Effectiveness of elbasvir/grazoprevir plus ribavirin for hepatitis C virus genotype 1a infection and baseline NS5A resistance.

INTRODUCTION AND OBJECTIVES: In clinical trials, patients with hepatitis C virus (HCV) genotype (GT)1a infection and baseline resistance-associated substitutions (RASs) at amino acid positions 28, 30, 31, or 93 receiving elbasvir/grazoprevir for 12 weeks achieved lower rates of sustained virologic response (SVR) than those without baseline RASs. SVR rates in patients with RASs were improved when elbasvir/grazoprevir treatment duration was extended from 12 to 16 weeks and administered concomitantly with ribavirin. MATERIALS AND METHODS: This was a retrospective, observational analysis using electronic health record abstraction. Patients with HCV GT1a infection and RASs at positions 28, 30, 31, or 93 who were prescribed 16 weeks of elbasvir/grazoprevir and ≥ 1 prescription for ribavirin were included. SVR was defined as HCV RNA below the lower limit of quantification ≥ 70 days after end of treatment. RESULTS: The primary analysis included patients with baseline RASs at positions 30, 31, or 93 (n = 76); a secondary analysis included patients with RASs at positions 28, 30, 31, or 93 (n = 93). SVR was achieved by 77.6% (59/76) of patients in the primary analysis and 80.6% (75/93) of those in the secondary analysis. Of the 18 (19.4%) patients in the secondary cohort who failed to achieve SVR, 8 relapsed (4 with treatment-emergent NS5A substitutions) and 10 did not have viral sequencing to distinguish relapse from reinfection. CONCLUSIONS: This analysis highlights the opportunities in leveraging real-world data to further understand treatment outcomes in smaller, discrete subgroups of patients with HCV infection who cannot be thoroughly evaluated in clinical trials.

Reinfection and Risk Behaviors After Treatment of Hepatitis C Virus Infection in Persons Receiving Opioid Agonist Therapy : A Cohort Study.

BACKGROUND: Hepatitis C virus (HCV) reinfection after successful treatment may reduce the benefits of cure among people who inject drugs. OBJECTIVE: To evaluate the rate of HCV reinfection for 3 years after successful treatment among people receiving opioid agonist therapy (OAT). DESIGN: A 3-year, long-term, extension study of persons enrolled in the CO-STAR (Hepatitis C Patients on Opioid Substitution Therapy Antiviral Response) study (ClinicalTrials.gov: NCT02105688). SETTING: 55 clinical trial sites in 13 countries. PATIENTS: Aged 18 years and older with chronic HCV infection with genotypes 1, 4, or 6 receiving stable OAT. INTERVENTION: No treatments were administered. MEASUREMENTS: Serum samples were assessed for HCV reinfection. Urine drug screening was performed. RESULTS: Among 296 participants who received treatment, 286 were evaluable for reinfection and 199 were enrolled in the long-term extension study. The rate of HCV reinfection was 1.7 [95% CI, 0.8 to 3.0] per 100 person-years; 604 person-years of follow-up). A higher rate of reinfection was seen among people with recent injecting drug use (1.9 [95% CI, 0.5 to 4.8] per 100 person-years; 212 person-years). Ongoing drug use and injecting drug use were reported by 59% and 21% of participants, respectively, at the 6-month follow-up visit and remained stable during 3 years of follow-up. LIMITATIONS: Participants were required to be 80% adherent to OAT at baseline and may represent a population with higher stability and lower risk for HCV reinfection. Rate of reinfection may be underestimated because all participants did not continue in the long-term extension study; whether participants who discontinued were at higher risk for reinfection is unknown. CONCLUSION: Reinfection with HCV was low but was highest in the first 24 weeks after treatment completion and among people with ongoing injecting drug use and needle-syringe sharing. PRIMARY FUNDING SOURCE: Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Safety and tolerability of elbasvir/grazoprevir in chronic hepatitis C virus therapy: Integrated analysis from clinical trials.

Direct-acting antiviral treatments for chronic hepatitis C virus (HCV) infection are generally safe; however, understanding the safety profile of each regimen is essential for their continued use. Safety data were pooled from 12 clinical trials of elbasvir/grazoprevir (EBR/GZR) that enrolled adult participants with HCV infection. Pooled analyses are presented for participants receiving EBR/GZR for 12 weeks and those receiving EBR/GZR plus ribavirin (RBV) for 16-18 weeks. Safety data are also presented for participants with comorbidities receiving EBR/GZR for 12 weeks in individual clinical trials (chronic kidney disease [CKD] stage 4/5, inherited blood disorders [IBLD] or receiving opioid agonist therapy [OAT]). Among 1743 participants receiving EBR/GZR for 12 weeks, 1068 (61.3%) reported ≥1 adverse event (AE) and 491 had AEs (28.2%) considered drug-related. The most frequent AEs were headache (10.6%), fatigue (8.7%), nasopharyngitis (5.8%), nausea (5.1%) and diarrhoea (5.0%). Serious AEs were reported by 37 participants (2.1%), and 12 (0.7%) discontinued treatment due to an AE. In populations with CKD 4/5 or IBLD or receiving OAT, safety was similar in participants receiving EBR/GZR for 12 weeks and those receiving placebo. Some AEs occurred at higher frequencies in participants receiving RBV compared with those receiving EBR/GZR alone: fatigue (32.7% vs 8.7%); headache (21.6% vs 10.6%); and nausea (15.8% vs 5.1%). Safety was similar in participants with and those without cirrhosis. Grade 3/4 alanine aminotransferase elevations were reported in 0.7% participants. EBR/GZR is a safe treatment option for individuals with HCV genotype (GT) 1 or GT4 infections, even those with challenging comorbidities such as CKD or IBLD and those receiving OAT.

