD-1 blocking therapies is also explored. Experimental Design: Biochemical and cellular assays were applied to evaluate the potency of JAB-3312 in SHP2 inhibition. Tumor cell lines and cell line– and patient-derived xenografts were used to test different combinations of JAB-3312 with KRASG12C, MEK, EGFR, and PD-1 inhibitors. Results: JAB-3312 produced potent in vitro inhibition of SHP2 activity and downstream ERK phosphorylation, with IC50 values of 1.44 nmol/L and 0.68 to 4.84 nmol/L, respectively. When used in combination, JAB-3312 significantly increased the antitumor activity of the KRASG12C inhibitor glecirasib in naïve and resistant models. The combination of JAB-3312 with MEK inhibitors significantly delayed RTK signaling reactivation and enhanced tumor growth inhibition in KRAS-mutated cancer models. The JAB-3312–osimertinib combination exhibited great efficacy in osimertinib-resistant non–small cell lung cancer models. Additionally, JAB-3312 enhanced the efficacy of PD-1 blockade therapies by promoting an antitumor microenvironment. Representative cases of patients who responded to the combination therapies from two ongoing clinical trials (NCT05288205 and NCT04720976) were reported. Conclusions: JAB-3312 in combination with RTK/RAS/MAPK or PD-1 blockade therapies is a promising strategy that warrants further clinical investigation.

Abstract Clonal hematopoiesis (CH) of indeterminate potential (CHIP), driven by somatic mutations in leukemia-associated genes, confers increased risk of hematologic malignancies, cardiovascular disease, and all-cause mortality. In blood of healthy individuals, small CH clones can expand over time to reach 2% variant allele frequency (VAF), the current threshold for CHIP. Nevertheless, reliable detection of low-VAF CHIP mutations is challenging, often relying on deep targeted sequencing. Here, we present UNISOM, a streamlined workflow for enhancing CHIP detection from whole-genome and whole-exome sequencing data that are underpowered, especially for low VAFs. UNISOM utilizes a meta-caller for variant detection, in couple with machine learning models which classify variants into CHIP, germline, and artifact. In whole-exome sequencing data, UNISOM recovered nearly 80% of the CHIP mutations identified via deep targeted sequencing in the same cohort. Applied to whole-genome sequencing data from Mayo Clinic Biobank, it recapitulated the patterns previously established in much larger cohorts, including the most frequently mutated CHIP genes and predominant mutation types and signatures, as well as strong associations of CHIP with age and smoking status. Notably, 30% of the identified CHIP mutations had < 5% VAFs, demonstrating its high sensitivity toward small mutant clones. This workflow is applicable to CHIP screening in population genomic studies. The UNISOM pipeline is freely available at https://github.com/shulanmayo/UNISOM and https://ngdc.cncb.ac.cn/biocode/tool/7816.

Human immune system (HIS) mice constructed in various ways are widely used for investigations of human immune responses to pathogens, transplants, and immunotherapies. In HIS mice that generate T cells de novo from hematopoietic progenitors, T cell-dependent multisystem autoimmune disease occurs, most rapidly when the human T cells develop in the native NOD.Cg- Prkdc scid Il2rg tm1Wjl (NSG) mouse thymus, where negative selection is abnormal. Disease develops very late when human T cells develop in human fetal thymus grafts, where robust negative selection is observed. We demonstrate here that PD-1 + CD4 + peripheral (Tph) helper-like and follicular (Tfh) helper-like T cells developing in HIS mice can induce autoimmune disease. Tfh-like cells were more prominent in HIS mice with a mouse thymus, in which the highest levels of IgG were detected in plasma, compared to those with a human thymus. While circulating IgG and IgM antibodies were autoreactive to multiple mouse antigens, in vivo depletion of B cells and antibodies did not delay the development of autoimmune disease. Conversely, adoptive transfer of enriched Tfh- or Tph-like cells induced disease and autoimmunity-associated B cell phenotypes in recipient mice containing autologous human APCs without T cells. Tfh/Tph cells from mice with a human thymus expanded and induced disease more rapidly than those originating in a murine thymus, implicating HLA-restricted T cell-APC interactions in this process. Since Tfh, Tph, autoantibodies, and lymphopenia-induced proliferation (LIP) have all been implicated in various forms of human autoimmune disease, the observations here provide a platform for the further dissection of human autoimmune disease mechanisms and therapies.

