The Cyclophilin Inhibitor Rencofilstat Decreases HCV-Induced Hepatocellular Carcinoma Independently of Its Antiviral Activity

There is an urgent need for the identification of new drugs that inhibit HCV-induced hepatocellular carcinoma (HCC). Our work demonstrates that cyclophilin inhibitors (CypIs) represent such new drugs. We demonstrate that the nonimmunosuppressive cyclosporine A (CsA) analog (CsAa) rencofilstat possesses dual therapeutic activities for the treatment of HCV infection and HCV-induced HCC. Specifically, we show that the HCV infection of humanized mice results in the progressive development of HCC. This is true for the four genotypes tested (1 to 4). Remarkably, we demonstrate that rencofilstat inhibits the development of HCV-induced HCC in mice even when added 16 weeks after infection when HCC is well established. Importantly, we show that rencofilstat drastically reduces HCC progression independently of its anti-HCV activity. Indeed, the CypI rencofilstat inhibits HCC, while other anti-HCV agents such as NS5A (NS5Ai) and NS5B (NS5Bi) fail to reduce HCC. In conclusion, this study shows for the first time that the CypI rencofilstat represents a potent therapeutic agent for the treatment of HCV-induced HCC.

The Cyclophilin Inhibitor Rencofilstat Decreases HCV-induced Hepatocellular Carcinoma Independently of Its Antiviral Activity

There is an urgent need for the identification of new drugs that inhibit HCV-induced hepatocellular carcinoma (HCC). Our work demonstrates that cyclophilin inhibitors (CypI) represent such new drugs. We demonstrated that the non-immunosuppressive cyclosporine A (CsA) analog (CsAa) rencofilstat possesses dual therapeutic activities for the treatment of HCV infection and HCV-induced HCC. Specifically, we showed that HCV infection of humanized mice results in the progressive development of HCC. This was true for four genotypes tested (1 to 4). Remarkably, we demonstrated that rencofilstat inhibits the development of HCV-induced HCC in mice even when added 16 weeks post-infection when HCC is well established. Importantly, we showed that rencofilstat drastically reduces HCC progression independently of its anti-HCV activity. Indeed, the CypI rencofilstat inhibits HCC while other anti-HCV agents such as NS5A (NS5Ai) and NS5B (NS5Bi) fail to reduce HCC. In conclusion, this study shows for the first time that the CypI rencofilstat represents a potent therapeutic agent for the treatment of HCV-induced HCC.

Abstract 4125: Rencofilstat exerts a dominant role in synergistic anti-PD1-combination effects in a fatty liver model of hepatocellular carcinoma

Rencofilstat is a clinical-phase drug candidate that inhibits multiple cyclophilin isomerases and affects many cellular processes. The objectives of this study were to characterize rencofilstat’s anti-tumor effects alone and in combination with anti-PD1 in a murine model of fatty liver-associated hepatocellular carcinoma (HCC). Murine Hep53.4 HCC cells were orthotopically implanted into livers of C57BL/6 mice fed either a normal diet or western diet. Treatments included rencofilstat and anti-PD1 IgG, alone or in combination, from Weeks 2-4 post-implantation. End-of-study analyses included tumor growth, survival, and tumor gene expression by bulk RNA sequencing. Hep53.4 tumors in fatty livers (“fatty tumors”) were more resistant to treatments compared to tumors in nonfatty livers (“nonfatty tumors”). On the normal liver background, rencofilstat and anti-PD1 IgG as monotherapies or in combination decreased tumor volumes by 76-83%. In contrast, only combination treatment consistently decreased tumor volumes (84%) in fatty livers. Rencofilstat plus anti-PD1 IgG also extended mouse survival in the fatty liver model. Tumor transcriptomic analyses revealed marked differences between treatments and tumor types. Rencofilstat altered the expression of 3-times more genes than anti-PD1 in fatty tumors (differentially expressed genes; DEGs), whereas the two treatments affected similar number of genes in nonfatty tumors. The same was true when analysis was restricted to only those genes whose expression correlated with tumor volume. The identities of the DEGs were very different between rencofilstat and anti-PD1 treatments in nonfatty tumors. In contrast, in fatty tumors, 40% of the anti-PD1 DEGs also occurred in rencofilstat-treated tumors, suggesting that rencofilstat can moderately mimic anti-PD1 in fatty tumors. Rencofilstat DEGs also overlapped significantly with combination-treatment DEGs (46%) in fatty tumors, whereas only 7% of the anti-PD1 DEGs were represented in the combination treatment tumors. DEG pathway mapping revealed that the biological pathways predicted to be affected by rencofilstat and anti-PD1 were highly dependent on the type of tumor. In nonfatty tumors both drug treatments predominantly affected cellular biology processes such as protein processing and metabolism, but in fatty tumors both drug treatments overwhelmingly affected immune-related processes such as T cell differentiation, natural killer cells, checkpoint pathways, and cytokine-chemokine signaling. These results highlight major differences in phenotype and treatment response of tumors in fatty livers compared to nonfatty livers. Furthermore, they suggest that a combination of a checkpoint inhibitor with rencofilstat may be especially efficacious for HCC in individuals with NAFLD or NASH, due in part to rencofilstat’s multi-pathway targeting.

