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Ligand-targeting drug delivery systems have made significant strides for disease treatments with numerous clinical approvals in this era of precision medicine. Herein, we report a class of small molecule-based immune checkpoint-targeting maytansinoid conjugates. From the ligand targeting ability, pharmacokinetics profiling

Chemotherapy-induced neurotoxicity is a common adverse effect of cancer treatment. No medication has been shown to be effective in the prevention or treatment of chemotherapy-induced neurotoxicity. Using minoxidil as an initial template for structural modifications in conjunction with an in vitro neurite outgrowth assay, an image-based high-content screening platform, and mouse behavior models, an effective neuroprotective agent CN016 was discovered. Our results showed that CN016 could inhibit paclitaxel-induced inflammatory responses and infiltration of immune cells into sensory neurons significantly. Thus, the suppression of proinflammatory factors elucidates, in part, the mechanism of action of CN016 on alleviating paclitaxel-induced peripheral neuropathy. Based on excellent efficacy in improving behavioral functions, high safety profiles (MTD500 mg/kg), and a large therapeutic window (MTD/MED50) in mice, CN016 might have great potential to become a peripherally neuroprotective agent to prevent neurotoxicity caused by chemotherapeutics as typified by paclitaxel.

Colony-stimulating factor-1 receptor (CSF1R) is implicated in tumor-associated macrophage (TAM) repolarization and has emerged as a promising target for cancer immunotherapy. Herein, we describe the discovery of orally active and selective CSF1R inhibitors by property-driven optimization of BPR1K871 (9), our clinical multitargeting kinase inhibitor. Molecular docking revealed an additional nonclassical hydrogen-bonding (NCHB) interaction between the unique 7-aminoquinazoline scaffold and the CSF1R hinge region, contributing to CSF1R potency enhancement. Structural studies of CSF1R and Aurora kinase B (AURB) demonstrated the differences in their back pockets, which inspired the use of a chain extension strategy to diminish the AURA/B activities. A lead compound BPR1R024 (12) exhibited potent CSF1R activity (IC50 = 0.53 nM) and specifically inhibited protumor M2-like macrophage survival with a minimal effect on antitumor M1-like macrophage growth. In vivo, oral administration of 12 mesylate delayed the MC38 murine colon tumor growth and reversed the immunosuppressive tumor microenvironment with the increased M1/M2 ratio.

The A-type Aurora kinase is upregulated in many human cancers, and it stabilizes MYC-family oncoproteins, which have long been considered an undruggable target. Here, we describe the design and synthesis of a series of pyrimidine-based derivatives able to inhibit Aurora A kinase activity and reduce levels of cMYC and MYCN. Through structure-based drug design of a small molecule that induces the DFG-out conformation of Aurora A kinase, lead compound 13 was identified, which potently (IC50 < 200 nM) inhibited the proliferation of high-MYC expressing small-cell lung cancer (SCLC) cell lines. Pharmacokinetic optimization of 13 by prodrug strategies resulted in orally bioavailable 25, which demonstrated an 8-fold higher oral AUC (F = 62.3%). Pharmacodynamic studies of 25 showed it to effectively reduce cMYC protein levels, leading to >80% tumor regression of NCI-H446 SCLC xenograft tumors in mice. These results support the potential of 25 for the treatment of MYC-amplified cancers including SCLC.

We report the design, synthesis and evaluation of a class of phosphatidylserine-targeting zinc (II) dipicolylamine drug conjugates and show that conjugate 16b elicits immune cell infiltration and remodels the "cold" hepatic tumor microenvironment to the inflamed "hot" tumor. Structure-property relationship study via linker modifications and subsequent pharmacokinetics profiling were carried out to improve the solubility and stability of the conjugates in vivo. In a spontaneous hepatocellular carcinoma mouse model, we showed that conjugate 16b exhibited better antitumor efficacy than sorafenib. In particular, significant increase of CD8

Upregulation of Aurora kinases has been associated with increased tumor progression, and thus they are appealing targets for the development of anti-cancer therapies. In addition to have a critical role in cell cycle regulation, Aurora kinases have been shown to stabilize MYC-family oncoproteins for the maintenance of malignancy. Aurora kinase inhibitors such as Alisertib has demonstrated compelling anti-tumor efficacies; however, the reported side effects including serious haematological disturbances have limited its risk-benefit ratio in clinical use. In this study we discovered a novel pyrimidine-based Aurora kinase inhibitor compound A that degraded MYC- and MYCN- oncoproteins with better potency than Alisertib. The acyl-based prodrug design leads to the discovery of compound B which was able to regress MYC- or MYCN- overexpressing tumor xenografts including small cell lung cancer, neuroblastoma, hepatocellular carcinoma and medulloblastoma using a once-a-week (QW) oral dosing regimen. Pharmacokinetic studies revealed that the tumor/plasma ratio of compound B was about 20 at 24 h post drug administration, and the active compound remained detectable in the tumors after 7 days. No significant haematological or liver/kidney biochemical aberration was observed in mice treated with up to 500 mg/kg of DBPR728 on a QW dosing regimen in a 21-day cycle. The unique pharmacokinetic and molecular properties of compound B hold potential clinical promise for treating MYC- and MYCN- amplified tumors with manageable on-target haematological adverse effects caused by Aurora kinase inhibition. Citation Format: Ya-Hui Chi, Chun-Ping Chang, Teng-Kuang Yeh, Wan-Ping Wang, Yen-Ting Chen, Chia-Hua Tsai, Yan-Fu Chen, Yi-Yu Ke, Jing-Ya Wang, Ching-Ping Chen, Tsung-Chih Hsieh, Mine-Hsine Wu, Chiung-Tong Chen. Targeting myc-amplified cancers with a novel prodrug inhibiting aurora A kinase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 523.

