Isoform-selective Inhibitors Research Articles

Rationalizing Predictions of Isoform-Selective Phosphoinositide 3-Kinase Inhibitors Using MolAnchor Analysis.

Explaining the predictions of machine learning models is of critical importance for integrating predictive modeling in drug discovery projects. We have generated a test system for predicting isoform selectivity of phosphoinositide 3-kinase (PI3K) inhibitors and systematically analyzed correct predictions of selective inhibitors using a new methodology termed MolAnchor, which is based on the "anchors" concept from explainable artificial intelligence. The approach is designed to generate chemically intuitive explanations of compound predictions. For nearly all correctly predicted isoform-selective inhibitors, well-defined structural fragments determining the predictions were identified, and in most cases, an individual substructure was responsible for the prediction outcome. For inhibitors with different isoform selectivities, recurrent substructures determining the predictions were distinct. The comparison of newly identified anchor substructures with independent explanations based on calculated feature importance values supported the superior interpretability of MolAnchor explanations. Two highly recurrent substructures determining correct predictions were found to be directly implicated in isoform selectivity of PI3K inhibitors, thus indicating a causal relationship between decisive substructures and selectivity determinants.

Isoform-selective and non-selective rho-kinase inhibitors do not affect collagenase-induced intracerebral hemorrhage outcomes in mice: Influence of sex and circadian cycle.

Rho-associated protein kinase (ROCK) inhibitors are therapeutic candidates in ischemic stroke and subarachnoid hemorrhage. However, their efficacy in intracerebral hemorrhage (ICH) is unknown. Here, we tested the efficacy of fasudil (10 mg/kg), an isoform-nonselective ROCK inhibitor, and NRL-1049 (10 mg/kg), a novel inhibitor with 43-fold higher selectivity for ROCK2 isoform compared with ROCK1, in a collagenase-induced ICH model in mice. Both short (1-3 days) and prolonged (14 days) therapeutic paradigms were tested using robust sample sizes in both males and females and in active and inactive circadian stages. Outcome readouts included weight loss, mortality, hematoma volume, hemispheric swelling, brain water content, BBB permeability to large molecules, and sensorimotor and cognitive function. We found the treatments safe but not efficacious in improving the hematoma volume, BBB disruption, or neurological deficits in this collagenase-induced ICH model. Intriguingly, however, induction of ICH during the active circadian stage was associated with worse tissue and behavioral outcomes compared with the inactive stage.

Development and Discovery of a Selective Degrader of Casein Kinases 1 δ/ε.

Members of the casein kinase 1 (CK1) family have emerged as key regulators of cellular signaling and as potential drug targets. Functional annotation of the 7 human isoforms would benefit from isoform-selective inhibitors, allowing studies on the role of these enzymes in normal physiology and disease pathogenesis. However, due to significant sequence homology within the catalytic domain, isoform selectivity is difficult to achieve with conventional small molecules. Here, we used a PROTAC (Proteolysis TArgeting Chimeras) approach to develop a highly selective degrader AH078 (37) targeting CK1δ and CK1ε with excellent selectivity over the highly related CK1α isoform. The developed PROTAC, AH078 (37) selectively degraded CK1δ and CK1ε with a DC50 of 200 nM. Characterization of AH078 (37) revealed a VHL and Ubiquitin-dependent degradation mechanism. Thus, AH078 (37) represents a versatile chemical tool to study CK1δ and CK1ε function in cellular systems.

Protein arginine methyltransferase 7 modulators in disease therapy: Current progress and emerged opportunity.

Protein arginine methyltransferase 7 (PRMT7) is an essential epigenetic and post-translational regulator in eukaryotic organisms. Dysregulation of PRMT7 is intimately related to multiple types of human diseases, particularly cancer. In addition, PRMT7 exerts multiple effects on cellular processes such as growth, migration, invasion, apoptosis, and drug resistance in various cancers, making it as a promising target for anti-tumor therapeutics. In this review, we initially provide an overview of the structure and biological functions of PRMT7, along with its association with diseases. Subsequently, we summarized the PRMT inhibitors in clinical trials and the co-crystal structural of PRMT7 inhibitors. Moreover, we also focus on recent progress in the design and development of modulators targeting PRMT7, including isoform-selective and non-selective PRMT7 inhibitors, and the dual-target inhibitors based on PRMT7, from the perspectives of rational design, pharmacodynamics, pharmacokinetics, and the clinical status of these modulators. Finally, we also provided the challenges and prospective directions for PRMT7 targeting drug discovery in cancer therapy.

