The pan-RAF-MEK non degrading molecular glue NST-628 is a potent and brain penetrant inhibitor of the RAS-MAPK pathway with activity across diverse RAS- and RAF-driven cancers.

Alterations in the RAS-MAPK signaling cascade are common across multiple solid tumor types and is a driver for many cancers. NST-628 is a potent pan-RAF-MEK molecular glue that prevents phosphorylation and activation of MEK by RAF, overcoming the limitations of traditional RAS-MAPK inhibitors and leading to deep durable inhibition of the pathway. Cellular, biochemical, and structural analysis of RAF-MEK complexes show that NST-628 engages all isoforms of RAFand prevents the formation of BRAF-CRAF heterodimers, a differentiated mechanism from all current RAF inhibitors. With a potent and durable inhibition of the RAF-MEK signaling complex as well as high intrinsic permeability into the brain, NST-628 demonstrates broad efficacy in cellular and patient-derived tumor models harboring diverse MAPK pathway alterations, including orthotopic intracranial models. Given its functional and pharmacokinetic mechanisms that are differentiated from previous therapies , NST-628 is positioned to make an impact clinically in an areas of unmet patient need.

Hyperlactatemia in patients undergoing pulmonary endarterectomy with deep hypothermic circulatory arrest: Risk factors and its effects on the outcome.

INTRODUCTION: To determine the risk factors of hyperlactatemia in pulmonary endarterectomy (PEA) surgery and assess whether elevated blood lactate levels are associated with adverse outcomes. METHODS: In this retrospective observational study, a total of 111 consecutive patients who underwent PEA for chronic thromboembolic pulmonary hypertension at the XXX Hospital between December 2016 and January 2022 were included. We retrospectively evaluated arterial blood samples analyzed intraoperatively. The pre- and intraoperative risk factors for hyperlactatemia and the postoperative outcomes were recorded. RESULTS: Lactate levels gradually increased during surgery. The optimal cut-off lactate level for major postoperative complications, calculated using receiver operating characteristic analysis, was 7.0 mmol/L. Deep hypothermic circulatory arrest (DHCA) duration, nadir hematocrit, and preoperative pulmonary vascular resistance were risk factors for lactate levels >7 mmol/L. Moreover, the intraoperative peak lactate level during PEA under DHCA was found to be a statistically significant predictor of major complications being associated with longer mechanical ventilation time (r = 0.294; p = .003) and intensive care unit length of stay (r = 0.327; p = .001). CONCLUSIONS: Deep hypothermic circulatory arrest duration, nadir hematocrit, and preoperative pulmonary vascular resistance were associated with hyperlactatemia. Increased lactate levels were independent predictors of longer mechanical ventilation time, intensive care unit length of stay, and major complications.

Discovery of MK-8768, a Potent and Selective mGluR2 Negative Allosteric Modulator.

Glutamate plays a key role in cognition and mood, and it has been shown that inhibiting ionotropic glutamate receptors disrupts cognition, while enhancing ionotropic receptor activity is pro-cognitive. One approach to elevating glutamatergic tone has been to antagonize presynaptic metabotropic glutamate receptor 2 (mGluR2). A desire for selectivity over the largely homologous mGluR3 motivated a strategy to achieve selectivity through the identification of mGluR2 negative allosteric modulators (NAMs). Extensive screening and optimization efforts led to the identification of a novel series of 4-arylquinoline-2-carboxamides. This series was optimized for mGluR2 NAM potency, clean off-target activity, and desirable physical properties, which resulted in the identification of improved C4 and C7 substituents. The initial lead compound from this series was Ames-positive in a single strain with metabolic activation, indicating that a reactive metabolite was likely responsible for the genetic toxicity. Metabolic profiling and Ames assessment across multiple analogs identified key structure-activity relationships associated with Ames positivity. Further optimization led to the Ames-negative mGluR2 negative allosteric modulator MK-8768.

[Risk factors of hyperlactatemia during pulmonary endarterectomy under deep hypothermic circulatory arrest and its influence on prognosis].

