Amit Khatri

Ombitasvir, Paritaprevir Co-dosed With Ritonavir, Dasabuvir, and Ribavirin for Hepatitis C in Patients Co-infected With HIV-1: A Randomized Trial

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.

Phase 2b Trial of Interferon-free Therapy for Hepatitis C Virus Genotype 1

BACKGROUND An interferon-free combination of the protease inhibitor ABT-450 with ritonavir (ABT-450/r), the nonnucleoside polymerase inhibitor ABT-333, and ribavirin showed efficacy against the hepatitis C virus (HCV) in a pilot study involving patients with HCV genotype 1 infection. The addition of another potent agent, the NS5A inhibitor ABT-267, may improve efficacy, especially in difficult-to-treat patients. This study was designed to evaluate multiple regimens of direct-acting antiviral agents and ribavirin in patients with HCV genotype 1 infection who had not received therapy previously or who had no response to prior therapy with pegylated interferon and ribavirin. METHODS In this phase 2b, open-label study with 14 treatment subgroups, 571 patients without cirrhosis who had not received treatment previously or who had not had a response to prior therapy were randomly assigned to a regimen of ABT-450/r, combined with ABT-267 or ABT-333 or both, for 8, 12, or 24 weeks and received at least one dose of therapy. All the subgroups but 1 also received ribavirin (dose determined according to body weight). The primary end point was sustained virologic response at 24 weeks after the end of treatment. The primary efficacy analysis compared rates between previously untreated patients who received three direct-acting antiviral agents and ribavirin for 8 weeks and those who received the same therapy for 12 weeks. RESULTS Among previously untreated patients who received three direct-acting antiviral agents (with the ABT-450/r dose administered as 150 mg of ABT-450 and 100 mg of ritonavir) plus ribavirin, the rate of sustained virologic response at 24 weeks after treatment was 88% among those who received the therapy for 8 weeks and 95% among those who received the therapy for 12 weeks (difference, -7 percentage points; 95% confidence interval, -19 to 5; P=0.24). The rates of sustained virologic response across all treatment subgroups ranged from 83 to 100%. The most frequent adverse events were fatigue, headache, nausea, and insomnia. Eight patients (1%) discontinued treatment owing to adverse events. CONCLUSIONS In this phase 2b study, all-oral regimens of antiviral agents and ribavirin were effective both in patients with HCV genotype 1 infection who had not received therapy previously and in those who had not had a response to prior therapy. (Funded by AbbVie; ClinicalTrials.gov number, NCT01464827.).

Drug-drug interaction profile of the all-oral anti-hepatitis C virus regimen of paritaprevir/ritonavir, ombitasvir, and dasabuvir

BACKGROUND & AIMS Paritaprevir (administered with ritonavir, PTV/r), ombitasvir (OBV), and dasabuvir (DSV) are direct-acting antiviral agents (DAAs) for the treatment of chronic hepatitis C virus (HCV) infection. Thirteen studies were conducted to characterize drug-drug interactions for the 3D regimen of OBV, PTV/r, and DSV and various medications in healthy volunteers to inform dosing recommendations in HCV-infected patients. METHODS Mechanism-based drug-drug interactions were evaluated for gemfibrozil, ketoconazole, carbamazepine, warfarin, omeprazole, digoxin, pravastatin, and rosuvastatin. Drug-drug interactions with medications commonly used in HCV-infected patients were evaluated for amlodipine, furosemide, alprazolam, zolpidem, duloxetine, escitalopram, methadone, buprenorphine/naloxone, and oral contraceptives. Ratios of geometric means with 90% confidence intervals for maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) were used to determine the magnitude of interaction. RESULTS Coadministration with the 3D regimen of OBV, PTV/r, and DSV resulted in a <2-fold change in mean Cmax and AUC for most medications and the DAAs, indicating minimal to modest interactions. Carbamazepine decreased PTV, ritonavir, and DSV exposures substantially, while gemfibrozil increased DSV exposures substantially. Although coadministration with ethinyl estradiol-containing contraceptives resulted in elevated alanine aminotransferase levels, coadministration with a progestin-only contraceptive did not. CONCLUSIONS The majority of medications can be coadministered with the 3D regimen of OBV, PTV/r, and DSV without dose adjustment, or with clinical monitoring or dose adjustment. Although no dose adjustment is necessary for the 3D regimen when coadministered with 17 of the 20 medications, coadministration with gemfibrozil, carbamazepine, or ethinyl estradiol-containing contraceptives is contraindicated.

