Platelet activation and endothelial dysfunction biomarkers in acute coronary syndrome: the impact of PCSK9 inhibition.

AIMS: Platelet activation and endothelial dysfunction contribute to adverse outcomes in patients with acute coronary syndromes (ACS). The goals of this study were to assess the impact of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition on markers of platelet activation and endothelial dysfunction in ACS patients and the interaction among PCSK9, platelets, and endothelial cells (ECs) on left internal mammary artery (LIMA) vascular endothelium using specimens obtained during coronary artery bypass surgery (CABG). METHODS AND RESULTS: Acute coronary syndromes patients enrolled in the Evolocumab in ACS trials were randomized to placebo or a single dose of 420 mg evolocumab within 24 h of hospitalization. Serum samples for analysis of platelet factor 4 (PF4) and P-selectin, markers of platelet activation, and von Willebrand factor (vWF), a marker of endothelial dysfunction, were obtained at baseline and 30 days. Additionally, LIMA segments obtained during CABG from patients who were and were not receiving evolocumab were immunostained with PCSK9; CD61, a platelet-specific marker; and CD31, an endothelial cell-specific marker. Forty-six participants were randomized to placebo or to evolocumab. Controlling for baseline levels, PF4 and vWF were significantly lower in the evolocumab, than in the placebo, group at 30 days. Immunostaining of LIMA specimens from twelve participants undergoing CABG revealed colocalization of PCSK9, CD61, and CD31 at the vascular endothelium. Administration of evolocumab was associated with decreased overlap of PCSK9, CD61, and CD31. CONCLUSIONS: Proprotein Convertase Subtilisin/Kexin 9 inhibition decreases markers of platelet activation and endothelial dysfunction in ACS patients. PCSK9 is associated with platelets and vascular ECs in LIMA segments and PCSK9 inhibition decreases that interaction.

Practical Guidance for the Management of Adverse Events in Patients with KRASG12C-Mutated Non-Small Cell Lung Cancer Receiving Adagrasib.

Adagrasib (MRTX849) is a KRASG12C inhibitor with favorable properties, including long half-life (23 h), dose-dependent pharmacokinetics, and central nervous system (CNS) penetration. As of September 1, 2022, a total of 853 patients with KRASG12C-mutated solid tumors, including patients with CNS metastases, had received adagrasib (monotherapy or in combination). Adagrasib-related treatment-related adverse events (TRAEs) are generally mild to moderate in severity, start early in treatment, resolve quickly with appropriate intervention, and result in a low rate of treatment discontinuation. Common TRAEs seen in clinical trials included gastrointestinal-related toxicities (diarrhea, nausea, and vomiting); hepatic toxicities (increased alanine aminotransferase/aspartate aminotransferase) and fatigue, which can be managed through dose modifications, dietary modifications, concomitant medications (such as anti-diarrheals and anti-emetics/anti-nauseants) and the monitoring of liver enzymes and electrolytes. To manage common TRAEs effectively, it is imperative that clinicians are informed, and patients are fully counseled on management recommendations at treatment initiation. In this review, we provide practical guidance on the management of adagrasib TRAEs and discuss some best practices for patient and caregiver counseling to facilitate optimal outcomes for patients. Safety and tolerability data from the phase II cohort of the KRYSTAL-1 study will be reviewed and presented with practical management recommendations based on our experience as clinical investigators.

A Comparison of Tissue Dissection Techniques for Diagnostic, Prognostic, and Theragnostic Analysis of Human Disease.

Histopathology has historically been the critical technique for the diagnosis and treatment of human disease. Today, genomics, transcriptomics, and proteomics from specific cells, rather than bulk tissue, have become key to understanding underlying disease mechanisms and rendering useful diagnostic information. Extraction of desired analytes, i.e., nucleic acids or proteins, from easily accessible formalin-fixed paraffin-embedded tissues allows for clinically relevant activities, such as sequencing biomarker mutations or typing amyloidogenic proteins. Genetic profiling has become routine for cancers as varied as non-small cell lung cancer and prostatic carcinoma. The five main tissue dissection techniques that have been developed thus far include: bulk scraping, manual macrodissection, manual microdissection, laser-capture microdissection, and expression microdissection. In this review, we discuss the importance of tissue dissection in clinical practice and research, the basic methods, applications, as well as some advantages and disadvantages for each modality.

