Glecaprevir and pibrentasvir are pangenotypic direct-acting antiviral agents for the treatment of chronic hepatitis C virus infection. The aim of the present study was to evaluate the drug–drug interaction and safety of glecaprevir and pibrentasvir coadministration in healthy volunteers.

Glecaprevir (an NS3/4A protease inhibitor) and pibrentasvir (an NS5A inhibitor) are potent and pangenotypic hepatitis C virus (HCV) direct-acting antivirals. This report describes the baseline polymorphisms and treatment-emergent substitutions in NS3 or NS5A detected in samples from HCV genotype 1-infected patients receiving 3-day monotherapy of glecaprevir or pibrentasvir, respectively. None of the NS3 polymorphisms detected in the 47 baseline samples collected prior to glecaprevir monotherapy conferred reduced susceptibility to glecaprevir. The NS3 A156T substitution, which conferred resistance to glecaprevir but had low replication efficiency, emerged in one genotype 1a-infected patient among the 35 patients with available post-baseline sequence data. Baseline NS5A polymorphisms were detected in 12 of 40 patients prior to pibrentasvir monotherapy; most polymorphisms were single-position NS5A amino acid substitutions that did not confer resistance to pibrentasvir. Among the 19 patients with available post-baseline NS5A sequence data, 3 had treatment-emergent NS5A substitutions during pibrentasvir monotherapy. All treatment-emergent NS5A substitutions were linked multiple-position, almost exclusively double-position, substitutions that conferred resistance to pibrentasvir. Replicons engineered with these double-position substitutions had low replication efficiency. In conclusion, resistance-conferring substitutions emerged in a small number of genotype 1-infected patients during glecaprevir or pibrentasvir monotherapy; unlike other NS5A inhibitors, pibrentasvir did not select single-position NS5A substitutions during monotherapy.

This first-in-human dose-ascending study investigated pharmacokinetics, safety, and tolerability of pibrentasvir following single and multiple doses in healthy volunteers. Additionally, the effects of food and ritonavir on pibrentasvir were assessed in a crossover study design. The starting dose of pibrentasvir was selected based on the no-observed-adverse-effect-level exposure from preclinical studies. Dose escalations of subsequent cohorts were dependent on reviews of the safety, tolerability, and pharmacokinetic data from previous dose cohorts. Pibrentasvir exposures increased in a greater than dose-proportional manner across the 1.5- to 120-mg dose range and became linear across the 120- to 600-mg dose range. Following multiple dosing, pibrentasvir steady state was attained by day 5 with an accumulation ratio of 25% to 35%. Pibrentasvir harmonic mean terminal half-life ranged from 20 to 22 hours. Food had minimal effect (<14%) on pibrentasvir bioavailability, but ritonavir increased pibrentasvir peak concentration and area under the concentration-time curve by 60% and 89%, respectively. All adverse events were assessed by the investigator as mild, and no clinically significant vital signs, electrocardiogram, or clinical laboratory values were observed. The pharmacokinetic results from this study support once-daily dosing and administration of pibrentasvir without regard to food. A maximum tolerated dose was not attained in the single- and multiple-ascending-dose assessments for pibrentasvir.

INTRODUCTION:A unique anti-interleukin (IL)-13 monoclonal antibody, RPC4046, was generated on the basis of differential IL-13 receptor (R) blockade as assessed in a murine asthma model; the safety, tolerability, pharmacokinetics, and pharmacodynamics of RPC4046 were evaluated in a first-in-human study.METHODS:Anti-IL-13 antibodies with varying receptor blocking specificity were evaluated in the ovalbumin-induced murine asthma model. A randomized, double-blind, placebo-controlled, dose-escalation first-in-human study (NCT00986037) was conducted with RPC4046 in healthy adults and patients with mild to moderate controlled asthma.RESULTS:In the ovalbumin model, blocking IL-13 binding to both IL-13Rs (IL-13Rα1 and IL-13Rα2) inhibited more asthma phenotypic features and more fully normalized the distinct IL-13 gene transcription associated with asthma compared with blocking IL-13Rα1 alone. In humans, RPC4046 exposure increased dose-dependently; pharmacokinetics were similar in healthy and asthmatic subjects, and blockade of both IL-13Rs uniquely affected IL-13 gene transcription. A minority of participants (28%) had antidrug antibodies, which were transient and appeared not to affect pharmacokinetics. Adverse event profiles were similar in healthy and asthmatic subjects, without dose-related or administration route differences, systemic infusion-related reactions, or asthma symptom worsening. Adverse events were mild to moderate, with none reported as probably related to RPC4046 or leading to discontinuations. Non-serious upper respiratory tract infections were more frequent with RPC4046 versus placebo.CONCLUSION:RPC4046 is a novel anti-IL-13 antibody that blocks IL-13 binding to both receptors and more fully blocks the asthma phenotype. These results support further investigation of RPC4046 for IL-13-related allergic/inflammatory diseases (e.g., asthma and eosinophilic esophagitis).FUNDING:AbbVie Inc. sponsored the studies and contributed to the design and conduct of the studies, data management, data analysis, interpretation of the data, and in the preparation and approval of the manuscript.

