The worldwide prevalence of chronic hepatitis C virus (HCV) infection is estimated to be approaching 200 million people. Current therapy relies upon a combination of pegylated interferon-alpha and ribavirin, a poorly tolerated regimen typically associated with less than 50% sustained virological response rate in those infected with genotype 1 virus. The development of direct-acting antiviral agents to treat HCV has focused predominantly on inhibitors of the viral enzymes NS3 protease and the RNA-dependent RNA polymerase NS5B. Here we describe the profile of BMS-790052, a small molecule inhibitor of the HCV NS5A protein that exhibits picomolar half-maximum effective concentrations (EC(50)) towards replicons expressing a broad range of HCV genotypes and the JFH-1 genotype 2a infectious virus in cell culture. In a phase I clinical trial in patients chronically infected with HCV, administration of a single 100-mg dose of BMS-790052 was associated with a 3.3 log(10) reduction in mean viral load measured 24 h post-dose that was sustained for an additional 120 h in two patients infected with genotype 1b virus. Genotypic analysis of samples taken at baseline, 24 and 144 h post-dose revealed that the major HCV variants observed had substitutions at amino-acid positions identified using the in vitro replicon system. These results provide the first clinical validation of an inhibitor of HCV NS5A, a protein with no known enzymatic function, as an approach to the suppression of virus replication that offers potential as part of a therapeutic regimen based on combinations of HCV inhibitors.

Once-daily oral daclatasvir plus sofosbuvir was associated with high rates of sustained virologic response among patients infected with HCV genotype 1, 2, or 3, including patients with no response to prior therapy with telaprevir or boceprevir. (Funded by Bristol-Myers Squibb and Pharmasset (Gilead); A1444040 ClinicalTrials.gov number, NCT01359644.).

BMS-790052 is the most potent hepatitis C virus (HCV) inhibitor reported to date, with 50% effective concentrations (EC 50 s) of <50 pM against genotype 1 replicons. This exceptional potency translated to rapid viral load declines in a phase I clinical study. By targeting NS5A, BMS-790052 is distinct from most HCV inhibitors in clinical evaluation. As an initial step toward correlating in vitro and in vivo resistances, multiple cell lines and selective pressures were used to identify BMS-790052-resistant variants in genotype 1 replicons. Similarities and differences were observed between genotypes 1a and 1b. For genotype 1b, L31F/V, P32L, and Y93H/N were identified as primary resistance mutations. L23F, R30Q, and P58S acted as secondary resistance substitutions, enhancing the resistance of primary mutations but themselves not conferring resistance. For genotype 1a, more sites of resistance were identified, and substitutions at these sites (M28T, Q30E/H/R, L31M/V, P32L, and Y93C/H/N) conferred higher levels of resistance. For both subtypes, combining two resistance mutations markedly decreased inhibitor susceptibility. Selection studies with a 1b/1a hybrid replicon highlighted the importance of the NS5A N-terminal region in determining genotype-specific inhibitor responses. As single mutations, Q30E and Y93N in genotype 1a conferred the highest levels of resistance. For genotype 1b, BMS-790052 retained subnanomolar potency against all variants with single amino acid substitutions, suggesting that multiple mutations will likely be required for significant in vivo resistance in this genetic background. Importantly, BMS-790052-resistant variants remained fully sensitive to alpha interferon and small-molecule inhibitors of HCV protease and polymerase.Hepatitis C virus (HCV) is a major cause of chronic liver disease, affecting up to 180 million people worldwide (24, 32). HCV is an enveloped, positive-strand RNA virus and is the sole member of the Hepacivirus genus of the Flaviviridae family (17). HCV is classified into six major genotypes, each with multiple subtypes, based on sequence diversity (17, 33). The current standard of care for HCV infection includes therapy with a combination of pegylated alpha interferon (pegIFN-␣) and ribavirin. This treatment is often associated with limiting side effects, and effectiveness is highly genotype dependent (3,30,38). For genotypes 1a and 1b, accounting for ϳ60% of global infections, long-term efficacy or a sustained virological response is achieved in only ϳ50% of chronically infected individuals (3, 24). An increasing number of small-molecule inhibitors targeting specific viral proteins are entering into clinical evaluation (1,25,27,30,38). Collectively, these inhibitors are often referred to as direct-acting antiviral agents (DAA). The most advanced of these inhibitors target enzymatic activities of the HCV nonstructural proteins NS3 (serine protease) and NS5B (RNA-dependent RNA polymerase) (1, 27). We recently described a potent inhibitor of HCV RNA replication, BMS-79005...