Identifying selective PDHK inhibitors using coupled tensor matrix completion and experimental validation

Drug discovery often involves targeting specific members within a family of similar proteins. For example, pyruvate dehydrogenase kinase (PDHK) exists as four isozymes, which exhibit varying expression patterns across multiple tissues. Different PDHK isozymes have been implicated in conditions such as cancer, heart failure, and diabetes, suggesting that targeting them with inhibitors may offer therapeutic benefits. However, simultaneous inhibition of all four PDHK isozymes has the potential to be counterproductive, or poorly tolerated, highlighting a need for isoform-selective PDHK inhibitors. Despite multiple prior reports of PDHK inhibitors, identifying isoform-specific inhibitors for each PDHK isozyme has proven elusive. In this work, we propose a comprehensive framework that combines a machine learning-based prediction method and biochemical testing to screen a library of novel and previously reported compounds, thereby identifying selective inhibitors for PDHK isozymes. Initially, a coupled tensor matrix completion (CTMC) approach is employed to predict compound-target interaction (CTI) and pinpoint target-specific inhibitors. Subsequently, biochemical testing is performed to validate the predicted CTIs. Utilizing this approach, we successfully identified five novel PDHK1-specific inhibitors, underscoring the reliability of this approach as a screening method in the early stages of drug discovery and hit identification.

Medicinal Chemistry Insights in Neuronal Nitric Oxide Synthase Inhibitors Containing Nitrogen Heterocyclic Compounds: A Mini Review.

Many scientific reports over the last two decades have focused on the discovery and development of novel nNOS inhibitors. The structural identity of isoforms, bioavailability, pharmacokinetic, and safety profile issues remain major obstacles in the discovery of more potent and selective nNOS inhibitors. This review aims to provide an in-depth overview of the molecular interaction patterns between nNOS active site and inhibitors containing structurally diverse nitrogen heterocyclic compounds and highlight the structural properties needed to develop selective nNOS inhibitors. Previously published data allowed the usage of the structure-driven approach in the designing of selective nNOS inhibitors, which relies on the specific structural features required to achieve isoform-selectivity towards nNOS. The incorporation of chiral pyrrolidine ring, two aminopyridine heads, or a specific amino tail group, along with the inhibitor's capacity to adopt the curled conformation in the nNOS environment significantly strengthens the molecular interaction between the inhibitor and nNOS residues by forming specific electrostatic interactions and non-bonded contacts that are vital for isoform selectivity. Additional structure-activity relationship investigations are necessary to elucidate more structural characteristics that will ultimately resolve the exact structural basis required for isoform-selective inhibition of nNOS.

Small-Molecule Modulators Targeting Coactivator-Associated Arginine Methyltransferase 1 (CARM1) as Therapeutic Agents for Cancer Treatment: Current Medicinal Chemistry Insights and Emerging Opportunities.

Overexpression of coactivator associated arginine methyltransferase 1 (CARM1) is associated with various diseases including cancer. Therefore, CARM1 has emerged as an attractive therapeutic target and a drug response biomarker for anticancer drug discovery. However, the development of conventional CARM1 inhibitors has been hampered by their limited clinical efficacy, acquired resistance, and inability to inhibit nonenzymatic functions of CARM1. To overcome these challenges, new strategies such as isoform-selective inhibitors, dual-acting inhibitors, targeted protein degradation technology (e.g., PROTACs), and even activators, are essential to enhance the anticancer activity of CARM1 modulators. In this perspective, we first summarize the structure and biofunctions of CARM1 and its association with cancer. Next, we focus on the recent advances in CARM1 modulators, including isoform-selective CARM1 inhibitors, dual-target inhibitors, PROTAC degraders, and activators, from the perspectives of rational design, pharmacodynamics, pharmacokinetics, and clinical status. Finally, we discuss the challenges and future directions for CARM1-based drug discovery.

