Is atrial fibrillation in HFpEF a distinct phenotype? Insights from multiparametric MRI and circulating biomarkers.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) frequently co-exist. There is a limited understanding on whether this coexistence is associated with distinct alterations in myocardial remodelling and mechanics. We aimed to determine if patients with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) represent a distinct phenotype. METHODS: In this secondary analysis of adults with HFpEF (NCT03050593), participants were comprehensively phenotyped with stress cardiac MRI, echocardiography and plasma fibroinflammatory biomarkers, and were followed for the composite endpoint (HF hospitalisation or death) at a median of 8.5 years. Those with AF were compared to sinus rhythm (SR) and unsupervised cluster analysis was performed to explore possible phenotypes. RESULTS: 136 subjects were included (SR = 75, AF = 61). The AF group was older (76 ± 8 vs. 70 ± 10 years) with less diabetes (36% vs. 61%) compared to the SR group and had higher left atrial (LA) volumes (61 ± 30 vs. 39 ± 15 mL/m2, p < 0.001), lower LA ejection fraction (EF) (31 ± 15 vs. 51 ± 12%, p < 0.001), worse left ventricular (LV) systolic function (LVEF 63 ± 8 vs. 68 ± 8%, p = 0.002; global longitudinal strain 13.6 ± 2.9 vs. 14.7 ± 2.4%, p = 0.003) but higher LV peak early diastolic strain rates (0.73 ± 0.28 vs. 0.53 ± 0.17 1/s, p < 0.001). The AF group had higher levels of syndecan-1, matrix metalloproteinase-2, proBNP, angiopoietin-2 and pentraxin-3, but lower level of interleukin-8. No difference in clinical outcomes was observed between the groups. Three distinct clusters were identified with the poorest outcomes (Log-rank p = 0.029) in cluster 2 (hypertensive and fibroinflammatory) which had equal representation of SR and AF. CONCLUSIONS: Presence of AF in HFpEF is associated with cardiac structural and functional changes together with altered expression of several fibro-inflammatory biomarkers. Distinct phenotypes exist in HFpEF which may have differing clinical outcomes.

Integrating Full Bayesian Inference and Student's t-Distribution Method for Enhanced Outlier Handling in Caffeine Population Pharmacokinetics: Assessing Drug-Drug Interactions with Enasidenib in Relapsed or Refractory AML and MDS Patients.

As the first-in-class, selective, and potent inhibitor of the isocitrate dehydrogenase-2 (IDH2) mutant protein, enasidenib was approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (AML) with an IDH2 mutation. Known for its interactions with various cytochrome P450 (CYP) enzymes and transporters in vitro, a clinical pharmacokinetics (PK) trial was initiated to assess the impact of multiple doses of enasidenib on the single-dose PK of sensitive probe substrates of several cytochrome P450 enzymes and transporters. In this study, a population pharmacokinetic analysis approach was employed to address challenges posed by high, nonzero baseline caffeine concentrations. Moreover, we integrated full Bayesian inference into this approach innovatively for a more detailed understanding of parameter uncertainty and greater modeling flexibility, alongside Student's t-distribution for robust error modeling in handling the abnormal outlier caffeine concentration data observed in this trial. Our analyses demonstrated that multiple doses of enasidenib altered caffeine clearance to a clinically meaningful extent, as evidenced by an approximate 8-fold decrease. This finding led to a specific recommendation in the package insert to avoid the concurrent use of certain CYP1A2 substrates with enasidenib, unless directed otherwise in the prescribing information. Furthermore, this research underlines the technical benefits of integrating full Bayesian inference and incorporating Student's t-distribution for residual error modeling in the PK field.

Prognostic Significance and Biologic Associations of Senescence-Associated Secretory Phenotype Biomarkers in Heart Failure.