A major obstacle to nanodrugs-mediated cancer therapy is their rapid uptake by the reticuloendothelial system that decreases the systemic exposure of the nanodrugs to tumors and also increases toxicities. Intralipid has been shown to reduce nano-oxaliplatin-mediated toxicity while improving bioavailability. Here, we have found that Intralipid reduces the cytotoxicity of paclitaxel for human monocytic cells, but not for breast, lung, or pancreatic cancer cells. Intralipid also promotes the polarization of macrophages to the anti-cancer M1-like phenotype. Using a xenograft breast cancer mouse model, we have found that Intralipid pre-treatment significantly increases the amount of paclitaxel reaching the tumor and promotes tumor apoptosis. The combination of Intralipid with half the standard clinical dose of Abraxane reduces the tumor growth rate as effectively as the standard clinical dose. Our findings suggest that pre-treatment of Intralipid has the potential to be a powerful agent to enhance the tumor cytotoxic effects of Abraxane and to reduce its off-target toxicities.

Drug resistance due to acquired mutations that constitutively activate c-KIT is a significant challenge in the treatment of patients with gastrointestinal stromal tumors (GISTs). Herein, we identified 1-(5-ethyl-isoxazol-3-yl)-3-(4-{2-[6-(4-ethylpiperazin-1-yl)pyrimidin-4-ylamino]-thiazol-5-yl}phenyl)urea (10a) as a potent inhibitor against unactivated and activated c-KIT. The binding of 10a induced rearrangements of the DFG motif, αC-helix, juxtamembrane domain, and the activation loop to switch the activated c-KIT back to its structurally inactive state. To the best of our knowledge, it is the first structural evidence demonstrating how a compound can inhibit the activated c-KIT by switching back to its inactive state through a sequence of conformational changes. Moreover, 10a can effectively inhibit various c-KIT mutants and the proliferation of several GIST cell lines. The distinct binding features and superior inhibitory potency of 10a, together with its excellent efficacy in the xenograft model, establish 10a as worthy of further clinical evaluation in the advanced GISTs.

CXCR4 antagonists have been claimed to reduce mortality after myocardial infarction in myocardial infarction (MI) animals, presumably due to suppressing inflammatory responses caused by myocardial ischemia-reperfusion injury, thus, subsequently facilitating tissue repair and cardiac function recovery. This study aims to determine whether a newly designed CXCR4 antagonist DBPR807 could exert better vascular-protective effects than other clinical counterparts (e.g., AMD3100) to alleviate cardiac damage further exacerbated by reperfusion. Consequently, we find that instead of traditional continuous treatment or multiple-dose treatment at different intervals of time, a single-dose treatment of DBPR807 before reperfusion in MI animals could attenuate inflammation via protecting oxidative stress damage and preserve vascular/capillary density and integrity via mobilizing endothelial progenitor cells, leading to a desirable fibrosis reduction and recovery of cardiac function, as evaluated with the LVEF (left ventricular ejection fraction) in infarcted hearts in rats and mini-pigs, respectively. Thus, it is highly suggested that CXCR4 antagonists should be given at a single high dose prior to reperfusion to provide the maximal cardiac functional improvement. Based on its favorable efficacy and safety profiles indicated in tested animals, DBPR807 has a great potential to serve as an adjunctive medicine for percutaneous coronary intervention (PCI) therapies in acute MI patients.

Insulin resistance and obesity are pivotal features of type 2 diabetes mellitus. Peroxisome proliferator-activated receptor γ (PPARγ) is a master transcriptional regulator of systemic insulin sensitivity and energy balance. The anti-diabetic drug thiazolidinediones are potent synthetic PPARγ ligands and insulin sensitizers with undesirable side effects including increased adiposity, fluid retention, and osteoporosis, which limit their clinical use. We and others have proved that 15-keto-PGE2 is an endogenous natural PPARγ ligand. 15-keto-PGE2 is catalyzed by prostaglandin reductase 2 (PTGR2) to become inactive metabolites. We found that 15-keto-PGE2 level is increased in Ptgr2 knockout mice. Ptgr2 knockout mice were protected from diet-induced obesity, insulin resistance, and hepatic steatosis without fluid retention nor reduced bone mineral density. Diet-induced obese mice have drastically reduced 15-keto-PGE2 levels compared to lean mice. Administration of 15-keto-PGE2 markedly improved insulin sensitivity and prevented diet-induced obesity in mice. We demonstrated that 15-keto-PGE2 activates PPARγ through covalent binding to its cysteine 285 residue at helix 3, which restrained its binding pocket between helix 3 and β-sheets of the PPARγ ligand binding domain. This binding mode differs from the helix12-dependent binding mode of thiazolidinediones. We further identified a small-molecule PTGR2 inhibitor BPRPT245, which interferes the interaction between the substrate-binding sites of PTGR2 and 15-keto-PGE2. BPRPT245 increased 15-keto-PGE2 concentration, activated PPARγ, and promoted glucose uptake in adipocytes. BPRPT245 also prevented diet-induced obesity, improved insulin sensitivity and glucose tolerance, lowers fasting glucose without fluid retention and osteoporosis. In humans, reduced serum 15-keto-PGE2 levels were observed in patients with type 2 diabetes compared with controls. Furthermore, serum 15-keto-PGE2 levels correlate inversely with insulin resistance and fasting glucose in non-diabetic humans. In conclusion, we identified a new therapeutic approach to improve insulin sensitivity and protect diet-induced obesity through increasing endogenous natural PPARγ ligands without side effects of thiazolidinediones.