Objective: To investigate the incidence, risk factors, and outcomes of hyperlactatemia after pulmonary endarterectomy (PEA) under deep hypothermic circulatory arrest (DHCA). Methods: From December 2016 to January 2022, patients receiving PEA in China-Japan Friendship Hospital were enrolled in the study. Arterial blood samples were analyzed intraoperatively. Multivariate logistic regression analysis was performed to identify the predictors of intraoperative lactate elevation as well as major factors influencing the clinical outcome of the surgery. Results: A total of 110 patients (69 males and 41 females) were enrolled, aged (50.6±12.8) years. Receiver operating characteristic curve yielded an optimal cut-off lactate level of 7 mmol/L for predicting major postoperative complications (re-operation, re-intubation, postoperative renal failure requiring renal replacement therapy, wound infection, stroke, atrial fibrillation, and perioperative extracorporeal membrane oxygenation usage within 48 hours after surgery). Thirty-nine patients (35.5%) had an intraoperative peak arterial lactate level of≥7 mmol/L. According to intraoperative peak arterial lactate level, the patients were divided into two groups (<7 mmol/L and≥7 mmol/L). There were no statistically significant differences in age, sex and body mass index between the two groups (all P>0.05). Intraoperative peak lactate level was associated with prolonged mechanical ventilation time (r=0.262, P=0.008) and intensive care unit length of stay (r=0.304, P=0.002). Multivariate logistic regression analysis identified three key variables associated with lactate level≥7 mmol/L: DHCA duration (OR=1.186, 95%CI: 1.027-1.370, P=0.020), nadir hematocrit (HCT) (OR=0.580, 95%CI: 0.341-0.988, P=0.045) and preoperative pulmonary vascular resistance (PVR) (OR=1.096, 95%CI: 1.020-1.177, P=0.012). Patients with lactate≥7 mmol/L carried a higher rate of major complications (P=0.001). For patients with lactate≥7 mmol/L, 41.0% (16 out of 39 cases) had major complications, while for patients with lactate<7 mmol/L, only 14.1% (10 out of 71) had major complications. There was no statistically significant difference in mortality (8.5% vs 10.3%, P=0.753) between patients with different lactate levels. Moreover, intraoperative peak lactate level was a predictor of postoperative combined morbidity (OR=1.625, 95%CI: 1.176-2.245, P=0.003). Conclusion: High intraoperative lactate levels are associated with higher preoperative PVR, lower nadir HCT, and longer DHCA duration. Intraoperative lactate levels are independently associated with increased combined morbidity.

Oxetane Promise Delivered: Discovery of Long-Acting IDO1 Inhibitors Suitable for Q3W Oral or Parenteral Dosing.

3,3-Disubstituted oxetanes have been utilized as bioisosteres for gem-dimethyl and cyclobutane functionalities. We report the discovery of a novel class of oxetane indole-amine 2,3-dioxygenase (IDO1) inhibitors suitable for Q3W (once every 3 weeks) oral and parenteral dosing. A diamide class of IDO inhibitors was discovered through an automated ligand identification system (ALIS). Installation of an oxetane and fluorophenyl dramatically improved the potency. Identification of a biaryl moiety as an unconventional amide isostere addressed the metabolic liability of amide hydrolysis. Metabolism identification (Met-ID)-guided target design and the introduction of polarity resulted in the discovery of potent IDO inhibitors with excellent pharmacokinetic (PK) profiles in multiple species. To enable rapid synthesis of the key oxetane intermediate, a novel oxetane ring cyclization was also developed, as well as optimization of a literature route on kg scale. These IDO inhibitors may enable unambiguous proof-of-concept testing for the IDO1 inhibition mechanism for oncology.

