Andre van Vliet

Evaluation of the safety, tolerability and pharmacokinetics of ALN-RSV01, a novel RNAi antiviral therapeutic directed against respiratory syncytial virus (RSV).

Small interfering RNAs (siRNAs) work through RNA interference (RNAi), the natural RNA inhibitory pathway, to down-regulate protein production by inhibiting targeted mRNA in a sequence-specific manner. ALN-RSV01 is an siRNA directed against the mRNA encoding the N-protein of respiratory syncytial virus (RSV) that exhibits specific in vitro and in vivo anti-RSV activity. The results of two safety and tolerability studies with ALN-RSV01 involving 101 healthy adults (65 active, 36 placebo, single- and multiple dose, observer-blind, randomized dose-escalation) are described. Intranasal administration of ALN-RSV01 was well tolerated over a dose range up through 150mg as a single dose and for five daily doses. Adverse events were similar in frequency and severity to placebo (normal saline) and were transient, mild to moderate, with no dose-dependent trend. The frequency or severity of adverse events did not increase with increasing ALN-RSV01 exposure. All subjects completed all treatments and assessments with no early withdrawals or serious adverse events. Physical examinations, vital signs, ECGs and laboratory tests were normal. Systemic bioavailability of ALN-RSV01 was minimal. ALN-RSV01 appears safe and well tolerated when delivered intranasally and is a promising therapeutic candidate for further clinical development.

Rapid HCV-RNA Decline With Once Daily TMC435: A Phase I Study in Healthy Volunteers and Hepatitis C Patients

BACKGROUND & AIMS The search for targeted anti-hepatitis C virus (HCV) drugs is driven by the adverse effect profile and limited efficacy of the current standard of care (pegylated interferon-alpha/ribavirin). In a first-in-human trial, we tested the safety, tolerability, and pharmacokinetics of the macrocyclic HCV NS3/4A protease inhibitor TMC435 in healthy volunteers, followed by HCV genotype 1-infected patients to assess antiviral activity. METHODS The TMC435350-C101 study was a phase I, randomized, double-blind, placebo-controlled trial in 49 healthy volunteers, followed by an open-label, nonplacebo-controlled panel in 6 genotype 1 hepatitis C patients. Healthy volunteers received oral, single, ascending doses (up to 600 mg) or 5-day multiple ascending doses (200 mg twice daily or 100, 200, or 400 mg once daily). Patients received 200 mg once daily for 5 days. Pharmacokinetics and safety were evaluated for all panels, and plasma HCV-RNA levels were determined in patients. RESULTS There were no serious adverse events, no grade 3 reactions, and no treatment-related discontinuations; pharmacokinetics supported a once daily dosing regimen. Plasma HCV-RNA levels dropped rapidly in all patients, with a median maximal reduction of 3.9-log(10) IU/mL and a median of 6 days to maximal reduction. The initial steep reduction of HCV-RNA (median 3.5-log(10) IU/mL at day 3) was followed by a more gradual decline that was maintained over the dosing period. No viral breakthroughs (>1-log(10) IU/mL HCV-RNA increase from nadir) were observed during treatment nor in the 3 days posttreatment; HCV-RNA returned to pretreatment levels by week 4. CONCLUSIONS Once daily TMC435 given orally was generally safe and well tolerated and demonstrated potent antiviral activity.

Long-term safety and efficacy of microRNA-targeted therapy in chronic hepatitis C patients