Significance A highly selective, safe, and potent CXCR4 antagonist, BPRCX807, has been designed and experimentally validated in various hepatocellular carcinoma models. Through combination therapy, it can synergize with either a kinase (e.g., sorafenib) or checkpoint inhibitor (e.g. anti–PD-1) to augment effectiveness of current anticancer treatments. With its unique mode of action, a new anticancer strategy for preventing cell migration and metastasis is provided., The CXC chemokine receptor type 4 (CXCR4) receptor and its ligand, CXCL12, are overexpressed in various cancers and mediate tumor progression and hypoxia-mediated resistance to cancer therapy. While CXCR4 antagonists have potential anticancer effects when combined with conventional anticancer drugs, their poor potency against CXCL12/CXCR4 downstream signaling pathways and systemic toxicity had precluded clinical application. Herein, BPRCX807, known as a safe, selective, and potent CXCR4 antagonist, has been designed and experimentally realized. In in vitro and in vivo hepatocellular carcinoma mouse models it can significantly suppress primary tumor growth, prevent distant metastasis/cell migration, reduce angiogenesis, and normalize the immunosuppressive tumor microenvironment by reducing tumor-associated macrophages (TAMs) infiltration, reprogramming TAMs toward an immunostimulatory phenotype and promoting cytotoxic T cell infiltration into tumor. Although BPRCX807 treatment alone prolongs overall survival as effectively as both marketed sorafenib and anti–PD-1, it could synergize with either of them in combination therapy to further extend life expectancy and suppress distant metastasis more significantly.

Niclosamide has been demonstrated with inhibitory activity on the replication of SARS-CoV in Vero E6 cells. This study examined the pharmacokinetics and oral bioavailability of niclosamide and its two analogs, BPR1H366 and BPRIH369, in male Sprague-Dawley rats. After a single 2-mg/kg intravenous dose, the total body clearance (CL) of niclosamide, BPR1H366 and BPR1H369 was 20.0±2.9, 26.7±4.4 and 39.4±6.7 mL/kg/min, and the volume of distribution at steady state (Vss) was 0.9±0.4, 0.3±0.1 and 1.1±0.2 L/kg, respectively. The half-life (t(subscript 1/2) of BPR1H366 and BPR1H369 was 2.6±0.3 and 3.7±1.1 hr, respectively, shorter than 6.7±2.0 hr of niclosamide. The AUC was 1413±118, 1019±203 and 750±113 ng/mL×hr for niclosamide, BPR1H366 and BPR1H369, respectively. After a single 5-mg/kg oral dose, all three compounds were rapidly absorbed. Niclosamide showed the highest C(subscript max) of 354±152 ng/mL within 30 min after oral gavage. The oral bioavailability of niclosamide, BPR1H366 and BPR1H369 was 10%, l2% and 15%, respectively. Our results demonstrated that the extents of drug exposure of the three compounds were comparable in rats. The pharmacokinetic properties of the compounds in humans are needed to be determined before their potential uses in SARS-CoV infected patients.

Background The ongoing COVID-19 pandemic has caused more than 193,825 deaths during the past few months. A quick-to-be-identified cure for the disease will be a therapeutic medicine that has prior use experiences in patients in order to resolve the current pandemic situation before it could become worsening. Artificial intelligence (AI) technology is hereby applied to identify the marketed drugs with potential for treating COVID-19. Methods An AI platform was established to identify potential old drugs with anti-coronavirus activities by using two different learning databases; one consisted of the compounds reported or proven active against SARS-CoV, SARS-CoV-2, human immunodeficiency virus, influenza virus, and the other one containing the known 3C-like protease inhibitors. All AI predicted drugs were then tested for activities against a feline coronavirus in in vitro cell-based assay. These assay results were feedbacks to the AI system for relearning and thus to generate a modified AI model to search for old drugs again. Results After a few runs of AI learning and prediction processes, the AI system identified 80 marketed drugs with potential. Among them, 8 drugs (bedaquiline, brequinar, celecoxib, clofazimine, conivaptan, gemcitabine, tolcapone, and vismodegib) showed in vitro activities against the proliferation of a feline infectious peritonitis (FIP) virus in Fcwf-4 cells. In addition, 5 other drugs (boceprevir, chloroquine, homoharringtonine, tilorone, and salinomycin) were also found active during the exercises of AI approaches. Conclusion Having taken advantages of AI, we identified old drugs with activities against FIP coronavirus. Further studies are underway to demonstrate their activities against SARS-CoV-2 in vitro and in vivo at clinically achievable concentrations and doses. With prior use experiences in patients, these old drugs if proven active against SARS-CoV-2 can readily be applied for fighting COVID-19 pandemic.

In an effort to develop new cancer therapeutics, we have reported clinical candidate BPR1K871 (1) as a potentanticancercompound in MOLM-13 and MV4-11 leukemia models, as well as in colorectal and pancreatic animal models. As BPR1K871 lacks oral bioavailability, we continued searching for orally bioavailable analogs through drug-like property optimization. We optimized both the physicochemical properties (PCP) as well as in vitro rat liver microsomal stability of 1, with concomitant monitoring of aurora kinase enzyme inhibition as well as cellular anti-proliferative activity in HCT-116 cell line. Structural modification at the 6- and 7-position of quinazoline core of 1 led to the identification of 34 as an orally bioavailable (F% = 54) multi-kinase inhibitor, which exhibits potent anti-proliferative activity against various cancer cell lines. Quinazoline 34 is selected as a promising oral lead candidate for further preclinical evaluation.