Efficacy and safety of elbasvir/grazoprevir for 8 or 12 weeks for hepatitis C virus genotype 4 infection: A randomized study.

BACKGROUND & AIMS: Hepatitis C virus (HCV) genotype (GT) 4 infection is prevalent in sub-Saharan Africa and the Middle East, particularly in Egypt. This study evaluated the safety and efficacy of elbasvir/grazoprevir administered for 8 and 12 weeks in participants with HCV GT4 infection. METHODS: In this partially randomized, open-label multicentre study conducted in France (NCT03111108; Protocol MK5172-096), treatment-naive participants with GT4 infection and F0-F2 fibrosis were randomized 2:1 to elbasvir (50 mg)/grazoprevir (100 mg) for 8 or 12 weeks. Treatment-naive participants with F3-F4 fibrosis and all treatment-experienced participants (F0-F4) were assigned to elbasvir/grazoprevir for 12 weeks. The primary endpoint was sustained virologic response (SVR) 12 weeks after the end of therapy. RESULTS: One hundred and seventeen participants were enrolled. Among treatment-naive participants with F0-F2 fibrosis, SVR was achieved by 94% (50/53) and 96% (26/27) of those receiving elbasvir/grazoprevir for 8 or 12 weeks, respectively, and four participants relapsed. In the 12-week arm, 95% (35/37) achieved SVR and two participants relapsed. NS5A resistance-associated substitutions were present at baseline and virologic failure in five of the participants with relapse. Drug-related adverse events occurred in 42% (n = 22) and 50% (n = 32) of participants receiving 8 and 12 weeks of treatment, respectively. No participant discontinued treatment owing to an adverse event. CONCLUSION: These data confirm the efficacy of elbasvir/grazoprevir administered for 12 weeks in treatment-experienced individuals with HCV GT4 infection and those with advanced fibrosis. Treatment-naive individuals with mild fibrosis can be treated effectively with an 8-week regimen.

Efficacy and safety of ruzasvir 60 mg and uprifosbuvir 450 mg for 12 weeks in adults with chronic hepatitis C virus genotype 1, 2, 3, 4 or 6 infection.

In clinical trials, the three-drug regimen of ruzasvir (RZR) 60 mg, uprifosbuvir (UPR) 450 mg and grazoprevir 100 mg, with or without ribavirin, has demonstrated promising efficacy and excellent tolerability across a wide range of hepatitis C virus (HCV)-infected individuals. The present study assessed the efficacy and safety of the two-drug combination of RZR 60 mg plus UPR 450 mg administered for 12 weeks in participants with HCV genotype (GT) 1-6 infection. In this open-label clinical trial, treatment-naive or -experienced and cirrhotic or noncirrhotic participants with chronic HCV GT1-6 infection received RZR 60 mg plus UPR 450 mg orally once daily for 12 weeks (NCT02759315/protocol PN035). The primary efficacy endpoint was sustained virologic response at 12 weeks after the end of therapy (SVR12). One hundred and sixty participants were enrolled. SVR12 rates were 96% (52 of 54) in participants with GT1a infection; 100% (15 of 15) in those with GT1b infection; 97% (28 of 29) in those with GT2 infection; 77% (30 of 39) in those with GT3 infection; 90% (18 of 20) in those with GT4 infection; and 67% (2 of 3) in those with GT6 infection. Drug-related adverse events (AEs) reported by >5% of participants were fatigue (n = 10, 6.3%) and diarrhoea (n = 9, 5.6%). Five participants reported a total of 11 serious AEs, none considered drug-related. One participant experienced on-treatment alanine aminotransferase/aspartate aminotransferase elevations that resolved without intervention. Data from the present study indicate that the combination of RZR 60 mg plus UPR 450 mg once daily for 12 weeks was well tolerated overall but was effective only for certain genotypes.

Efficacy and safety of a two-drug direct-acting antiviral agent regimen ruzasvir 180 mg and uprifosbuvir 450 mg for 12 weeks in adults with chronic hepatitis C virus genotype 1, 2, 3, 4, 5 or 6.