Citation Format: Daren Ure, Jack Leslie, Lacey Haddon, Claude Fu, Jelena Mann, Derek Mann. Rencofilstat exerts a dominant role in synergistic anti-PD1-combination effects in a fatty liver model of hepatocellular carcinoma. [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 4125.

Effect of a High-Fat Meal on Single-Dose Rencofilstat (CRV431) Oral Bioavailability in Healthy Human Subjects

Rencofilstat (RCF) is a novel cyclophilin inhibitor under development for the treatment of nonalcoholic steatohepatitis and hepatocellular carcinoma. This phase 1, randomized, open-label study in healthy participants assessed the relative bioavailability of a single dose of RCF 225-mg soft gelatin capsules in both fasted and high-fat conditions. Forty-four participants were enrolled to either the fasted (n = 24) or the high-fat fed (n = 20) arm. Noncompartmental pharmacokinetics were evaluated following a single 225-mg oral dose. Administration of RCF with a high-fat meal led to increases in maximum concentration, area under the concentration-time curve (AUC) from time 0 to 24 hours, and AUC from time 0 to infinity fed-to-fasted geometric mean ratios of 102.2%, 114.5%, and 132.9%, respectively. All AUC geometric mean ratios were outside of the 80% to 125% range, suggesting that a high-fat meal can increase the extent of RCF exposure. Time to maximum concentration increased from 1.5 to 1.8 hours in the fasted and high-fat groups, respectively, suggesting slightly delayed absorption. High fat intake may delay gastric emptying while increasing the absorption and bioavailability of RCF. No treatment-emergent adverse events were observed in the fasted group, and 1 treatment-emergent adverse event occurred in the high-fat meal group. The differences in observed whole-blood concentrations are unlikely to have clinically relevant effects given the wide therapeutic index of RCF demonstrated in previous phase 1 studies.

The combination of the NS5A and cyclophilin inhibitors results in an additive anti-HCV inhibition in humanized mice without development of resistance

We and others previously reported that the direct-acting agents (DAA) NS5A inhibitors (NS5Ai) and the host-targeting agents cyclophilin inhibitors (CypIs) inhibit HCV replication in vitro. In this study, we investigated whether the combination of NS5Ai and CypI offers a potent anti-HCV effect in vivo. A single administration of NS5Ai or CypI alone to HCV-infected humanized-mice inhibits HCV replication. The combination of NS5Ai with CypI suppresses HCV (GT1a, GT2a, GT3a and GT4a) replication in an additive manner. NS5Ai/CypI combinations provide a statistically more profound anti-HCV inhibition for GT2a and GT3a than GT1a and GT4a, leading to a fastest and deepest inhibition of GT2a and GT3a replications. Combining CypI with NS5Ai prevents the viral rebound normally observed in mice treated with NS5Ai alone. Results were confirmed in mice implanted with human hepatocytes from different donors. Therefore, the combination of NS5Ai with CypI may serve as a regimen for the treatment of HCV patients with specific genotypes and disorder conditions, which diminish sustain viral response levels to DAA, such as GT3a infection, cirrhosis, and DAA resistance associated with the selection of resistance-associated substitutions present at baseline or are acquired during treatment.

The cyclophilin inhibitor CRV431 inhibits liver HBV DNA and HBsAg in transgenic mice

