Citations

Activating mutations in the calcium sensor STIM1 underlie Stormorken Syndrome (SS), a rare congenital disorder that causes thrombocytopenia and tubular aggregate myopathy. We recently identified two patients with SS and confirmed mutations in STIM1 (R304W and S88G), who were found to have features consistent with myelofibrosis (MF), as indicated by bone marrow biopsies demonstrating megakaryocyte hyperplasia and atypia in conjunction with marked reticulin fibrosis. The unusual MF findings in these two patients raised the hypothesis that altered calcium signaling represents a shared hallmark of congenital platelet disorders such as Stormorken Syndrome and myeloproliferative neoplasms (MPNs) including MF. Analyzing gene expression data from public datasets, we found increased expression of STIM1 in megakaryocyte progenitors and platelets, as well as CD34+ hematopoietic stem/progenitor cells (HSPCs), from MPN patients (including those with CALR or JAK2 mutations) vs healthy controls. These findings led us to hypothesize that dysregulation of STIM1 and store operated calcium entry (SOCE) signaling may contribute to altered megakaryopoiesis and development of fibrosis in both SS and MPNs. To further delineate these processes, we analyzed samples from our two SS patients, demonstrating constitutive activation of SOCE causing increased calcium flux, as well as decreased aggregation in mature platelets. We also performed transmission electron microscopy (TEM) and identified platelets with abnormal granularity in dense and alpha granules. We also performed single cell RNA-seq on SS patient peripheral blood mononuclear cells, which revealed enhanced NFkB inflammatory signaling, suggesting that altered signaling driven by STIM1 mutations may drive aberrant inflammation to contribute to MF development. To corroborate these initial observations, we identified a separate family cohort of 9 individuals in Italy with SS and confirmed STIM1 mutation (L92V). In ex vivo megakaryocytic differentiation assays, cells derived from these patients demonstrated a defect in thrombopoiesis with significantly decreased pro-platelet formation and adhesion to extracellular matrix. To further characterize the effects of the gain of function STIM1 mutations seen in our patients, we developed a novel, conditional knock-in mouse model of the heterozygous R304W mutation in the coiled coil (CC) domain of Stim1. Induction of hematopoietic-specific expression of mutant Stim1 via Vav-Cre resulted in recapitulation of hematological features of SS, including thrombocytopenia and a mild bleeding tendency, with confirmation of increased SOCE activity and calcium flux. Notably, we confirmed the development of bone marrow fibrosis, as well as findings of severe osteosclerosis, in these mice. TEM imaging confirmed that platelets from Stim1R304W/+Vav-Cre mice exhibit abnormal granularity, similar to what we observed from our SS patients. Noting that we identified increased STIM1 expression in samples from MPN patients harboring either JAK2 or CALR mutations, we further characterized the role of STIM1 in MPN disease development. NSGS mice were engrafted with CALR-mutant CD34+ cells subjected to CRISPR ablation of STIM1. Recipient mice exhibited decreased human CD45+ cell engraftment in conjunction with prolonged survival. In contrast, targeting of STIM1 in JAK2-mutant CD34+ cells led to exacerbated disease phenotypes, as manifested by enhanced human CD45+ cell engraftment, worsened splenomegaly, and early lethality. Taken together, these findings suggest a striking, differential relationship between mutant JAK2 and CALR and STIM1 activity and their relationship to MF development. Altogether, this study represents the first demonstration of MF development in patients with Stormorken Syndrome, and reveals a previously unrecognized hallmark of altered calcium signaling via aberrant STIM1 activation underlying SS and MPNs. We further demonstrate recapitulation of these hematologic features in a novel knock-in Stim1R304W/+Vav-Cre mouse model. These findings implicate an important role for STIM1and SOCE activity in MF development, and further uncover important distinctions between JAK2 vs CALR mutations and their interaction with altered STIM1 activity. These studies may contribute to the development of novel therapeutic approaches for these disorders.