Selective Covalent Inhibiting JNK3 by Small Molecules for Parkinson's Diseases.

c-Jun N-terminal kinases (JNKs) including JNK1/2/3 are key members of mitogen-activated protein kinase family. Wherein JNK3 is specifically expressed in brain and emerges as therapeutic target, especially for neurodegenerative diseases. However, developing JNK3 selective inhibitors as chemical probes to investigate its therapeutic potential in diseases remains challenging. Here, we adopted the covalent strategy for identifying JNK3-selective covalent inhibitor JC16I, with high inhibitory activity against JNK3. Despite targeting a conserved cysteine in the vicinity of ATP pocket in JNK family, JC16I exerted a greater than 160-fold selectivity for JNK3 over JNK1/2. Importantly, even at low concentration, JC16I showed enhanced and long-lasting inhibition against cellular JNK3. In addition, its alkyne-containing probe JC-P1 could label JNK3 in SH-SY5Y cell lysate and living cells, with good proteome-wide selectivity. JC16I selectively suppressed the abnormal activation of JNK3 signaling and sufficiently exhibited neuroprotective effect in Parkinson's diseases (PD) models. Overall, our findings highlight the potential of developing isoform-selective and cell-active JNK3 inhibitors by covalent drug design strategy targeting a conserved cysteine. This work not only provides a valuable chemical probe for JNK3-targeted investigations in vitro and in vivo but also opens new avenues for the treatment of PD.

Y-27632 targeting ROCK1&2 modulates cell growth, fibrosis and epithelial-mesenchymal transition in hyperplastic prostate by inhibiting β-catenin pathway

Benign prostatic hyperplasia (BPH) is a prevalent condition affecting the male urinary system, with its molecular mechanisms of pathogenesis remaining unclear. Y-27632, a non-isoform-selective Rho kinase inhibitor, has shown therapeutic potential in various diseases but its effects on static factors and fibrosis in BPH remain unexplored. This study investigated human prostate tissues, human prostate cell lines, and BPH rat model using immunofluorescence, flow cytometry, quantitative reverse transcription polymerase chain reaction, western blotting, and cell counting kit-8. ROCK1 and ROCK2 were significantly up-regulated in BPH tissues, correlating with clinical parameters. Y-27632 targeted the inhibition of ROCK1 & ROCK2 expression and inhibited cell proliferation, fibrosis, epithelial-mesenchymal transition (EMT), while induced cell apoptosis in a dose-dependent manner. Moreover, knockdown of either ROCK isoform inhibited fibrosis and EMT, induced apoptosis, while ROCK overexpression had the opposite effects. ROCK downregulation inhibited the β-catenin signaling pathway (such as C-MYC, Snail and Survivin) and decreased β-catenin protein stability, while inhibiting TGF-β/Smad2/3 signaling. At the in vivo level, Y-27632 reversed prostatic hyperplasia and fibrosis in BPH model rats to some extent. Our study sheds light on the therapeutic potential of Y-27632 in regulating prostate cell growth, fibrosis and EMT, and demonstrates for the first time the regulatory effect of ROCK isoforms on prostate cells, providing the basis for future research of ROCK isoform-selective inhibitors.

Hiding in plain sight: Optimizing topoisomerase IIα inhibitors into Hsp90β selective binders