Glecaprevir and pibrentasvir are direct‐acting antiviral agents being developed as combination therapy for the treatment of chronic hepatitis C virus infection. The aim of the present studies was to assess the effect of race and ethnicity (white, Han Chinese, Japanese) on the pharmacokinetics and safety of multiple oral doses of glecaprevir and pibrentasvir given alone and in combination. Two multiple‐dose, single‐center, phase 1 studies were conducted in healthy adult male and female subjects (n = 170) of respective Asian and white race/ethnicity. Glecaprevir (100, 200, 300, or 700 mg once daily) and pibrentasvir (80, 120, or 160 mg once daily) were administered alone for 7 days followed by the combination of both direct‐acting antiviral agents for another 7 days. Intensive blood sampling was performed, and pharmacokinetic parameters were estimated by noncompartmental analyses. ANOVA was employed to evaluate for differences of steady‐state glecaprevir and pibrentasvir exposures between Asian (Japanese or Han Chinese) and white subjects. Glecaprevir and pibrentasvir exposures in Han Chinese and Japanese were similar to those in whites across dose levels. The nonlinear dose‐exposure relationships for glecaprevir and pibrentasvir were similar across Japanese, Han Chinese, and white subjects, and the safety profiles of the agents were comparable across these groups. The results of these studies demonstrate that race/ethnicity has no clinically meaningful impact on direct‐acting antiviral agent exposures, safety, or tolerability of the glecaprevir and pibrentasvir combination. This is supported in part by the large global registration program of the pangenotypic, coformulated fixed‐dose glecaprevir/pibrentasvir regimen and allows for inclusion of diverse ethnic populations.

ABT-493 is a hepatitis C virus nonstructural protein 3/4A protease inhibitor with pangenotypic antiviral activity. This study investigated the pharmacokinetics, safety, and tolerability of single and multiple ascending doses of ABT-493 and the effect of food and ritonavir coadministration on ABT-493 pharmacokinetics in healthy adults. In the blinded, randomized, placebo-controlled phase 1 single- and multiple-dose portions of the study, ABT-493 25-800 mg were evaluated as single doses, and 200, 400, and 800 mg were evaluated as multiple doses. The effect of food and ritonavir was assessed in a crossover unblinded fashion. ABT-493 pharmacokinetic parameters were estimated using noncompartmental methods. ABT-493 25-800 mg showed a greater than dose-proportional increase in exposures. Minimal accumulation (≤15%) was observed after ABT-493 200- and 400-mg multiple dosing; higher accumulations (approximately 80%) were observed after the 800-mg dose. ABT-493 harmonic mean half-life was 6-9 hours. Food had a minimal effect on ABT-493 exposures. All adverse events were assessed by the investigator as mild to moderate in severity, no serious adverse events were reported, and no subjects discontinued from the study. No clinically significant laboratory tests, vital signs, or electrocardiogram values were reported. A maximum tolerated dose was not reached.