Ruzasvir (MK-8408, an NS5A inhibitor) and uprifosbuvir (MK-3682, a nonstructural protein 5B nucleotide inhibitor) are highly potent direct-acting antiviral agents for the treatment of hepatitis C virus (HCV) infection. A phase III clinical trial evaluating the two-drug combination of ruzasvir 60 mg plus uprifosbuvir 450 mg suggested suboptimal efficacy in certain HCV genotypes (C-BREEZE 1; NCT02759315). The aim of the present study was to evaluate the efficacy and safety of ruzasvir in combination with uprifosbuvir administered at a higher dose than that assessed in the earlier study (C-BREEZE 2: NCT02956629/Merck protocol PN041). Treatment-naïve or interferon (with or without ribavirin)-experienced participants with or without compensated cirrhosis were enrolled. All participants received ruzasvir 180 mg plus uprifosbuvir 450 mg once daily for 12 weeks. The primary objectives were the proportion of participants with HCV RNA <15 lU/mL at 12 weeks after the end of study therapy (SVR12), and safety and tolerability of the study drug. Overall, 282 participants were enrolled. SVR12 (n/N) was 91.3% (42/46) in participants infected with HCV genotype (GT) 1a; GT1b, 96.7% (29/30); GT2, 91.5% (43/47); GT3, 73.8% (45/61); GT4, 98.2% (55/56); GT5, 100.0% (18/18); and GT6, 90.9% (20/22). Adverse events (AEs) were reported by 61.3% of participants; drug-related AEs were reported by 33.3%. The most frequent (≥5% of participants) drug-related AEs in all participants were fatigue (7.8%) and headache (7.4%). In conclusion, the two-drug combination of ruzasvir 180 mg plus uprifosbuvir 450 mg for 12 weeks was highly effective and well tolerated in participants infected with HCV GT1, GT2, GT4, GT5 and GT6, with a lower efficacy in GT3-infected persons.

Elbasvir/grazoprevir and sofosbuvir for hepatitis C virus genotype 3 infection with compensated cirrhosis: A randomized trial.

Many direct-acting antiviral regimens have reduced activity in people with hepatitis C virus (HCV) genotype (GT) 3 infection and cirrhosis. The C-ISLE study assessed the efficacy and safety of elbasvir/grazoprevir (EBR/GZR) plus sofosbuvir (SOF) with and without ribavirin (RBV) in compensated cirrhotic participants with GT3 infection. This was a phase 2, randomized, open-label study. Treatment-naive participants received EBR/GZR + SOF + RBV for 8 weeks or EBR/GZR + SOF for 12 weeks, and peginterferon/RBV treatment-experienced participants received EBR/GZR + SOF ± RBV for 12 weeks or EBR/GZR + SOF for 16 weeks. The primary endpoint was HCV RNA <15 IU/mL 12 weeks after the end of treatment (sustained virologic response at 12 weeks [SVR12]). Among treatment-naive participants, SVR12 was 91% (21/23) in those treated with RBV for 8 weeks and 96% (23/24) in those treated for 12 weeks. Among treatment-experienced participants, SVR12 was 94% (17/18) and 100% (17/17) in the 12-week arm, with and without RBV, respectively, and 94% (17/18) in the 16-week arm. Five participants failed to achieve SVR: 2 relapsed (both in the 8-week arm), 1 discontinued due to vomiting/cellulitis (16-week arm), and 2 discontinued (consent withdrawn/lost to follow-up). SVR12 was not affected by the presence of resistance-associated substitutions (RASs). There was no consistent change in insulin resistance, and 5 participants reported serious adverse events (pneumonia, chest pain, opiate overdose, cellulitis, decreased creatinine). High efficacy was demonstrated in participants with HCV GT3 infection and cirrhosis. Treatment beyond 12 weeks was not required, and efficacy was maintained regardless of baseline RASs. CONCLUSION: Data from this study support the use of EBR/GZR plus SOF for 12 weeks without RBV for treatment-naive and peginterferon/RBV-experienced people with GT3 infection and cirrhosis (ClinicalTrials.gov NCT02601573). (Hepatology 2018;67:2113-2126).

Safety and efficacy of elbasvir/grazoprevir in Asian participants with hepatitis C virus genotypes 1 and 4 infection.

BACKGROUND AND AIM: Estimates suggest that in Asia, more than 31 million individuals have hepatitis C virus infection. The present analysis was conducted to assess the efficacy and safety of elbasvir/grazoprevir in Asian participants enrolled in the elbasvir/grazoprevir phase 2/3 clinical trials. METHODS: This is an integrated analysis of data from 12 international phase 2/3 clinical trials. Asian participants with chronic hepatitis C virus genotype 1 or 4 infection who received elbasvir 50 mg/grazoprevir 100 mg once daily for 12 weeks or elbasvir/grazoprevir plus ribavirin for 16 weeks were included in this analysis. The primary end point was sustained virologic response at 12 weeks after completion of therapy (SVR12). RESULTS: Seven hundred eighty Asian participants from 15 countries were included in this analysis. SVR12 was achieved by 756/780 (96.9%) of all participants, including 748/772 (96.9%) of those who received elbasvir/grazoprevir for 12 weeks and 8/8 (100%) of those who received elbasvir/grazoprevir plus ribavirin for 16 weeks. In the genotype 1b-infected population, the SVR12 rate was 691/709 (97.5%), and there was no impact of age, high baseline viral load, or presence of cirrhosis. The most frequently reported adverse events were nasopharyngitis (8.0%), upper respiratory tract infection (5.4%), and diarrhea (5.2%). Twenty participants receiving elbasvir/grazoprevir for 12 weeks reported a total of 25 serious adverse events, and 7 (0.9%) discontinued treatment because of an adverse event. CONCLUSION: Elbasvir/grazoprevir administered for 12 weeks is an effective and generally well-tolerated treatment option for Asian individuals with hepatitis C virus genotype 1b infection.