Abstract Background: Replication checkpoint modulators (RCMs), including inhibitors of CHK1, ATR, and WEE1, have been widely studied for their ability to inhibit cell cycle checkpoints and enhance the toxicity of agents that stall replication forks. In preclinical studies each of these inhibitors also demonstrates notable activity as a single agent against relapsed/refractory acute myeloid leukemia (R/R AML). In particular, our prior study (PMID: 33414171) demonstrated that several myeloid cell lines underwent cell death at nanomolar concentrations, with a median IC50 of 9 nM irrespective of the TP53 status. Examination of pathways involved in RCM-induced leukemia cell killing demonstrated that CHK1 inhibition induces CDC25A upregulation accompanied by activation of a death program that involves a CDK2-initiated 10- to 50-fold upregulation of TNFα and downstream engagement of the extrinsic apoptotic pathway. Here we have comprehensively characterized the processes that occur between the interruption of replication checkpoints and leukemic cell death in these sensitive cells versus cells selected for RCM resistance. Methods: Using the CHK1 inhibitors MK8776 and prexasertib, ATR inhibitors berzosertib and ceralasertib, and WEE1 inhibitor adavosertib as paradigm drugs, we examined signaling in two AML cell lines, U937 and THP.1, that were selected for CHK1 inhibitor resistance, examined cross-resistance patterns, and assessed the biochemical basis for leukemic cell death. Changes in gene expression and signaling induced by RCMs were analyzed in isogenic pairs using RNA sequencing, flow cytometry and immunoblotting. Results: In contrast to parental U937 and THP.1 cells, CHK1 inhibitor-selected U937 and THP.1 cell exhibited a lack of TNFα mRNA induction and did not undergo cell death in response to multiple CHK1 inhibitors. RNA sequencing of CHK1 inhibitor-selected AML lines revealed an almost complete absence of induction of CDK2-activated genes following prexasertib treatment. Interestingly, unlike solid tumors, AML cell lines that were resistant to CHK1 inhibitors exhibited hypersensitivity to WEE1 or ATR inhibition. Further studies demonstrated that CHK1 inhibitor response was varied in primary AML samples, with 50% of primary AML specimens resistant to CHK1i monotherapy, again without any relationship to TP53 status. The common features among sensitive vs. resistant leukemias was the successful inhibition of CDK2 phosphorylation and the associated induction of TNFα. Conclusions: Our findings reveals critical new insights into the factors that influence the response to CHK1 inhibitors in AML. Importantly, we found no evidence of cross-resistance to inhibitors of other replication checkpoint proteins, enabling alternative options. Citation Format: Annapoorna Venkatachalam, Husheng Ding, Nicole Vincelette, Cordelia McGehee, Kevin Peterson, Paula Schneider, Cristina Correia, Hu Li, Scott Kaufmann. CDK2 activation mediates response of acute myeloid leukemia to CHK1, ATR and WEE1 inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 423.

ABSTRACT Objective Although fetal sex chromosome complement prediction by prenatal cell‐free DNA (cfDNA) screening is highly accurate, discordance between the cfDNA‐inferred chromosomal sex and phenotypic sex observed via ultrasonography or at birth, that is, “fetal sex discordance”, does rarely occur. Such discordance may be caused by differences in sex development (DSD) or technical or biological artifacts. This study aims to provide insights into the proportion of fetal sex discordance cases caused by DSD versus non‐DSD artifacts. Method We retrospectively reviewed 122,748 cases that underwent diagnostic testing at the Mayo Clinic Cytogenetics Laboratory between 2015 and 2023. Thirty‐three singleton‐gestation cases tested for fetal sex discordances were identified. Results Fetal sex discordance was attributed to non‐DSD artifacts in 24 (73%) of the 33 patients. In these cases, the phenotypic sex matched the chromosomal sex revealed by diagnostic cytogenetic testing. The remaining 9 patients included one with mosaic 46,X,psu idic(Y)(q11.21)/45,X, 5 with 46,XY DSD, and 3 with 46,XX DSD. Conclusion The majority of fetal sex discordance cases are caused by non‐DSD artifacts rather than DSD. Accurate clinical counseling of fetal sex discordance requires distinguishing between DSD and non‐DSD causes, emphasizing the need for diagnostic cytogenetic testing.

Abstract This study explores parallels between systemic hypoxia adaptation in high-altitude populations and tumorigenesis. We identified EPAS1, a gene critical for hypoxia adaptation in populations such as Tibetans and Sherpas, as playing a similar adaptive role in tumors arising under hypoxic conditions. Tumors from patients with chronic hypoxia displayed impaired DNA repair and frequent emergence of EPAS1 variants, with frequencies reaching up to 90%, echoing the positive selection seen in high-altitude dwellers. Mechanistically, EPAS1 gain-of-function mutations promote COX4I2 expression, reducing cellular oxygen consumption and supporting tumor proliferation in hypoxia. Analysis of clinical data from patients with hypoxia revealed tissue-specific and time-sensitive tumorigenic effects, particularly impacting oxygen-sensitive cells in the postnatal period. Our findings suggest that EPAS1-driven adaptation mechanisms in high-altitude populations provide a model for understanding tumor evolution under hypoxic stress, highlighting how genetic adaptations to diverse stressors in natural populations may yield insights into tumorigenesis and cancer progression. Significance: This study reveals a broad convergence in genetic adaptation to hypoxia between natural populations and tumors, suggesting that insights from natural populations could enhance our understanding of cancer biology and identify novel therapeutic targets. See related commentary by Lee, p. 875