Citations

Percutaneous transluminal renal angioplasty and stenting (PTRS) for RVH may not revert the secondary cardiac dysfunction and remodeling. In experimental RVH, infusion of the tetrapeptide Bendavia (that inhibits mitochondrial permeability transition pore opening) during PTRS attenuated stenotic kidney inflammatory injury and improved its function. We hypothesized that adjunct Bendavia during PTRS would also attenuate cardiac remodeling after reversal of RVH. RVH was induced in 18 pigs, of which 6 were sham treated (RVH) and 12 underwent PTRS plus a 4h IV infusion of Bendavia (0.05 mg/kg) or vehicle (n=6, each); 6 normal pigs served as controls. Cardiac oxygenation and function were assessed 4 wks later by blood oxygen level‐dependent (BOLD)‐MRI and CT, and tissue studies performed. PTRS normalized blood pressure (Table). Systolic function was unchanged. Apoptotic activity (caspase‐3), hypoxia (BOLD‐R2*), inflammation (TNF‐α, IL‐6), and fibrosis (trichrome) remained elevated and diastolic function (E/A) impaired in PTRS+Vehicle, but all improved in PTRS+Bendavia (Figure). Thus, novel cardioprotective properties of Bendavia enhance cardiac recovery after reversal of experimental RVH, and may provide a novel therapeutic option.

Abstract Purpose:Quantify in vivo biomechanical tissue properties in various breast densities and in normal risk and high risk women using Magnetic Resonance Imaging (MRI)/MRE and examine the association between breast biomechanical properties and cancer risk.Methods: Patients with normal risk or high risk of breast cancer underent 3.0 T breast MR imaging and elastography. Breast parenchymal enhancement (BPE), density (from most recent mammogram), stiffness, elasticity, and viscosity were recorded. Within each breast density group (non-dense versus dense), stiffness, elasticity, and viscosity were compared across risk groups (normal versus high). A multivariable logistic regression model was used to evaluate whether the MRE parameters (separately for stiffness, elasticity, and viscosity) predicted risk status after controlling for clinical factors.Results: 50 normal risk and 86 high risk patients were included. Risk groups were similar on age, density, and menopausal status. Among patients with dense breasts, mean stiffness, elasticity, and viscosity were significantly higher in high risk patients (N = 55) compared to normal risk patients (N = 34; all p < 0.001). Stiffness remained a significant predictor of risk status (OR=4.26, 95% CI [1.96, 9.25]) even after controlling for breast density, BPE, age, and menopausal status. Similar results were seen for elasticity and viscosity.Conclusion: A structurally-based, quantitative biomarker of tissue stiffness obtained from MRE is associated with differences in breast cancer risk in dense breasts. Tissue stiffness could provide a novel prognostic marker to help identify high risk women with dense breasts who would benefit from increased surveillance and/or risk reduction measures.

Abstract CRLF2-rearranged (CRLF2r) acute lymphoblastic leukemia (ALL) accounts for more than half of Philadelphia chromosome-like (Ph-like) ALL and is associated with a poor outcome in children and adults. Overexpression of CRLF2 results in activation of Janus kinase (JAK)-STAT and parallel signaling pathways in experimental models, but existing small molecule inhibitors of JAKs show variable and limited efficacy. Here, we evaluated the efficacy of proteolysis-targeting chimeras (PROTACs) directed against JAKs. Solving the structure of type I JAK inhibitors ruxolitinib and baricitinib bound to the JAK2 tyrosine kinase domain enabled the rational design and optimization of a series of cereblon (CRBN)-directed JAK PROTACs utilizing derivatives of JAK inhibitors, linkers, and CRBN-specific molecular glues. The resulting JAK PROTACs were evaluated for target degradation, and activity was tested in a panel of leukemia/lymphoma cell lines and xenograft models of kinase-driven ALL. Multiple PROTACs were developed that degraded JAKs and potently killed CRLF2r cell lines, the most active of which also degraded the known CRBN neosubstrate GSPT1 and suppressed proliferation of CRLF2r ALL in vivo, e.g. compound 7 (SJ988497). Although dual JAK/GSPT1-degrading PROTACs were the most potent, the development and evaluation of multiple PROTACs in an extended panel of xenografts identified a potent JAK2-degrading, GSPT1-sparing PROTAC that demonstrated efficacy in the majority of kinase-driven xenografts that were otherwise unresponsive to type I JAK inhibitors, e.g. compound 8 (SJ1008030). Together, these data show the potential of JAK-directed protein degradation as a therapeutic approach in JAK-STAT–driven ALL and highlight the interplay of JAK and GSPT1 degradation activity in this context.