BACKGROUND: The role of cellular senescence in human heart failure (HF) remains unclear. The senescence-associated secretory phenotype (SASP) is composed of proteins released by senescent cells. We assessed the prognostic significance and biologic pathways associated with the SASP in human HF using a plasma proteomics approach. METHODS AND RESULTS: We measured 25 known SASP proteins among 2248 PHFS (Penn HF Study) participants using the SOMAScan V4 assay. We extracted the common variance in these proteins to generate SASP factor scores and assessed the relationship between these SASP factor scores and (1) all-cause death and (2) the composite of death or HF hospital admission. We also assessed the relationship of each SASP factor to 4746 other proteins, correcting for multiple comparisons, followed by pathway analyses. Two SASP factors were identified. Both factors were associated with older age, lower estimated glomerular filtration rate, and more advanced New York Heart Association class, among other clinical variables. Both SASP factors exhibited a significant positive association with the risk of death independent of the Meta-Analysis of Global-Group in Chronic HF score and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. The 2 identified SASP factors were associated with 1201 and 1554 proteins, respectively, belonging to various pathways including the coagulation system, complement system, acute phase response signaling, and retinoid X receptor-related pathways that regulate cell metabolism. CONCLUSIONS: Increased SASP components are independently associated with adverse outcomes in HF. Biologic pathways associated with SASP are predominantly related to coagulation, inflammation, and cell metabolism.

Model based assessment of food and acid reducing agent effects on oral absorption of mezigdomide (CC-92480), a novel cereblon E3 ligase modulator.

Mezigdomide is a novel cereblon E3 ligase modulator (CELMoD) agent with enhanced autonomous cell-killing activity in multiple myeloma (MM) cells, and promising immunomodulatory and antitumor activity in patients with MM. We developed a population pharmacokinetics (PKs) model for mezigdomide in healthy subjects (HSs), and quantified effects of high-fat meal and proton pump inhibitor (PPI) on human disposition parameters. Plasma concentrations from 64 HS in two phase I clinical studies (NCT03803644 and NCT04211545) were used to develop a population PK model. The HSs received single oral doses of 0.4-3.2 mg mezigdomide with full PK profiles collected. A two-compartment linear PK model with first-order absorption and lag time best described mezigdomide PK profiles in HSs. The population PK parameters of absorption rate constant, lag time, central volume of distribution, clearance, peripheral volume of distribution, and intercompartmental clearance were estimated to be 1.18 h-1 (interoccasion variability [IOV]: 65%), 0.423 h (IOV: 31%), 440 L (interindividual variability [IIV]: 63%), 35.1 L/h (IIV: 40%), 243 L (IIV: 26%), and 36.8 L/h (IIV: 26%), respectively. High-fat meal increased oral bioavailability by ~30% and PPI co-administration decreased oral bioavailability by ~64%. Mezigdomide demonstrated a linear dose-exposure relationship in HSs. The PK model suggests a modest effect of high-fat meal, and a substantial effect of PPIs on mezigdomide oral bioavailability. This population PK model enables data integration across studies to identify important covariate effects and is being used to guide dose selection in clinical study designs for mezigdomide in patients with MM.

Assessment of Transporter-Mediated Drug Interactions for Enasidenib Based on a Cocktail Study in Patients With Relapse or Refractory Acute Myeloid Leukemia or Myelodysplastic Syndrome.

As a first-in-class, selective, potent inhibitor of the isocitrate dehydrogenase-2 (IDH2) mutant protein, enasidenib was approved by the US Food and Drug Administration in 2017 for the treatment of adult patients with relapsed or refractory acute myeloid leukemia with an isocitrate dehydrogenase-2 mutation. An in vitro study showed that enasidenib at clinically relevant concentrations has effects on multiple drug metabolic enzymes and transporters, including inhibition of P-glycoprotein, breast cancer resistance protein, organic anion transporter (OAT) P1B1, and OATP1B3 transporters. Therefore, a drug-drug interaction study was conducted to assess the impact of enasidenib at steady state on the pharmacokinetics of several probe compounds in patients with relapsed or refractory acute myeloid leukemia or myelodysplastic syndrome, including the probes herein described in this article, digoxin and rosuvastatin. Results from 8 patients (all Asian) with a mean age of 67.1 years showed that following coadministration of enasidenib (100 mg, 28-day once-daily schedule) for 28 days (at steady state), digoxin's (0.25 mg) area under the plasma concentration-time curve from time 0 to 30 days was 1.2-fold (90% confidence interval, 0.9-1.6), compared with digoxin alone. Following coadministration of enasidenib (100 mg, 28-day once-daily schedule) for 28 days (at steady state), rosuvastatin's (10 mg) area under the plasma concentration-time curve from time 0 to infinity was 3.4-fold (90% confidence interval, 2.6-4.5) compared with rosuvastatin alone. These results should serve as the basis for dose recommendations for drugs that are substrates of P-glycoprotein, breast cancer resistance protein, OATP1B1, and OATP1B3 transporters, when used concomitantly with enasidenib.

