Potent and selective bivalent inhibitors of BET bromodomains.

Proteins of the bromodomain and extraterminal (BET) family, in particular bromodomain-containing protein 4 (BRD4), are of great interest as biological targets. BET proteins contain two separate bromodomains, and existing inhibitors bind to them monovalently. Here we describe the discovery and characterization of probe compound biBET, capable of engaging both bromodomains simultaneously in a bivalent, in cis binding mode. The evidence provided here was obtained in a variety of biophysical and cellular experiments. The bivalent binding results in very high cellular potency for BRD4 binding and pharmacological responses such as disruption of BRD4-mediator complex subunit 1 foci with an EC50 of 100 pM. These compounds will be of considerable utility as BET/BRD4 chemical probes. This work illustrates a novel concept in ligand design-simultaneous targeting of two separate domains with a drug-like small molecule-providing precedent for a potentially more effective paradigm for developing ligands for other multi-domain proteins.

Patient Characteristics by Type of Hypersexuality Referral: A Quantitative Chart Review of 115 Consecutive Male Cases.

Hypersexuality remains an increasingly common but poorly understood patient complaint. Despite diversity in clinical presentations of patients referred for hypersexuality, the literature has maintained treatment approaches that are assumed to apply to the entire phenomenon. This approach has proven ineffective, despite its application over several decades. The present study used quantitative methods to examine demographic, mental health, and sexological correlates of common clinical subtypes of hypersexuality referrals. Findings support the existence of subtypes, each with distinct clusters of features. Paraphilic hypersexuals reported greater numbers of sexual partners, more substance abuse, initiation to sexual activity at an earlier age, and novelty as a driving force behind their sexual behavior. Avoidant masturbators reported greater levels of anxiety, delayed ejaculation, and use of sex as an avoidance strategy. Chronic adulterers reported premature ejaculation and later onset of puberty. Designated patients were less likely to report substance abuse, employment, or finance problems. Although quantitative, this article nonetheless presents a descriptive study in which the underlying typology emerged from features most salient in routine sexological assessment. Future studies might apply purely empirical statistical techniques, such as cluster analyses, to ascertain to what extent similar typologies emerge when examined prospectively.

Prolonged Cancer Control With Adagrasib in Patients With Metastatic, KRASG12C-Mutated NSCLC After Sotorasib-Induced Hepatotoxicity: A Case Report.

Both sotorasib and adagrasib are approved for use in metastatic KRASG12C-mutated NSCLC after cancer progression on chemotherapy and immunotherapy. Hepatoxicity is a commonly encountered adverse effect of both agents, and little data exists about the safety of sequential use of these agents when hepatotoxicity is encountered. In this case report, we describe a patient who developed recurrent hepatotoxicity with sotorasib and was able to switch to adagrasib without hepatotoxicity and subsequently experienced a prolonged cancer response. We also describe a previously unreported adagrasib adverse effect of photoinduced skin hyperpigmentation.

Discovery of AZD3514, a small-molecule androgen receptor downregulator for treatment of advanced prostate cancer.

Removal of the basic piperazine nitrogen atom, introduction of a solubilising end group and partial reduction of the triazolopyridazine moiety in the previously-described lead androgen receptor downregulator 6-[4-(4-cyanobenzyl)piperazin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (1) addressed hERG and physical property issues, and led to clinical candidate 6-(4-{4-[2-(4-acetylpiperazin-1-yl)ethoxy]phenyl}piperidin-1-yl)-3-(trifluoromethyl)-7,8-dihydro[1,2,4]triazolo[4,3-b]pyridazine (12), designated AZD3514, that is being evaluated in a Phase I clinical trial in patients with castrate-resistant prostate cancer.

Predictors of Dropout From a 20-Week Dialectical Behavior Therapy Skills Group for Suicidal Behaviors and Borderline Personality Disorder.

Treatment dropout among individuals with borderline personality disorder (BPD) is associated with negative psychosocial outcomes. Identifying predictors of dropout among this population is critical to understanding how to improve treatment retention. The present study extends the current literature by examining both static and dynamic predictors of dropout. Chronically suicidal outpatients diagnosed with BPD (N = 42) were randomly assigned to a 20-week dialectical behavior therapy (DBT) skills training group. Static and dynamic predictors were assessed at baseline, 5, 10, 15, 20 weeks, and 3 months post-intervention. A post-hoc two-stage logistic regression analysis was conducted to predict dropout propensity. Receiving disability benefits at baseline and decreases in mindfulness were associated with significantly increased probability of dropout. Clinicians working with chronically self-harming outpatients diagnosed with BPD would benefit from prioritizing clinical interventions that enhance mindfulness in order to decrease dropout propensity.