Gregory J. Dore, Brian Conway, Yan Luo, Ewa Janczewska, Brygida Knysz, Yan Liu, Adrian Streinu-Cercel, Florin Alexandru Caruntu, Manuela Curescu, Richard Skoien, Wayne Ghesquiere, Wlodzimierz Mazur, Alejandro Soza, Francisco Fuster, Susan Greenbloom, Adriana Motoc, Victoria Arama, David Shaw, Istvan Tornai, Joseph Sasadeusz, Olav Dalgard, Danielle Sullivan, Xuan Liu, Mudra Kapoor, Andrew Campbell, Thomas Podsadecki

Objectives: To examine the safety and efficacy of ombitasvir and ABT-450 with ritonavir (ABT-450/r) perpendicular to ribavirin (RBV) in treatment-naive, non-cirrhotic adults with chronic HCV genotype 1-3 infection.Methods: Patients in this open-label, exploratory, phase 2, multicenter study received ombitasvir (25 mg QD) and ABT-450/r (200/100 mg QD) +/- RBV for 12 weeks. Primary efficacy endpoint was HCV RNA < lower limit of quantitation (LLOQ) from week 4 through 12. Sustained virologic response 12 weeks post-treatment (SVR12) was a secondary endpoint.Results: Sixty-one patients were enrolled. Among genotype 1-, 2-, and 3-infected patients, respectively, HCV RNA was<LLOQ from week 4 through 12 in 10 (100%; 95% CI 69-100), 9 (90%; 56-100), and 7 (70%; 35-93) receiving the RBV-containing regimen and 9 (90%; 56-100), 8 (80%; 44-97), and 2 (18%; 2-52) receiving the RBV-free regimen. Among genotype 1-, 2-, and 3-infected patients, respectively, SVR12 was achieved by 10 (100%), 8 (80%), and 5 (50%) receiving the RBV-containing regimen, and 6 (60%), 6 (60%), and 1 (9%) receiving the RBV-free regimen. The most common adverse events were fatigue, nausea, and headache. One patient discontinued due to an adverse event.Conclusions: In this study, ombitasvir and ABT-450/r +/- RBV regimens were generally well-tolerated. Sustained virologic response was achieved in most patients with HCV genotype 1 or 2 infection, but low SVR rates were observed in HCV genotype 3-infected patients. (C) 2014 The Authors. Published by Elsevier Ltd on behalf of the The British Infection Association. This is an open access article under the CC BY-NC-SA license (http://creativecommons.org/licenses/by-nc-sa/3.0/).

ABSTRACT ABT-493 is a hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor, and ABT-530 is an HCV NS5A inhibitor. These direct-acting antivirals (DAAs) demonstrated potent antiviral activity against major HCV genotypes and high barriers to resistance in vitro . In this open-label dose-ranging trial, antiviral activity and safety were assessed during 3 days of monotherapy with ABT-493 or ABT-530 in treatment-naive adults with HCV genotype 1 infection, with or without compensated cirrhosis. The presence of baseline resistance-associated variants (RAVs) was also evaluated. The mean maximal decreases in HCV RNA levels from baseline were approximately 4 log 10 IU/ml for all ABT-493 doses ranging from 100 mg to 700 mg and for ABT-530 doses of ≥40 mg. There were no meaningful differences in viral load declines for patients with versus without compensated cirrhosis. Twenty-four (50%) of the baseline samples from patients treated with ABT-493 had RAVs to NS3/4A protease inhibitors. Among 40 patients treated with ABT-530, 6 (15%) carried baseline RAVs to NS5A inhibitors. Viral load declines in patients with single baseline NS5A RAVs were similar to those in patients without RAVs. One patient harbored baseline RAVs at 3 NS5A positions and appeared to have a slightly less robust viral load decline on day 3 of monotherapy. No serious or grade 3 (severe) or higher adverse events and no clinically relevant laboratory abnormalities were observed with either compound. ABT-493 and ABT-530 demonstrated potent antiviral activity and acceptable safety during 3-day monotherapy in patients with HCV genotype 1 infection, with or without compensated cirrhosis. Based on these results, phase II studies assessing the combination of these DAAs for the treatment of chronic HCV infection in patients with or without compensated cirrhosis have been initiated. (This study has been registered at ClinicalTrials.gov under registration no. NCT01995071.)