Introduction Genomic alterations are common in multiple myeloma precursor stages, monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). However, commonly used stratification systems do not include somatic alterations that play a role in the disease. To address this clinical need, we generated a comprehensive genomic map of MM and precursors by harmonizing and analyzing mostly WGS data from 1,030 patients. We used these data to define a simple MM-like score, that is able to discriminate which premalignant patients are at risk to progress. Methods We collected, enriched, and performed WGS of tumor plasma cells and matched normals from 138 participants with MGUS or SMM, including those in low, intermediate, and high-risk groups. We combined our precursor dataset with genomic profiles from MM (n=20) and external sources of 872 individuals with MGUS (n=18), SMM (n=62), and MM (n=792) for a cohort of 1,030 individuals with MM or a precursor condition. In 16 patients, we could perform WGS serially from the bone marrow or circulating tumor cells (n=39) and reassess the presence of mutations. Results To develop a simple score that reflects the similarity of precursor genomes to full-blown multiple myeloma disease, we searched among the 107 common driver events (occurring in >1% of patients) and initiating translocations for ones that are differently altered in precursor conditions versus MM. We found 26 differentially altered events: only MAF and MAFB translocations were enriched in MGUS/SMM whereas 24 events were enriched in MM, including known drivers MYC, KRAS, FAM46C, del(1p) and gain(1q). We then defined a simple “MM-like” score for each tumor as the number of MM-enriched drivers minus the number of MGUS-enriched drivers. As expected, the MM-like score in our cohort increased throughout MM development (MM-like score median of 1 in MGUS, 2 in SMM, and 3 in MM). Even among SMM patients, we found a gradual increase of the MM-like score from low- (median=1), to intermediate (median=2), to high-risk (median=3) groups that match the overall medians in MGUS, SMM and MM (p=2e-5). We tested whether the MM-like score can be used to estimate risk of progression. Among untreated SMM patients characterized with WGS, an MM-like score greater than 2 was associated with a higher likelihood of progression (HR=5.3, P=0.03). Using an independent dataset of 87 patients with SMM, we were able to validate that a MM-like score greater than 2 was indeed associated with a higher risk of progression (HR=3.3, P=5x10-5). 11 patients who did not progress and for whom we performed longitudinal WGS, has stable MM-like scores over time, while three patients clinically progressed and their MM-like score increased at the time of progression (due to newly detected mutations in KRAS and NRAS). For the two remaining patients, their MM-like score increased, and we observed growth of the subclone that acquired the additional MM-like driver. In the first patient with MGUS/low-risk SMM, a novel hyperdiploid clone was detected in addition to a TP53 bi-allelic hit and t(11;14) translocation and was shown to increase in clonal fraction with tumor burden (light chains +104% within three years). In the second non-progressor with an increasing MM-like score, a novel del(1p) was detected, and other subclones in the phylogenetic tree either shrank or were stable over three years. Finally, because the MM-like score can place tumors on a gradual axis of evolution towards a more genomically-mature tumor, we tested whether the MM-like score was also predictive of survival in patients treated with a newly diagnosed MM. To do so, we calculated the MM-like score in patients from the publicly available CoMMpass database. We found that an increased score significantly correlated with shorter progression-free survival (median PFS1: 3 years in high score, versus 5 years in low/intermediate score; p=1e-3) and overall survival (median OS: 4.5 years in high score, versus not reached in low/intermediate score; p=1e-5). Conclusion Overall, we demonstrate that it is possible to stratify precursor stages of MM by discovering drivers, detecting those that are associated with the stage of the disease, and defining a genomically-based score that can be used to assess risk of progression and is easy to implement in the clinic.