MGAT2 inhibitor decreases liver fibrosis and inflammation in murine NASH models and reduces body weight in human adults with obesity.

Monoacylglycerol acyltransferase 2 (MGAT2) is an important enzyme highly expressed in the human small intestine and liver for the regulation of triglyceride absorption and homeostasis. We report that treatment with BMS-963272, a potent and selective MGAT2 inhibitor, decreased inflammation and fibrosis in CDAHFD and STAM, two murine nonalcoholic steatohepatitis (NASH) models. In high-fat-diet-treated cynomolgus monkeys, in contrast to a selective diacylglycerol acyltransferase 1 (DGAT1) inhibitor, BMS-963272 did not cause diarrhea. In a Phase 1 multiple-dose trial of healthy human adults with obesity (NCT04116632), BMS-963272 was safe and well tolerated with no treatment discontinuations due to adverse events. Consistent with the findings in rodent models, BMS-963272 elevated plasma long-chain dicarboxylic acid, indicating robust pharmacodynamic biomarker modulation; increased gut hormones GLP-1 and PYY; and decreased body weight in human subjects. These data suggest MGAT2 inhibition is a promising therapeutic opportunity for NASH, a disease with high unmet medical needs.

First-in-Human, Single- and Multiple-Ascending-Dose Studies in Healthy Subjects to Assess Pharmacokinetics, Pharmacodynamics, and Safety/Tolerability of Iberdomide, a Novel Cereblon E3 Ligase Modulator.

Pharmacokinetics, pharmacodynamics, and safety/tolerability of iberdomide (CC-220), a highly potent oral cereblon E3 ligase modulator (CELMoD), were evaluated in escalating single-dose (0.03, 0.1, 0.3, 1, 2, 4, 6 mg) and multiple-dose (0.3 mg once daily for 14 days, 1 mg once daily for 28 days, 0.3 mg once daily for 28 days, or 1 mg once daily for 7 days with a 7-day washout, then once daily for 7 more days) studies in healthy subjects (n = 99). Iberdomide exposure increased in a dose-proportional manner. Terminal half-life was 9-13 hours after a single dose. Iberdomide decreased peripheral CD19+ B lymphocytes (Emax , 92.4%; EC50 , 0.718 ng/mL), with modest reductions in CD3+ T lymphocytes (Emax , 34.8%; EC50 , 0.932 ng/mL). Lipopolysaccharide-stimulated proinflammatory cytokines (IL-1α, IL-1ß) were reduced, but anti-CD3-stimulated IL-2 and interferon-γ were increased. Iberdomide 1 mg once daily partially decreased T-cell-independent antibody responses to PPV23 but did not change tetanus toxoid recall response. Pharmacodynamic data suggest dose-dependent, differential immunomodulatory effects on B and T lymphocytes. Iberdomide was tolerated up to 6 mg as a single dose and at 0.3 mg once daily for 4 weeks. Grade 3 asymptomatic neutropenia was observed following 1 mg once daily for 21 days; a 7-day drug holiday alleviated neutropenia. Further investigation of iberdomide in autoimmune and hematological diseases is warranted.

Evaluation of the Potential for QTc Prolongation With Repeated Oral Doses of Fedratinib in Patients With Advanced Solid Tumors.