Efficacy and safety of elbasvir/grazoprevir in participants with hepatitis C virus genotype 1, 4, or 6 infection from the Asia-Pacific region and Russia: Final results from the randomized C-CORAL study.

BACKGROUND AND AIM: Although treatment with direct-acting antivirals has dramatically improved morbidity and mortality attributable to chronic hepatitis C virus infection, universal access to these medicines has been slow in the Asia-Pacific region and Russia. This study evaluated efficacy and safety of elbasvir/grazoprevir in participants with hepatitis C virus infection from Asia-Pacific countries and Russia (C-CORAL). METHODS: C-CORAL was a phase 3, randomized, placebo-controlled study (NCT02251990). Treatment-naive, HIV-negative, cirrhotic and non-cirrhotic participants with chronic hepatitis C genotype 1, 4, or 6 infection were randomized to elbasvir 50 mg/grazoprevir 100 mg once daily for 12 weeks (immediate-treatment group) or placebo followed by deferred treatment with elbasvir/grazoprevir (deferred-treatment group). The primary efficacy outcome was sustained virologic response at 12 weeks, and the primary safety outcome was a comparison between the immediate-treatment group and placebo phase of the deferred-treatment group. RESULTS: A total of 489 participants were randomized (immediate-treatment group, n = 366; deferred-treatment group, n = 123). Sustained virologic response at 12 weeks in the combined immediate/deferred-treatment groups was 94.4% (459/486; 95% confidence interval = 92.4-96.5%). Sustained virologic response at 12 weeks was 98.2% in participants with genotype 1b, 91.9% with genotype 1a, and 66.7% with genotype 6 infection. Similar rates of adverse events and drug-related adverse events were seen in the immediate-treatment group versus placebo phase of the deferred-treatment group (51.0% vs 50.4% and 21.4% vs 21.1%). CONCLUSIONS: Elbasvir/grazoprevir for 12 weeks represents an effective and well-tolerated treatment option for treatment-naive people with genotype 1 infection from Asia-Pacific countries and Russia.

Pharmacokinetics and safety results from the Phase 3 randomized, open-label, study of intravenous posaconazole in patients at risk of invasive fungal disease.

OBJECTIVES: A two-part (Phase 1B/3), sequential, open-label, multicentre study evaluated the pharmacokinetics (PK) and safety of intravenous (iv) posaconazole given as antifungal prophylaxis to neutropenic patients with AML or myelodysplastic syndrome (MDS) or to recipients at risk of invasive fungal disease (IFD) after allogeneic HSCT. METHODS: Patients (N = 237) received 300 mg of posaconazole iv twice daily on day 1, followed by 300 mg of posaconazole iv once daily for 4-28 days. After at least 5 days, patients were randomly assigned to receive posaconazole oral suspension, 400 mg twice daily or 200 mg three times daily, to complete a 28 day treatment course. Primary PK parameters were steady-state average concentration over the dosing interval (Cavg) and posaconazole trough levels (Cmin). RESULTS: Mean posaconazole Cmin was 1320 ng/mL (day 6) and 1297 ng/mL (day 8); steady-state Cmin was 1090 ng/mL (day 10). Mean steady-state posaconazole Cavg was 1500 ng/mL (day 10 or 14) and was similar in HSCT recipients (1560 ng/mL) and AML/MDS patients (1470 ng/mL). The most commonly reported treatment-related adverse events were diarrhoea (8%), nausea (5%) and rash (5%). IFD was reported in 3/237 patients (1%; 2 proven, 1 probable). CONCLUSIONS: Intravenous posaconazole at 300 mg was well tolerated, resulted in adequate steady-state systemic exposure and was associated with a low incidence of IFD in this population at high risk. TRIAL REGISTRY AND NUMBER: ClinicalTrials.gov, NCT01075984.

Elbasvir/grazoprevir does not worsen renal function in patients with hepatitis C virus infection and pre-existing renal disease.