BACKGROUND AND AIMS MicroRNA-122 (miR-122) is an important host factor for hepatitis C virus (HCV) and promotes HCV RNA accumulation. Decreased intra-hepatic levels of miR-122 were observed in patients with hepatocellular carcinoma, suggesting a potential role of miR-122 in the development of HCC. Miravirsen targets miR-122 and resulted in a dose dependent and prolonged decrease of HCV RNA levels in chronic hepatitis C patients. The aim of this study was to establish the sustained virological response rate to peginterferon (P) and ribavirin (R) following miravirsen dosing and to assess long-term safety in patients treated with miravirsen. METHODS In this multicenter, retrospective follow-up study we included 36 treatment naïve patients with chronic hepatitis C genotype 1 who received five weekly subcutaneous injections with miravirsen or placebo over a 29-day period in a phase 2a study. Patients were offered PR therapy 3weeks (3mg/kg group) or 6weeks (5 or 7mg/kg group) after completion of miravirsen or placebo dosing. RESULTS PR therapy was started in 14/36 patients of whom 12 had received miravirsen. SVR was achieved in 7/12 patients previously dosed with miravirsen. All patients dosed with 7mg/kg miravirsen who were subsequently treated with PR achieved SVR. One patient had a prolonged undetectable HCV RNA period from week 14 to week 29 after baseline without subsequent antiviral therapy and relapsed thereafter. None of the patients treated with anti-miR-122 developed HCC or other liver-related complications. CONCLUSION No long-term safety issues were observed among 27 miravirsen-treated patients. Targeting miR-122 may be an effective and safe treatment strategy for HCV infection and should be investigated in larger clinical trials.

Pharmacodynamics and pharmacokinetics of the novel PAR-1 antagonist vorapaxar (formerly SCH 530348) in healthy subjects

PurposeThe aim of our study was to evaluate the pharmacology of vorapaxar (SCH 530348), an oral PAR-1 antagonist, in healthy volunteers.Methods and resultsIn two randomized, placebo-controlled studies, subjects received either single ascending doses of vorapaxar (0.25, 1, 5, 10, 20, or 40 mg; n = 50), multiple ascending doses of vorapaxar (1, 3, or 5 mg/day for 28 days; n = 36), a loading dose (10 or 20 mg) followed by daily maintenance doses (1 mg) for 6 days (n = 12), or placebo. Single 20- and 40-mg doses of vorapaxar completely inhibited thrombin receptor activating peptide (TRAP)-induced platelet aggregation (>80% inhibition) at 1 h and sustained this level of inhibition for ≥72 h. Multiple doses yielded complete inhibition on Day 1 (5 mg/day) and Day 7 (1 and 3 mg/day). Adverse events were generally mild, transient, and unrelated to dose.ConclusionVorapaxar provided rapid and sustained dose-related inhibition of platelet aggregation without affecting bleeding or clotting times.

Reproducibility of 3.0 Tesla Magnetic Resonance Spectroscopy for Measuring Hepatic Fat Content

To investigate reproducibility of proton magnetic resonance spectroscopy (1H‐MRS) to measure hepatic triglyceride content (HTGC).

Pharmacodynamics, Pharmacokinetics, Safety, and Tolerability of Encenicline, a Selective α7 Nicotinic Receptor Partial Agonist, in Single Ascending-dose and Bioavailability Studies

PURPOSE Encenicline (EVP-6124) is a selective α7 nicotinic acetylcholine receptor partial agonist being developed for cognitive impairment in Alzheimers disease and schizophrenia. We report on 2 single-dose studies to assess the relative bioavailability, pharmacokinetic profile, tolerability, and cognitive effects of encenicline in healthy volunteers. METHODS A single ascending-dose study assessed the safety, tolerability, pharmacokinetic, and pharmacodynamic profiles of encenicline in healthy male volunteers. Subjects received a single 1-, 3.5-, 7-, 20-, 60-, or 180-mg oral solution dose of encenicline or placebo. A second single-dose, randomized, open-label, 3-period, crossover study in healthy male and female subjects compared the relative bioavailability of a 1-mg oral capsule versus a 1-mg oral solution dose of encenicline and evaluated the effects of food and sex on encenicline pharmacokinetic profile. FINDINGS In the first study, encenicline was well tolerated and dose-proportional increases in C(max) (mean range 0.59-100 ng/mL) and AUC0-∞ (mean range 45.6-8890 ng·h/mL) were observed over a 1- to 180-mg dose range. Procognitive effects on the Digit Symbol Substitution Test were maximal at the 20-mg dose. In the second study, encenicline 1-mg oral capsules and oral solution were bioequivalent and there was no observed food effect on encenicline pharmacokinetic profile with the 90% confidence intervals of the treatment ratios for both comparisons (ie, capsule to solution and fed to fasted) for Cmax and AUC being within 80% to 125%. A 30% to 40% higher encenicline exposure in female subjects than respective values in male subjects was consistent with a 33% higher weight of the male subjects. No clinically relevant safety profile or tolerability effects of encenicline were observed. IMPLICATIONS Encenicline was well tolerated at single doses up to 180 mg, and doses as low as 1 mg had dose- and time-dependent pharmacodynamic effects on the central nervous system. Oral capsule and solution were bioequivalent and were not affected by food. Although a sex effect on pharmacokinetic profile was observed, it was attributable to weight differences. Clinical Trial Registration at EudraCT: 2006-005623-42 and EudracT: 2008-000029-20.