Burden of chemotherapy in patients with relapsed/refractory acute myeloid leukemia in the United States: a retrospective claims database study.

BACKGROUND: Real-world estimates of relapsed or refractory (R/R) acute myeloid leukemia (AML) chemotherapy episode costs are scarce. We quantified chemotherapy episode-related costs and healthcare resource use (HRU) in R/R AML. RESEARCH DESIGN AND METHODS: This real-world, retrospective analysis of United States claims from IQVIA's PharMetrics® Plus database (October 2008-September 2019) identified adults with R/R AML and ≥1 chemotherapy episode. Chemotherapy episode (ie, low- [LIC] or high-intensity [HIC] chemotherapy) costs and HRU were determined using inpatient, outpatient, and pharmacy claims. RESULTS: Mean (SD) and median total all-cause healthcare costs per R/R AML chemotherapy episode were $230,799 ($300,770) and $129,117. Mean (SD) and median adjusted direct R/R AML chemotherapy episode costs were $116,384 ($151,425) and $63,298, with increases noted from the first to the second and subsequent episodes and with HIC. Hospitalizations were the major cost driver; 64.1% of patients had ≥1 hospitalization and 36% required an intensive care unit stay. CONCLUSIONS: R/R AML chemotherapy episode costs were high, with higher costs reported with HIC and increasing lines of chemotherapy. Hospitalizations were a main cost driver. Novel therapies with comparable or improved effectiveness and decreased need for hospitalizations versus chemotherapy may help alleviate the clinical and economic burden of R/R AML.

Spatial Proteomic Approach to Characterize Skeletal Muscle Myofibers.

Skeletal muscle myofibers have differential protein expression resulting in functionally distinct slow- and fast-twitch types. While certain protein classes are well-characterized, the depth of all proteins involved in this process is unknown. We utilized the Human Protein Atlas (HPA) and the HPASubC tool to classify mosaic expression patterns of staining across 49,600 unique tissue microarray (TMA) images using a visual proteomic approach. We identified 2164 proteins with potential mosaic expression, of which 1605 were categorized as "likely" or "real." This list included both well-known fiber-type-specific and novel proteins. A comparison of the 1605 mosaic proteins with a mass spectrometry (MS)-derived proteomic dataset of single human muscle fibers led to the assignment of 111 proteins to fiber types. We additionally used a multiplexed immunohistochemistry approach, a multiplexed RNA-ISH approach, and STRING v11 to further assign or suggest fiber types of newly characterized mosaic proteins. This visual proteomic analysis of mature skeletal muscle myofibers greatly expands the known repertoire of twitch-type-specific proteins.

Economic and Clinical Burden of Acute Myeloid Leukemia Episodes of Care in the United States: A Retrospective Analysis of a Commercial Payer Database.