AIM: Treatment options have been limited for patients with hepatitis C virus (HCV) infection and chronic kidney disease stage 4/5 (CKD 4/5). The aim of this analysis was to evaluate the impact of elbasvir/grazoprevir (EBR/GZR) on estimated glomerular filtration rate (eGFR) in patients with CKD stage 3 enrolled in phase II/III clinical trials. METHODS: We undertook a retrospective integrated analysis of patients with CKD 3 enrolled in the EBR/GZR phase II/III clinical trials. All patients were required to have chronic HCV infection and have received EBR 50 mg/GZR 100 mg, with or without ribavirin, for 8-18 weeks. Patients with CKD 3 (eGFR <60 to ≥30 mL/min/1.73 m2 ) at baseline plus ≥1 eGFR assessment postbaseline were included. In all studies, the primary endpoint was sustained virologic response 12 weeks after completion of therapy. RESULTS: Thirty-two patients with CKD 3 were identified from a pooled dataset of 1689 patients enrolled in the EBR/GZR clinical trial program. Thirty-one (97%) patients achieved SVR12 and one patient relapsed. In these 32 patients, there was no decline in median eGFR at the end of treatment or at follow-up week 12 compared with baseline. Median eGFR values were 56 mL/min/1.73 m2 (range, 45-59) at baseline, 58 mL/min/1.73 m2 (range, 41-78) at the end of treatment and 59 mL/min/1.73 m2 (range, 38-78) 12 weeks after completing treatment. DISCUSSION: Elbasvir/grazoprevir is a safe and effective treatment option for patients with compromised renal function, irrespective of baseline eGFR.

Elbasvir-Grazoprevir to Treat Hepatitis C Virus Infection in Persons Receiving Opioid Agonist Therapy: A Randomized Trial.

Background: Hepatitis C virus (HCV) infection is common in persons who inject drugs (PWID). Objective: To evaluate elbasvir-grazoprevir in treating HCV infection in PWID. Design: Randomized, placebo-controlled, double-blind trial. (ClinicalTrials.gov: NCT02105688). Setting: Australia, Canada, France, Germany, Israel, the Netherlands, New Zealand, Norway, Spain, Taiwan, the United Kingdom, and the United States. Patients: 301 treatment-naive patients with chronic HCV genotype 1, 4, or 6 infection who were at least 80% adherent to visits for opioid agonist therapy (OAT). Intervention: The immediate-treatment group (ITG) received elbasvir-grazoprevir for 12 weeks; the deferred-treatment group (DTG) received placebo for 12 weeks, no treatment for 4 weeks, then open-label elbasvir-grazoprevir for 12 weeks. Measurements: The primary outcome was sustained virologic response at 12 weeks (SVR12), evaluated separately in the ITG and DTG. Other outcomes included SVR24, viral recurrence or reinfection, and adverse events. Results: The SVR12 was 91.5% (95% CI, 86.8% to 95.0%) in the ITG and 89.5% (95% CI, 81.5% to 94.8%) in the active phase of the DTG. Drug use at baseline and during treatment did not affect SVR12 or adherence to HCV therapy. Among 18 patients with posttreatment viral recurrence through 24-week follow-up, 6 had probable reinfection. If the probable reinfections were assumed to be responses, SVR12 was 94.0% (CI, 89.8% to 96.9%) in the ITG. One patient in the ITG (1 of 201) and 1 in the placebo-phase DTG (1 of 100) discontinued treatment because of an adverse event. Limitation: These findings may not be generalizable to PWID who are not receiving OAT, nor do they apply to persons with genotype 3 infection, a common strain in PWID. Conclusion: Patients with HCV infection who were receiving OAT and treated with elbasvir-grazoprevir had high rates of SVR12, regardless of ongoing drug use. These results support the removal of drug use as a barrier to interferon-free HCV treatment for patients receiving OAT. Primary Funding Source: Merck & Co.

Grazoprevir, Elbasvir, and Ribavirin for Chronic Hepatitis C Virus Genotype 1 Infection After Failure of Pegylated Interferon and Ribavirin With an Earlier-Generation Protease Inhibitor: Final 24-Week Results From C-SALVAGE.

BACKGROUND: The phase 2 C-SALVAGE study (Hepatitis C-Salvage Study for Patients who Failed DAA/PR Therapy) demonstrated a 96.2% sustained virologic response at 12 weeks (SVR12) rate using the NS3/4A protease inhibitor grazoprevir and the NS5A inhibitor elbasvir together with ribavirin in treatment-experienced patients with chronic hepatitis C virus (HCV) genotype 1 infection. METHODS: C-SALVAGE was a prospective open-label trial of grazoprevir 100 mg once daily and elbasvir 50 mg once daily coadministered with weight-based ribavirin twice daily for 12 weeks in genotype 1-infected cirrhotic and noncirrhotic patients who had failed treatment with ≥ 4 weeks of pegylated interferon and ribavirin plus either boceprevir, telaprevir, or simeprevir. Although the primary efficacy outcome was SVR12, patients were also evaluated 24 weeks after cessation of study therapy. Population sequencing was performed at baseline and periodically in virologic failures throughout the 24-week posttherapy follow-up period. RESULTS: SVR24 rates were 76 of 79 (96.2%) overall, with all 3 relapses occurring by posttherapy week 8. Every NS3 and NS5A variant detected at baseline reappeared at the time of relapse and persisted throughout the available follow-up period. NS3_A156T emerged in virus from each patient at relapse, but rapidly disappeared over the ensuing 2 weeks in 2 patients. NS5A_Y93H emerged in virus from 2 patients at relapse and persisted for the entire follow-up period. CONCLUSIONS: Grazoprevir and elbasvir with ribavirin for 12 weeks maintained HCV suppression for at least 24 weeks posttherapy without late relapses. Baseline resistance-associated variants (RAVs) stably reappeared at relapse in all 3 patients with virologic failure. NS5A_RAVs emerging at relapse persisted for the full 24-week follow-up period. If confirmed, this finding could complicate retreatment of the small number of patients failing regimens containing an NS5A inhibitor. CLINICAL TRIALS REGISTRATION: NCT02105454.

