Resistance analysis following sotrovimab treatment in participants with COVID-19 during the phase III COMET-ICE study.

Aim: Sotrovimab is an engineered human monoclonal antibody that binds a conserved region of the SARS-CoV-2 spike protein. The COMET-ICE phase III study evaluated sotrovimab for treatment of mild to moderate COVID-19 in nonhospitalized participants with ≥1 risk factor for severe disease progression. Materials & methods: We evaluated the presence of circulating SARS-CoV-2 variants of concern or interest (VOCs/VOIs) and characterized the presence of baseline, post-baseline and emergent amino acid substitutions detected in the epitope of sotrovimab in SARS-CoV-2. Results: None of the sotrovimab-treated participants with baseline epitope substitutions, and 1 of 48 sotrovimab-treated participants with post-baseline epitope substitutions, met the primary clinical endpoint for progression. Conclusion: Overall, progression was not associated with identified VOC/VOI or the presence of epitope substitutions in sotrovimab-treated participants.

Analysis of the genetics of the SARS-CoV-2 virus from participants in a clinical study for treatment of COVID-19 In a large clinical study, the ability of the monoclonal antibody sotrovimab to treat patients with mild to moderate COVID-19 was looked at. This paper focuses on the genetics of the SARS-CoV-2 viruses from participants in this clinical study. Overall, most participants in the study were infected with the original 'wild type' variant of SARS-CoV-2. We also looked for changes in the virus at the positions on the viral spike protein where sotrovimab binds. In participants treated with sotrovimab, changes in the virus at the site where sotrovimab binds on the viral surface protein were not associated with negative outcomes in participants. Clinical Trial Registration: NCT04545060 (ClinicalTrials.gov).

Neutralization, effector function and immune imprinting of Omicron variants.

Currently circulating SARS-CoV-2 variants have acquired convergent mutations at hot spots in the receptor-binding domain1 (RBD) of the spike protein. The effects of these mutations on viral infection and transmission and the efficacy of vaccines and therapies remains poorly understood. Here we demonstrate that recently emerged BQ.1.1 and XBB.1.5 variants bind host ACE2 with high affinity and promote membrane fusion more efficiently than earlier Omicron variants. Structures of the BQ.1.1, XBB.1 and BN.1 RBDs bound to the fragment antigen-binding region of the S309 antibody (the parent antibody for sotrovimab) and human ACE2 explain the preservation of antibody binding through conformational selection, altered ACE2 recognition and immune evasion. We show that sotrovimab binds avidly to all Omicron variants, promotes Fc-dependent effector functions and protects mice challenged with BQ.1.1 and hamsters challenged with XBB.1.5. Vaccine-elicited human plasma antibodies cross-react with and trigger effector functions against current Omicron variants, despite a reduced neutralizing activity, suggesting a mechanism of protection against disease, exemplified by S309. Cross-reactive RBD-directed human memory B cells remained dominant even after two exposures to Omicron spikes, underscoring the role of persistent immune imprinting.

Safety, Virology, Pharmacokinetics, and Clinical Experience of High-Dose Intravenous Sotrovimab for the Treatment of Mild to Moderate COVID-19: An Open-Label Clinical Trial.

Background: Five hundred milligrams of intravenous (IV) sotrovimab has been shown to be well tolerated and efficacious against pre-Omicron strains in treating patients with mild to moderate coronavirus disease 2019 (COVID-19) at high risk for disease progression. Methods: This was an open-label, single-arm substudy of phase 3 COMET-TAIL (NCT04913675) assessing the safety and tolerability of a 2000 mg IV dose of sotrovimab. Symptomatic patients (aged ≥18 years) with COVID-19 at high risk for progression were enrolled from June 30 through July 11, 2022, when Omicron BA.5, BA.2.12.1, and BA.4 were the predominant circulating variants in the United States. The primary end point was the occurrence of adverse events (AEs), serious AEs (SAEs), AEs of special interest, and COVID-19 disease-related events (DREs) through day 8. Safety, pharmacokinetics, viral load, and hospitalization >24 hours for acute management of illness or death through day 29 were assessed. Results: All participants (n = 81) were Hispanic, 58% were female, and 51% were aged ≥55 years. Through day 8, no AEs, including infusion-related reactions or hypersensitivity, were reported; 2 participants reported DREs (mild cough, n = 2). One SAE (acute myocardial infarction), which was considered unrelated to sotrovimab or COVID-19 by the investigator, occurred on day 27 and was the only hospitalization reported. Maximum serum concentration (geometric mean) was 745.9 µg/mL. Viral load decreased from baseline through day 29; only 2 (3%) participants had a persistently high viral load (≥4.1 log10 copies/mL) at day 8. Conclusions: Two thousand milligrams of IV sotrovimab was well tolerated, with no safety signals observed. Trial registration: ClinicalTrials.gov Identifier: NCT04913675.