WNT5B promotes vascular smooth muscle cell dedifferentiation via mitochondrial dynamics regulation in chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by proliferative vascular remodeling. Abnormal vascular smooth muscle cell (VSMC) phenotype switching is crucial to this process, highlighting the need for VSMC metabolic changes to cover cellular energy demand in CTEPH. We report that elevated Wnt family member 5B (WNT5B) expression is associated with vascular remodeling and promotes VSMC phenotype switching via mitochondrial dynamics regulation in CTEPH. Using primary culture of pulmonary artery smooth muscle cells, we show that high WNT5B expression activates VSMC proliferation and migration and results in mitochondrial fission via noncanonical Wnt signaling in CTEPH. Abnormal VSMC proliferation and migration were abolished by mitochondrial division inhibitor 1, an inhibitor of mitochondrial fission. Secreted frizzled-related protein 2, a soluble scavenger of Wnt signaling, attenuates VSMC proliferation and migration by accelerating mitochondrial fusion. These findings indicate that WNT5B is an essential regulator of mitochondrial dynamics, contributing to VSMC phenotype switching in CTEPH.

Utilization of Metabolite Identification and Structural Data to Guide Design of Low-Dose IDO1 Inhibitors.

Herein the discovery of potent IDO1 inhibitors with low predicted human dose is discussed. Metabolite identification (MetID) and structural data were used to strategically incorporate cyclopropane rings into this tetrahydronaphthyridine series of IDO1 inhibitors to improve their metabolic stability and potency. Enabling synthetic chemistry was developed to construct these unique fused cyclopropyl compounds, leading to inhibitors with improved pharmacokinetics and human whole blood potency and a predicted human oral dose as low as 9 mg once daily (QD).

Discovery of IDO1 inhibitors containing a decahydroquinoline, decahydro-1,6-naphthyridine, or octahydro-1H-pyrrolo[3,2-c]pyridine scaffold.

A series of IDO1 inhibitors containing a decahydroquinoline, decahydro-1,6-naphthyridine, or octahydro-1H-pyrrolo[3,2-c]pyridine scaffold were identified with good cellular and human whole blood activity against IDO1. These inhibitors contain multiple chiral centers and all diastereomers were separated. The absolute stereochemistry of each isomers were not determined. Compounds 15 and 27 stood out as leads due to their good cellular as well as human whole blood IDO1 inhibition activity, low unbound clearance, and reasonable mean residence time in rat cassette PK studies.

SAR towards indoline and 3-azaindoline classes of IDO1 inhibitors.

A novel series of IDO1 inhibitors have been identified with good IDO1 Hela cell and human whole blood activity. These inhibitors contain an indoline or a 3-azaindoline scaffold. Their structure-activity-relationship studies have been explored. Compounds 37 and 41 stood out as leads due to their good potency in IDO1 Hela assay, good IDO1 unbound hWB IC50s, reasonable unbound clearance, and good MRT in rat and dog PK studies.

Combination of EP4 antagonist MF-766 and anti-PD-1 promotes anti-tumor efficacy by modulating both lymphocytes and myeloid cells.

Prostaglandin E2 (PGE2), an arachidonic acid pathway metabolite produced by cyclooxygenase (COX)-1/2, has been shown to impair anti-tumor immunity through engagement with one or more E-type prostanoid receptors (EP1-4). Specific targeting of EP receptors, as opposed to COX-1/2 inhibition, has been proposed to achieve preferential antagonism of PGE2-mediated immune suppression. Here we describe the anti-tumor activity of MF-766, a potent and highly selective small-molecule inhibitor of the EP4 receptor. EP4 inhibition by MF-766 synergistically improved the efficacy of anti-programmed cell death protein 1 (PD-1) therapy in CT26 and EMT6 syngeneic tumor mouse models. Multiparameter flow cytometry analysis revealed that treatment with MF-766 promoted the infiltration of CD8+ T cells, natural killer (NK) cells and conventional dendritic cells (cDCs), induced M1-like macrophage reprogramming, and reduced granulocytic myeloid-derived suppressor cells (MDSC) in the tumor microenvironment (TME). In vitro experiments demonstrated that MF-766 restored PGE2-mediated inhibition of lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production in THP-1 cells and human blood, and PGE2-mediated inhibition of interleukin (IL)-2-induced interferon (IFN)-γ production in human NK cells. MF-766 reversed the inhibition of IFN-γ in CD8+ T-cells by PGE2 and impaired suppression of CD8+ T-cells induced by myeloid-derived suppressor cells (MDSC)/PGE2. In translational studies using primary human tumors, MF-766 enhanced anti-CD3-stimulated IFN-γ, IL-2, and TNF-α production in primary histoculture and synergized with pembrolizumab in a PGE2 high TME. Our studies demonstrate that the combination of EP4 blockade with anti-PD-1 therapy enhances antitumor activity by differentially modulating myeloid cell, NK cell, cDC and T-cell infiltration profiles.