Grazoprevir-Elbasvir Combination Therapy for Treatment-Naive Cirrhotic and Noncirrhotic Patients With Chronic Hepatitis C Virus Genotype 1, 4, or 6 Infection: A Randomized Trial.

BACKGROUND: Novel interferon- and ribavirin-free regimens are needed to treat hepatitis C virus (HCV) infection. OBJECTIVE: To evaluate the safety and efficacy of grazoprevir (NS3/4A protease inhibitor) and elbasvir (NS5A inhibitor) in treatment-naive patients. DESIGN: Randomized, blinded, placebo-controlled trial. (ClinicalTrials.gov: NCT02105467). SETTING: 60 centers in the United States, Europe, Australia, Scandinavia, and Asia. PATIENTS: Cirrhotic and noncirrhotic treatment-naive adults with genotype 1, 4, or 6 infection. INTERVENTION: Oral, once-daily, fixed-dose grazoprevir 100 mg/elbasvir 50 mg for 12 weeks, stratified by fibrosis and genotype. Patients were randomly assigned 3:1 to immediate or deferred therapy. MEASUREMENTS: Proportion of patients in the immediate-treatment group achieving unquantifiable HCV RNA 12 weeks after treatment (SVR12); adverse events in both groups. RESULTS: Among 421 participants, 194 (46%) were women, 157 (37%) were nonwhite, 382 (91%) had genotype 1 infection, and 92 (22%) had cirrhosis. Of 316 patients receiving immediate treatment, 299 of 316 (95% [95% CI, 92% to 97%]) achieved SVR12, including 144 of 157 (92% [CI, 86% to 96%]) with genotype 1a, 129 of 131 (99% [CI, 95% to 100%]) with genotype 1b, 18 of 18 (100% [CI, 82% to 100%]) with genotype 4, 8 of 10 (80% [CI, 44% to 98%]) with genotype 6, 68 of 70 (97% [CI, 90% to 100%]) with cirrhosis, and 231 of 246 (94% [CI, 90% to 97%]) without cirrhosis. Virologic failure occurred in 13 patients (4%), including 1 case of breakthrough infection and 12 relapses, and was associated with baseline NS5A polymorphisms and emergent NS3 or NS5A variants or both. Serious adverse events occurred in 9 (2.8%) and 3 (2.9%) patients in the active and placebo groups, respectively (difference <0.05 percentage point [CI, -5.4 to 3.1 percentage points]); none were considered drug related. The most common adverse events in the active group were headache (17%), fatigue (16%), and nausea (9%). LIMITATION: The study lacked an active-comparator control group and included relatively few genotype 4 and 6 infections. CONCLUSION: Grazoprevir-elbasvir achieved high SVR12 rates in treatment-naive cirrhotic and noncirrhotic patients with genotype 1, 4, or 6 infection. This once-daily, all-oral, fixed-combination regimen represents a potent new therapeutic option for chronic HCV infection. PRIMARY FUNDING SOURCE: Merck & Co.

Grazoprevir and elbasvir plus ribavirin for chronic HCV genotype-1 infection after failure of combination therapy containing a direct-acting antiviral agent.

BACKGROUND & AIMS: The Phase-2 C-SALVAGE study evaluated an investigational interferon-free combination of grazoprevir (a NS3/4A protease inhibitor) and elbasvir (a NS5A inhibitor) with ribavirin for patients with chronic HCV genotype-1 infection who had failed licensed DAA-containing therapy. METHODS: C-SALVAGE was an open-label study of grazoprevir 100 mg and elbasvir 50 mg QD with weight-based ribavirin BID for 12 weeks in cirrhotic and non-cirrhotic patients with chronic HCV genotype-1 infection who had not attained SVR after ⩾4 weeks of peginterferon and ribavirin plus either boceprevir, telaprevir, or simeprevir. Exclusion criteria included decompensated liver disease, hepatocellular carcinoma, and HIV or HBV co-infection. The primary efficacy outcome was SVR12 defined as a HCV RNA level below the assay limit of quantification 12 weeks after the end of treatment. RESULTS: Of the 79 patients treated with ⩾1 dose of study drug, 66 (84%) patients had a history of virologic failure on a regimen containing a NS3/4A protease inhibitor; 12 of the other 13 patients discontinued prior treatment because of adverse experiences. At entry, 34 (43.6%) of 78 evaluable patients harbored NS3 RAVs. SVR12 rates were 76/79 (96.2%) overall, including 28/30 (93.3%) patients with genotype 1a infection, 63/66 (95.5%) patients with prior virologic failure, 43/43 (100%) patients without baseline RAVs, 31/34 (91.2%) patients with baseline NS3 RAVs, 6/8 (75.0%) patients with baseline NS5A RAVs, 4/6 (66.7%) patients with both baseline NS3 and RAVs, and 32/34 (94.1%) cirrhotic patients. None of the five reported serious adverse events were considered drug-related. CONCLUSIONS: Grazoprevir and elbasvir plus ribavirin for 12 weeks provides a promising new treatment option for patients after failure of triple therapy containing an earlier-generation protease inhibitor.