Background. Study of myeloid neoplasms (MN) has been rapidly transformed by genome characterization. Gene mutations have been reported to influence disease phenotype and risk of disease progression, and the evaluation of mutational status can provide valuable insights to improve the decision-making process. In this international study, we evaluated the clinical impact of mutational screening in patients with CMML, which is characterized by significant clinical and genomic heterogeneity, including a substantial proportion of patients with poor outcomes and unmet needs. Currently, only limited molecular information has been incorporated into CMML classification and prognostication. Methods. We retrospectively collected 3182 CMML patients. We used MOSAIC, an AI-based framework for multimodal analysis in rare cancers (PMID: 38875514) to develop innovative, molecular-based tools for classification and prognostication. An independent validation of the results on 516 prospectively collected patients was performed. Results. Bayesian Networs and Hierarchical Dirichlet Processes were used to identify genomic associations and define a CMML molecular classification. We identified 11 clusters with distinct clinical and genomic features, including splicing machinery, signal transduction and tyrosine kinase pathways aberrations, and high-risk molecular signatures (i.e., AML-like and TP53 mutations). Up to 15% of patients showed clear genomic overlap with other MN. Importantly, extensive multi-color flow cytometry on T lymphocytes, NK and myeloid cells (BD FACSymphony A5 Cell Analyzer) revealed specific immunologic and inflammation signatures associated with molecular subgroups. We then integrated molecular and clinical information to build an international CMML Prognostic Scoring System (iCPSS). We assessed the performance of different statistical and AI-based methods; L1-penalized Cox Model resulted as the best performing method. Selected features included hematological parameters (WBC, Hb, PLT and marrow blasts), cytogenetic abnormalities, and mutations in 10 genes (ASXL1, DNMT3A, EZH2, NRAS, RUNX1, SETBP1, STAG2, TET2, TP53, U2AF1). By Bayesian thresholds optimization, we identified 5 risk classes (i.e., very-low, low, intermediate, high and very-high) with median overall survival (OS) ranging from 99 to 9 months (P<.001), and median leukemia-free survival (LFS) ranging from 210 to 18 months (P<.001). iCPSS provided better patient discrimination across all clinical endpoints compared to currently available prognostic tools, with a Concordance Index (CI) for OS of 0.75 versus 0.62-0.64, respectively. Notably, compared to available scoring systems, up to 40% of patients were reassigned to higher or lower risk classes by the iCPSS. External validation on an independent prospective cohort confirmed that the performance of iCPSS is superior to existing prognostic models (CI for OS 0.71 vs 0.54-0.61, respectively) To demonstrate the clinical utility of iCPSS, we focused on 753 patients who underwent allogeneic stem cell transplantation (HSCT). In multivariable analysis, iCPSS stratified the probability of OS post-HSCT (P<.001) and identified groups of patients with different probabilities of disease relapse, ranging from 9% to 62% (P<.001). We employed a clinical- and genomic-based decision support system (PMID: 38723212) to determine the optimal timing of HSCT. Preliminary analyses indicated that higher-risk patients according to iCPSS (i.e., intermediate, high, and very high) benefit from an immediate HSCT strategy. Lower-risk patients (i.e., very low and low) had life expectancy maximized with delayed HSCT. Modeling decision analysis using iCPSS compared to conventional scores, resulted in a change in transplantation policy for a significant proportion of patients (up to 25%). Conclusion. Molecular information significantly improves the classification of CMML patients, providing a basis for refining diagnostic boundaries with other MN and for a more rational inclusion of patients in clinical trials. The iCPSS demonstrated superior performance over currently available scoring systems and improved HSCT decision making process.