Due to their impact on several oncogenic client proteins, the Hsp90 family of chaperones has been widely studied for the development of potential anticancer agents. Although several Hsp90 inhibitors have entered clinical trials, most were unsuccessful because they induced a heat shock response (HSR). This issue can be circumvented by using isoform-selective inhibitors, but the high similarity in the ATP-binding sites between the isoforms presents a challenge. Given that Hsp90 shares a conserved Bergerat fold with bacterial DNA gyrase B and human topoisomerase IIα, we repurposed our ATP-competitive inhibitors of these two proteins for Hsp90 inhibition. We virtually screened a library of in-house inhibitors and identified eleven hits for evaluation of Hsp90 binding. Among these, compound 11 displayed low micromolar affinity for Hsp90 and demonstrated a 12-fold selectivity for Hsp90β over its closest isoform, Hsp90α. Out of 29 prepared analogs, 16 showed a preference for Hsp90β over Hsp90α. Furthermore, eleven of these compounds inhibited the growth of several cancer cell lines in vitro. Notably, compound 24e reduced intracellular levels of Hsp90 client proteins in MCF-7 cells, leading to cell cycle arrest in the G0/G1 phase without inducing HSR. This inhibitor exhibited at least a 27-fold preference for Hsp90β and was selective against topoisomerase IIα, a panel of 22 representative protein kinases, and proved to be non-toxic in a zebrafish larvae toxicology model. Finally, molecular modeling, corroborated by STD NMR studies, and the binding of 24e to the S52A mutant of Hsp90α confirmed that the serine to alanine switch drives the selectivity between the two cytoplasmic isoforms.

Discovery of organosulfur-based selective HDAC8 inhibitors with anti-neuroblastoma activity

Histone deacetylases (HDACs) are important epigenetic regulators of gene expression and various cellular processes, and are potential targets for anticancer therapy. In particular, HDAC8 is a promising therapeutic target for childhood neuroblastoma. To date, five HDAC inhibitors have been approved as anticancer drugs; however, all are non-selective HDAC inhibitors with various side effects. Furthermore, many promising HDAC inhibitors incorporate hydroxamic acid as a zinc binding group (ZBG), which may be associated with toxicity. Therefore, identification of isoform-selective HDAC inhibitors with novel ZBG is crucial. Here, a series of sulfur-based selective HDAC8 inhibitors featuring a novel ZBG were identified by modifying the early hit, ajoene, a component of garlic. Structure-activity relationship studies uncovered potent and selective HDAC8 inhibitors, and docking studies provided a structural rationale for HDAC8 inhibitory activity. One of the potent compounds, (Z)-1-phenyl-7-(4-methoxyphenyl)-2,3,7-trithiahepta-4-ene-7-oxide (15c), exhibited antiproliferative activity, with a GI50 of 2 µM, against neuroblastoma cell lines. 15c also showed significant in vivo efficacy in a neuroblastoma BE(2)-C xenograft model.

A Phase Ib Study of Linperlisib in the Treatment of Patients with Relapsed and/or Refractory Peripheral T-cell Lymphoma.

Relapsed and/or refractory peripheral T-cell lymphoma (r/r PTCL) is an aggressive and heterogeneous hematologic malignancy with high unmet need. Previously, PI3K inhibitors were shown to be efficacious in B- and T-cell lymphomas, but as a drug class, these agents have frequently been observed to have tolerability limitations. Next-generation agents that improve the tolerability while maintaining efficacy are desirable. A phase Ib clinical study was conducted with the oral PI3K-delta isoform-selective small-molecule inhibitor, linperlisib, in patients with r/r PTCL, and the clinical benefit was explored by the evaluation of safety and efficacy. In this clinical study, 43 patients with r/r PTCL in China were treated with continuous dosing of 80-mg linperlisib once a day. Treatment-related adverse events (AE) were manageable. The most frequently reported grade 3 AE were neutropenia (21%), pneumonia (11.6%), and hypertriglyceridemia (7%). All other AE were either absent or reported in <5% of the patients. Linperlisib treatment for these patients with r/r PTCL, consisting of the major PTCL subtypes, was observed to have a 60.5% overall response rate with 35% complete responses and led to a median duration of response of 11.1 months, median progression-free survival of 11.8 months, and a median overall survival of >38 months (not reached). With the very promising clinical activity against r/r PTCL, the results of this study support the further investigation of linperlisib for the treatment of r/r PTCL.