The combination of MK-5172, peginterferon, and ribavirin is effective in treatment-naive patients with hepatitis C virus genotype 1 infection without cirrhosis.

BACKGROUND & AIMS: MK-5172 is an inhibitor of the hepatitis C virus (HCV) nonstructural protein 3/4A protease; MK-5172 is taken once daily and has a higher potency and barrier to resistance than licensed protease inhibitors. We investigated the efficacy and tolerability of MK-5172 with peginterferon and ribavirin (PR) in treatment-naive patients with chronic HCV genotype 1 infection without cirrhosis. METHODS: We performed a multicenter, double-blind, randomized, active-controlled, dose-ranging, response-guided therapy study. A total of 332 patients received MK-5172 (100, 200, 400, or 800 mg) once daily for 12 weeks in combination with PR. Patients in the MK-5172 groups received PR for an additional 12 or 36 weeks, based on response at week 4. Patients in the control group (n = 66) received a combination of boceprevir and PR, dosed in accordance with boceprevir's US product circular. RESULTS: At 24 weeks after the end of therapy, sustained virologic responses were achieved in 89%, 93%, 91%, and 86% of the patients in the groups given the combination of PR and MK-5172 (100, 200, 400, or 800 mg), respectively, vs 61% of controls. In the MK-5172 group receiving 100 mg, 91% of patients had undetectable levels of HCV RNA at week 4 and qualified for the short duration of therapy. The combination of MK-5172 and PR generally was well tolerated. Transient increases in transaminase levels were noted in the MK-5172 groups given 400 and 800 mg, at higher frequencies than in the MK-5172 groups given 100 or 200 mg, or control groups. CONCLUSIONS: Once-daily MK-5172 (100 mg) with PR for 24 or 48 weeks was highly effective and well tolerated among treatment-naive patients with HCV genotype 1 infection without cirrhosis. Studies are underway to evaluate interferon-free MK-5172-based regimens. ClinicalTrials.gov number: NCT01353911.

HIV-1 vaccine-induced T-cell responses cluster in epitope hotspots that differ from those induced in natural infection with HIV-1.

Several recent large clinical trials evaluated HIV vaccine candidates that were based on recombinant adenovirus serotype 5 (rAd-5) vectors expressing HIV-derived antigens. These vaccines primarily elicited T-cell responses, which are known to be critical for controlling HIV infection. In the current study, we present a meta-analysis of epitope mapping data from 177 participants in three clinical trials that tested two different HIV vaccines: MRKAd-5 HIV and VRC-HIVAD014-00VP. We characterized the population-level epitope responses in these trials by generating population-based epitope maps, and also designed such maps using a large cohort of 372 naturally infected individuals. We used these maps to address several questions: (1) Are vaccine-induced responses randomly distributed across vaccine inserts, or do they cluster into immunodominant epitope hotspots? (2) Are the immunodominance patterns observed for these two vaccines in three vaccine trials different from one another? (3) Do vaccine-induced hotspots overlap with epitope hotspots induced by chronic natural infection with HIV-1? (4) Do immunodominant hotspots target evolutionarily conserved regions of the HIV genome? (5) Can epitope prediction methods be used to identify these hotspots? We found that vaccine responses clustered into epitope hotspots in all three vaccine trials and some of these hotspots were not observed in chronic natural infection. We also found significant differences between the immunodominance patterns generated in each trial, even comparing two trials that tested the same vaccine in different populations. Some of the vaccine-induced immunodominant hotspots were located in highly variable regions of the HIV genome, and this was more evident for the MRKAd-5 HIV vaccine. Finally, we found that epitope prediction methods can partially predict the location of vaccine-induced epitope hotspots. Our findings have implications for vaccine design and suggest a framework by which different vaccine candidates can be compared in early phases of evaluation.

Phase 1B study of the pharmacokinetics and safety of posaconazole intravenous solution in patients at risk for invasive fungal disease.