Background and Purpose: XO (xanthine oxidase) is a key enzyme of uric acid metabolism and is thought to contribute to oxidative pathways that promote atherosclerotic plaque progression, yet its role in plaque destabilization is not well elucidated. We hypothesized that XO is expressed in carotid plaque from symptomatic patients in association with cardiovascular risk factors. Methods: Patients were stratified by symptoms, defined as presentation with an ipsilateral cerebral ischemic event. Carotid atherosclerotic plaques were obtained from 44 patients with symptomatic plaque and 44 patients without ischemic cerebral events. Protein expression of XO was evaluated by immunohistochemical staining and the percentage of cells expressing XO and CD68 (macrophage marker) compared between the groups. Biochemical and demographic cardiometabolic risk factors of study participants also were measured. Results: Carotid atherosclerotic plaques from symptomatic patients were associated with significantly higher XO expression versus asymptomatic plaque (median [interquartile range]: 1.24 [2.09] versus 0.16 [0.34]; P <0.001) and with significantly higher circulating uric acid levels (mean±SD: 7.36±2.10 versus 5.37±1.79 mg/dL; P <0.001, respectively). In addition, XO expression in atherosclerotic carotid plaque was inversely associated with serum high-density lipoproteins cholesterol levels ( P =0.010, r =−0.30) and directly with circulating uric acid levels ( P <0.001, r =0.45). The average percentage of macrophages that expressed XO was significantly higher in symptomatic versus asymptomatic plaques (median [interquartile range]: 93.37% [25] versus 46.15% [21], respectively; P <0.001). Conclusions: XO overexpression in macrophages is associated with increased serum uric acid and low high-density lipoproteins cholesterol levels and may potentially have a mechanistic role in carotid plaque destabilization. The current study supports a potential role for uric acid synthesis pathway as a target for management of carotid atherosclerosis in humans.

Abstract Lineage-ambiguous leukemias are high-risk malignancies of poorly understood genetic basis. Here, we describe a distinct subgroup of acute leukemia with expression of myeloid, T lymphoid, and stem cell markers driven by aberrant allele-specific deregulation of BCL11B, a master transcription factor responsible for thymic T-lineage commitment and specification. Mechanistically, this deregulation was driven by chromosomal rearrangements that juxtapose BCL11B to superenhancers active in hematopoietic progenitors, or focal amplifications that generate a superenhancer from a noncoding element distal to BCL11B. Chromatin conformation analyses demonstrated long-range interactions of rearranged enhancers with the expressed BCL11B allele and association of BCL11B with activated hematopoietic progenitor cell cis-regulatory elements, suggesting BCL11B is aberrantly co-opted into a gene regulatory network that drives transformation by maintaining a progenitor state. These data support a role for ectopic BCL11B expression in primitive hematopoietic cells mediated by enhancer hijacking as an oncogenic driver of human lineage-ambiguous leukemia. Significance: Lineage-ambiguous leukemias pose significant diagnostic and therapeutic challenges due to a poorly understood molecular and cellular basis. We identify oncogenic deregulation of BCL11B driven by diverse structural alterations, including de novo superenhancer generation, as the driving feature of a subset of lineage-ambiguous leukemias that transcend current diagnostic boundaries. This article is highlighted in the In This Issue feature, p. 2659

10541 Background: Biomechanical tissue properties may vary in the breasts of patients at elevated risk for breast cancer. We aim to quantify in vivo biomechanical tissue properties in various breast densities and in both normal risk and high risk women using Magnetic Resonance Imaging (MRI)/MRE and examine the association of biomechanical properties of the breast with cancer risk. Methods: In this IRB–approved prospective single-institution study, we recruited two groups of women differing by breast cancer risk to undergo a 3.0 T dynamic contrast enhanced MRI/MRE of the breast. Low-average risk women were defined as having no personal or significant family history of breast cancer, no prior high risk breast biopsies and a negative mammography within 12 months. High-risk breast cancer patients were recruited from those patients who underwent standard of care breast MR. Within each breast density group (non-dense versus dense), two-sample t-tests were used to compare breast stiffness, elasticity, and viscosity across risk groups (low-average vs high). Results: There were 50 low-average risk and 86 high-risk patients recruited to the study. The risk groups were similar on age (mean age = 55.6 and 53.6 years), density (68% vs. 64% dense breasts) and menopausal status (66.0% vs. 69.8%). Among patients with dense breasts, mean stiffness, elasticity, and viscosity were significantly higher in high risk patients ( N = 55) compared to low-average risk patients ( N = 34; all p < 0.001). In the multivariate logistic regression model, breast stiffness remained a significant predictor of risk status (OR=4.26, 95% CI [1.96, 9.25]) even after controlling for breast density, MRI BPE, age, and menopausal status. Similar results were seen for breast elasticity (OR=4.88, 95% CI [2.08, 11.43]) and viscosity (OR=11.49, 95% CI [1.15, 114.89]). Conclusions: Structurally-based, quantitative biomarker of tissue stiffness obtained from global 3D breast MRE is associated with differences in breast cancer risk in dense breasts. As such, tissue stiffness could provide a novel prognostic marker to help identify the subset of high-risk women with dense breasts who would benefit from increased surveillance.[Table: see text]