Stack-HDAC3i: A high-precision identification of HDAC3 inhibitors by exploiting a stacked ensemble-learning framework

Epigenetics involves reversible modifications in gene expression without altering the genetic code itself. Among these modifications, histone deacetylases (HDACs) play a key role by removing acetyl groups from lysine residues on histones. Overexpression of HDACs is linked to the proliferation and survival of tumor cells. To combat this, HDAC inhibitors (HDACi) are commonly used in cancer treatments. However, pan-HDAC inhibition can lead to numerous side effects. Therefore, isoform-selective HDAC inhibitors, such as HDAC3i, could be advantageous for treating various medical conditions while minimizing off-target effects. To date, computational approaches that use only the SMILES notation without any experimental evidence have become increasingly popular and necessary for the initial discovery of novel potential therapeutic drugs. In this study, we develop an innovative and high-precision stacked-ensemble framework, called Stack-HDAC3i, which can directly identify HDAC3i using only the SMILES notation. Using an up-to-date benchmark dataset, we first employed both molecular descriptors and Mol2Vec embeddings to generate feature representations that cover multi-view information embedded in HDAC3i, such as structural and contextual information. Subsequently, these feature representations were used to train baseline models using nine popular ML algorithms. Finally, the probabilistic features derived from the selected baseline models were fused to construct the final stacked model. Both cross-validation and independent tests showed that Stack-HDAC3i is a high-accuracy prediction model with great generalization ability for identifying HDAC3i. Furthermore, in the independent test, Stack-HDAC3i achieved an accuracy of 0.926 and Matthew’s correlation coefficient of 0.850, which are 0.44–6.11% and 0.83–11.90% higher than its constituent baseline models, respectively.

Repurposing of known drugs from multiple libraries to identify novel and potential selective inhibitors of HDAC6 via in silico approach and molecular modeling

Histone deacetylase 6 (HDAC6, Class IIb) is a promising target for anticancer drugs. So far, few nonselective HDAC inhibitors have received regulatory approval as anticancer agents. However, they are associated with cell toxicity. Thus, isoform-selective inhibitors may be desirable. Here, we conducted structure-based virtual screening of multiple libraries containing a total of 2,250,135 compounds against HDAC6. The top hits with good docking scores and potential selectivity over HDAC10 (Class IIb) were submitted to 100 ns molecular dynamics simulation to monitor their dynamic behaviors and stability in the binding pockets of these enzymes. Furthermore, the drug-likeness and ADMET properties of these hits were estimated computationally. Four diverse compounds from different sources, including NCI and ZINC databases (BDH33926500, CID667061, Cromolyn, and ZINC000103531486), show potential selectivity for HDAC6.

The contribution of NaV1.6 to the efficacy of voltage-gated sodium channel inhibitors in wild type and NaV1.6 gain-of-function (GOF) mouse seizure control.

Inhibitors of voltage-gated sodium channels (NaVs) are important anti-epileptic drugs, but the contribution of specific channel isoforms is unknown since available inhibitors are non-selective. We aimed to create novel, isoform selective inhibitors of Nav channels as a means of informing the development of improved antiseizure drugs. We created a series of compounds with diverse selectivity profiles enabling block of NaV1.6 alone or together with NaV1.2. These novel NaV inhibitors were evaluated for their ability to inhibit electrically evoked seizures in mice with a heterozygous gain-of-function mutation (N1768D/+) in Scn8a (encoding NaV1.6) and in wild-type mice. Pharmacologic inhibition of NaV1.6 in Scn8aN1768D/+ mice prevented seizures evoked by a 6-Hz shock. Inhibitors were also effective in a direct current maximal electroshock seizure assay in wild-type mice. NaV1.6 inhibition correlated with efficacy in both models, even without inhibition of other CNS NaV isoforms. Our data suggest NaV1.6 inhibition is a driver of efficacy for NaV inhibitor anti-seizure medicines. Sparing the NaV1.1 channels of inhibitory interneurons did not compromise efficacy. Selective NaV1.6 inhibitors may provide targeted therapies for human Scn8a developmental and epileptic encephalopathies and improved treatments for idiopathic epilepsies.

First-in-human study of RLY-2608, a pan-mutant and isoform selective PI3Kα inhibitor, as a single agent in patients (pts) with advanced solid tumors and in combination with fulvestrant in pts with advanced breast cancer.