Highlights d Development of two potent FTO inhibitors with IC 50 values in the low nanomolar range d KD of FTO or pharmacological inhibition of FTO suppresses LSC/LIC self-renewal d Targeting FTO suppresses immune checkpoint gene expression and immune evasion d Targeting FTO by potent inhibitors holds therapeutic promise against various cancers

Hypoxia, a common feature within many types of solid tumors, is known to be closely associated with limited efficacy for cancer therapies, including radiotherapy (RT) in which oxygen is essential to promote radiation-induced cell damage. Here, an artificial nanoscale red-blood-cell system is designed by encapsulating perfluorocarbon (PFC), a commonly used artificial blood substitute, within biocompatible poly(d,l-lactide-co-glycolide) (PLGA), obtaining PFC@PLGA nanoparticles, which are further coated with a red-blood-cell membrane (RBCM). The developed PFC@PLGA-RBCM nanoparticles with the PFC core show rather efficient loading of oxygen, as well as greatly prolonged blood circulation time owing to the coating of RBCM. With significantly improved extravascular diffusion within the tumor mass, owing to their much smaller nanoscale sizes compared to native RBCs with micrometer sizes, PFC@PLGA-RBCM nanoparticles are able to effectively deliver oxygen into tumors after intravenous injection, leading to greatly relieved tumor hypoxia and thus remarkably enhanced treatment efficacy during RT. This work thus presents a unique type of nanoscale RBC mimic for efficient oxygen delivery into solid tumors, favorable for cancer treatment by RT, and potentially other types of therapy as well.

Although targeting cancer metabolism is a promising therapeutic strategy, clinical success will depend on an accurate diagnostic identification of tumor subtypes with specific metabolic requirements. Through broad metabolite profiling, we successfully identified three highly distinct metabolic subtypes in pancreatic ductal adenocarcinoma (PDAC). One subtype was defined by reduced proliferative capacity, whereas the other two subtypes (glycolytic and lipogenic) showed distinct metabolite levels associated with glycolysis, lipogenesis, and redox pathways, confirmed at the transcriptional level. The glycolytic and lipogenic subtypes showed striking differences in glucose and glutamine utilization, as well as mitochondrial function, and corresponded to differences in cell sensitivity to inhibitors of glycolysis, glutamine metabolism, lipid synthesis, and redox balance. In PDAC clinical samples, the lipogenic subtype associated with the epithelial (classical) subtype, whereas the glycolytic subtype strongly associated with the mesenchymal (QM-PDA) subtype, suggesting functional relevance in disease progression. Pharmacogenomic screening of an additional ∼200 non-PDAC cell lines validated the association between mesenchymal status and metabolic drug response in other tumor indications. Our findings highlight the utility of broad metabolite profiling to predict sensitivity of tumors to a variety of metabolic inhibitors.metabolite profiling | metabolic subtypes in PDAC | glycolysis | lipid synthesis | biomarkers for metabolic inhibitors M etabolic reprogramming during tumorigenesis is an essential process in nearly all cancer cells. Tumors share a common phenotype of uncontrolled cell proliferation and must efficiently generate the energy and macromolecules required for cellular growth. The first example of metabolic reprogramming was discovered more than 80 y ago by Otto Warburg: tumor cells can shift from oxidative to fermentative metabolism in the course of oncogenesis (1). More recently, there has been a resurgence of interest in targeting cancer metabolism (2-4) because it may not only be effective in inhibiting tumor growth, but may also provide a therapeutic window (5, 6). For example, inactivation of lactate dehydrogenase-A (LDHA), an enzyme that catalyzes the final step of aerobic glycolysis, thereby reducing pyruvate to lactate, decreases tumorigenesis and induces regression of established tumors in mouse models of lung cancer driven by oncogenic KRAS or epidermal growth factor receptor (EGFR) while minimally affecting normal cell function (7). The finding that cancers have altered metabolism has prompted substantial investigation, both preclinically and in clinical trials, of several metabolically targeted agents, including those that elevate reactive oxygen species (ROS) or block glycolysis, lipid synthesis, mitochondrial function, and glutamine synthesis pathways (8).The identification of distinct metabolic reprogramming events or metabolic subtypes in cancer may inform patient selection for investigational...