7552 Background: Axi-cel is approved in the US for the treatment of adult patients with relapsed or refractory LBCL after 2 or more lines of systemic therapy. Post-market long term follow up study of commercial Axi-cel recipients using the Center for International Blood and Marrow Transplant Research was recently completed. Methods: From October 2017 to August 2020, 1,500 Axi-cel recipients from 79 centers were enrolled. Of these, 1001 patients with at least 6 months of follow-up were included in this analysis. Outcomes include complete and overall responses rates (CR and ORR), duration of response (DOR), progression-free and overall survival (PFS and OS), cytokine release syndrome (CRS) (Lee D 2014 and American Society for Transplantation and Cellular Therapy [ASTCT]), immune effector cell associated neurotoxicity syndrome (ICANS), hematologic recovery and subsequent neoplasm (SN). Subgroup analysis by sensitivity to therapy, defined as responsive to the last line of therapy prior to Axi-cel. Median follow-up was 12 months (range, 6-28 months). Results: The median age overall was 62 years, 37% were ≥ 65 years, 83% with Eastern Cooperative Oncology Group (ECOG) performance score 0-1, 28% with transformed lymphoma, 14% with high grade lymphoma, 29% with prior autologous transplant, and 66% with chemotherapy-resistant disease prior to Axi-cel. The median time from diagnosis to Axi-cel infusion was 15 months. Best ORR was 70% (CR 53%). Landmark analysis of patients in CR at 6 months post Axi-cel demonstrates a low number of subsequent progression/death events. With respect to outcomes for chemotherapy-sensitive disease versus resistant disease, the ORR, CR, 12-month PFS and OS were 78% vs. 66%, 60% vs. 48%, 55% (95% CI, 48-62%) vs. 40% (95% CI, 37-44%), and 70% (95% CI, 63-76%) vs. 54% (95% CI, 50-58%), respectively. CRS of any grade was reported in 83% of patients. Incidence of Grades ≥ 3 CRS was 10% according to Lee et al 2014, and 13% according to ASTCT Consensus Grading. Median time to any grade CRS was 4 days (range, 1-28 days), and 93% of CRS cases resolved with a median duration of 7 days (range, 1-121 days). ICANS were reported in 576 (57%) patients, grade >3 was 26%. The median time to onset of ICANS was 7 days (range, 1-82 days), and 86% resolved with a median duration of 9 days (range, 1 to 115 days). Twenty-nine patients (2.9%) reported SN: hematologic (N = 17), solid tumors (N = 12). Conclusions: This is the largest report on Axi-cel in the real-world setting and demonstrates consistent efficacy outcomes and further characterizes safety outcomes. Patients in CR at 6 months have sustained disease control with low number of relapse events. Although patients with therapy-sensitive disease experience better outcomes than patients with therapy-resistant, the overall outcomes on both groups of patients are favorable.

e16137 Background: Hepatocellular Carcinoma (HCC) is the leading cause of cancer-related mortality in Nigeria. HIV and viral hepatitis B (HBV) and C (HCV) co-infection are common in Nigeria that significantly accelerates liver disease progression including HCC. Aging-related DNA methylation signatures obtained in liquid biopsy, such as circulating cell-free DNA (ccfDNA) extracted from serum/plasma are promising minimally-invasive biomarkers that may inform HIV-associated HCC. We examined the epigenetic age acceleration (EpiAgeAccel) in ccfDNA in HCC patients with HIV. Methods: The study included three groups of participants: a) HIV positive with HCC (n=7); b) HIV positive and cancer-free (n=45); and c) HIV negative with HCC (n=33). Epigenetic age was estimated by Horvath’s calculator using genome-wide ccfDNA methylation data profiled by Illumina EPIC array. EpiAgeAccel was computed as the residuals of a linear model of epigenetic age on chronological age, namely the unexplained portion of epigenetic age by chronological age. We used multiple linear regression to compare EpiAgeAccel between HIV/HCC groups, adjusting for sex, age, education, alcohol intake, and HBV/HCV infection. Results: Among HIV positive participants, there was a higher percentage of men (57% vs. 22%, p<0.001), HBV infection (29% vs. 11%, p=0.004), and HCV infection (57% vs. 2%, p<0.001) in the HCC group compared to the cancer-free group. EpiAgeAccel was 4.8 years higher in HIV positive patients with HCC compared to cancer-free HIV positives (p=0.02). Among HCC patients, EpiAgeAccel was 2.1 years higher in HIV positives compared to HIV negative but not statistically significant. Conclusions: Epigenetic age in ccfDNA is accelerated in HIV-positive HCC patients. EpiAgeAccel measured in ccfDNA may be developed into a surrogate biomarker for minimally invasive HCC detection among HIV-infected patients in low- and middle-income countries.