Hepatitis B virus (HBV) infection is a major health burden worldwide with 240 million chronically infected individuals. Nucleos(t)ide analogs and interferons are the current standards of care due to their suppression of HBV replication, but the treatments rarely eradicate HBV from individuals. Similar to current treatments for human immunodeficiency virus type-1 (HIV-1) and hepatitis C virus (HCV) patients, improved HBV therapies will require the combination of multiple drugs which target distinct steps of the HBV life cycle. In this study, we tested the potential of a cyclophilin inhibitor, CRV431, to affect HBV replication in transgenic mice. We found that oral treatment with CRV431 (50 mg/kg/day) for a period of 16 days significantly reduced liver HBV DNA levels and moderately decreased serum HBsAg levels. We observed an additive inhibitory effect on liver HBV DNA levels in mice treated with a combination of low doses of CRV431 (10 mg/kg/day) and the nucleotide prodrug, tenofovir exalidex (TXL), (5 mg/kg/day). No toxicity was observed in CRV431-treated mice. Although it is well known that CRV431 neutralizes the peptidyl-prolyl isomerase activity of cyclophilins, its anti-HBV mechanism(s) of action remains unknown. Nevertheless, this study provides the first demonstration of a beneficial effect of a cyclophilin inhibitor in vivo in an HBV transgenic mouse model. Altogether our data reveal the potential of CRV431 to be part of improved new therapies for HBV patients.

Abstract POSTER-TECH-1131: Next generation protein multiplexing

While a variety of technologies exist to measure proteins, such as ELISA’s, Mass Spec, and 2D Gel’s, the most promising for screening multiple proteins are biochip or microarray based technologies. However, even with biochip devices, measuring specific interactions between multiple protein combinations remains problematic. Proteins are complex and fragile bio-molecules and often interact in complex and unpredictable ways with other proteins and/or protein analysis equipment, causing non-specific (false) signals. Furthermore, many proteins of interest to the life science industry are present in samples at very different concentrations, limiting which proteins can be screened in a single multiplex test and sample dilution.

To address these problems, Inanovate has developed a new multiplexed protein quantification technology called Longitudinal Assay Screening (LAS), combining high sensitivity confocal imaging and microfluidics alongside protein based microarrays. Inanovate has completed testing and benchmarking of the first platform integrating LAS technology across a range of demonstration assays. Instead of depending on a 96-well micro-titer plate, the new LAS platform utilizes a glass slide based protein microarray and microfluidics for dispensing and binding samples and detection antibodies. In its most basic form, the protein microarray is composed of capture antibodies for the proteins being measured, as well as positive and negative quality control features for ensuring sample to sample, run to run, lot to lot, and user to user consistency. Conceptually very similar to a real-time PCR reaction, the LAS platform iteratively flows small volumes of sample and labeled detection antibodies across the protein microarray (housed on Inanovate’s fluidic cartridges) and fluorescently measures the formation of the sandwich between capture antibody, analyte of interest, and detection antibody in real-time.

Due to the time-resolved nature of the assay, the resulting data is a rate of reaction, instead of a simple final fluorescent reading. This ‘rate of reaction’ based analysis helps deliver the following core advantages of LAS technology, each of which has been demonstrated through the development and validation of a five-plex assay consisting of CRP, IL-6, IL-1a, IL-8 and IL-1b.

1. Large detection range: LAS enables the accurate quantitation of protein concentrations across a 7 log range in a single multiplex test. This eliminates the need for serial dilutions, making multiplexing faster, cheaper and helping preserve precious samples.

2. Multiplexing flexibility: Due to its large detection range, LAS allows users to run virtually any assay of interest in one test, enabling the development of biologically relevant multiplexes.

3. Improved accuracy: LAS produces and analyses real-time kinetic data on protein interactions (rate of reaction data), improving identification and discrimination of background and nonspecific signals, delivering more accurate quantitation at low analyte concentrations.

LAS technology holds the potential to become to proteomics what PCR was to genomics. It offers a new approach to multiplexed protein screening that helps address many of the problems presently affecting the utility of biochips in protein biomarker discovery, validation and clinical screening applications. The Poster will both summarize the technical components of the new LAS based platform and present data from the five-plex demonstration work plus recent work on serology assays.

Citation Format: Sloan D, Nelson J, Ure D, Votaw G, Stevens E. Next generation protein multiplexing [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-TECH-1131.

The Novel Cyclophilin Inhibitor CPI-431-32 Concurrently Blocks HCV and HIV-1 Infections via a Similar Mechanism of Action

