Discovery of a highly potent, selective, orally bioavailable inhibitor of KAT6A/B histone acetyltransferases with efficacy against KAT6A-high ER+ breast cancer.

KAT6A, and its paralog KAT6B, are histone lysine acetyltransferases (HAT) that acetylate histone H3K23 and exert an oncogenic role in several tumor types including breast cancer where KAT6A is frequently amplified/overexpressed. However, pharmacologic targeting of KAT6A to achieve therapeutic benefit has been a challenge. Here we describe identification of a highly potent, selective, and orally bioavailable KAT6A/KAT6B inhibitor CTx-648 (PF-9363), derived from a benzisoxazole series, which demonstrates anti-tumor activity in correlation with H3K23Ac inhibition in KAT6A over-expressing breast cancer. Transcriptional and epigenetic profiling studies show reduced RNA Pol II binding and downregulation of genes involved in estrogen signaling, cell cycle, Myc and stem cell pathways associated with CTx-648 anti-tumor activity in ER-positive (ER+) breast cancer. CTx-648 treatment leads to potent tumor growth inhibition in ER+ breast cancer in vivo models, including models refractory to endocrine therapy, highlighting the potential for targeting KAT6A in ER+ breast cancer.

Do people agree on how they and others are acting? Examining the degree of target-observer and observer-observer agreement about current behavior as it changes across situations.

The purpose of the present research was to test the level of agreement between targets and observers both at any given moment and as the targets' current behavior (assessed as personality states) change across moments. Ninety-seven target participants participated in 22 different activities across 20 1-hour long sessions in a laboratory setting while reporting their current behavior, and their behavior was evaluated by 183 observers (total of 3,493 target self-reports, 2,973 of which had a corresponding observer report from at least one observer). Target-observer and observer-observer agreement was significant for all personality states (and was substantial for extraversion, conscientiousness, and openness to experience), and was observed in different situations, across all situations, and after accounting for normative agreement. The findings from this study-the first to examine within-person agreement on in-person behavioral states-provide evidence that people can accurately report their current behavior, that people agree on changes in behaviors across situations, and by extension that intensive assessment methodologies (such as experience-sampling methodology) have validity as assessments of momentary behavior. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Expanding control of the tumor cell cycle with a CDK2/4/6 inhibitor.

The CDK4/6 inhibitor, palbociclib (PAL), significantly improves progression-free survival in HR+/HER2- breast cancer when combined with anti-hormonals. We sought to discover PAL resistance mechanisms in preclinical models and through analysis of clinical transcriptome specimens, which coalesced on induction of MYC oncogene and Cyclin E/CDK2 activity. We propose that targeting the G1 kinases CDK2, CDK4, and CDK6 with a small-molecule overcomes resistance to CDK4/6 inhibition. We describe the pharmacodynamics and efficacy of PF-06873600 (PF3600), a pyridopyrimidine with potent inhibition of CDK2/4/6 activity and efficacy in multiple in vivo tumor models. Together with the clinical analysis, MYC activity predicts (PF3600) efficacy across multiple cell lineages. Finally, we find that CDK2/4/6 inhibition does not compromise tumor-specific immune checkpoint blockade responses in syngeneic models. We anticipate that (PF3600), currently in phase 1 clinical trials, offers a therapeutic option to cancer patients in whom CDK4/6 inhibition is insufficient to alter disease progression.

Discovery of PF-06873600, a CDK2/4/6 Inhibitor for the Treatment of Cancer.

Control of the cell cycle through selective pharmacological inhibition of CDK4/6 has proven beneficial in the treatment of breast cancer. Extending this level of control to additional cell cycle CDK isoforms represents an opportunity to expand to additional tumor types and potentially provide benefits to patients that develop tumors resistant to selective CDK4/6 inhibitors. However, broad-spectrum CDK inhibitors have a long history of failure due to safety concerns. In this approach, we describe the use of structure-based drug design and Free-Wilson analysis to optimize a series of CDK2/4/6 inhibitors. Further, we detail the use of molecular dynamics simulations to provide insights into the basis for selectivity against CDK9. Based on overall potency, selectivity, and ADME profile, PF-06873600 (22) was identified as a candidate for the treatment of cancer and advanced to phase 1 clinical trials.

Adherence after treatment switch from a multiple tablet antiretroviral regimen to a single tablet antiretroviral regimen.