// Yung Chang Hsu 1, * , Mohane Selvaraj Coumar 2, * , Wen-Chieh Wang 1, * , Hui-Yi Shiao 1, * , Yi-Yu Ke 1 , Wen-Hsing Lin 1 , Ching-Chuan Kuo 1 , Chun-Wei Chang 1 , Fu-Ming Kuo 1 , Pei-Yi Chen 1 , Sing-Yi Wang 1 , An-Siou Li 1 , Chun-Hwa Chen 1 , Po-Chu Kuo 1 , Ching-Ping Chen 1 , Ming-Hsine Wu 1 , Chen-Lung Huang 1 , Kuei-Jung Yen 1 , Yun-I Chang 1 , John T.-A. Hsu 1 , Chiung-Tong Chen 1 , Teng-Kuang Yeh 1 , Jen-Shin Song 1 , Chuan Shih 1 , Hsing-Pang Hsieh 1,3 1 Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Taiwan, ROC 2 Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Kalapet, Puducherry, India 3 Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, ROC * These authors contributed equally to this work Correspondence to: Hsing-Pang Hsieh, email: hphsieh@nhri.org.tw Keywords: acute myeloid leukemia, aurora kinase, FLT3, quinazoline, multi-kinase inhibitor Received: July 25, 2016 Accepted: November 07, 2016 Published: November 15, 2016 ABSTRACT The design and synthesis of a quinazoline-based, multi-kinase inhibitor for the treatment of acute myeloid leukemia (AML) and other malignancies is reported. Based on the previously reported furanopyrimidine 3, quinazoline core containing lead 4 was synthesized and found to impart dual FLT3/AURKA inhibition (IC 50 = 127/5 nM), as well as improved physicochemical properties. A detailed structure-activity relationship study of the lead 4 allowed FLT3 and AURKA inhibition to be finely tuned, resulting in AURKA selective (5 and 7; 100-fold selective over FLT3), FLT3 selective (13; 30-fold selective over AURKA) and dual FLT3/AURKA selective (BPR1K871; IC 50 = 19/22 nM) agents. BPR1K871 showed potent anti-proliferative activities in MOLM-13 and MV4-11 AML cells (EC 50 ~ 5 nM). Moreover, kinase profiling and cell-line profiling revealed BPR1K871 to be a potential multi-kinase inhibitor. Functional studies using western blot and DNA content analysis in MV4-11 and HCT-116 cell lines revealed FLT3 and AURKA/B target modulation inside the cells. In vivo efficacy in AML xenograft models (MOLM-13 and MV4-11), as well as in solid tumor models (COLO205 and Mia-PaCa2), led to the selection of BPR1K871 as a preclinical development candidate for anti-cancer therapy. Further detailed studies could help to investigate the full potential of BPR1K871 as a multi-kinase inhibitor.

Objectives Enterovirus 71 (EV-A71) is an important pathogen that can cause severe neurological symptoms and even death. Our aim was to identify potent anti-EV-A71 compounds and study their underlying mechanisms and in vivo activity. Methods We identified a potent imidazolidinone derivative (abbreviated to PR66) as an inhibitor of EV-A71 infection from the screening of compounds and subsequent structure-based modification. Time-course treatments and resistant virus selection of PR66 were employed to study the mode of mechanism of PR66. In vivo activity of PR66 was tested in the ICR strain of new-born mice challenged with EV-A71/4643/MP4. Results PR66 could impede the uncoating process during viral infection via interaction with capsid protein VP1, as shown by a resistant virus selection assay. Using site-directed mutagenesis, we confirmed that a change from valine to phenylalanine in the 179th amino acid residue of the cDNA-derived resistant virus resulted in resistance to PR66. PR66 increased the virion stability of WT viruses, but not the PR66-resistant mutant, in a particle stability thermal release assay. We further showed that PR66 had excellent anti-EV-A71 activity in an in vivo mouse model of disease, with a dose-dependent increase in survival rate and in protection against virus-induced hind-limb paralysis following oral or intraperitoneal administration. This was associated with reductions of viral titres in brain and muscle tissues. Conclusions We demonstrated here for the first time that an imidazolidinone derivative (PR66) could protect against EV-A71-induced neurological symptoms in vivo by suppressing EV-A71 replication. This involved binding to and restricting viral uncoating.

Small cell lung cancer (SCLC) accounts for approximately 15% of all lung cancers, leading to ~30,000 deaths each year in the United States. SCLC patients often present with metastasis at time of diagnosis, excluding surgery as a treatment option. While patients show high response rate to standard chemotherapy such as cisplatin/etoposide, they soon develop drug resistance and disease progression. Therefore, new therapeutic strategies are urgently needed for SCLC. BPR6K609S0 is a novel Aurora kinase inhibitor which has been designed to inhibit the kinase activity of Aurora A, and induces proteasome-mediated degradation of MYC. The BPR6K609S0 active molecule provokes cell apoptosis and inhibits proliferation of several SCLC cell lines with IC50 < 100 nM. Oral administration of BPR6K609 induces >60 % tumor regression in a NCI-H446 xenograft mouse model. In addition, BPR6K609 further reduces tumor progression in NCI-H446 xenograft mice pre-treated with LY3295668, an Aurora A-selective inhibitor which is currently under clinical investigation. These results support the clinical potential of BRP6K609S0 for the treatment of SCLC. Citation Format: Ya-Hui Chi, Chun-Ping Chang, Yi-Yu Ke, Wen-Hsing Lin, Wan-Ping Wang, Chia-Hua Tsai, Yen-Ting Chen, Yu-Jie Su, Ming-Chun Hung, Zhong-Wei Wu, Mine-Hsine Wu, Teng-Kuang Yeh, Ching-Ping Chen, Jen-Shin Song, Chiung-Tong Chen, Chuan Shih. BPR6K609: An Aurora kinase inhibitor targeting small cell lung cancer with MYC amplification [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1937.

Sodium-dependent glucose co-transporter 2 (SGLT2) inhibition has been demonstrated to efficiently control hyperglycemia via an insulin secretion-independent pathway. The unique mode of action eliminates the risk of hypoglycemia and makes SGLT2 inhibitors an attractive option for the treatment of type 2 diabetes. In a continuation of our previous studies on SGLT2 inhibitors bearing different sugar moieties, sixteen new N-glucosyl indole derivatives were designed, synthesized, and evaluated for their inhibitory activity against hSGLT2. Of these sixteen, acethydrazide-containing N-glucosyl indole 9d was found to be the most potent SGLT2 inhibitor, and caused a significant elevation in urine glucose excretion in rats at 50 mg/kg, relative to the vehicle control.