Implication of ZNF217 in Accelerating Tumor Development and Therapeutically Targeting ZNF217-Induced PI3K-AKT Signaling for the Treatment of Metastatic Osteosarcoma.

We previously identified ZNF217 as an oncogenic driver of a subset of osteosarcomas using the Sleeping Beauty (SB) transposon system. Here, we followed up by investigating the genetic role of ZNF217 in osteosarcoma initiation and progression through the establishment of a novel genetically engineered mouse model, in vitro assays, orthotopic mouse studies, and paired these findings with preclinical studies using a small-molecule inhibitor. Throughout, we demonstrate that ZNF217 is coupled to numerous facets of osteosarcoma transformation, including proliferation, cell motility, and anchorage independent growth, and ultimately promoting osteosarcoma growth, progression, and metastasis in part through positive modulation of PI3K-AKT survival signaling. Pharmacologic blockade of AKT signaling with nucleoside analogue triciribine in ZNF217+ orthotopically injected osteosarcoma cell lines reduced tumor growth and metastasis. Our data demonstrate that triciribine treatment may be a relevant and efficacious therapeutic strategy for patients with osteosarcoma with ZNF217+ and p-AKT rich tumors. With the recent revitalization of triciribine for clinical studies in other solid cancers, our study provides a rationale for further evaluation preclinically with the purpose of clinical evaluation in patients with incurable, ZNF217+ osteosarcoma.

PLX3397 treatment inhibits constitutive CSF1R-induced oncogenic ERK signaling, reduces tumor growth, and metastatic burden in osteosarcoma.

Osteosarcoma (OSA) is a heterogeneous and aggressive solid tumor of the bone. We recently identified the colony stimulating factor 1 receptor (Csf1r) gene as a novel driver of osteosarcomagenesis in mice using the Sleeping Beauty (SB) transposon mutagenesis system. Here, we report that a CSF1R-CSF1 autocrine/paracrine signaling mechanism is constitutively activated in a subset of human OSA cases and is critical for promoting tumor growth and contributes to metastasis. We examined CSF1R and CSF1 expression in OSAs. We utilized gain-of-function and loss-of-function studies (GOF/LOF) to evaluate properties of cellular transformation, downstream signaling, and mechanisms of CSF1R-CSF1 action. Genetic perturbation of CSF1R in immortalized osteoblasts and human OSA cell lines significantly altered oncogenic properties, which were dependent on the CSF1R-CSF1 autocrine/paracrine signaling. These functional alterations were associated with changes in the known CSF1R downstream ERK effector pathway and mitotic cell cycle arrest. We evaluated the recently FDA-approved CSF1R inhibitor Pexidartinib (PLX3397) in OSA cell lines in vitro and in vivo in cell line and patient-derived xenografts. Pharmacological inhibition of CSF1R signaling recapitulated the in vitro genetic alterations. Moreover, in orthotopic OSA cell line and subcutaneous patient-derived xenograft (PDX)-injected mouse models, PLX3397 treatment significantly inhibited local OSA tumor growth and lessened metastatic burden. In summary, CSF1R is utilized by OSA cells to promote tumorigenesis and may represent a new molecular target for therapy.

Discovery of a Series of 3-Cinnoline Carboxamides as Orally Bioavailable, Highly Potent, and Selective ATM Inhibitors.

We report the discovery of a novel series of 3-cinnoline carboxamides as highly potent and selective ataxia telangiectasia mutated (ATM) kinase inhibitors. Optimization of this series focusing on potency and physicochemical properties (especially permeability) led to the identification of compound 21, a highly potent ATM inhibitor (ATM cell IC50 0.0028 µM) with excellent kinase selectivity and favorable physicochemical and pharmacokinetics properties. In vivo, 21 in combination with irinotecan showed tumor regression in the SW620 colorectal tumor xenograft model, superior inhibition to irinotecan alone. Compound 21 was selected for preclinical evaluation alongside AZD0156.

