Comparing Quantitative Immunohistochemical Markers of Angiogenesis to Contrast-Enhanced Subharmonic Imaging.

OBJECTIVES: Different methods for obtaining tumor neovascularity parameters based on immunohistochemical markers were compared to contrast-enhanced subharmonic imaging (SHI). METHODS: Eighty-five athymic nude female rats were implanted with 5 × 10(6) breast cancer cells (MDA-MB-231) in the mammary fat pad. The contrast agent Definity (Lantheus Medical Imaging, North Billerica, MA) was injected, and SHI was performed using a modified Sonix RP scanner (Analogic Ultrasound, Richmond, British Columbia, Canada) with a L9-4 linear array (transmitting/receiving frequencies, 8/4 MHz). Afterward, specimens were stained for endothelial cells (CD31), vascular endothelial growth factor (VEGF), and cyclooxygenase 2 (COX-2). Tumor neovascularity was assessed in 4 different ways using a histomorphometry system (×100 magnification: (1) over the entire tumor; (2) in small sub-regions of interest (ROIs); (3) in the tumor periphery and centrally; and (4) in 3 regions of maximum marker expression (so-called hot spots). Results from specimens and from SHI were compared by linear regression. RESULTS: Fifty-four rats (64%) showed tumor growth, and 38 were successfully imaged. Subharmonic imaging depicted the tortuous morphologic characteristics of tumor neovessels and delineated small areas of necrosis. The immunohistochemical markers did not correlate with SHI measures over the entire tumor area or over small sub-ROIs (P > .18). However, when the specimens were subdivided into central and peripheral regions, COX-2 and VEGF correlated with SHI in the periphery (r = -0.42; P = .005; and r = -0.32; P = .049, respectively). CONCLUSIONS: When comparing quantitative contrast measures of tumor neovascularity to immunohistochemical markers of angiogenesis in xenograft models, ROIs corresponding to the biologically active region should be used to account for tumor heterogeneity.

SOHO State of the Art Updates and Next Questions: Understanding and Overcoming Venetoclax Resistance in Hematologic Malignancies.

The discovery of Venetoclax (VEN) has transformed the therapeutic landscape of acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL). However, the response is heterogeneous with 10% to 50% of newly diagnosed AML patients not responding to hypomethylating agent (HMA) and VEN. Furthermore, up to 40% of responding patients relapse shortly. This review discusses the mechanism of action of Venetoclax and the major mechanisms of inherent and acquired resistance to VEN. VEN is highly specific to BCL-2 binding, as such other antiapoptotic proteins in BCL-2 family induce resistance. These antiapoptotic proteins can also be upregulated via a number of compensatory cell signaling pathways including PI3K/AKT/mTOR, the MAPK/ERK pathway, and mutant FLT3-ITD. Mutations can occur in BCL-2 and BAX proteins, or they can be silenced by TP53 mutations and other epigenetic changes. Changes to mitochondrial structure and metabolism can induce resistance. Key metabolic regulators include OXPHOS and alternative amino acid metabolism. Finally microenvironmental factors can influence VEN responses. This paper evaluates subsets of AML by differentiation, histology, cytogenetics and molecular markers and their different responses to VEN; with spliceosome mutations, ASXL1, NPM1 and IDH1/2 being favorable while others such as FLT3, TP53 and BCL-2 mutations being less responsive. Currently intensive multiagent chemotherapy and Venetoclax combinations such as 7+3+VEN are favored in fit younger AML patients. However, with resistant patients' subsets targeted combination therapies are becoming an increasingly attractive option. We explore the incorporation of non-BCL-2 inhibitors, next-generation BCL-2 and multi-protein agents, other inhibitors most prominently FLT-3 inhibitors in addition to Venetoclax, and other novel approaches for resolving Venetoclax resistance.

AML treatment: conventional chemotherapy and emerging novel agents.

Acute myeloid leukemia (AML) is driven by complex mutations and cytogenetic abnormalities with profound tumoral heterogeneity, making it challenging to treat. Ten years ago, the 5-year survival rate of patients with AML was only 29% with conventional chemotherapy and stem cell transplantation. All attempts to improve conventional therapy over the previous 40 years had failed. Now, new genomic, immunological, and molecular insights have led to a renaissance in AML therapy. Improvements to standard chemotherapy and a wave of new targeted therapies have been developed. However, how best to incorporate these advances into frontline therapy and sequence them in relapse is not firmly established. In this review, we highlight current treatments of AML, targeted agents, and pioneering attempts to synthesize these developments into a rational standard of care (SoC).