TPS1128 Background: Oncogenic mutations in PIK3CA occur in ~35% of HR+, HER2– breast cancer (BC) and are frequent in multiple solid tumors. The approval of alpelisib, a non-mutant selective PI3Kα inhibitor, validates PI3Kα as a therapeutic target. However, inhibition of wild-type PI3Kα leads to significant toxicity, including hyperglycemia and rash. RLY-2608, a novel, oral allosteric PI3Kα inhibitor, is designed to overcome these limitations via mutant- and isoform-selective PI3Kα inhibition for greater target coverage, improved tolerability, and anti-tumor activity. ReDiscover (NCT05216432) is the ongoing, first-in-human study to investigate the maximum tolerated dose (MTD), recommended phase 2 doses (RP2Ds), safety, pharmacokinetics (PK), pharmacodynamics (PD) and anti-tumor activity of RLY-2608 monotherapy in pts with PIK3CA-mutant advanced solid tumors; and of RLY-2608 plus fulvestrant with or without ribociclib in pts with PIK3CA-mutant, HR+, HER2– BC. To date RLY-2608 plus fulvestrant has completed dose escalation; 400 and 600 mg BID is being investigated in the combination regimens, based on safety, PK, PD, and anti-tumor activity. Methods: This global, multi-center, dose escalation/expansion study of RLY-2608 monotherapy includes adult pts with advanced solid tumors who are refractory or intolerant to, or have declined, standard therapy. RLY-2608 is also being investigated in combination with fulvestrant and in combination with fulvestrant and ribociclib, each in previously treated pts with HR+, HER2– advanced/metastatic BC. Eligibility criteria include presence of a PIK3CA mutation (blood or tumor) per local assessment, ECOG performance status 0–1, evaluable disease per RECIST 1.1, and no prior treatment with a PI3K pathway inhibitor. RLY-2608 is administered daily in 4-week cycles. Adverse events (AEs) per CTCAE v5, PK, biomarkers (pAKT, mutant ctDNA and insulin pathway markers) and anti-tumor activity are assessed serially. Dose escalation employs a Bayesian Optimal Interval design to identify the MTD. Following dose escalation, expansion cohorts are enrolling patients with select PIK3CA-mutated solid tumors for treatment with RLY-2608 monotherapy and patients with HR+, HER2– metastatic BC for treatment with RLY-2608 plus fulvestrant with or without ribociclib. Primary endpoints are MTD/RP2D and AE profile; key secondary endpoints are PIK3CA genotype in blood and tumor, PK, biomarkers, and overall response rate. All dose expansion cohorts in ReDiscover are now enrolling in the United States and Europe. Clinical trial information: NCT05216432 .

1,3-Diaryl Triazenes Incorporating Disulfonamides Show Both Antiproliferative Activity and Effective Inhibition of Tumor-associated Carbonic Anhydrases IX and XII.

The aim of this study was to synthesize a library of novel di-sulfa drugs containing 1,3- diaryltriazene derivatives TS (1-13) by conjugation of diazonium salts of primary sulfonamides with sulfa drugs to investigate the cytotoxic effect of these new compounds in different cancer types and to determine their inhibitory activity against tumor-associated carbonic anhydrases IX and XII. A carbonic anhydrase inhibitory activity of the obtained compounds was evaluated against four selected human carbonic anhydrase isoforms (hCA I, hCA II, hCA IX and hCA XII) by a stoppedflow CO2 hydrase assay. In addition, in vitro, cytotoxicity studies were applied by using A549 (lung cancer), BEAS-2B (normal lung), MCF-7 (breast cancer), MDA-MB-231 (breast cancer), CRL-4010 (normal breast epithelium), HT-29 (colon cancer), and HCT -116 (colon cancer) cell lines. As a result of the inhibition data, the 4-aminobenzenesulfonamide derivatives were more active than their 3-aminobenzenesulfonamide counterparts. More specifically, compounds TS-1 and TS-2, both of which have primary sulfonamides on both sides of the triazene linker, showed the best inhibitory activity against hCA IX with Ki values of 19.5 and 13.7 nM and also against hCA XII with Ki values of 6.6 and 8.3 nM, respectively. In addition, in vitro cytotoxic activity on the human breast cancer cell line MCF-7 showed that some derivatives of di-sulfa triazenes, such as TS-5 and TS-13, were more active than SLC-0111. With the aim of developing more potent and isoform-selective CA inhibitors, these novel hybrid molecules containing sulfa drugs, triazene linkers, and the classical primary sulfonamide chemotype may be considered an interesting example of effective enzyme inhibitors and important anticancer agents.