Background & Aims: Telaprevir plus pegylated interferon/ribavirin (TPV + PegIFN/RBV) remains a therapeutic option for chronic hepatitis C virus (HCV) genotype (GT) 1 infection in many regions. We conducted two open-label, phase IIIb trials comparing safety and efficacy of all-oral ombitasvir/paritaprevir/ritonavir and dasabuvir +/- ribavirin (OBV/PTV/r + DSV +/- RBV) and TPV + PegIFN/RBV.Methods: Treatment-naive (MALACHITE-I) or PegIFN/RBVexperienced (MALACHITE-II) non-cirrhotic, chronic HCV GT1-infected patients were randomized to OBV/PTV/r + DSV + weight-based RBV, OBV/PTV/r + DSV (treatment-naive, GT1b-infected patients only), or 12 weeks of TPV + PegIFN + weight-based RBV and 12-36 additional weeks of PegIFN/RBV. The primary endpoint was sustained virologic response 12 weeks post-treatment (SVR12). Patient-reported outcome questionnaires evaluated mental and physical health during the studies.Results: Three hundred eleven treatment-naive and 148 treatment-experienced patients were randomized and dosed. Among treatment-naive patients, SVR12 rates were 97% (67/69) and 82% (28/34), respectively, in OBV/PTV/r + DSV + RBV and TPV + PegIFN/RBV-treated GT1a-infected patients; SVR12 rates were 99% (83/84), 98% (81/83), and 78% (32/41) in OBV/PTV/r+ DSV + RBV, OBV/PTV/r + DSV, and TPV + PegIFN/RBV-treated GT1b-infected patients. Among treatment-experienced patients, SVR12 rates were 99% (100/101) and 66% (31/47) with OBV/PTV/r + DSV + RBV and TPV + PegIFN/RBV. Mental and physical health were generally better with OBV/PTV/r + DSV +/- RBV than TPV + PegIFN/RBV. Rates of discontinuation due to adverse events (0-1% and 8-11%, respectively, p < 0.05) and rates of hemoglobin decline to < 10 g/dl (0-4% and 34-47%, respectively, p < 0.05) were lower for OBV/PTV/r + DSV +/- RBV than TPV + PegIFN/RBV.Conclusions: Among non-cirrhotic, HCV GT1-infected patients, SVR12 rates were 97-99% with 12 week, multi-targeted OBV/PTV/r + DSV +/- RBV regimens and 66-82% with 24-48 total weeks of TPV + PegIFN/RBV. OBV/PTV/r + DSV +/- RBV was associated with a generally better mental and physical health, more favorable tolerability, and lower rates of treatment discontinuation due to adverse events. (C) 2015 The Authors. Published by Elsevier B.V. on behalf of the European Association for the Study of the Liver.

IMPORTANCE:Patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are at high risk for liver disease progression. However, interferon-based treatments for HCV infection have significant toxicities, limiting treatment uptake. OBJECTIVE:To assess the all-oral 3 direct-acting antiviral (3D) regimen of ombitasvir, paritaprevir (co-dosed with ritonavir [paritaprevir/r]), dasabuvir, and ribavirin in HCV genotype 1-infected adults with HIV-1 co-infection, including patients with cirrhosis. DESIGN, SETTING, AND PARTICIPANTS:TURQUOISE-I is a randomized, open-label study. Part 1a of this pilot study was conducted at 17 sites in the United States and Puerto Rico between September 2013 and August 2014 and included 63 patients with HCV genotype 1 and HIV-1 co-infection who were HCV treatment-naive or had history of prior treatment failure with peginterferon plus ribavirin therapy. The study allowed enrollment of patients, including those with cirrhosis, with a CD4+ count of 200/mm3 or greater or CD4+ percentage of 14% or more and plasma HIV-1 RNA suppressed while taking a stable atazanavir- or raltegravir-inclusive antiretroviral regimen. INTERVENTIONS:Ombitasvir/paritaprevir/r, dasabuvir, and ribavirin for 12 or 24 weeks of treatment as randomized. MAIN OUTCOMES AND MEASURES:The primary assessment was the proportion of patients with sustained virologic response (HCV RNA <25 IU/mL) at posttreatment week 12 (SVR12). RESULTS:Among patients receiving 12 or 24 weeks of 3D and ribavirin, SVR12 was achieved by 29 of 31 (94%; 95% CI, 79%-98%) and 29 of 32 patients (91%; 95% CI, 76%-97%), respectively. Of the 5 patients who did not achieve SVR, 1 withdrew consent, 2 had confirmed virologic relapse or breakthrough, and 2 patients had clinical history and phylogenetic evidence consistent with HCV reinfection. The most common treatment-emergent adverse events were fatigue (48%), insomnia (19%), nausea (18%), and headache (16%). Adverse events were generally mild, with none reported as serious or leading to discontinuation. No patient had a confirmed HIV-1 breakthrough of 200 copies/mL or greater during treatment. CONCLUSIONS AND RELEVANCE:In this open-label, randomized uncontrolled study, treatment with the all-oral, interferon-free 3D-plus-ribavirin regimen resulted in high SVR rates among patients co-infected with HCV genotype 1 and HIV-1 whether treated for 12 or 24 weeks. Further phase 3 studies of this regimen are warranted in patients with co-infection. TRIAL REGISTRATION:clinicaltrials.gov Identifier: NCT01939197.