Bilateral sensory abnormalities in patients with unilateral neuropathic pain; a quantitative sensory testing (QST) study.

In patients who experience unilateral chronic pain, abnormal sensory perception at the non-painful side has been reported. Contralateral sensory changes in these patients have been given little attention, possibly because they are regarded as clinically irrelevant. Still, bilateral sensory changes in these patients could become clinically relevant if they challenge the correct identification of their sensory dysfunction in terms of hyperalgesia and allodynia. Therefore, we have used the standardized quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain (DFNS) to investigate somatosensory function at the painful side and the corresponding non-painful side in unilateral neuropathic pain patients using gender- and age-matched healthy volunteers as a reference cohort. Sensory abnormalities were observed across all QST parameters at the painful side, but also, to a lesser extent, at the contralateral, non-painful side. Similar relative distributions regarding sensory loss/gain for non-nociceptive and nociceptive stimuli were found for both sides. Once a sensory abnormality for a QST parameter at the affected side was observed, the prevalence of an abnormality for the same parameter at the non-affected side was as high as 57% (for Pressure Pain Threshold). Our results show that bilateral sensory dysfunction in patients with unilateral neuropathic pain is more rule than exception. Therefore, this phenomenon should be taken into account for appropriate diagnostic evaluation in clinical practice. This is particularly true for mechanical stimuli where the 95% Confidence Interval for the prevalence of sensory abnormalities at the non-painful side ranges between 33% and 50%.

Lack of Pharmacokinetic Interaction for ISIS 113715, a 2′-0-Methoxyethyl Modified Antisense Oligonucleotide Targeting Protein Tyrosine Phosphatase 1B Messenger RNA, with Oral Antidiabetic Compounds Metformin, Glipizide or Rosiglitazone

BackgroundISIS 113715 is a 20-mer phosphorothioate antisense oligonucleotide (ASO) that is complementary to the protein tyrosine phosphatase 1B (PTP-1B) messenger RNA and subsequently reduces translation of the PTP-1B protein, a negative regulator of insulin receptor. ISIS 113715 is currently being studied in early phase II clinical studies to determine its ability to improve or restore insulin receptor sensitivity in patients with type 2 diabetes mellitus. Future work will investigate the combination of ISIS 113715 with antidiabetic compounds.MethodsIn vitro ultrafiltration human plasma protein binding displacement studies and a phase I clinical study were used to characterise the potential for pharmacokinetic interaction of ISIS 113715 and three marketed oral antidiabetic agents. ISIS 113715 was co-incubated with glipizide and rosiglitazone in whole human plasma and tested for increased free drug concentrations. In a phase I clinical study, 23 healthy volunteers received a single oral dose of an antidiabetic compound (either metformin, glipizide or rosiglitazone) both alone and together with subcutaneous ISIS 113715 200mg in a sequential crossover design. A comparative pharmacokinetic analysis was performed to determine if there were any effects that resulted from coadministration of ISIS 113715 with these antidiabetic compounds.ResultsIn vitro human plasma protein binding displacement studies showed only minor effects on rosiglitazone and no effect on glipizide when co-incubated with ISIS 113715. The results of the phase I clinical study further indicate that there were no measurable changes in glipizide (5mg), metformin (500mg) or rosiglitazone (2mg) exposure parameters, maximum plasma concentration and the area under the concentration-time curve, or pharmacokinetic parameter, elimination half-life when coadministered with ISIS 113715. Furthermore, there was no effect of ISIS 113715, administered in combination with metformin, on the urinary excretion of metformin. Conversely, there were no observed alterations in ISIS 113715 pharmacokinetics when administered in combination with any of the oral antidiabetic compounds.ConclusionThese data provide evidence that ISIS 113715 exhibits no clinically relevant pharmacokinetic interactions on the disposition and clearance of the oral antidiabetic drugs. The results of these studies support further study of ISIS 113715 in combination with antidiabetic compounds.