4079 Background: Cell-free circulating tumor DNA (ctDNA) holds significant promise and is being used for clinical decision making in multiple tumors. This study aimed to evaluate the prognostic value of pre-treatment ctDNA in metastatic biliary tract cancers (BTC) treated with platinum based first-line chemotherapy treatment. Methods: We performed a retrospective analysis of 67 patients who underwent ctDNA testing before platinum-based chemotherapy for first-line treatment for metastatic BTC. For analysis we considered the detected gene with highest variant allele frequency (VAF). Results of ctDNA analysis were correlated with patients’ demographics, progression-free survival (PFS) and overall survival (OS). Results: The median age of patients was 67 y/o (27-90). 54 (80.6%) of 67 patients evaluated had intrahepatic cholangiocarcinoma; seven had extrahepatic cholangiocarcinoma and six gallbladder cancer. 46 (68.6%) of the patients were treated with cisplatin plus gemcitabine, 14 (21%) patients received gemcitabine and other platinum (carboplatin or oxaliplatin) combinations while 7 (10.4%) patients were treated on a clinical trial with gemcitabine and cisplatin plus additional targeted agents (CX4945 or PEGPH20). TP53, KRAS, APC, FGFR2 and IDH1 were the genes with highest frequency as dominant clone. The median dominant clone allele frequency (DCAF) was 3% (0-97%). DCAF >3% was associated with statistically significant worse PFS (median PFS: 4.05 vs. 7.70 months, p=0.046) and OS (median OS: 10.8 vs. 18.8 months, p=0.056). Each 1% increase in DCAF is associated with a hazard ratio of 26.21 in OS when adjusting for subtypes, age, treatment type, and CA19-9 [Table]. Conclusions: Patients with metastatic BTC with DCAF > 3% at diagnosis have worse PFS and OS compared to patients with low ctDNA when treated with upfront platinum-based chemotherapy.[Table: see text]

Abstract Background MR elastography can determine organ‐related stiffness, which reflects the degree of fibrosis. Liver stiffness increases in cirrhosis, and stiffness increases further post‐prandially due to increased portal blood in‐flow. Non‐selective beta‐blockers (NSBB) reduce the portal venous inflow, but their effect on liver and spleen stiffness are disputed. Aims To assess whether MR elastography of the liver or spleen reflects the severity of cirrhosis, whether treatment with NSBB changes liver and spleen stiffness and whether changes in stiffness can predict the effect of NSBB on portal pressure. Methods Fifty‐two patients with cirrhosis underwent liver vein catheterization and two‐dimensional (2D) MR elastography on separate days. Thirty‐six of the patients had a hepatic venous pressure gradient (HVPG) of ≥12 mmHg and were tested prior to, and after, intravenous infusion of NSBB using HVPG measurement and MR elastography. Results HVPG showed a strong, positive, linear relationship with liver stiffness ( r 2 = 0.92; P < .001) and spleen stiffness ( r 2 = 0.94; P < .001). The cut‐off points for identifying patients with a HVPG ≥ 12 mmHg were 7.7 kPa for liver stiffness (sensitivity 0.78, specificity 0.64) and 10.5 kPa for spleen stiffness (sensitivity 0.8, specificity 0.79). Intravenous administration of NSBB significantly decreased spleen stiffness by 6.9% (CI: 3.5‐10.4, P < .001), but NSBB had no consistent effect on liver stiffness. However, changes in spleen stiffness were not related to the HVPG response ( P = .75). Conclusions Two‐dimensional MR elastographic estimation of liver or spleen stiffness reflects the degree of portal hypertension in patients with liver cirrhosis, but changes in stiffness after NSBB do not predict the effect on HVPG.