Role of pyroptosis in atherosclerosis and its therapeutic implications.

Atherosclerosis is a significant cardiovascular burden and a leading cause of death worldwide, recognized as a chronic sterile inflammatory disease. Pyroptosis is a novel proinflammatory regulated cell death, characterized by cell swelling, plasma membrane bubbling, and robust release of proinflammatory cytokines (such as interleukin IL-1ß and IL-18). Mounting studies have addressed the crucial contribution of pyroptosis to atherosclerosis and clarified the candidate therapeutic agents targeting pyroptosis for atherosclerosis. Herein, we review the initial characterization of pyroptosis, the detailed mechanisms of pyroptosis, current evidence about pyroptosis and atherosclerosis, and potential therapeutic strategies that target pyroptosis in the development of atherosclerosis.

Carbamate and N-Pyrimidine Mitigate Amide Hydrolysis: Structure-Based Drug Design of Tetrahydroquinoline IDO1 Inhibitors.

Indoleamine-2,3-dioxygenase-1 (IDO1) has emerged as an attractive target for cancer immunotherapy. An automated ligand identification system screen afforded the tetrahydroquinoline class of novel IDO1 inhibitors. Potency and pharmacokinetic (PK) were key issues with this class of compounds. Structure-based drug design and strategic incorporation of polarity enabled the rapid improvement on potency, solubility, and oxidative metabolic stability. Metabolite identification studies revealed that amide hydrolysis in the D-pocket was the key clearance mechanism for this class. Strategic survey of amide isosteres revealed that carbamates and N-pyrimidines, which maintained exquisite potencies, mitigated the amide hydrolysis issue and led to an improved rat PK profile. The lead compound 28 is a potent IDO1 inhibitor, with clean off-target profiles and the potential for quaque die dosing in humans.

Surgical treatment of primary pulmonary artery sarcoma.

OBJECTIVE: Primary pulmonary artery sarcoma (PAS) is a rare tumor that originates from the intimal layer of the pulmonary artery or pulmonary valve and has a poor prognosis. The standard treatment for this devastating disease remains unclear. This study aimed to summarize the current standard treatments for PAS. METHODS: From September 2015 to January 2020, six patients were diagnosed with PAS and underwent pulmonary endarterectomy (PEA) at our department. Their medical records were retrospectively reviewed to analyze the clinical characteristics, histopathological features, and postoperative outcomes. Fourteen articles, each reporting at least 6 cases, identified 201 patients diagnosed with PAS, and 158 patients had detailed treatments and follow-up data. RESULTS: All of the patients who successfully underwent PEA were alive at follow-up, with a mean survival duration of 11.6 months (7-28 months), and one patient developed recurrence in the right upper lobe lung. Two patients received postoperative chemotherapy. In one patient, the tumor invaded the pulmonary valve. CONCLUSIONS: PAS resection combined with PEA via the aid of cardiopulmonary bypass and deep hypothermic circulatory arrest could achieve maximal tumor resection in patients without metastatic lesions. An individualized surgery strategy relies on a precise preoperative imaging examination. Moreover, postoperative adjuvant therapy could yield improved survival outcomes.

Selective Synthesis of 1-Dialkylamino-2-alkylbicyclo-[1.1.1]pentanes.