This was a phase 1B, dose-ranging, multicenter, pharmacokinetics, and safety study of cyclodextrin-based posaconazole intravenous (i.v.) solution administered through a central line to subjects at high risk for invasive fungal disease (part 1 of a 2-part study [phase 1B/3]). Initially, the safety and tolerability of single-dose posaconazole i.v. 200 mg (n = 10) were compared with those of a placebo (n = 11). Subsequently, 2 doses were evaluated, posaconazole i.v. 200 mg once daily (q.d.) (n = 21) and 300 mg q.d. (n = 24). The subjects received twice-daily (b.i.d.) posaconazole i.v. on day 1, followed by 13 days of posaconazole i.v. q.d., then 14 days of posaconazole oral suspension 400 mg b.i.d. The steady-state (day 14) exposure target (average concentration [areas under concentration-time curve {AUCs}/24 h, average concentrations at steady state {Cavgs}], of ≥ 500 to ≤ 2,500 ng/ml in ≥ 90% of the subjects) was achieved by 94% of the subjects for 200 mg posaconazole q.d. and by 95% of subjects for 300 mg posaconazole q.d. The desired exposure target (mean steady-state Cavg, ∼ 1,200 ng/ml) was 1,180 ng/ml in the 200-mg dosing cohort and was exceeded in the 300-mg dosing cohort (1,430 ng/ml). Posaconazole i.v. was well tolerated. Posaconazole i.v. 300 mg q.d. was selected for the phase 3 study segment. (This study has been registered at ClinicalTrials.gov under registration no. NCT01075984.).

Low-dose penile SIVmac251 exposure of rhesus macaques infected with adenovirus type 5 (Ad5) and then immunized with a replication-defective Ad5-based SIV gag/pol/nef vaccine recapitulates the results of the phase IIb step trial of a similar HIV-1 vaccine.

The Step Trial showed that the MRKAd5 HIV-1 subtype B Gag/Pol/Nef vaccine did not protect men from HIV infection or reduce setpoint plasma viral RNA (vRNA) levels but, unexpectedly, it did modestly enhance susceptibility to HIV infection in adenovirus type 5 (Ad5)-seropositive, uncircumcised men. As part of the process to understand the results of the Step Trial, we designed a study to determine whether rhesus macaques chronically infected with a host-range mutant Ad5 (Ad5hr) and then immunized with a replication defective Ad5 SIVmac239 Gag/Pol/Nef vaccine were more resistant or susceptible to SIV infection than unimmunized rhesus macaques challenged with a series of escalating dose penile exposures to SIVmac 251. The Ad5 SIV vaccine induced CD8(+) T cell responses in 70% of the monkeys, which is similar to the proportion of humans that responded to the vaccine in the Step Trial. However, the vaccine did not protect vaccinated animals from penile SIV challenge. At the lowest SIV exposure dose (10(3) 50% tissue culture infective doses), 2 of 9 Ad5-seropositive animals immunized with the Ad5 SIV vaccine became infected compared to 0 of 34 animals infected in the other animal groups (naive animals, Ad5-seropositive animals immunized with the empty Ad5 vector, Ad5-seronegative animals immunized with the Ad5 SIV vaccine, and Ad5-seronegative animals immunized with the empty Ad5 vector). Penile exposure to more concentrated virus inocula produced similar rates of infection in all animal groups. Although setpoint viral loads were unaffected in Step vaccinees, the Ad5 SIV-immunized animals had significantly lower acute-phase plasma vRNA levels compared to unimmunized animals. Thus, the results of the nonhuman primate (NHP) study described here recapitulate the lack of protection against HIV acquisition seen in the Step Trial and suggest a greater risk of infection in the Ad5-seropositive animals immunized with the Ad5 SIV vaccine. Further studies are necessary to confirm the enhancement of virus acquisition and to discern associated mechanisms.

Extended follow-up confirms early vaccine-enhanced risk of HIV acquisition and demonstrates waning effect over time among participants in a randomized trial of recombinant adenovirus HIV vaccine (Step Study).

BACKGROUND: The Step Study tested whether an adenovirus serotype 5 (Ad5)-vectored human immunodeficiency virus (HIV) vaccine could prevent HIV acquisition and/or reduce viral load set-point after infection. At the first interim analysis, nonefficacy criteria were met. Vaccinations were halted; participants were unblinded. In post hoc analyses, more HIV infections occurred in vaccinees vs placebo recipients in men who had Ad5-neutralizing antibodies and/or were uncircumcised. Follow-up was extended to assess relative risk of HIV acquisition in vaccinees vs placebo recipients over time. METHODS: We used Cox proportional hazard models for analyses of vaccine effect on HIV acquisition and vaccine effect modifiers, and nonparametric and semiparametric methods for analysis of constancy of relative risk over time. RESULTS: One hundred seventy-two of 1836 men were infected. The adjusted vaccinees vs placebo recipients hazard ratio (HR) for all follow-up time was 1.40 (95% confidence interval [CI], 1.03-1.92; P= .03). Vaccine effect differed by baseline Ad5 or circumcision status during first 18 months, but neither was significant for all follow-up time. The HR among uncircumcised and/or Ad5-seropositive men waned with time since vaccination. No significant vaccine-associated risk was seen among circumcised, Ad5-negative men (HR, 0.97; P=1.0) over all follow-up time. CONCLUSIONS: The vaccine-associated risk seen in interim analysis was confirmed but waned with time from vaccination.