HCV-related liver disease is the main cause of morbidity and mortality of HCV/HIV-1 co-infected patients. Despite the recent advent of anti-HCV direct acting antivirals (DAAs), the treatment of HCV/HIV-1 co-infected patients remains a challenge, as these patients are refractory to most therapies and develop liver fibrosis, cirrhosis and liver cancer more often than HCV mono-infected patients. Until the present study, there was no suitable in vitro assay to test the inhibitory activity of drugs on HCV/HIV-1 co-infection. Here we developed a novel in vitro "co-infection" model where HCV and HIV-1 concurrently replicate in their respective main host target cells--human hepatocytes and CD4+ T-lymphocytes. Using this co-culture model, we demonstrate that cyclophilin inhibitors (CypI), including a novel cyclosporin A (CsA) analog, CPI-431-32, simultaneously inhibits replication of both HCV and HIV-1 when added pre- and post-infection. In contrast, the HIV-1 protease inhibitor nelfinavir or the HCV NS5A inhibitor daclatasvir only blocks the replication of a single virus in the "co-infection" system. CPI-431-32 efficiently inhibits HCV and HIV-1 variants, which are normally resistant to DAAs. CPI-431-32 is slightly, but consistently more efficacious than the most advanced clinically tested CypI--alisporivir (ALV)--at interrupting an established HCV/HIV-1 co-infection. The superior antiviral efficacy of CPI-431-32 over ALV correlates with its higher potency inhibition of cyclophilin A (CypA) isomerase activity and at preventing HCV NS5A-CypA and HIV-1 capsid-CypA interactions known to be vital for replication of the respective viruses. Moreover, we obtained evidence that CPI-431-32 prevents the cloaking of both the HIV-1 and HCV genomes from cellular sensors. Based on these results, CPI-431-32 has the potential, as a single agent or in combination with DAAs, to inhibit both HCV and HIV-1 infections.

Mutant huntingtin impairs axonal trafficking in mammalian neurons in vivo and in vitro

Recent data in invertebrates demonstrated that huntingtin (htt) is essential for fast axonal trafficking. Here, we provide direct and functional evidence that htt is involved in fast axonal trafficking in mammals. Moreover, expression of full-length mutant htt (mhtt) impairs vesicular and mitochondrial trafficking in mammalian neurons in vitro and in whole animals in vivo. Particularly, mitochondria become progressively immobilized and stop more frequently in neurons from transgenic animals. These defects occurred early in development prior to the onset of measurable neurological or mitochondrial abnormalities. Consistent with a progressive loss of function, wild-type htt, trafficking motors, and mitochondrial components were selectively sequestered by mhtt in human Huntington's disease-affected brain. Data provide a model for how loss of htt function causes toxicity; mhtt-mediated aggregation sequesters htt and components of trafficking machinery leading to loss of mitochondrial motility and eventual mitochondrial dysfunction.

Extensive injury of descending neurons demonstrated by retrograde labeling in a virus-induced murine model of chronic inflammatory demyelination

Persistent Theiler's virus infection of SJL/J mice was used as a model to quantitatively assess the extent of descending neuron injury by chronic inflammatory demyelination of the spinal cord. By 9 months postinfection, inflammatory demyelinating lesions were present throughout the spinal cord, affecting up to 31% of the cross-sectional area of the ventrolateral columns. Axon dropout was evident in the lesions by electron microscopy and by quantitation of axons in normal-appearing white matter. Axon number in the ventrolateral columns at L1/L2 was reduced by 23% and total axon area was reduced by 37%, compared with uninfected mice. The most informative data on descending neuron injury, however, was a reduction in retrograde. Fluoro-Gold labeling. Labeling from T11/T12 of rubrospinal, reticulospinal/raphespinal, and vestibulospinal neurons was reduced by 60%, 70%, and 93%, respectively. Retrograde responses to axonal injury were observed, consisting of atrophied cell bodies, indented nuclei, and abundant lipofuscin, but cell body dropout was minimal. The number of cell bodies of vestibulospinal neurons was reduced by only 35%, whereas the number of cell bodies of rubrospinal neurons was unchanged. These results demonstrate that chronic inflammatory demyelination can severely injure axons and emphasize the need to design neuroprotective therapies in human multiple sclerosis.

Glycopyrrolate reduces nausea during spinal anaesthesia for caesarean section without affecting neonatal outcome

We have tested the hypotheses that glycopyrrolate, administered immediately before induction of subarachnoid anaesthesia for elective Caesarean section, reduces the incidence and severity of nausea, with no adverse effects on neonatal Apgar scores, in a double-blind, randomized, controlled study. Fifty women received either glycopyrrolate 200 micrograms or saline (placebo) i.v. during fluid preload, before induction of spinal anaesthesia with 2.5 ml of 0.5% isobaric bupivacaine. Patients were questioned directly regarding nausea at 3-min intervals throughout operation and asked to report symptoms as they arose. The severity of nausea was assessed using a verbal scoring system and was treated with increments of i.v. ephedrine and fluids. Patients in the group pretreated with glycopyrrolate reported a reduction in the frequency (P = 0.02) and severity (P = 0.03) of nausea. Glycopyrrolate also reduced the severity of hypotension, as evidenced by reduced ephedrine requirements (P = 0.02). There were no differences in neonatal Apgar scores between groups.