ABSTRACT Ombitasvir (ABT-267) is a hepatitis C virus (HCV) NS5A inhibitor with picomolar potency, pan-genotypic activity, and 50% effective concentrations (EC 50 s) of 0.82 to 19.3 pM against HCV genotypes 1 to 5 and 366 pM against genotype 6a. Ombitasvir retained these levels of potency against a panel of 69 genotype 1 to 6 chimeric replicons containing the NS5A gene derived from HCV-infected patients, despite the existence of natural sequence diversity within NS5A. In vitro resistance selection identified variants that conferred resistance to ombitasvir in the HCV NS5A gene at amino acid positions 28, 30, 31, 58, and 93 in genotypes 1 to 6. Ombitasvir was evaluated in vivo in a 3-day monotherapy study in 12 HCV genotype 1-infected patients at 5, 25, 50, or 200 mg dosed once daily. All patients in the study were HCV genotype 1a infected and were without preexisting resistant variants at baseline as determined by clonal sequencing. Decreases in HCV RNA up to 3.1 log 10 IU/ml were observed. Resistance-associated variants at position 28, 30, or 93 in NS5A were detected in patient samples 48 hours after the first dose. Clonal sequencing analysis indicated that wild-type virus was largely suppressed by ombitasvir during 3-day monotherapy, and at doses higher than 5 mg, resistant variant M28V was also suppressed. Ombitasvir was well tolerated at all doses, and there were no serious or severe adverse events. These data support clinical development of ombitasvir in combination with inhibitors targeting HCV NS3/4A protease (ABT-450 with ritonavir) and HCV NS5B polymerase (ABT-333, dasabuvir) for the treatment of chronic HCV genotype 1 infection. (Study M12-116 is registered at ClinicalTrials.gov under registration no. NCT01181427.)

BACKGROUNDInterferon-containing regimens for the treatment of hepatitis C virus (HCV) infection are associated with increased toxic effects in patients who also have cirrhosis. We evaluated the interferon-free combination of the protease inhibitor ABT-450 with ritonavir (ABT-450/r), the NS5A inhibitor ombitasvir (ABT-267), the nonnucleoside polymerase inhibitor dasabuvir (ABT-333), and ribavirin in an open-label phase 3 trial involving previously untreated and previously treated adults with HCV genotype 1 infection and compensated cirrhosis.METHODSWe randomly assigned 380 patients with Child-Pugh class A cirrhosis to receive either 12 or 24 weeks of treatment with ABT-450/r-ombitasvir (at a once-daily dose of 150 mg of ABT-450, 100 mg of ritonavir, and 25 mg of ombitasvir), dasabuvir (250 mg twice daily), and ribavirin administered according to body weight. The primary efficacy end point was a sustained virologic response 12 weeks after the end of treatment. The rate of sustained virologic response in each group was compared with the estimated rate with a telaprevir-based regimen (47%; 95% confidence interval [CI], 41 to 54). A noninferiority margin of 10.5 percentage points established 43% as the noninferiority threshold; the superiority threshold was 54%.RESULTSA total of 191 of 208 patients who received 12 weeks of treatment had a sustained virologic response at post-treatment week 12, for a rate of 91.8% (97.5% CI, 87.6 to 96.1). A total of 165 of 172 patients who received 24 weeks of treatment had a sustained virologic response at post-treatment week 12, for a rate of 95.9% (97.5% CI, 92.6 to 99.3). These rates were superior to the historical control rate. The three most common adverse events were fatigue (in 32.7% of patients in the 12-week group and 46.5% of patients in the 24-week group), headache (in 27.9% and 30.8%, respectively), and nausea (in 17.8% and 20.3%, respectively). The hemoglobin level was less than 10 g per deciliter in 7.2% and 11.0% of patients in the respective groups. Overall, 2.1% of patients discontinued treatment owing to adverse events.CONCLUSIONSIn this phase 3 trial of an oral, interferon-free regimen evaluated exclusively in patients with HCV genotype 1 infection and cirrhosis, multitargeted therapy with the use of three new antiviral agents and ribavirin resulted in high rates of sustained virologic response. Drug discontinuations due to adverse events were infrequent.