Teclistamab in relapsed refractory multiple myeloma: multi-institutional real-world study.

The objective of our study was to report real-world data on the safety and efficacy of standard-of-care teclistamab in patients with relapsed/refractory multiple myeloma (MM). This is a multi-institutional retrospective cohort study and included all consecutive patients that received at least one dose of teclistamab up until August 2023. One hundred and ten patients were included, of whom, 86% had triple-class refractory disease, 76% penta-refractory disease, and 35% had prior exposure to B-cell maturation antigen (BCMA)-targeting therapies. The overall response rate (ORR) in our cohort was 62%, with a ≥ very good partial remission (VGPR) rate of 51%. The ORR in patients with and without prior BCMA-targeted therapies was 54% vs 67%, respectively (p = 0.23). At a median follow-up of 3.5 months (range, 0.39-10.92), the estimated 3 month and 6 month progression free survival (PFS) was 57% (95% CI, 48%, 68%) and 52% (95% CI, 42%, 64%) respectively. The incidence of cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) was 56% and 11% respectively, with grade ≥3 CRS and ICANS noted in 3.5% and 4.6% of patients respectively. 78 unique infections were diagnosed in 44 patients, with the incidence of all-grade and grade ≥3 infections being 40% vs 26% respectively. Primary prophylaxis with intravenous immunoglobulin (IVIG) was associated with a significantly lower infection risk on multivariate analysis (Hazard ratio [HR] 0.33; 95% CI 0.17, 0.64; p = 0.001).

Pulmonary Large Cell Neuroendocrine Carcinoma: A Rare Type of Non-Small Cell Lung Cancer.

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is an uncommon type of non-small cell lung cancer (NSCLC) with an incidence of approximately 3% of all lung cancer diagnoses. The patient was a 60-year-old male with a 90-pack year smoking history who presented with dyspnea on exertion and productive cough for five weeks. Decreased breath sounds without respiratory distress and generalized cachexia were noted on the initial physical exam. Laboratory results were unremarkable except for chronic microcytic anemia. Computed tomography revealed extensive lymphadenopathy of the paratracheal, paraaortic, hilar, and nodes surrounding the left pulmonary arteries. Additionally, there were areas of necrosis in the left upper lobe, lingula, and left lower lobe with extensive pleural thickening extending to the abdomen and subcutaneous tissue of the anterior chest wall. Biopsy and staining showed disorganized tight cell clusters with irregular and prominent nuclei and numerous lymphocytes consistent with LCNEC. Immunohistochemistry was positive for neural cell adhesion molecule CD56 and synaptophysin, which was indicative of neuroendocrine origin. It was also positive for pan-cytokeratin antibody AE1 and AE3 and cytokeratin (CAM) 5.2, which arise from epithelial origin consistent with NSCLCs. Lastly, the patient's tissue was positive for thyroid transcription factor-1, which confirmed the tumor's primary lung origin. This combination of neuroendocrine and primary lung tumor markers, in conjunction with the histology, confirmed the patient's diagnosis of LCNEC.

Matched Cohort Study of Convalescent COVID-19 Plasma Treatment in Severely or Life Threateningly Ill COVID-19 Patients.

BACKGROUND: The utility of convalescent coronavirus disease 2019 (COVID-19) plasma (CCP) in the current pandemic is not well defined. We sought to evaluate the safety and efficacy of CCP in severely or life threateningly ill COVID-19 patients when matched with a contemporaneous cohort. METHODS: Patients with severe or life-threatening COVID-19 were treated with CCP according to Food and Drug Administration criteria, prioritization by an interdisciplinary team, and based on CCP availability. Individual-level matched controls (1:1) were identified from patients admitted during the prior month when no CCP was available. The safety outcome was freedom from adverse transfusion reaction, and the efficacy outcome was a composite of death or worsening O2 support. Demographic, clinical, and laboratory data were analyzed by univariate and multivariable regression analyses accounting for matched design. RESULTS: Study patients (n = 94, 47 matched pairs) were 62% male with a mean age of 58, and 98% (90/94) were minorities (53% Hispanic, 45% Black, non-Hispanic) in our inner-city population. Seven-day composite and mortality outcomes suggested a nonsignificant benefit in CCP-treated patients (adjusted hazard ratio [aHR], 0.70; 95% CI, 0.23-2.12; P = .52; aHR, 0.23; 95% CI, 0.04-1.51; P = .13, respectively). Stratification by pretransfusion mechanical ventilation status showed no differences between groups. No serious transfusion reactions occurred. CONCLUSIONS: In this short-term matched cohort study, transfusion with CCP was safe and showed a nonsignificant association with study outcomes. Randomized and larger trials to identify appropriate timing and dosing of CCP in COVID-19 are warranted. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04420988.