Indoleamine 2,3-dioxygenase is a heme-containing enzyme implicated in the down regulation of the anti-tumor immune response, and considered a promising anti-cancer drug target. Several pharmaceutical companies, including Pfizer, Merck, and Bristol-Myers Squibb, are known to be in pursuit of IDO inhibitors, and Incyte recently reported good results in the phase II clinical trial of the IDO inhibitor Epacadostat. In previous work, we developed a series of IDO inhibitors based on a sulfonylhydrazide core structure, and explored how they could serve as potent IDO inhibitors with good drug profiles. Herein, we disclose the development of the 4-bromophenylhydrazinyl benzenesulfonylphenylurea 5k, a potent IDO inhibitor which demonstrated 25% tumor growth inhibition in a murine CT26 syngeneic model on day 18 with 100 mg/kg oral administration twice daily, and a 30% reduction in tumor weight. Pharmacodynamic testing of 5k found it to cause a 25% and 21% reduction in kyn/trp ratio at the plasma and tumor, respectively. In the CT26 tumor model, 5k was found to slightly increase the percentage of CD3+ T cells and lymphocyte responsiveness, indicating that 5k may have potential in modulating anti-tumor immunity. These data suggest 5k to be worthy of further investigation in the development of anti-tumor drugs.

Background Lung cancer has the highest rate of morbidity and mortality among various cancer types, being responsible for over 1.69 million deaths per year. Approximately 80–85% of the lung cancer patients diagnosed present non-small cell lung cancer (NSCLC), while 10–15% present small cell lung cancer (SCLC). Mutations in the epidermal growth factor receptor (EGFR) have been observed in ∼50% of patients, in particular, in East Asian NSCLC patients. The single-point mutation L858R (exon 21) and amino acids deletions in the tyrosine kinase (TK) domain (exon 19) constitute 90% of all EGFR-activating mutations. Methods We introduced an acrylamide group as a Michael acceptor, resulting in compound 2, which showed potent in vitroactivity in both wild and mutant EGFR kinases and potent anti-proliferative activity in HCC827 lung cancer cell line. In this work, we apply SBDD to guide the optimization of lead compound 2and perform a detailed structure-activity relationship (SAR) study to bring this drug candidate into the next development stage. Results We optimized the compound 2by scaffold hopping and by exploiting the potent inhibitory activity of various warhead groups. The results of the multi-objective optimization obtained the clinical candidate, compound 78 (DBPR112), which not only displayed a potent inhibitory activity against EGFR L858R/T790M double mutations, but also exhibited 10-fold potency better than 3rd generation inhibitor, osimertinib, against three EGFR and one HER2 exon 20 insertion mutations, since there are currently no EGFR-directed therapies approved specifically for the treatment of this mutation. Conclusions X-ray co-crystal study of EGFRWTKinase and compound 78 revealed the potential of future design for mutant-selective inhibitors. Finally, furanopyrimidine 78 was selected as a clinical candidate to conduct all preclinical experiments and is currently undergoing phase 1 clinical trial in Taiwan. Clinical trial identification NCT03246854. Legal entity responsible for the study The authors. Funding National Health Research Institutes, Taiwan. Disclosure All authors have declared no conflicts of interest.

Zinc(II)-dipicolylamine (Zn-DPA) have been described to specifically complex with phosphatidylserine (PS), which has a higher level at the external surface of cancer cells in tumorigenic condition. BPRDP056 is a Zn-DPA-SN38 conjugate designed to provide a PS-targeting drug delivery of cytotoxic payload SN-38 at the tumor microenvironment, thereby, decrease the dosage of SN38, while induce apoptosis in cancer cells. The in vivo therapeutic efficacy of BPRDP056 against the growths of human tumors has been shown significant in mice subcutaneously bearing a tumor type of pancreas, prostate, colon, liver, breast and glioblastoma, as well as in mice with an orthotopic pancreatic tumor. BPRDP056 shrunk tumors at a lower dosing intensity (~20%) of SN38 compared to CPT-11 in all models tested. Micro-Western assays showed that BPRDP056 exhibited apoptotic cell death signal levels similar to those of CPT-11 in the treated tumors in mice. Furthermore, pharmacokinetic and preliminary toxicology studies showed that BPRDP056 has a good stability in circulation with an acceptable therapeutic safety window in mice. BPRDP056 has been demonstrated with a tumor targeting ability and thus increases the cytotoxic payload SN38 concentration in situ for improved efficacy. Its therapeutic spectrum against malignant neoplasm will be expected to cover the PS-rich tumor microenvironment of all cancer types. BPRDP056 is a first-in-class Small Molecule Drug Conjugate for anti-cancer therapy. Citation Format: Chia-Yu Hsu, Yun-Yu Chen, Chen-Fu Lo, Tai-Yu Chiu, Ching-Ping Chen, Chen-Lung Huang, Chung-Yu Huang, Min-Hsien Wang, Yu-Sheng Chao, Joe C. Shih, Teng-Kuang Yeh, Lun K. Tsou, Chiung-Tong Chen. BPRDP056, a novel small molecule drug conjugate specifically targeting phosphatidylserine for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 227.