Therapeutic and vaccine-induced cross-reactive antibodies with effector function against emerging Omicron variants.

Currently circulating SARS-CoV-2 variants acquired convergent mutations at receptor-binding domain (RBD) hot spots. Their impact on viral infection, transmission, and efficacy of vaccines and therapeutics remains poorly understood. Here, we demonstrate that recently emerged BQ.1.1. and XBB.1 variants bind ACE2 with high affinity and promote membrane fusion more efficiently than earlier Omicron variants. Structures of the BQ.1.1 and XBB.1 RBDs bound to human ACE2 and S309 Fab (sotrovimab parent) explain the altered ACE2 recognition and preserved antibody binding through conformational selection. We show that sotrovimab binds avidly to all Omicron variants, promotes Fc-dependent effector functions and protects mice challenged with BQ.1.1, the variant displaying the greatest loss of neutralization. Moreover, in several donors vaccine-elicited plasma antibodies cross-react with and trigger effector functions against Omicron variants despite reduced neutralizing activity. Cross-reactive RBD-directed human memory B cells remained dominant even after two exposures to Omicron spikes, underscoring persistent immune imprinting. Our findings suggest that this previously overlooked class of cross-reactive antibodies, exemplified by S309, may contribute to protection against disease caused by emerging variants through elicitation of effector functions.

Imprinted antibody responses against SARS-CoV-2 Omicron sublineages.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant-neutralizing antibody that is a strong candidate for clinical development.

Imprinted antibody responses against SARS-CoV-2 Omicron sublineages.

SARS-CoV-2 Omicron sublineages carry distinct spike mutations and represent an antigenic shift resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters result in potent plasma neutralizing activity against Omicron BA.1 and BA.2 and that breakthrough infections, but not vaccination-only, induce neutralizing activity in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1 and BA.2 receptor-binding domains whereas Omicron primary infections elicit B cells of narrow specificity. While most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant antibody, that is unaffected by any Omicron lineage spike mutations and is a strong candidate for clinical development.

HIV-1 is Transported into the Central Nervous System by Trafficking Infected Cells.

Background: In this work, we carried out a cross-sectional study examining HIV-1 and HCV free virus concentrations in blood and cerebrospinal fluid (CSF) to determine whether HIV-1 enters the central nervous system (CNS) passively as virus particles or in the context of migrating infected cells. If virions migrate freely across the blood-cerebrospinal fluid barrier (BCSFB) or the blood-brain barrier (BBB) then HCV and HIV-1 would be detectable in the CSF at proportions similar to that in the blood. Alternatively, virus entry as an infected cell would favor selective entry of HIV-1. Methods: We measured HIV-1 and HCV viral loads in the CSF and blood plasma of 4 co-infected participants who were not on antiviral regimens for either infection. We also generated HIV-1 env sequences and performed phylogenetic analyses to determine whether HIV-1 populations in the CSF of these participants were being maintained by local replication. Results: While CSF samples taken from all participants had detectable levels of HIV-1, HCV was not detectable in any of the CSF samples despite participants having HCV concentrations in their blood plasma, which exceeded that of HIV-1. Further, there was no evidence of compartmentalized HIV-1 replication in the CNS (Supplementary Figure 1). These results are consistent with a model where HIV-1 particles cross the BBB or the BCSFB within infected cells. In this scenario, we would expect HIV-1 to reach the CSF more readily because the blood contains a much greater number of HIV-infected cells than HCV-infected cells. Conclusions: HCV entry into the CSF is restricted, indicating that virions do not freely migrate across these barriers and supporting the concept that HIV-1 is transported across the BCSFB and/or BBB by the migration of HIV-infected cells as part of an inflammatory response or normal surveillance.