The Identification of Potent, Selective, and Orally Available Inhibitors of Ataxia Telangiectasia Mutated (ATM) Kinase: The Discovery of AZD0156 (8-{6-[3-(Dimethylamino)propoxy]pyridin-3-yl}-3-methyl-1-(tetrahydro-2 H-pyran-4-yl)-1,3-dihydro-2 H-imidazo[4,5- c]quinolin-2-one).

ATM inhibitors, such as 7, have demonstrated the antitumor potential of ATM inhibition when combined with DNA double-strand break-inducing agents in mouse xenograft models. However, the properties of 7 result in a relatively high predicted clinically efficacious dose. In an attempt to minimize attrition during clinical development, we sought to identify ATM inhibitors with a low predicted clinical dose (<50 mg) and focused on strategies to increase both ATM potency and predicted human pharmacokinetic half-life (predominantly through the increase of volume of distribution). These efforts resulted in the discovery of 64 (AZD0156), an exceptionally potent and selective inhibitor of ATM based on an imidazo[4,5- c]quinolin-2-one core. 64 has good preclinical phamacokinetics, a low predicted clinical dose, and a high maximum absorbable dose. 64 has been shown to potentiate the efficacy of the approved drugs irinotecan and olaparib in disease relevant mouse models and is currently undergoing clinical evaluation with these agents.

A Pilot Trial of a Sexual Health Counseling Intervention for HIV-Positive Gay and Bisexual Men Who Report Anal Sex without Condoms.

BACKGROUND: Even in the presence of promising biomedical treatment as prevention, HIV incidence among men who have sex with men has not always decreased. Counseling interventions, therefore, continue to play an important role in reducing HIV sexual transmission behaviors among gay and bisexual men and other men who have sex with men. The present study evaluated effects of a small-group counseling intervention on psychosocial outcomes and HIV sexual risk behavior. METHOD: HIV-positive (HIV+) peer counselors administered seven 2-hour counseling sessions to groups of 5 to 8 HIV+ gay and bisexual men. The intervention employed information provision, motivational interviewing, and behavioral skills building to reduce sexual transmission risk behaviors. RESULTS: There was a significant reduction in condomless anal sex (CAS) with HIV-negative and unknown HIV-status partners, from 50.0% at baseline to 28.9% of the sample at 3-month follow-up. Findings were robust even when controlling for whether the participant had an undetectable viral load at baseline. Significant reductions were also found in the two secondary psychosocial outcomes, loneliness and sexual compulsivity. CONCLUSIONS: The findings provide preliminary evidence that this intervention may offer an efficient way of concurrently reducing CAS and mental health problems, such as sexual compulsivity and loneliness, for HIV+ gay and bisexual men. TRIAL REGISTRATION: ClinicalTrials.gov NCT02546271.

Optimization of a Series of Bivalent Triazolopyridazine Based Bromodomain and Extraterminal Inhibitors: The Discovery of (3R)-4-[2-[4-[1-(3-Methoxy-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)-4-piperidyl]phenoxy]ethyl]-1,3-dimethyl-piperazin-2-one (AZD5153).

Here we report the discovery and optimization of a series of bivalent bromodomain and extraterminal inhibitors. Starting with the observation of BRD4 activity of compounds from a previous program, the compounds were optimized for BRD4 potency and physical properties. The optimized compound from this campaign exhibited excellent pharmacokinetic profile and exhibited high potency in vitro and in vivo effecting c-Myc downregulation and tumor growth inhibition in xenograft studies. This compound was selected as the development candidate, AZD5153. The series showed enhanced potency as a result of bivalent binding and a clear correlation between BRD4 activity and cellular potency.

AZD3514: a small molecule that modulates androgen receptor signaling and function in vitro and in vivo.

Continued androgen receptor (AR) expression and signaling is a key driver in castration-resistant prostate cancer (CRPC) after classical androgen ablation therapies have failed, and therefore remains a target for the treatment of progressive disease. Here, we describe the biological characterization of AZD3514, an orally bioavailable drug that inhibits androgen-dependent and -independent AR signaling. AZD3514 modulates AR signaling through two distinct mechanisms, an inhibition of ligand-driven nuclear translocation of AR and a downregulation of receptor levels, both of which were observed in vitro and in vivo. AZD3514 inhibited testosterone-driven seminal vesicle development in juvenile male rats and the growth of androgen-dependent Dunning R3327H prostate tumors in adult rats. Furthermore, this class of compound showed antitumor activity in the HID28 mouse model of CRPC in vivo. AZD3514 is currently in phase I clinical evaluation.