3 SAFETY AND EFFICACY OF INTERFERON-FREE REGIMENS OF ABT-450/r, ABT-267, ABT-333 +/− RIBAVIRIN IN PATIENTS WITH CHRONIC HCV GT1 INFECTION: RESULTS FROM THE AVIATOR STUDY

3 SAFETY AND EFFICACY OF INTERFERON-FREE REGIMENS OF ABT-450/r, ABT-267, ABT-333 +/− RIBAVIRIN IN PATIENTS WITH CHRONIC HCV GT1 INFECTION: RESULTS FROM THE AVIATOR STUDY K.V. Kowdley, E. Lawitz, F. Poordad, D.E. Cohen, D. Nelson, S. Zeuzem, G.T. Everson, P. Kwo, G.R. Foster, M. Sulkowski, W. Xie, L. Larsen, A. Khatri, T. Podsadecki, B. Bernstein. Digestive Disease Institute, Virginia Mason Medical Center, Seattle, WA, University of Texas Health Science Center, San Antonio, TX, Abbott Laboratories, Abbott Park, IL, University of Florida College of Medicine, Gainesville, FL, USA; J.W. Goethe University, Frankfurt, Germany; University of Colorado Denver, Aurora, CO, Indiana University, Indianapolis, IN, USA; Queen Marys University of London, Barts Health, London, UK; Johns Hopkins University, Baltimore, MD, USA E-mail: kris.kowdley@vmmc.org

Pharmacokinetics and safety of co-administered paritaprevir plus ritonavir, ombitasvir, and dasabuvir in hepatic impairment

BACKGROUND & AIMS Paritaprevir, ombitasvir, and dasabuvir are direct-acting antivirals for treatment of chronic hepatitis C virus (HCV) infection. The aim of this study was to characterize the effects of mild, moderate, and severe hepatic impairment on the pharmacokinetics of these drugs. METHODS HCV-negative subjects with normal hepatic function (n=7) or mild (Child-Pugh A, n=6), moderate (Child-Pugh B, n=6), or severe (Child-Pugh C, n=5) hepatic impairment received a single-dose of the combination of paritaprevir plus ritonavir (paritaprevir/r, 200/100 mg), ombitasvir (25 mg), and dasabuvir (400 mg). Plasma samples were collected through 144 hours after administration for pharmacokinetic assessments. RESULTS Paritaprevir, ombitasvir, dasabuvir, and ritonavir exposures (maximal plasma concentration, C(max), and area under the concentration-time curve, AUC) were minimally affected in subjects with mild or moderate hepatic impairment. Differences in exposures between healthy controls and subjects with mild or moderate hepatic impairment were less than 35%, except for 62% higher paritaprevir AUC in subjects with moderate hepatic impairment. Paritaprevir and dasabuvir AUC were significantly higher in subjects with severe hepatic impairment (950% and 325%, respectively). However, ombitasvir AUC was 54% lower and ritonavir AUC was comparable. Adverse events included eye stye, insomnia, and pain from an infiltrated intravenous line. CONCLUSIONS The changes observed in paritaprevir, ritonavir, ombitasvir, and dasabuvir exposures in subjects with mild or moderate hepatic impairment do not necessitate dose adjustment. Subjects with severe hepatic impairment had substantially higher paritaprevir and dasabuvir exposures.

Evaluation of Drug-Drug Interactions Between Hepatitis C Antiviral Agents Ombitasvir, Paritaprevir/Ritonavir, and Dasabuvir and HIV-1 Protease Inhibitors.