Small cell lung cancer (SCLC) is one the most aggressive tumors with poor survival rate. SCLC patients often present with metastasis at time of diagnosis, excluding surgery as a treatment option. While patients show high response rate to standard chemotherapy such as cisplatin/etoposide, they soon develop drug resistance and disease progression. Therefore, new therapeutic strategies are urgently needed for SCLC. Several characteristics of SCLC such as aggressiveness and drug resistance could attribute to the existence of a cancer stem cell (CSC) subpopulation in SCLC. The SCLC cell line NCI-H446 has been shown to present high degree of stemness and express stem cell markers including CD133, OCT4, MYC and Nestin. Here we develop a pyrimidine-based small molecule BPR6K471 which potently inhibits Aurora kinase activities in enzymatic- and cell- based assays. BPR6K471 efficiently (IC50 = 66 nM) inhibits proliferation of NCI-H446, and reduces the expression of stem-cell markers. In addition, intravenous injection of BPR6K471 inhibits >90 % progression of NCI-H446 in a mouse xenograft model. These results suggest that targeting Aurora kinases may be a potential therapeutic strategy to combat the CSC subpopulation in SCLC. Citation Format: Chun-Ping Chang, Yi-Yu Ke, Wen-Hsing Lin, Dai-Hui Jhuo, Wan-Ping Wang, Chia-Hua Tsai, Yen-Ting Chen, Yu-Jie Su, Ming-Chun Hung, Zhong-Wei Wu, Po-Chu Kuo, Teng-Kuang Yeh, Ching-Ping Chen, Jen-Shin Song, Chiun-Tong Chen, Chuan Shih, Ya-Hui Chi. An Aurora kinase inhibitor BPR6K471 inhibits tumor growth and reduces the cancer stem cell-like properties of small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3851.

The authors investigated the pharmacology and signaling pathways of the opioid receptors modulated by compound 1, 1-(2,4-dibromophenyl)-3,6,6-trimethyl-1,5,6,7-tetrahydro-4H-indazol-4-one.In vitro studies of compound 1 were assessed by using a radioligand-binding assay (n = 3), a cyclic adenosine monophosphate assay (n = 3), a β-arrestin assay (n = 3), an internalization assay (n = 3), and an immunohistochemistry (n = 8). In vivo studies of compound 1 were characterized using a tail-flick test (n = 5 to 6), tail-clip test (n = 7), von Frey hair test (n = 5), and charcoal meal test (n = 5).Compound 1 elicited robust effects in μ-opioid (mean ± SD; binding affinity: 15 ± 2 nM; cyclic adenosine monophosphate assay: 24 ± 6 nM), δ-opioid (82 ± 7 nM; 1.9 ± 0.1 μM), and κ-opioid (76 ± 9 nM; 1.4 ± 0.5 μM) receptor-expressing cells. Compound 1 acts as a full agonist of β-arrestin-2 recruitment in μ-opioid (1.1 ± 0.3 μM) and δ-opioid (9.7 ± 1.9 μM) receptor-expressing cells. Compound 1 caused less gastrointestinal dysfunction (charcoal meal test: morphine: 82 ± 5%; compound 1: 42 ± 5%) as well as better antinociception in mechanical pain hypersensitivity (tail-clip test: morphine: 10 ± 3 s; compound 1: 19 ± 1 s) and in cancer-induced pain (von Frey hair test: morphine: 0.1 ± 0.1 g; compound 1: 0.3 ± 0.1 g) than morphine at equi-antinociceptive doses.Compound 1 produced antinociception with less gastrointestinal dysfunction than morphine.

Series of N-substituted carbazole analogues bearing an indole ring were synthesized as anti-methicillin-resistant Staphylococcus aureus (MRSA) agents from a molecular hybridization approach. The representative compound 19 showed an MIC = 1 μg/mL against a panel of MRSA clinical isolates as it possessed comparable in vitro activities to that of vancomycin. Moreover, compound 19 also exhibited MIC = 1 μg/mL activities against a recent identified Z172 MRSA strain (vancomycin-intermediate and daptomycin-nonsusceptible phenotype) and the vancomycin-resistant Enterococcus faecalis (VRE) strain. In a mouse model with lethal infection of MRSA (4N216), a 75% survival rate was observed after a single dose of compound 19 was intravenously administered at 20 mg/kg. In light of their equipotent activities against different MRSA isolates and VRE strain, the data underscore the importance of designed hybrid series for the development of new N-substituted carbazoles as potential anti-MRSA agents.

A series of 1-arylsulfonyl-5-(N-hydroxyacrylamide)indoles has been identified as a new class of histone deacetylase inhibitors. Compounds 8, 11, 12, 13, and 14 demonstrated stronger antiproliferative activities than 1 (SAHA) with GI(50) values ranging from 0.36 to 1.21 μM against Hep3B, MDA-MB-231, PC-3, and A549 human cancer cell lines. Lead compound 8 showed remarkable HDAC 1, 2, and 6 isoenzymes inhibitory activities with IC(50) values of 12.3, 4.0, 1.0 nM, respectively, which are comparable to 1. In in vivo efficacy evaluation against lung A549 xenograft model, 8 displayed better antitumor activity than compound 1.

Hepatitis C virus (HCV) is a global health problem, affecting approximately 3% of the world's population. The standard treatment for HCV infection is often poorly tolerated and ineffective. Therefore, the development of novel or more effective treatment strategies to treat chronic HCV infection is urgently needed. In this report, BP008, a potent small-molecule inhibitor of HCV replication, was developed from a class of compounds with thiazol core structures by means of utilizing a cell-based HCV replicon system. The compound reduced the reporter expression of the HCV1b replicon with a 50% effective concentration (EC 50 ) and selective index value of 4.1 ± 0.7 nM and >12,195, respectively. Sequencing analyses of several individual clones derived from BP008-resistant RNAs purified from cells harboring HCV1b replicon revealed that amino acid substitutions mainly within the N-terminal region (domain I) of NS5A were associated with decreased inhibitor susceptibility. Q24L, P58S, and Y93H are the key substitutions for resistance selection; F149L and V153M play the compensatory role in the replication and drug resistance processes. Moreover, BP008 displayed synergistic effects with alpha interferon (IFN-α), NS3 protease inhibitor, and NS5B polymerase inhibitor, as well as good oral bioavailability in SD rats and favorable exposure in rat liver. In summary, our results pointed to an effective small-molecule inhibitor, BP008, that potentially targets HCV NS5A. BP008 can be considered a part of a more effective therapeutic strategy for HCV in the future.