Compared to the abundance of methodologies accessing 1-substituted and 1,3-disubstuted bicyclo[1.1.1] pentanes (BCPs), the synthetic accessibility of BCPs with substitutions at the methylene position has been limited. Herein, we report a selective synthesis of 1-dialkylamino-2-alkylbicyclo[1.1.1]pentanes from prefunctionalized starting materials. We also achieved further functionalizations of these 1,2-disubstituted BCPs and developed a synthesis of these compounds with minimum necessity of chromatographic purifications starting from 1,3-dichloroacetone. Finally, we also detailed the synthesis of a 1,2,3-trisubstituted BCP analogue.

Discovery of Potent and Orally Available Bicyclo[1.1.1]pentane-Derived Indoleamine-2,3-dioxygenase 1 (IDO1) Inhibitors.

Indoleamine-2,3-dioxygenase 1 (IDO1) inhibition and its combination with immune checkpoint inhibitors like pembrolizumab have drawn considerable attention from both academia and the pharmaceutical industry. Here, we describe the discovery of a novel class of highly potent IDO1 heme-displacing inhibitors featuring a unique bicyclo[1.1.1]pentane motif. Compound 1, evolving from an ALIS (automated ligand identification system) hit, exhibited excellent potency but lacked the desired pharmacokinetic profile due to extensive amide hydrolysis of the benzamide moiety. Replacing the central phenyl ring in 1 with a bicyclo[1.1.1]pentane bioisostere effectively circumvented the amide hydrolysis issue, resulting in the discovery of compound 2 with a favorable overall profile such as excellent potency, selectivity, pharmacokinetics, and a low predicted human dose.

Strategic Incorporation of Polarity in Heme-Displacing Inhibitors of Indoleamine-2,3-dioxygenase-1 (IDO1).

Indoleamine-2,3-dioxygenase-1 (IDO1) has emerged as a target of significant interest to the field of cancer immunotherapy, as the upregulation of IDO1 in certain cancers has been linked to host immune evasion and poor prognosis for patients. In particular, IDO1 inhibition is of interest as a combination therapy with immune checkpoint inhibition. Through an Automated Ligand Identification System (ALIS) screen, a diamide class of compounds was identified as a promising lead for the inhibition of IDO1. While hit 1 possessed attractive cell-based potency, it suffered from a significant right-shift in a whole blood assay, poor solubility, and poor pharmacokinetic properties. Through a physicochemical property-based approach, including a focus on lowering AlogP98 via the strategic introduction of polar substitution, compound 13 was identified bearing a pyridyl oxetane core. Compound 13 demonstrated improved whole blood potency and solubility, and an improved pharmacokinetic profile resulting in a low predicted human dose.

Impact of pulmonary thromboendarterectomy on tricuspid regurgitation in patients with chronic thromboembolic pulmonary hypertension: a single-center prospective cohort experience.

BACKGROUND: For patients with chronic thromboembolic pulmonary hypertension (CTEPH) and tricuspid regurgitation (TR) undergoing pulmonary thromboendarterectomy (PTE), whether concomitant tricuspid annuloplasty should be carried out is still controversial. METHODS: The study population consisted of 45 consecutive patients with CTEPH who were scheduled to undergo PTE. All PTE surgeries were conducted with a median sternotomy and deep hypothermia circulatory arrest (DHCA). We collected and analyzed the demographics, surgical details, echocardiographic parameters, and right heart catheterization (RHC) results of these patients. RESULTS: Moderate to severe TR was documented in 48.9% (22/45) of the patients pre-operatively and 4.4% (2/45) of the patients post-operatively. In patients with grade 4 TR, severity decreased to grade 2 in 8 and to grade 1 in 1. In patients with grade 3 TR, severity decreased to grade 2 in 9, to grade 1 in 3, and 1 remained unchanged. In patients with grade 2 TR, severity decreased to grade 1 in 8, and 15 remained unchanged. The post-operative TR velocity was decreased significantly (431.9±53.4 vs. 196.5±154.0, P<0.001). Pulmonary artery systolic pressure was 84±17 mmHg pre-operatively and decreased to 38±14 mmHg post-operatively (P<0.001). The pre and post-operative pulmonary diastolic pressure was 29±9 and 17±7 mmHg, respectively (P<0.001). The pre and post-operative mean pulmonary pressure was 48±10 and 24±9 mmHg, respectively (P<0.001). The pulmonary vascular resistance (PVR) (1,025.4±465.0 vs. 476.6±181.2 dynes·sec·cm-5, P<0.001) and pulmonary artery wedge pressure (PAWP) (9±4 vs. 5±2 mmHg, P<0.001) decreased significantly after operation. The cardiac index (CI) increased significantly (1.9±0.5 vs. 2.3±0.4, P=0.003) after operation. CONCLUSIONS: In conclusion, functional TR could be alleviated after PTE even in patients with high PVR. However, the long-term results need to be further investigated.