BACKGROUND Guidelines for the treatment of human immunodeficiency virus (HIV) infection consistently recommend initiation of antiretroviral therapy in patients with hepatitis C virus (HCV)/HIV-1 coinfection. Therefore, potential drug interactions between antiretroviral drugs and HCV direct-acting antiviral agents (DAAs) must be carefully considered. The objective of this investigation was to evaluate the compatibility of a novel combination of DAAs (the 3D regimen) with commonly prescribed HIV-1 protease inhibitors (PIs). METHODS Five phase 1, multiple-dose, open-label pharmacokinetic studies were performed in 144 healthy volunteers. Participants in each study were randomly assigned 1:1 into cohorts assessing the effects of the steady-state 3D regimen on steady-state HIV-1 PIs or vice versa. The 3D regimen comprised ombitasvir (25 mg once daily), paritaprevir/ritonavir (150/100 mg once daily), and dasabuvir (250 or 400 mg twice daily). The HIV-1 PIs assessed included atazanavir, darunavir, and lopinavir (administered with ritonavir). Safety, tolerability, and pharmacokinetic parameters were assessed to evaluate the compatibility of the drug regimens. RESULTS Coadministration of the 3D regimen with the evaluated HIV-1 PIs was generally well tolerated in healthy volunteers. Morning administration of atazanavir (300 mg once daily) and darunavir regimens exhibited no clinically meaningful drug interactions with the 3D regimen. However, owing to higher paritaprevir and/or ritonavir exposures, evening administration of atazanavir (300 mg) plus ritonavir (100 mg) or lopinavir/ritonavir (800/200 mg) with the 3D regimen is not recommended. CONCLUSIONS The 3D regimen can be coadministered with morning atazanavir and darunavir regimens. However, evening atazanavir plus ritonavir and lopinavir/ritonavir regimens are not recommended in combination with the 3D regimen.

Drug Interactions with the Direct-Acting Antiviral Combination of Ombitasvir and Paritaprevir-Ritonavir

ABSTRACT The two direct-acting antiviral (2D) regimen of ombitasvir and paritaprevir (administered with low-dose ritonavir) is being developed for treatment of genotype subtype 1b and genotypes 2 and 4 chronic hepatitis C virus (HCV) infection. Drug-drug interactions were evaluated in healthy volunteers to develop dosing recommendations for HCV-infected subjects. Mechanism-based interactions were evaluated for ketoconazole, pravastatin, rosuvastatin, digoxin, warfarin, and omeprazole. Interactions were also evaluated for duloxetine, escitalopram, methadone, and buprenorphine-naloxone. Ratios of geometric means with 90% confidence intervals for the maximum plasma concentration and the area under the plasma concentration-time curve were estimated to assess the magnitude of the interactions. For most medications, coadministration with the 2D regimen resulted in a <50% change in exposures. Ketoconazole, digoxin, pravastatin, and rosuvastatin exposures increased by up to 105%, 58%, 76%, and 161%, respectively, and omeprazole exposures decreased by approximately 50%. Clinically meaningful changes in ombitasvir, paritaprevir, or ritonavir exposures were not observed. In summary, all 11 medications evaluated can be coadministered with the 2D regimen, with most medications requiring no dose adjustment. Ketoconazole, digoxin, pravastatin, and rosuvastatin require lower doses, and omeprazole may require a higher dose. No dose adjustment is required for the 2D regimen.

Evaluation of Drug-Drug Interactions Between Direct-Acting Anti-Hepatitis C Virus Combination Regimens and the HIV-1 Antiretroviral Agents Raltegravir, Tenofovir, Emtricitabine, Efavirenz, and Rilpivirine