The NS5A replication complex inhibitor, BMS-790052, inhibits hepatitis C virus (HCV) replication with picomolar potency in preclinical assays. This potency translated in vivo to a substantial antiviral effect in a single-ascending dose study and a 14-day multiple-ascending dose (MAD) monotherapy study. However, HCV RNA remained detectable in genotype 1a-infected patients at the end of the MAD study. In contrast, viral breakthrough was observed less often in patients infected with genotype 1b, and, in several patients, HCV RNA declined and remained below the level of quantitation (<25 IU/mL) through the duration of treatment. Here, we report on the results of the genotypic and phenotypic analyses of resistant variants in 24 genotype 1-infected patients who received BMS-790052 (1, 10, 30, 60, and 100 mg, once-daily or 30 mg twice-daily) in the 14-day MAD study. Sequence analysis was performed on viral complementary DNA isolated from serum specimens collected at baseline and days 1 (4, 8, and 12 hours), 2, 4, 7, and 14 postdosing. Analyses of the sequence variants (1) established a correlation between resistant variants emerging in vivo with BMS-790052 treatment and those observed in the in vitro replicon system (major substitutions at residues 28, 30, 31, and 93 for genotype 1a and residues 31 and 93 for genotype 1b); (2) determined the prevalence of variants at baseline and the emergence of resistance at different times during dosing; and (3) revealed the resistance profile and replicative ability (i.e., fitness) of the variants. Conclusion: Although resistance emerged during monotherapy with BMS-790052, the substantial anti-HCV effect of this compound makes it an excellent candidate for effective combination therapy. (HEPATOLOGY 2011;54:1924-1935 T he hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a multifunctional protein with key roles in HCV replication. NS5A has also been implicated in the modulation of cellular signaling pathways. 1,2 Because it is required in vivo and in vitro for viral replication and has no known human homologs, NS5A provides an attractive target for therapeutic intervention. 3 BMS-790052 is a potent HCV NS5A replication complex inhibitor, with 50% effective concentration (EC 50 ) values of 9 and 50 pM against genotype 1b and 1a replicons, respectively. 4,5 It is also potent against live virus (genotype 2a, JFH-1), with an EC 50 of $28 pM. 4 BMS-790052 has broad genotype coverage, with EC 50 values ranging from pM to low nM for replicons with NS5A sequences derived from genotype 2a, 3a, 4a, and 5a. 4

The development of activatable nanoplatforms to simultaneously improve diagnostic and therapeutic performances while reducing side effects is highly attractive for precision cancer medicine. Herein, we develop a one-pot, dopamine-mediated biomineralization method using a gas diffusion procedure to prepare calcium carbonate-polydopamine (CaCO-PDA) composite hollow nanoparticles as a multifunctional theranostic nanoplatform. Because of the high sensitivity of such nanoparticles to pH, with rapid degradation under a slightly acidic environment, the photoactivity of the loaded photosensitizer, i.e., chlorin e6 (Ce6), which is quenched by PDA, is therefore increased within the tumor under reduced pH, showing recovered fluorescence and enhanced singlet oxygen generation. In addition, due to the strong affinity between metal ions and PDA, our nanoparticles can bind with various types of metal ions, conferring them with multimodal imaging capability. By utilizing pH-responsive multifunctional nanocarriers, effective in vivo antitumor photodynamic therapy (PDT) can be realized under the precise guidance of multimodal imaging. Interestingly, at normal physiological pH, our nanoparticles are quenched and show much lower phototoxicity to normal tissues, thus effectively reducing skin damage during PDT. Therefore, our work presents a unique type of biomineralized theranostic nanoparticles with inherent biocompatibility, multimodal imaging functionality, high antitumor PDT efficacy, and reduced skin phototoxicity.