BACKGROUND: In the United States, the incidence of acute myeloid leukemia (AML) has steadily increased over the last decade; in 2019, it was estimated that AML would affect 21,450 new patients and lead to 10,920 deaths. Detailed real-world cost estimates and comparisons of key AML treatment episodes, such as in high-intensity chemotherapy (HIC), low-intensity chemotherapy (LIC), hematopoietic stem cell transplantation (HSCT), and relapsed/refractory (R/R), are scarce in the commercially insured U.S. OBJECTIVE: To examine health resource utilization (HRU), clinical burden, and direct health care costs across various AML treatment episodes in a large sample of commercially insured U.S. METHODS: A retrospective cohort analysis was conducted. Patients with newly diagnosed AML were followed to identify the key active treatment episodes across the course of their disease. Data were obtained from 2 sources: IQVIA's Real-World Data (RWD) Adjudicated Claims Database - U.S. (formerly known as PharMetrics Plus), which comprises adjudicated claims for more than 150 million unique enrollees across the United States, and IQVIA Charge Detail Master Hospital Database, which has detailed data regarding services received in an inpatient setting. Calculation of all-cause HRU was based on physician office visits, nonphysician office visits, emergency department visits, inpatient visits, and outpatient pharmacy utilization. Calculation of all-cause health care costs was based on total allowed costs and reported by the following cost components: physician office visits, nonphysician office visits, emergency department visits, inpatient visits, and outpatient pharmacy utilization. Symptom and toxicity events were estimated via proxies such as diagnosis codes, procedures, and treatments administered. RESULTS: The final study sample consisted of 1,542 HIC-induction (HIC-I), 591 HIC-consolidation (HIC-C), 628 LIC, 1,000 patients with HSCT, and 707 patients with R/R AML. Total mean episode costs were highest in R/R episodes ($439,104), followed by HSCT ($329,621), HIC-I ($198,657), HIC-C ($73,428), and LIC ($53,081) episodes. Across all treatment episodes, hospitalization was the largest contributor to cost with mean hospitalization costs ranging from $308,978 in the R/R setting to $49,580 for patients receiving LIC; of these, costs related to intensive care unit admission were a noteworthy contributor. In patients with R/R AML and HSCT, expenditures related to pharmacy utilization averaged $24,640 and $12,203, respectively, and expenditures related to physician office visits averaged $10,926 and $6,090, respectively; these expenditures were much lower across other episodes. Across all categories of symptom and toxicity events, cardiovascular events was the only category of event that was a significant predictor of higher cost across all episodes. Symptom and toxicity events commonly associated with AML were associated with significantly increased costs, especially in R/R episodes. CONCLUSIONS: This resource utilization and direct health care cost analysis highlights the substantial economic burden associated with key AML treatment episodes in the United States, specifically during HIC-I, HSCT, and R/R episodes. DISCLOSURES: This study was funded by Astellas Pharma. Astellas employees were involved in the study design, interpretation of data, writing of the manuscript, and the decision to submit the manuscript for publication. Pandya and Wilson are employees of Astellas Pharma U.S. Walsh was an employee of Astellas Pharma U.S. while the study was conducted. Chen, McGuiness, and Wade are employees of IQVIA, which received funding from Astellas Pharma U.S. Madeiros was employed at Stanford University while this study was conducted and received a consulting fee from Astellas for work on this study. Data discussed in this study were previously presented at the 59th Annual American Society for Hematology Meeting & Exposition, 2017; December 9-12, 2017; Atlanta, GA.

Cytochrome c Deficiency Confers Apoptosome and Mitochondrial Dysfunction in African-American Men with Prostate Cancer.

Although African-American (AA) patients with prostate cancer tend to develop greater therapeutic resistance and faster prostate cancer recurrence compared with Caucasian-American (CA) men, the molecular mechanisms of this racial prostate cancer disparity remain undefined. In this study, we provide the first comprehensive evidence that cytochrome c deficiency in AA primary tumors and cancer cells abrogates apoptosome-mediated caspase activation and contributes to mitochondrial dysfunction, thereby promoting therapeutic resistance and prostate cancer aggressiveness in AA men. In AA prostate cancer cells, decreased nuclear accumulation of nuclear respiration factor 1 (Nrf1) and its subsequent loss of binding to the cytochrome c promoter mediated cytochrome c deficiency. The activation of cellular Myc (c-Myc) and NF-κB or inhibition of AKT prevented nuclear translocation of Nrf1. Genetic and pharmacologic inhibition of c-Myc and NF-κB or activation of AKT promoted Nrf1 binding to cytochrome c promoter, cytochrome c expression, caspase activation, and cell death. The lack of p-Drp1S616 in AA prostate cancer cells contributed to defective cytochrome c release and increased resistance to apoptosis, indicating that restoration of cytochrome c alone may be insufficient to induce effective apoptosis. Cytochrome c deficiency promoted the acquisition of glycolytic phenotypes and mitochondrial dysfunction, whereas cytochrome c restoration via inhibition of c-Myc and NF-κB or activation of AKT attenuated glycolysis in AA prostate cancer cells. Inhibition of c-Myc and NF-κB enhanced the efficacy of docetaxel in tumor xenografts. Therefore, restoring cytochrome c may overcome therapeutic resistance and prostate cancer aggressiveness in AA men. Overall, this study provides the first comprehensive experimental, mechanistic, and clinical evidence for apoptosome and mitochondrial dysfunction in prostate cancer racial disparity. SIGNIFICANCE: Mechanistic insights on prostate cancer health disparity among American men provide novel approaches to restore mitochondrial function, which can address therapeutic resistance and aggressiveness in African-American men with prostate cancer.