Efficacy and safety of chidamide in combination with serplulimab and standard third-line treatments in advanced colorectal cancer: A single arm, exploratory phase 2 trial.

TPS3637 Background: The efficacy of third line and subsequent treatments for advanced colorectal cancer (mCRC) is suboptimal, and the available drug options are limited. Approximately 95% of mCRC patients belong to the type of satellite stability (MSS), which often shows poor response to single immunotherapy. Previous clinical trials have preliminarily demonstrated that the potential application of combining anti-angiogenesis drugs with immune checkpoint inhibitors (ICIs) in mCRC. Chidamide is an isoform selective inhibitor of histone deacetylase (HDAC). Studies have shown its synergistic effect with PD-1 monoclonal antibody in anti-tumor activity. Therefore, we aim to conduct further investigations centered on the combination of Chidamide+Serplulimab+standard third-line treatments in mCRC. Methods: This prospective, open-label, single-arm, exploratory multi-center clinical trial has been planned to enroll 30 patients with advanced CRC who have progressed after two lines of standard therapies. The key inclusion criteria are: pathologically confirmed colorectal malignancy; age ≥18 years, regardless of gender; estimated survival ≥3 months; ECOG score 0-1; at least one measurable lesion according to iRECIST criteria; requiring third-line or beyond treatment and no prior treatment with PD1 monoclonal antibody, regorafenib/fruquintinib or TAS-102±bevacizumab; adequate major organ function; and signed informed consent and good compliance, agreeing to cooperate with survival follow-up. Enrolled patients receive Chidamide (20mg twice a week), Serplulimab (3mg/kg on day 1 every two weeks), and standard third-line treatments (TAS-102 35mg/m² twice daily on days 1-5 and 8-12 of a 28-day cycle ± bevacizumab 5mg/kg on day 1 every two weeks or regorafenib 120mg daily or fruquintinib 5mg daily for three weeks followed by one week off ).The primary endpoints are safety and objective response rate (ORR) determined by investigators. Secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate(DCR), PFS rate at 6 months and 12 months, OS rate at 6 months and 12 months, DCR, quality of life score(QoL), and nutritional score PG-SGA. As of February 2024, eight patients have been enrolled in the study. Trial registration number: ChiCTR2300077213. Clinical trial information: ChiCTR2300077213.

Isocoumarins incorporating chalcone moieties act as isoform selective tumor-associated carbonic anhydrase inhibitors.

Aim: A series of isocoumarin-chalcone hybrids were prepared and assays for the inhibition of four isoforms of human carbonic anhydrase (hCA; EC 4.2.1.1), hCA I, II, IX and XII. Materials & methods: Isocoumarin-chalcone hybrids were synthesized by condensing acetyl-isocoumarin with aromatic aldehydes. They did not significantly inhibit off-target cytosolic isoforms hCA I and II (KI>100μM) but acted as low micromolar or submicromolar inhibitors for the tumor-associated isoforms hCA IX and XII. Results & conclusion: Our work provides insights into a new and scarcely investigated chemotype which provides interesting tumor-associated CA inhibitors, considering that some such derivatives like sulfonamide SLC-0111 are in advanced clinical trials for the management of metastatic advanced solid tumors.

2-Aminopyridines as Potent and Selective Nav1.8 Inhibitors Exhibiting Efficacy in a Nonhuman Primate Pain Model.

Herein we describe the discovery of a 2-aminopyridine scaffold as a potent and isoform selective inhibitor of the Nav1.8 sodium channel. Parallel library synthesis, guided by in silico predictions, rapidly transformed initial hits into a novel 2-aminopyridine lead class possessing good ADME and pharmacokinetic profiles that were able to display activity in a clinically translatable nonhuman primate capsaicin-sensitized thermode pharmacodynamic assay. Progress toward the lead identification, optimization, and in vivo efficacy of these compounds will be discussed.