BPR0C261 is a synthetic small molecule compound cytotoxic against human cancer cells and active prolonging the lifespan of leukemia mice. In the present study, we further investigated the mechanisms of its anticancer action and found that BPR0C261 inhibited microtubule polymerization through interacting with the colchicine binding sites on tubulins, disrupted microtubule arrangement and caused cell cycle arrest at G(2)/M phase in cancer cells. BPR0C261 also inhibited the clonogenic growths of cancer cells and showed cytotoxicity against human cervical cancer cells of multidrug-resistant phenotype. In addition, BPR0C261 concentration-dependently inhibited the proliferation and migration of HUVECs and disrupted the endothelial capillary-like tube formations in HUVEC and rat aorta ring cultures. Given orally, BPR0C261 inhibited angiogenesis in s.c. implanted Matrigel plugs in mice. Notably, its IC(50) values against the endothelial cell growths were approximately 10-fold lower than those against the cancer cells. It was found orally absorbable in mice and showed a good oral bioavailability (43%) in dogs. BPR0C261 permeated through the human intestinal Caco-2 cell monolayer, suggesting oral availability in humans. Orally absorbed BPR0C261 distributed readily into the s.c. xenografted tumors in nude mice in which the tumor tissue levels of BPR0C261 were found oral dose-dependent. BPR0C261 showed in vivo activities against human colorectal, gastric, and nasopharyngeal tumors in nude mice. Most interestingly, the combination of BPR0C261 plus cisplatin synergistically prolonged the lifespans of mice inoculated with murine leukemia cells. Thus, BPR0C261 is a novel orally active tubulin-binding antitumor agent with antimitotic, apoptosis-inducing, and vasculature disrupting activities.

Indoleamine 2,3-dioxygenase has been considered as a promising anti-cancer drug target. Several pharmaceutical companies, including Pfizer, Merck, and Bristol-Myers Squibb, are known to be in pursuit of IDO inhibitors, and Incyte recently reported good results in the phase II clinical trial of the IDO inhibitor Epacadostat. In previous work, we developed a series of IDO inhibitors based on a high-throughput screening core structure, sulfonylhydrazide. Further, we developed the 4-bromophenylhydrazinyl benzenesulfonylphenylurea, as a potent IDO inhibitor with an IC50 value within 100 nM in inhibiting IDO in vitro. This compound demonstrated a 30% reduction in tumor weight in a murine CT26 syngeneic model on day 18 with 100 mg/kg oral administration twice daily, indicating that the 4-bromophenylhydrazinyl benzenesulfonylphenylurea may have potential for further investigation in the development of anti-tumor drugs. Citation Format: Shau-Hua Ueng, Ching-Chuan Kuo, Shu-Yu Lin, Teng-Kuang Yeh, Jen-Shin Song, Ming-Shiu Hung, Chiung-Tong Chen. 4-Bromophenylhydrazinyl benzenesulfonylphenylureas inhibit indoleamine 2,3-dioxygenase in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1664.

To investigate whether diabetes-induced alterations of CYP2E1 and oxidative stress can be modulated by dietary taurine supplementation, male Wistar rats were divided into non-diabetic, diabetic, and diabetic taurine-supplemented groups (administered at 2% in the drinking water). Increased levels of CYP2E1-catalyzed p-nitrophenol hydroxylation were found in liver and kidney microsomes of rats with STZ-induced diabetes compared to those of non-diabetic control rats. Immunoblot and RT-PCR analyses of CYP2E1 protein and mRNA levels in the liver and kidneys showed the same trend as with enzyme activities. Taurine supplementation significantly decreased the enzyme activity and expression (protein and mRNA) of CYP2E1 in diabetic rat kidneys. Plasma beta-hydroxybutyrate concentration was significantly reduced in taurine-treated diabetic rats. The induction of heme oxygenase-1 mRNA was suppressed by taurine treatment in diabetic rat kidneys. An increase in reduced glutathione (GSH) and a higher ratio of reduced to oxidized glutathione (GSH/GSSG) together with lower values of thiobarbituric acid-reactive substances (TBARS) were observed in the kidneys of taurine-treated diabetic rats. However, taurine supplementation caused only a slight or insignificant effect on these alternations in the liver of diabetic rats. Our results show dietary taurine may reduce CYP2E1 expression and activity, and oxidative stress in kidneys of diabetic rats.

Tannic acid has been shown to decrease mutagenicity and/or carcinogenicity of several amine derivatives and polycyclic aromatic hydrocarbons in rodents. The purpose of this study was to evaluate the effect of tannic acid on cytochrome P450 (CYP)-catalyzed oxidations using rat liver microsomes (RLM) and human liver microsomes (HLM) as the enzyme sources. In RLM, tannic acid showed a non-selective inhibitory effect on 7-methoxyresorufin O-demethylation (MROD), 7-ethoxyresorufin O-deethylation (EROD), tolbutamide hydroxylation, p-nitrophenol hydroxylation and testosterone 6beta-hydroxylation activities with IC(50) values ranged from 14.9 to 27.4 microM. In HLM, tannic acid inhibited EROD, MROD and phenacetin O-deethylation activities with IC(50) values ranged from 5.1 to 7.5 microM, and diclofenac 4-hydroxylation, dextromethorphan O-demethylation, chlorzoxazone 6-hydroxylation and testosterone 6beta-hydroxylation with IC(50) values ranged from 20 to 77 microM. In baculovirus-insect cell-expressed human CYP 1A1 and 1A2, the IC(50) values of tannic acid for CYP 1A1- and 1A2-catalyzed EROD activities were 23.1 and 2.3 microM, respectively, indicating that tannic acid preferably inhibited the activity of CYP1A2. Tannic acid inhibited human CYP1A2 non-competitively with a Ki value of 4.8 microM. Tannic acid was also found to inhibit NADPH-CYP reductase in RLM and HLM with IC(50) values of 11.8 and 17.4 microM, respectively. These results suggested that the inhibition of CYP enzyme activities by tannic acid may be partially attributed to its inhibition of NADPH-CYP reductase activity.