The impact of repeated daily 500-mg fedratinib (an oral selective Janus kinase [JAK] 2 inhibitor) on QTc and other electrocardiogram (ECG) parameters was assessed in 60 patients with advanced solid tumors. Patients received placebo on day 1 and fedratinib 500 mg daily for 14 days. Concentration-QTc analysis was performed with change-from-baseline QTc corrected by Fridericia's formula (ΔQTcF) as the dependent variable. Fedratinib median time to maximum plasma concentration (Cmax ) was observed 3 hours postdose on day 15. The largest difference between means for fedratinib and placebo was 0.5 bpm (90%CI, -2.75 to 3.72 bpm) for heart rate (3 hours postdose) and 4.3 milliseconds (90%CI, 1.04-7.60 milliseconds) for QTcF (4 hours postdose). The estimated slope of the fedratinib concentration-QTcF relationship was shallow and not statistically significant: -0.0005 milliseconds per ng/mL (90%CI, -0.00145 to 0.00050 milliseconds per ng/mL). Predicted fedratinib placebo-corrected ΔQTcF was 0.6 milliseconds (90%CI, -1.80 to 2.93 milliseconds) at the geometric mean of the observed Cmax (3615 ng/mL). Fedratinib did not affect PR or QRS intervals. No patients had QTcF > 60 milliseconds, and no patients experienced QTcF ≥ 500 milliseconds. Fedratinib did not cause clinically relevant ECG effects or QTc prolongation. Safety findings were consistent with the known safety profile.

Targeting the Wnt signaling pathway through R-spondin 3 identifies an anti-fibrosis treatment strategy for multiple organs.

The Wnt/ß-catenin signaling pathway has been implicated in human proliferative diseases such as cancer and fibrosis. The functions of ß-catenin and several other components of this pathway have been investigated in fibrosis. However, the potential role of R-spondin proteins (RSPOs), enhancers of the Wnt/ß-catenin signaling, has not been described. A specific interventional strategy targeting this pathway for fibrosis remains to be defined. We developed monoclonal antibodies against members of the RSPO family (RSPO1, 2, and 3) and probed their potential function in fibrosis in vivo. We demonstrated that RSPO3 plays a critical role in the development of fibrosis in multiple organs. Specifically, an anti-RSPO3 antibody, OMP-131R10, when dosed therapeutically, attenuated fibrosis in carbon tetrachloride (CCl4)-induced liver fibrosis, bleomycin-induced pulmonary and skin fibrosis models. Mechanistically, we showed that RSPO3 induces multiple pro-fibrotic chemokines and cytokines in Kupffer cells and hepatocytes. We found that the anti-fibrotic activity of OMP-131R10 is associated with its inhibition of ß-catenin activation in vivo. Finally, RSPO3 was found to be highly elevated in the active lesions of fibrotic tissues in mouse models of fibrosis and in patients with idiopathic pulmonary fibrosis (IPF) and nonalcoholic steatohepatitis (NASH). Together these data provide an anti-fibrotic strategy for targeting the Wnt/ß-catenin pathway through RSPO3 blockade and support that OMP-131R10 could be an important therapeutic agent for fibrosis.

NKG2D-independent suppression of T cell proliferation by H60 and MICA.

The activating receptor NKG2D recognizes a wide range of different ligands, some of which are primarily expressed in "stressed" tissues or on tumor cells. Until now, similar stimulatory effects on natural killer and CD8+ T cells have been described for all NKG2D ligands, and the NKG2D receptor/ligand system has therefore been interpreted as a sensor system involved in tumor immune surveillance and activation of immune responses. We show here that the NKG2D ligands H60 and MIC class 1 chain-related protein A (MICA) can also mediate strong suppressive effects on T cell proliferation. Responsiveness to H60- and MICA-mediated suppression requires IL-10 and involves a receptor other than NKG2D. These findings might provide explanations for the observation that strong in vivo NKG2D ligand expression, such as that on tumor cells, sometimes fails to support effective immune responses and links this observation to a distinct subgroup of NKG2D ligands.