Introduction BCL-2 inhibition with venetoclax (ven) was a major advance in CLL treatment, but the 5-week dose ramp-up to mitigate the risk of tumor lysis syndrome and drug-drug interactions (DDIs) challenge treatment optimization. Lisaftoclax is an investigational, oral BCL-2i with a short half-life, allowing it to be ramped-up on a daily schedule. We present updated results of a phase 1b/2 study of lisaftoclax alone or combined with acalabrutinib or rituximab in pts with treatment-naïve (TN; lisaftoclax-acalabrutinib arm), relapsed/refractory, or prior ven-treated CLL/SLL (NCT04215809). Methods Pts were treated with a rapid 4- to 6-day daily ramp-up of lisaftoclax from 20 mg to a target dose of 400, 600, or 800 mg, receiving daily oral lisaftoclax alone or, plus continuous acalabrutinib or 6 cycles of rituximab in 28-day cycles, starting on Cycle 1 Day 8 (C1D8) until disease progression, complete response by C24, or unacceptable toxicity. Intensive blood samples were collected for pharmacokinetic (PK) and exposure-response (E-R) analyses. Results From March 20, 2020, to June 27, 2024, 176 pts were enrolled: 46 in monotherapy and 39 and 91 in rituximab and acalabrutinib combination cohorts, respectively; 154/176 (87.5%) were R/R and 22/176 (12.5%) TN. The median (range) age was 63 (34-80) years; 67% were male; 25.6% had del(17p) and/or TP53 mutation; and 70.6% had unmutated IGHV. Median (range) duration of treatment with lisaftoclax was 16.5 (1-54; monotherapy), 24 (3-39; rituximab), and 27 (1-43; acalabrutinib) months. In R/R pts, the median (range) number of prior lines of therapy was 2 (1-15), and 14 (9%) pts had been treated with ven. Prior ven pts had a median (range) age of 65 (51-78); 79% were male; of evaluable pts, 50% had del(17p), 36% TP53 mut, 64% del(11q), 38% complex karyotype (≥ 3 abnormalities), and 92% unmutated IGHV; 57% were BTKi naïve; and the median (range) number of prior therapies was 3 (1-6). Incidence and severity of TEAEs were similar across cohorts. Common (>10%) any-grade TEAEs in all cohorts combined were neutropenia (59 [33.5%]), diarrhea (38 [21.6%]), anemia (27 [15.3%]), and thrombocytopenia (26 [14.8%]). Grade ≥ 3 TEAEs were neutropenia in 15 (32.6%), 10 (25.6%), and 22 (24%) pts and anemia in 10 (21.7%), 5 (12.8%), and 12 (13.2%) pts in monotherapy, rituximab, and acalabrutinib combination cohorts, respectively. Comprehensive E-R analyses indicated that lisaftoclax had similar systemic exposure as monotherapy or when combined with acalabrutinib or rituximab; lisaftoclax had no DDI when combined with acalabrutinib or rituximab. No discontinuations were attributed to lisaftoclax TRAEs. Forty-four (95.7%) pts in monotherapy discontinued treatment. Most discontinuations were due to progressive disease (n = 41 [23.3%]) and 13 (7.4%), AEs; 9 (5.1%) pts withdrew consent; 7 (4%) achieved complete response or MRD negativity after ≥ 24 cycles; 5 (2.8%) died; and 18 (10.2%) discontinued for other reasons. Clinical (n = 2) and laboratory (n = 3) TLS was observed in 5 (2.8%) pts on lisaftoclax (by Howard/Cairo-Bishop criteria), with cases rapidly resolving to resume lisaftoclax safely. ORR for lisaftoclax plus acalabrutinib in 87 pts was 96.6%, and the median DOR (95% CI, 23-NR) and median PFS (95% CI, 34-NR) were not reached. The 12- and 18-month PFS rates were 89% and 86%, respectively. Fourteen R/R CLL ven-exposed pts received lisaftoclax plus acalabrutinib, of whom 9 had progressed on ven, 3 relapsed after completing ven, and 2 discontinued due to ven intolerance. Median (range) duration of treatment was 16 (3-25) months. Safety profile was similar to that of other study cohorts. ORR was 85.7% (12/14), 100% (8/8), and 66.7% (4/6) in the ven-exposed, ven-exposed but BTKi-naïve, and ven- and BTKi-exposed pts, respectively. The median duration of response (DOR) and progression-free survival (PFS) were not reached. The 12- and 18-month PFS rates were 84% and 73%, respectively. Conclusions Our data suggest that lisaftoclax combined with acalabrutinib is effective for pts with prior ven exposure, including those with progression on ven. In this updated analysis with longer follow-up, no DDIs or new safety findings were observed in TN or R/R CLL/SLL pts treated with lisaftoclax monotherapy/combinations. We continue to accrue pts with prior ven exposure to further evaluate this promising signal. A global registrational phase 3 study GLORA (NCT06104566) is recruiting.