OBJECTIVES: To evaluate adherence after treatment switch from a multiple-tablet regimen (MTR) to a single-tablet regimen (STR) in a national cohort of human immunodeficiency virus (HIV) patients. METHODS: This retrospective observational cohort, with data spanning January 1, 2000 to March 1, 2019, consisted of HIV infected patients receiving treatment from the Veterans Affairs (VA) health system. Patients were required to have a complete MTR regimen after January 1, 2006 and before December 31, 2018 with at least 60 days of treatment. Medical and pharmacy data were analyzed from the Veterans Affairs Informatics and Computing Infrastructure (VINCI) database. Statistical analyses examined differences in adherence when patients switched to a STR. Patients who switched to a STR were propensity score matched to those who never switched. Descriptive statistics and multivariable linear mixed effects models were utilized to evaluate differences in adherence between MTR and STR treatment in both the matched and unmatched samples. RESULTS: A total of 5021 patients met the study criteria, 3906 patients in the MTR only cohort and 1115 patients in the switch to STR cohort. The unmatched cohorts were similar in terms of sex, index year, drug/alcohol abuse, and viral load but differed in terms of race, Charlson comorbidity and mental health conditions. The one to one propensity score matched cohort included 2230 patients, 1115 patients in each cohort. Among patients that switched from a MTR to STR, adherence increased on average from 65.9% to 78.12%. We find overall adherence is higher with STRs than with MTR HIV regimens in both the matched and unmatched sample and adherence declines with time for both STR and MTR regimens. CONCLUSIONS: Switching to a STR is associated with higher adherence compared to MTR among patients with HIV treated with antiretrovirals. However, adherence declines over time with both STR and MTR regimens.

Design and Characterization of a Pyridone-Containing EZH2 Inhibitor Phosphate Prodrug.

A pyridone-derived phosphate prodrug of an enhancer of zeste homolog 2 (EZH2) inhibitor was designed and synthesized to improve the inhibitor's aqueous solubility. This prodrug (compound 5) was profiled in pharmacokinetic experiments to assess its ability to deliver the corresponding parent compound (compound 2) to animals in vivo following oral administration. Results from these studies showed that the prodrug was efficiently converted to its parent compound in vivo. In separate experiments, the prodrug demonstrated impressive in vivo tumor growth inhibition in a diffuse large B-cell lymphoma Karpas-422 cell line-derived xenograft model. The described prodrug strategy is expected to be generally applicable to poorly soluble pyridone-containing EZH2 inhibitors and provides a new option to enable such compounds to achieve sufficiently high exposures in vivo.

Structure-Based Drug Design and Synthesis of PI3Kα-Selective Inhibitor (PF-06843195).

The phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway is a frequently dysregulated pathway in human cancer, and PI3Kα is one of the most frequently mutated kinases in human cancer. A PI3Kα-selective inhibitor may provide the opportunity to spare patients the side effects associated with broader inhibition of the class I PI3K family. Here, we describe our efforts to discover a PI3Kα-selective inhibitor by applying structure-based drug design (SBDD) and computational analysis. A novel series of compounds, exemplified by 2,2-difluoroethyl (3S)-3-{[2'-amino-5-fluoro-2-(morpholin-4-yl)-4,5'-bipyrimidin-6-yl]amino}-3-(hydroxymethyl)pyrrolidine-1-carboxylate (1) (PF-06843195), with high PI3Kα potency and unique PI3K isoform and mTOR selectivity were discovered. We describe here the details of the design and synthesis program that lead to the discovery of 1.

Multifaceted Substrate-Ligand Interactions Promote the Copper-Catalyzed Hydroboration of Benzylidenecyclobutanes and Related Compounds.

A unified synthetic strategy to access tertiary four-membered carbo/heterocyclic boronic esters is reported. Use of a Cu(I) catalyst in combination with a modified dppbz ligand enables regioselective hydroboration of various trisubstituted benzylidenecyclobutanes and carbo/heterocyclic analogs. The reaction conditions are mild, and the method tolerates a wide range of medicinally relevant heteroarenes. The protocol can be conveniently conducted on gram-scale, and the tertiary boronic ester products undergo facile diversification into valuable targets. Reaction kinetics and computational studies indicate that the migratory insertion step is turnover-limiting and accelerated by electron-withdrawing groups on the dppbz ligand. Energy decomposition analysis (EDA) calculations reveal that electron-deficient P-aryl groups on the dppbz ligand enhance the T-shaped π/π interactions with the substrate and stabilize the migratory insertion transition state.

Inpatient, Outpatient, and Pharmacy Costs in Patients With and Without HIV in the US Veteran's Affairs Administration System.