A method for the quantification of salidroside, a major biologically active compound in Rhodiola, in rat plasma by on-line SPE LC/MS/MS in negative electrospray mode was developed and validated. A column-switching instrument and two HPLC pumping systems were employed, and salicin was used as the internal standard. A Waters Oasis HLB extraction column and an Agilent TC-C(18) analytical column in a column-switching set-up with gradient elution were utilized. The MS/MS ion transitions monitored were m/z 299.0/119.0 and 285.1/122.9 for salidroside and salicin, respectively. The standard curves were linear within a range of 50-5000 ng/mL using weighted linear regression analysis (1/x). The intra- and inter-day coefficients of variance ranged from 1% to 9%. The recovery was above 90%. The freeze/thaw and long-term stability were validated. This method was subsequently applied to a pharmacokinetic study of salidroside in rats.

The rationale for intraperitoneal (IP) chemotherapy is to expose peritoneal tumors to high drug concentrations. While multiple phase III trials have established the significant survival advantage by adding IP therapy to intravenous therapy in optimally debulked ovarian cancer patients, the use of IP chemotherapy is limited by the complications associated with indwelling catheters and by the local chemotherapy-related toxicity. The present study evaluated the effects of drug carrier on the disposition and efficacy of IP paclitaxel, for identifying strategies for further development of IP treatment.Three paclitaxel formulations, i.e., Cremophor micelles, Cremophor-free paclitaxel-loaded gelatin nanoparticles and polymeric microparticles, were evaluated for peritoneal targeting advantage and antitumor activity in mice after IP injection. Whole body autoradiography and scanning electron microscopy were used to visualize the spatial drug distribution in tissues. A kinetic model, depicting the multiple processes involved in the peritoneal-to-plasma transfer of paclitaxel and its carriers, was established to determine the mechanisms by which a drug carrier alters the peritoneal targeting advantage.Autoradiographic results indicated that IP injection yielded much higher paclitaxel concentrations in intestinal tissues relative to intravenous injection. Compared to the Cremophor and nanoparticle formulations, the microparticles showed slower drug clearance from the peritoneal cavity, slower absorption into the systemic circulation, longer residence time, 10- to 45-times greater peritoneal targeting advantage and approximately 2-times longer increase in survival time (p0.01 for all parameters).Our results indicate the important roles of drug carrier in determining the peritoneal targeting advantage and antitumor activity of IP treatment.

Purpose: The present report describes the development of paclitaxel-loaded gelatin nanoparticles for use in intravesical therapy of superficial bladder cancer. The commercial formulation of paclitaxel contains Cremophor, which forms micelles and thereby entraps the drug and reduces its partition across the urothelium. Experimental Design: Paclitaxel-loaded gelatin nanoparticles were prepared using the desolvation method, and their physicochemical and biological properties were characterized. Results: The size of the particles ranged from 600 to 1,000 nm and increased with the molecular weight of the gelatin polymer. Under optimal conditions, the yield was >80%, and the drug loading was 0.7%. Wide-angle X-ray diffraction analysis showed that the entrapped paclitaxel was present in an amorphous state, which has higher water solubility compared with the crystalline state. Identical, rapid drug release from nanoparticles was observed in PBS and urine, with ∼90% released at 37°C after 2 hours. Treatment with a protease (i.e., Pronase) rapidly degraded the nanoparticles, with half-lives of 23.8 minutes, 0.6 minute, and 0.4 minute in the presence of 0.01, 0.05, and 0.25 mg/mL Pronase, respectively. The paclitaxel-loaded nanoparticles were active against human RT4 bladder transitional cancer cells; the IC50 paclitaxel-equivalent concentrations were nearly identical to those of aqueous solutions of paclitaxel, i.e., ∼30 nmol/L (equivalent to ∼25 ng/mL) for 2-hour treatments and ∼4 nmol/L for 96-hour treatments. In dogs given an intravesical dose of paclitaxel-loaded particles, the drug concentrations in the urothelium and lamina propria tissue layers, where Ta and T1 tumors would be located, were 7.4 ± 4.3 μg/g (mean ± SD; 3 dogs; 9 tissue sections), which were 2.6× the concentrations we reported for dogs treated with the Cremophor formulation. Conclusions: Paclitaxel-loaded gelatin nanoparticles represent a rapid release, biologically active paclitaxel formulation that can be used for intravesical bladder cancer therapy.

Hepatitis C virus (HCV), a member of the Flaviviridae family, affects approximately 3% of the world's population and is becoming the leading cause of liver disease in the world. Therefore, the development of novel or more effective treatment strategies to treat chronic HCV infection is urgently needed. In our previous study, we identified a potential HCV NS5A inhibitor, BP008. After further systemic optimization, we discovered a more potent HCV inhibitor, DBPR110. DBPR110 reduced the reporter expression of the HCV1b replicon with a 50% effective concentration (EC 50 ) and a selective index value of 3.9 ± 0.9 pM and >12,800,000, respectively. DBPR110 reduced HCV2a replicon activity with an EC 50 and a selective index value of 228.8 ± 98.4 pM and >173,130, respectively. Sequencing analyses of several individual clones derived from the DBPR110-resistant RNAs purified from cells harboring genotype 1b and 2a HCV replicons revealed that amino acid substitutions mainly within the N-terminal region (domain I) of NS5A were associated with decreased inhibitor susceptibility. P58L/T and Y93H/N in genotype 1b and T24A, P58L, and Y93H in the genotype 2a replicon were the key substitutions for resistance selection. In the 1b replicon, V153M, M202L, and M265V play a compensatory role in replication and drug resistance. Moreover, DBPR110 displayed synergistic effects with alpha interferon (IFN-α), an NS3 protease inhibitor, and an NS5B polymerase inhibitor. In summary, our results present an effective small-molecule inhibitor, DBPR110, that potentially targets HCV NS5A. DBPR110 could be part of a more effective therapeutic strategy for HCV in the future.