Small Molecular Immune Modulators as Anticancer Agents.

After decades of intense effort, immune checkpoint inhibitors have been conclusively demonstrated to be effective in cancer treatments and thus are revolutionizing the concepts in the treatment of cancers. Immuno-oncology has arrived and will play a key role in cancer treatment in the foreseeable future. However, efforts to find novel methods to improve the immune response to cancer have not ceased. Small-molecule approaches offer inherent advantages over biologic immunotherapies since they can cross cell membranes, penetrate into tumor tissue and tumor microenvironment more easily, and are amenable to be finely controlled than biological agents, which may help reduce immune-related adverse events seen with biologic therapies and provide more flexibility for the combination use with other therapies and superior clinical benefit. On the one hand, small-molecule therapies can modulate the immune response to cancer by restoring the antitumor immunity, promoting more effective cytotoxic lymphocyte responses, and regulating tumor microenvironment, either directly or epigenetically. On the other hand, the combination of different mechanisms of small molecules with antibodies and other biologics demonstrated admirable synergistic effect in clinical settings for cancer treatment and may expand antibodies' usefulness for broader clinical applications. This chapter provides an overview of small-molecule immunotherapeutic approaches either as monotherapy or in combination for the treatment of cancer.

Discovery of Amino-cyclobutarene-derived Indoleamine-2,3-dioxygenase 1 (IDO1) Inhibitors for Cancer Immunotherapy.

Checkpoint inhibitors have demonstrated unprecedented efficacy and are evolving to become standard of care for certain types of cancers. However, low overall response rates often hamper the broad utility and potential of these breakthrough therapies. Combination therapy strategies are currently under intensive investigation in the clinic, including the combination of PD-1/PD-L1 agents with IDO1 inhibitors. Here, we report the discovery of a class of IDO1 heme-binding inhibitors featuring a unique amino-cyclobutarene motif, which was discovered through SBDD from a known and weakly active inhibitor. Subsequent optimization efforts focused on improving metabolic stability and were greatly accelerated by utilizing a robust SNAr reaction of a facile nitro-furazan intermediate to quickly explore different polar side chains. As a culmination of these efforts, compound 16 was identified and demonstrated a favorable overall profile with superior potency and selectivity. Extensive studies confirmed the chemical stability and drug-like properties of compound 16, rendering it a potential drug candidate.

A Selective Synthesis of 2,2-Difluorobicyclo[1.1.1]pentane Analogues: "BCP-F2".

The bicyclo[1.1.1]pentane (BCP) motif has been utilized as bioisosteres in drug candidates to replace phenyl, tert-butyl, and alkynyl fragments in order to improve physicochemical properties. However, bceause of the difficulty of synthesis, most BCP analogues prepared only bear 1,3-"para"-substituents. We report the first selective synthesis of 2,2-difluorobicyclo[1.1.1]pentanes via difluorocarbene insertion into bicyclo[1.1.0]butanes. Moreover, this methodology should inspire future studies on synthesis of other "ortho/meta-substituted" BCPs via similar mechanisms.