OBJECTIVES: To evaluate the association between human immunodeficiency virus (HIV) patients and medical costs (inpatient, outpatient, pharmacy, total) using a national cohort of HIV-infected Veterans and non-HIV matched controls within the Veteran's Affairs (VA) Administration system. DESIGN: This study used claims (January 2000 to December 2016) extracted from the VA Informatics and Computing Infrastructure and VA Health Economics Resource Center. Cases included Veterans with an International Classification of Diseases, Ninth Revision/International Classification of Diseases, Tenth Revision for HIV with at least 1 prescription for a complete antiretroviral therapy regimen (January 2000 to September 2016). Two non-HIV controls were exact matched on race, sex, month, and year of birth. All patients were followed until the earliest of the following: last date of VA activity, death, or December 31, 2016. RESULTS: A total of 79 578 patients (26 526 HIV and 53 052 non-HIV) met all study criteria. The average age was 49.3 years, 38% were black, 32% were white, and 97% were male for both the HIV and control cohorts. Adjusted multivariable logistic regression models demonstrated that HIV was associated with higher odds of incurring a pharmacy cost (odds ratio = 2286.45, 95% confidence interval: 322.79-16 195.82), 4-fold, and 2-fold higher odds of incurring both outpatient and inpatient costs compared to the matched controls, respectively. In adjusted multivariable gamma generalized linear models, HIV-positive patients had an almost 4-fold, 17-fold, and almost 2-fold higher cost than matched controls in total, pharmacy, and outpatient costs, respectively. CONCLUSIONS: This study found an association between HIV-positive patients having higher odds of incurring a medical cost as well as higher medical costs compared to non-HIV controls.

Optimization of Orally Bioavailable Enhancer of Zeste Homolog 2 (EZH2) Inhibitors Using Ligand and Property-Based Design Strategies: Identification of Development Candidate (R)-5,8-Dichloro-7-(methoxy(oxetan-3-yl)methyl)-2-((4-methoxy-6-methyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-3,4-dihydroisoquinolin-1(2H)-one (PF-06821497).

A new series of lactam-derived EZH2 inhibitors was designed via ligand-based and physicochemical-property-based strategies to address metabolic stability and thermodynamic solubility issues associated with previous lead compound 1. The new inhibitors incorporated an sp3 hybridized carbon atom at the 7-position of the lactam moiety present in lead compound 1 as a replacement for a dimethylisoxazole group. This transformation enabled optimization of the physicochemical properties and potency compared to compound 1. Analysis of relationships between calculated log D (clogD) values and in vitro metabolic stability and permeability parameters identified a clogD range that afforded an increased probability of achieving favorable ADME data in a single molecule. Compound 23a exhibited the best overlap of potency and pharmaceutical properties as well as robust tumor growth inhibition in vivo and was therefore advanced as a development candidate (PF-06821497). A crystal structure of 23a in complex with the three-protein PRC2 complex enabled understanding of the key structural features required for optimal binding.

Practical Singly and Doubly Electrophilic Aminating Agents: A New, More Sustainable Platform for Carbon-Nitrogen Bond Formation.

Given the importance of amines in a large number of biologically active natural products, active pharmaceutical ingredients, agrochemicals, and functional materials, the development of efficient C-N bond-forming methods with wide substrate scope continues to be at the frontier of research in synthetic organic chemistry. Here, we present a general and fundamentally new synthetic approach for the direct, transition-metal-free preparation of symmetrical and unsymmetrical diaryl-, arylalkyl-, and dialkylamines that relies on the facile single or double addition of readily available C-nucleophiles to the nitrogen atom of bench-stable electrophilic aminating agents. Practical single and double polarity reversal (i.e., umpolung) of the nitrogen atom is achieved using sterically and electronically tunable ketomalonate-derived imines and oximes. Overall, this novel approach represents an operationally simple, scalable, and environmentally friendly alternative to transition-metal-catalyzed C-N cross-coupling methods that are currently used to access structurally diverse secondary amines.

Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus): A range-wide synthesis.

Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size-fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size-fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change.

Design and Synthesis of Pyridone-Containing 3,4-Dihydroisoquinoline-1(2H)-ones as a Novel Class of Enhancer of Zeste Homolog 2 (EZH2) Inhibitors.

A new enhancer of zeste homolog 2 (EZH2) inhibitor series comprising a substituted phenyl ring joined to a dimethylpyridone moiety via an amide linkage has been designed. A preferential amide torsion that improved the binding properties of the compounds was identified for this series via computational analysis. Cyclization of the amide linker resulted in a six-membered lactam analogue, compound 18. This transformation significantly improved the ligand efficiency/potency of the cyclized compound relative to its acyclic analogue. Additional optimization of the lactam-containing EZH2 inhibitors focused on lipophilic efficiency (LipE) improvement, which provided compound 31. Compound 31 displayed improved LipE and on-target potency in both biochemical and cellular readouts relative to compound 18. Inhibitor 31 also displayed robust in vivo antitumor growth activity and dose-dependent de-repression of EZH2 target genes.