ABSTRACT Background Immune exclusion inhibits anti-tumor immunity and response to immunotherapy, but its mechanisms remain poorly defined. In triple-negative breast cancer (TNBC), an aggressive and generally immune-rich subtype, an immune-cold microenvironment predicts poor prognosis due to a limited response to chemotherapy and immune checkpoint inhibitors. This study aimed to identify mechanisms regulating immune infiltration in TNBC. Methods We performed spatial transcriptomic analysis comparing immune-enriched versus immune-cold treatment-naïve TNBCs. Functional analyses, including loss-of-function and reconstitution experiments, were conducted to investigate the role of Trophoblast Cell-Surface Antigen 2 (TROP2), a key target of anti-cancer Antibody Drug Conjugates (ADCs), in promoting TNBC progression. A humanized TROP2 syngeneic TNBC model was used to assess the effects of TROP2-targeting in combination with anti-PD1 therapy. Additionally, data from patients treated with immune checkpoint blockade were used to test hypotheses from the preclinical findings. Results We reveal that TROP2 controls barrier-mediated immune exclusion in TNBC through Claudin 7 association and tight junction regulation. TROP2 expression is inversely correlated with T cell infiltration and predicts poor outcomes in TNBC. We demonstrate that TROP2 is sufficient to drive tumor progression in vivo in a CD8 T cell-dependent manner, while its loss deregulates expression and localization of multiple tight junction proteins, enabling T cell infiltration. We show that TROP2 targeting via hRS7, the antibody component of the ADC Sacituzumab govitecan (SG), enhances the anti-PD1 response and improves T cell accessibility and effector function. Correspondingly, TROP2 expression is highly associated with lack of response to anti-PD1 therapy in human breast cancer. Conclusions This study defines a new mechanism of barrier-mediated immune exclusion in cancer controlled by TROP2-dependent tight junctions. This mechanism drives tumor progression but can be targeted via TROP2-directed therapy to activate anti-tumor immunity and enhance immunotherapy response. What is already known on this topic Barrier-mediated immune exclusion is emerging as a mechanism of immune evasion in cancer such as triple-negative breast cancer (TNBC), but its molecular underpinnings remain poorly understood. TROP2 is a surface glycoprotein targeted by antibody-drug conjugates such as Sacituzumab govitecan, yet its functional role beyond drug delivery has been unclear. What this study adds This study identifies TROP2 as a key regulator of tight junction-mediated immune exclusion in TNBC, independent of its intracellular signaling function. TROP2 promotes an immune-cold tumor microenvironment by enforcing mechanical barriers that limit T cell infiltration. How this study might affect research, practice or policy These findings establish TROP2 as a functional driver of immune evasion and provide a mechanistic rationale for combining TROP2-targeting therapies with immune checkpoint inhibitors to overcome resistance in immune-excluded tumors.

Importance Typical cysteine-altering NOTCH3 ( NOTCH3 cys ) variants are highly prevalent (approximately 1 in 300 individuals) and are associated with a broad spectrum of small vessel disease (SVD), ranging from early-onset stroke and dementia (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy [CADASIL]) to nonpenetrance. A staging system that captures the full NOTCH3 -SVD severity spectrum is needed and currently lacking. Objective To design a simple disease severity staging system that captures the broad clinicoradiological NOTCH3 -SVD severity spectrum. Design, Setting, and Participants A cohort study was performed in which the NOTCH3 -SVD severity staging system was developed using a discovery cohort (2019-2020) and validated in independent international CADASIL cohorts (1999-2023) and the UK Biobank. Clinical and imaging data were collected from participants originating from 23 international CADASIL cohorts and from the UK Biobank. Eligibility criteria were presence of a NOTCH3 cys variant, availability of brain magnetic resonance imaging, and modified Rankin Scale score. The discovery cohort consisted of 195 NOTCH3 cys -positive cases from families with CADASIL; the validation set included 1713 NOTCH3 cys -positive cases from 15 countries. The UK Biobank cohort consisted of 101 NOTCH3 cys -positive individuals. Data from 2-year (2019-2023) and 18-year (1999-2017) follow-up studies were also analyzed. Data analysis was performed from July 2023 to August 2024. Main Outcomes and Measures Percentage of cases following the sequence of events of the NOTCH3 -SVD stages, and the association between the stages and ischemic stroke, intracerebral hemorrhage, global cognition, processing speed, brain volume, brain microstructural damage, and serum neurofilament light chain (NfL) level. Results The NOTCH3 -SVD staging system encompasses 9 disease stages or substages, ranging from stage 0 (premanifest stage) to stage 4B (end stage). Of all 1908 cases, which included 195 in the discovery cohort (mean [SD] age, 52.4 [12.2] years) and 1713 in the validation cohorts (mean [SD] age, 53.1 [13.0] years), 1789 (94%) followed the sequence of events defined by the NOTCH3 -SVD staging system. The NOTCH3 -SVD stages were associated with neuroimaging outcomes in the NOTCH3 cys -positive cases in the CADASIL cohorts and in the UK Biobank and with cognitive outcomes and serum NfL level in cases from the CADASIL cohorts. The NOTCH3 -SVD staging system captured disease progression and was associated with 18-year survival. Conclusions and Relevance The NOTCH3 -SVD staging system captures the full disease spectrum, from asymptomatic individuals with a NOTCH3 cys variant to patients with end-stage disease. The NOTCH3 -SVD staging system is a simple but effective tool for uniform disease staging in the clinic and in research.