BACKGROUND:Interferon-containing regimens for the treatment of hepatitis C virus (HCV) infection are associated with increased toxic effects in patients who also have cirrhosis. We evaluated the interferon-free combination of the protease inhibitor ABT-450 with ritonavir (ABT-450/r), the NS5A inhibitor ombitasvir (ABT-267), the nonnucleoside polymerase inhibitor dasabuvir (ABT-333), and ribavirin in an open-label phase 3 trial involving previously untreated and previously treated adults with HCV genotype 1 infection and compensated cirrhosis. METHODS:We randomly assigned 380 patients with Child-Pugh class A cirrhosis to receive either 12 or 24 weeks of treatment with ABT-450/r-ombitasvir (at a once-daily dose of 150 mg of ABT-450, 100 mg of ritonavir, and 25 mg of ombitasvir), dasabuvir (250 mg twice daily), and ribavirin administered according to body weight. The primary efficacy end point was a sustained virologic response 12 weeks after the end of treatment. The rate of sustained virologic response in each group was compared with the estimated rate with a telaprevir-based regimen (47%; 95% confidence interval [CI], 41 to 54). A noninferiority margin of 10.5 percentage points established 43% as the noninferiority threshold; the superiority threshold was 54%. RESULTS:A total of 191 of 208 patients who received 12 weeks of treatment had a sustained virologic response at post-treatment week 12, for a rate of 91.8% (97.5% CI, 87.6 to 96.1). A total of 165 of 172 patients who received 24 weeks of treatment had a sustained virologic response at post-treatment week 12, for a rate of 95.9% (97.5% CI, 92.6 to 99.3). These rates were superior to the historical control rate. The three most common adverse events were fatigue (in 32.7% of patients in the 12-week group and 46.5% of patients in the 24-week group), headache (in 27.9% and 30.8%, respectively), and nausea (in 17.8% and 20.3%, respectively). The hemoglobin level was less than 10 g per deciliter in 7.2% and 11.0% of patients in the respective groups. Overall, 2.1% of patients discontinued treatment owing to adverse events. CONCLUSIONS:In this phase 3 trial of an oral, interferon-free regimen evaluated exclusively in patients with HCV genotype 1 infection and cirrhosis, multitargeted therapy with the use of three new antiviral agents and ribavirin resulted in high rates of sustained virologic response. Drug discontinuations due to adverse events were infrequent. (Funded by AbbVie; TURQUOISE-II ClinicalTrials.gov number, NCT01704755.).

2 of ascending colon (AC) emptying and bowel functions (analysis of variance, ANOVA, on ranks). Dunnett’s test compared each dose with placebo. A per protocol analysis (PPA) of time to first BM was assessed using a proportional hazards model. Results: There were 57 participants (56 female, 1 male; mean age 42.8±1.3y; mean BMI 25.3±0.5kg/m2) with baseline GE T1/2 of 125.0±4.3min (SEM) and GC24 of 1.83±0.05 respectively; 55 patients completed the study. YKP10811 was associated with accelerated GI transit (CF6), AC T1/ 2, and colonic transit at 4, 24, and 48h. PPA also showed overall acceleration of GE T1/2. YKP10811 was associated with accelerated time to pass BM after first dosing, and increased stool consistency over the 8-day treatment period. There were no deaths and no serious adverse events. Two subjects discontinued prematurely (1 on placebo, 1 on 20mg YKP10811). Conclusion: YKP10811 enhances GI and colonic transit and improves bowel functions, particularly stool consistency and time to first BM, during an 8-day treatment trial. Funding: Supported by a grant from SK Life Science.