Antiviral activity of narlaprevir combined with ritonavir and pegylated interferon in chronic hepatitis C patients

Narlaprevir (SCH 900518) is a potent inhibitor of the hepatitis C virus (HCV) nonstructural protein 3 serine protease that is primarily metabolized by the cytochrome P450‐3A4 system. In order to explore the use of ritonavir‐based pharmacokinetic enhancement of an HCV protease inhibitor, this study investigated the safety, tolerability, pharmacokinetics, and antiviral activity of narlaprevir (with or without ritonavir) administered as monotherapy and as combination therapy with pegylated interferon‐α‐2b (PEG‐IFN‐α‐2b) to HCV genotype 1–infected patients. This was a randomized, placebo‐controlled, two‐period, blinded study in 40 HCV genotype 1–infected patients (naïve and treatment‐experienced). In period 1, narlaprevir was administered for 7 days as 800 mg three times daily without ritonavir or 400 mg twice daily with 200 mg ritonavir twice daily. In period 2, after a 4‐week washout, the same dose and regimen of narlaprevir was administered in combination with PEG‐IFN‐α‐2b for 14 days. Upon completion of period 2, all patients initiated PEG‐IFN‐α‐2b and ribavirin treatment. A rapid and persistent decline in plasma HCV‐RNA was observed in both treatment‐experienced and treatment‐naïve patients during period 1, with a mean viral load decline of at least 4 log10 in all treatment groups. A high percentage of both treatment‐experienced (50%) and treatment‐naïve (≥60%) patients had undetectable HCV‐RNA (<25 IU/mL) after period 2. Standard of care resulted in sustained virological response (SVR) rates of 38% and 81% in treatment‐experienced and treatment‐naïve patients, respectively. Narlaprevir (with or without ritonavir) alone or in combination with PEG‐IFN‐α‐2b was safe and well tolerated. Conclusion: Narlaprevir administration resulted in a robust HCV‐RNA decline and high SVR rates when followed by standard of care in both treatment‐experienced and treatment‐naïve HCV genotype 1–infected patients. (HEPATOLOGY 2010

Potent immune activation in chronic hepatitis C patients upon administration of an oral inducer of endogenous interferons that acts via Toll-like receptor 7

BACKGROUND ANA773, an oral prodrug of a small-molecule Toll-like receptor (TLR)7 agonist, induces a dose-related decrease in serum HCV RNA levels in chronic hepatitis C patients. METHODS The prodrug ANA773 was administered to healthy individuals and chronic hepatitis C patients. At different time points during the course of treatment, modulation of the phenotype and function of peripheral leukocytes were evaluated to determine the role of distinct immune cells on the clinical outcome of therapy. RESULTS Early after administration of the TLR7 agonist, a mild transient reduction of the number of lymphocytes was observed in both healthy individuals and chronic hepatitis C patients. Moreover, repeated administration of ANA773 resulted in transiently reduced numbers of myeloid and plasmacytoid dendritic cells (DC) in blood. Interestingly, reduced plasmacytoid DC numbers as well as increased serum interferon (IFN)-α and IFN-γ inducible protein (IP)-10 levels were observed only in virological responders (≥1 log(10) IU/ml reduction of HCV RNA levels upon ANA773 treatment), but were absent in virological non-responders. In vitro stimulation of peripheral blood mononuclear cells from virological responders showed a high frequency of IFN-α-producing plasmacytoid DC upon stimulation in vitro with ANA773, whereas no IFN-α was induced in non-responders. CONCLUSIONS These findings indicate that the viral load decline in chronic hepatitis C patients treated with the TLR7 agonist ANA773 is likely due to intrinsic differences in the induction of endogenous IFNs and IFN-stimulated gene products (IFN-α and IP-10) upon TLR7 ligation.