Abstract Giant intracranial aneurysms require complex treatment strategies including clipping, coiling, stenting, parent artery occlusion, bypass, or combined procedures. Neurovascular hybrid operating rooms (h-OR) combine a conventional operating theatre with high-resolution digital subtraction angiography (DSA). We describe a one-step combined surgical and endovascular treatment in a h-OR for a pediatric internal carotid artery (ICA) giant aneurysm that can be an optimal solution to manage such challenging cases. An 11-year-old boy presented with rapid onset right hemiparesis and left eyelid ptosis. A 3-month history of headache associated with sporadic vomit was reported. A giant, unruptured, left ICA aneurysm was detected on imaging. The patient underwent surgical trapping of the aneurysm. Intraoperative DSA showed residual backflow from the posterior communicating artery and coils were placed to completely exclude the aneurysm. At 18-month follow-up, the patient showed a complete recovery and magnetic resonance imaging showed a progressive reduction of the sac aneurysm. Due to their morphological variability, intracranial giant aneurysms may require a different procedural strategy instead of direct clipping or coiling. The introduction of h-OR allows combined treatments to be performed simultaneously in the same room setting. The present case shows that combined treatment in a neurovascular h-OR can be an optimal solution to manage challenging cases, such as giant aneurysms, reducing operative time with the added benefit of selecting an appropriate strategy adjustment in a multidisciplinary effort.

Abstract Purpose: To determine the relationship between germline pathogenic variants (PV) in cancer predisposition genes and the risk of ductal carcinoma in situ (DCIS). Experimental Design: Germline PV frequencies in breast cancer predisposition genes (ATM, BARD1, BRCA1, BRCA2, CDH1, CHEK2, PALB2, RAD51C, and RAD51D) were compared between DCIS cases and unaffected controls and between DCIS and invasive ductal breast cancer (IDC) cases from a clinical testing cohort (n = 9,887), a population-based cohort (n = 3,876), and the UK Biobank (n = 2,421). The risk of contralateral breast cancer (CBC) for DCIS cases with PV was estimated in the population-based cohort. Results: Germline PV were observed in 6.5% and 4.6% of women with DCIS in the clinical testing and population-based cohorts, respectively. BRCA1, BRCA2, and PALB2 PV frequencies were significantly lower among women with DCIS than those with IDC (clinical cohort: 2.8% vs. 5.7%; population-based cohort: 1.7% vs. 3.7%), whereas the PV frequencies for ATM and CHEK2 were similar. ATM, BRCA1, BRCA2, CHEK2, and PALB2 PV were significantly associated with an increased risk of DCIS (OR > 2.0), but only BRCA2 PV were associated with high risk (OR > 4) in both cohorts. The cumulative incidence of CBC among carriers of PV in high-penetrance genes with DCIS was 23% over 15 years. Conclusions: The enrichment of PV in ATM, BRCA1, BRCA2, CHEK2, and PALB2 among women with DCIS suggests that multigene panel testing may be appropriate for women with DCIS. Elevated risks of CBC in carriers of PV in high-penetrance genes with DCIS confirmed the utility of testing for surgical decision-making.