Infectious Mononucleosis Causing Acute Liver Failure and Hemolytic Anemia in a Patient with Underlying Hereditary Hemochromatosis.

Infectious mononucleosis is a largely benign disease process that occurs secondary to infection with the Epstein-Barr virus. However, it can also present with more serious complications, including auto-immune hemolytic anemia and acute liver failure. Hereditary hemochromatosis is a genetic disorder that leads to organ damage via increased iron uptake and deposition. This case report describes a 25-year-old man who presented with acute liver failure and severe hemolytic anemia. Workup revealed that not only did he have a rare presentation of Epstein-Barr virus-induced acute liver failure and C3-positive IgG-negative hemolytic anemia, he also had previously undiagnosed hereditary hemochromatosis. This combined presentation of these pathologies presents a unique opportunity to study their interaction and possible synergistic pathophysiology. Furthermore, the evolving understanding of the disease mechanisms behind these disease processes is described.

Tasimelteon: a selective and unique receptor binding profile.

Hetlioz(®) (tasimelteon) is the first approved treatment in the United States for Non-24-Hour Sleep-Wake Disorder (Non-24). We present here data on the in vitro binding affinity of tasimelteon for both human melatonin receptors MT1 and MT2, as well as the extended screen of other receptors and enzymes. Results indicate that tasimelteon is a potent Dual Melatonin Receptor Agonist (DMRA) with 2.1-4.4 times greater affinity for the MT2 receptor believed to mediate circadian rhythm phase-shifting (Ki = 0.0692 nM and Ki = 0.17 nM in NIH-3T3 and CHO-K1 cells, respectively), than for the MT1 receptor (Ki = 0.304 nM and Ki = 0.35 nM, respectively). Tasimelteon was also shown to have no appreciable affinity for more than 160 other pharmacologically relevant receptors and several enzymes.

High and low frequency subharmonic imaging of angiogenesis in a murine breast cancer model.

This project compared quantifiable measures of tumor vascularity obtained from contrast-enhanced high frequency (HF) and low frequency (LF) subharmonic ultrasound imaging (SHI) to 3 immunohistochemical markers of angiogenesis in a murine breast cancer model (since angiogenesis is an important marker of malignancy and the target of many novel cancer treatments). Nineteen athymic, nude, female rats were implanted with 5×10(6) breast cancer cells (MDA-MB-231) in the mammary fat pad. The contrast agent Definity (Lantheus Medical Imaging, N Billerica, MA) was injected in a tail vein (dose: 180µl/kg) and LF pulse-inversion SHI was performed with a modified Sonix RP scanner (Analogic Ultrasound, Richmond, BC, Canada) using a L9-4 linear array (transmitting/receiving at 8/4MHz in SHI mode) followed by HF imaging with a Vevo 2100 scanner (Visualsonics, Toronto, ON, Canada) using a MS250 linear array transmitting and receiving at 24MHz. The radiofrequency data was filtered using a 4th order IIR Butterworth bandpass filter (11-13MHz) to isolate the subharmonic signal. After the experiments, specimens were stained for endothelial cells (CD31), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2). Fractional tumor vascularity was calculated as contrast-enhanced pixels over all tumor pixels for SHI, while the relative area stained over total tumor area was calculated from specimens. Results were compared using linear regression analysis. Out of 19 rats, 16 showed tumor growth (84%) and 11 of them were successfully imaged. HF SHI demonstrated better resolution, but weaker signals than LF SHI (0.06±0.017 vs. 0.39±0.059; p<0.001). The strongest overall correlation in this breast cancer model was between HF SHI and VEGF (r=-0.38; p=0.03). In conclusion, quantifiable measures of tumor neovascularity derived from contrast-enhanced HF SHI appear to be a better method than LF SHI for monitoring angiogenesis in a murine xenograft model of breast cancer (corresponding in particular to the expression of VEGF); albeit based on a limited sample size.