ABSTRACT The three direct-acting antiviral agent (3D) regimen is a novel combination of direct-acting antiviral agents (DAAs) that has proven effective for the treatment of hepatitis C virus (HCV) infection. Given the potential for coadministration in patients with human immunodeficiency virus infection, possible drug interactions with antiretroviral drugs must be carefully considered. Four phase 1, multiple-dose pharmacokinetic studies were conducted in healthy volunteers (n = 66). The 3D regimen of 150/100 mg daily paritaprevir/ritonavir, 25 mg daily ombitasvir, and 400 mg twice-daily dasabuvir was administered alone or in combination with 200 mg daily of emtricitabine and 300 mg daily of tenofovir disoproxil fumarate (tenofovir DF), 25 mg daily of rilpivirine, or 400 mg of raltegravir twice daily. A 2-DAA regimen of 150/100 mg daily paritaprevir/ritonavir and 400 mg of dasabuvir twice daily was also studied in combination with efavirenz/emtricitabine/tenofovir DF at 600/200/300 mg daily, respectively (Atripla; Bristol-Myers Squibb). Pharmacokinetic parameters were determined from plasma drug concentrations. No clinically significant drug interactions were observed (≤32% change in exposure) between the 3D regimen and that of emtricitabine plus tenofovir DF. Raltegravir exposure was increased up to 134% when the drug was coadministered with the 3D regimen. Although coadministration with rilpivirine was well tolerated in healthy volunteers, observed elevations in rilpivirine exposures may increase the potential for adverse drug reactions. Concomitant use of the 2-DAA regimen and efavirenz/emtricitabine/tenofovir DF was discontinued owing to poor tolerability and adverse events. No dose adjustment is required during coadministration of raltegravir, tenofovir DF, or emtricitabine with the 3D regimen. Rilpivirine is not recommended and efavirenz is contraindicated for coadministration with the 3D regimen.

Safety and efficacy of ombitasvir – 450/r and dasabuvir and ribavirin in HCV/HIV-1 co-infected patients receiving atazanavir or raltegravir ART regimens

Whether concomitant HIV antiretroviral therapy (ART) affects the safety and efficacy of interferon‐free HCV therapies or whether HCV treatment may negatively affect HIV control is unclear. We assessed the 3 direct‐acting antiviral (3D) regimen of ombitasvir, ABT‐450 (identified by AbbVie and Enanta; co‐dosed with ritonavir) and dasabuvir with ribavirin (RBV) in HCV/HIV‐1 co‐infected patients with and without cirrhosis, including HCV treatment‐experienced, receiving atazanavir (ATV)‐ or raltegravir (RAL)‐based ART therapy.

Metabolism and Disposition of the Hepatitis C Protease Inhibitor Paritaprevir in Humans

Paritaprevir (also known as ABT-450), a potent NS3-4A serine protease inhibitor [identified by AbbVie (North Chicago, IL) and Enanta Pharmaceuticals (Watertown, MA)] of the hepatitis C virus (HCV), has been developed in combination with ombitasvir and dasabuvir in a three–direct-acting antiviral agent (DAA) oral regimen for the treatment of patients infected with HCV genotype 1. This article describes the mass balance, metabolism, and disposition of paritaprevir in humans. After the administration of a single 200-mg oral dose of [14C]paritaprevir coadministered with 100 mg of ritonavir to four male healthy volunteers, the mean total percentage of the administered radioactive dose recovered was 96.5%, with recovery in individual subjects ranging from 96.0% to 96.9%. Radioactivity derived from [14C]paritaprevir was primarily eliminated in feces (87.8% of the dose). Radioactivity recovered in urine accounted for 8.8% of the dose. The biotransformation of paritaprevir in humans involves: 1) P450-mediated oxidation on the olefinic linker, the phenanthridine group, the methylpyrazinyl group, or combinations thereof; and 2) amide hydrolysis at the acyl cyclopropane-sulfonamide moiety and the pyrazine-2-carboxamide moiety. Paritaprevir was the major component in plasma [90.1% of total radioactivity in plasma, AUC from time 0 to 12 hours (AUC0–12hours) pool]. Five minor metabolites were identified in plasma, including the metabolites M2, M29, M3, M13, and M6; none of the metabolites accounted for greater than 10% of the total radioactivity. Paritaprevir was primarily eliminated through the biliary-fecal route followed by microflora-mediated sulfonamide hydrolysis to M29 as a major component in feces (approximately 60% of dose). In summary, the biotransformation and clearance pathways of paritaprevir were characterized, and the structures of metabolites in circulation and excreta were elucidated.