Polycomb repressive complex 2 structure with inhibitor reveals a mechanism of activation and drug resistance.

Polycomb repressive complex 2 (PRC2) mediates gene silencing through chromatin reorganization by methylation of histone H3 lysine 27 (H3K27). Overexpression of the complex and point mutations in the individual subunits of PRC2 have been shown to contribute to tumorigenesis. Several inhibitors of the PRC2 activity have shown efficacy in EZH2-mutated lymphomas and are currently in clinical development, although the molecular basis of inhibitor recognition remains unknown. Here we report the crystal structures of the inhibitor-bound wild-type and Y641N PRC2. The structures illuminate an important role played by a stretch of 17 residues in the N-terminal region of EZH2, we call the activation loop, in the stimulation of the enzyme activity, inhibitor recognition and the potential development of the mutation-mediated drug resistance. The work presented here provides new avenues for the design and development of next-generation PRC2 inhibitors through establishment of a structure-based drug design platform.

Discovery of 1-{(3R,4R)-3-[({5-Chloro-2-[(1-methyl-1H-pyrazol-4-yl)amino]-7H-pyrrolo[2,3-d]pyrimidin-4-yl}oxy)methyl]-4-methoxypyrrolidin-1-yl}prop-2-en-1-one (PF-06459988), a Potent, WT Sparing, Irreversible Inhibitor of T790M-Containing EGFR Mutants.

First generation EGFR TKIs (gefitinib, erlotinib) provide significant clinical benefit for NSCLC cancer patients with oncogenic EGFR mutations. Ultimately, these patients' disease progresses, often driven by a second-site mutation in the EGFR kinase domain (T790M). Another liability of the first generation drugs is severe adverse events driven by inhibition of WT EGFR. As such, our goal was to develop a highly potent irreversible inhibitor with the largest selectivity ratio between the drug-resistant double mutants (L858R/T790M, Del/T790M) and WT EGFR. A unique approach to develop covalent inhibitors, optimization of reversible binding affinity, served as a cornerstone of this effort. PF-06459988 was discovered as a novel, third generation irreversible inhibitor, which demonstrates (i) high potency and specificity to the T790M-containing double mutant EGFRs, (ii) minimal intrinsic chemical reactivity of the electrophilic warhead, (iii) greatly reduced proteome reactivity relative to earlier irreversible EGFR inhibitors, and (iv) minimal activity against WT EGFR.

Agar transfer devices for environmental sampling in the compounding pharmacy: science and compliance.

This article provides the results of a study evaluating the sampling efficiency of a flat paddle sampling device against a round surface sampling device in controlled studies. Each device is supplied with identical microbial-growth media, and laboratory studies document equivalent performance of the media in the devices. Both devices perform sampling by the same process (agar transfer of microorganisms from the facility surface to the agar surface), and the performance of the two devices was shown to be equivalent in laboratory studies. Either the commonly used flat paddle sampler or the round contact plate is suitable for surface monitoring in the compounding pharmacy.

Critical analysis of common canister programs: a review of cross-functional considerations and health system economics.

Respiratory inhalers constitute a large percentage of hospital pharmacy expenditures. Metered-dose inhaler (MDI) canisters usually contain enough medication to last 2 to 4 weeks, while the average hospital stay for acute hospitalizations of respiratory illnesses is only 4-5 days. Hospital pharmacies are often unable to operationalize relabeling of inhalers at discharge to meet regulatory requirements. This dilemma produces drug wastage. The common canister (CC) approach is a method some hospitals implemented in an effort to minimize the costs associated with this issue. The CC program uses a shared inhaler, an individual one-way valve holding chamber, and a cleaning protocol. This approach has been the subject of considerable controversy. Proponents of the CC approach reported considerable cost savings to their institutions. Opponents of the CC approach are not convinced the benefits outweigh even a minimal risk of cross-contamination since adherence to protocols for hand washing and disinfection of the MDI device cannot be guaranteed to be 100% (pathogens from contaminated devices can enter the respiratory tract through inhalation). Other cost containment strategies, such as unit dose nebulizers, may be useful to realize similar reductions in pharmacy drug costs while minimizing the risks of nosocomial infections and their associated medical costs. The CC strategy may be appropriate for some hospital pharmacies that face budget constraints, but a full evaluation of the risks, benefits, and potential costs should guide those who make hospital policy decisions.

Synthesis and biological evaluation of acyclic phosphonic acid nucleoside derivatives.

As part of a project to generate a library of nucleosides as potential antiviral agents, a small subset of novel acyclic phosphonic acid nucleosides was prepared. Practical synthetic routes are described for three targets, which were then tested against HIV, hepatitis C virus (HCV), and Dengue virus.