Linkage of resistance-associated substitutions in GT1 sofosbuvir + NS5A inhibitor failures treated with glecaprevir/pibrentasvir.

BACKGROUND & AIMS: Retreatment with glecaprevir/pibrentasvir (G/P) resulted in a rate of sustained virologic response 12 weeks after treatment completion (SVR12) of >90% in HCV genotype 1 (GT1) patients who previously failed a regimen of sofosbuvir plus an NS5A inhibitor (NS5Ai). This study investigated the prevalence and impact of baseline NS3 and NS5A resistance-associated substitutions (RASs) on the efficacy of G/P in prior GT1 sofosbuvir+NS5Ai failures and the persistence of treatment-emergent RASs. METHODS: Longitudinal samples from 177 patients enrolled in a phase IIIb, randomized pragmatic clinical trial were analyzed. Patients without cirrhosis were randomized to 12 or 16 weeks of G/P, and patients with compensated cirrhosis were randomized to G/P and ribavirin for 12 weeks or G/P for 16 weeks. Linkage of RAS was identified using Primer-ID next-generation sequencing at a 15% cut-off. RESULTS: Of 177 patients, 169 (95.5%) were PI-naïve. All 33 GT1b-infected patients achieved SVR12. In GT1a-infected patients, baseline NS5A RASs were prevalent (74.5%, 105/141) but NS3 RASs were uncommon. Baseline NS3 RASs had no impact on G/P efficacy and patients with baseline NS5A RASs showed a numerically but not statistically significantly lower SVR12 rate compared to those without NS5A RASs (89% vs. 97%). SVR12 was achieved in 34 of 35 (97%) patients without NS5A baseline substitution, and 53 of 57 (93%), 35 of 40 (88%), 5 of 8 (63%) with single, double-linked, and triple-linked NS5A substitutions, respectively. Among 13 patients with virologic failure, 4 acquired treatment-emergent NS3 RASs and 10 acquired NS5A RASs. CONCLUSION: Baseline NS5A RASs were highly prevalent. The presence of an increasing number of linked NS5A RASs in GT1a showed a trend in decreasing SVR12 rates, although no specific NS5A RASs or their linkage pattern were associated with lower SVR12 rates. LAY SUMMARY: Direct-acting antivirals have revolutionized the treatment of chronic hepatitis C infection, but treatment failure occurs in some patients. Retreatment of patients who previously failed a regimen consisting of sofosbuvir and an NS5A inhibitor with a regimen of glecaprevir and pibrentasvir (G/P) is >90% effective. Herein, we analyzed samples from these patients and showed that retreatment efficacy with G/P is lower in patients with double- or triple-linked NS5A resistance mutations than in patients with single or no NS5A resistance mutations. CLINICAL TRIAL NUMBER: NCT03092375.

Efficacy and safety of glecaprevir/pibrentasvir in patients with HCV genotype 5/6: An integrated analysis of phase 2/3 studies.

BACKGROUND & AIMS: Hepatitis C virus (HCV) has high genetic diversity with six major genotypes (GT) GT1-6 and global distribution. HCV GT5 and 6 are rare with < 10 million people infected worldwide. Data on direct-acting antiviral use in these rare HCV genotypes are limited. The study aimed to evaluate the efficacy and safety of glecaprevir/pibrentasvir (G/P) in a pooled analysis of phase 2/3 trials in HCV GT5 or 6-infected patients without cirrhosis or with compensated cirrhosis. METHODS: Patients with chronic HCV GT5 or 6 infection received oral G/P (300 mg/120 mg) once daily for 8 or 12 weeks. The primary efficacy endpoint was sustained virological response at post-treatment week 12 (SVR12) in the intention-to-treat population. RESULTS: One hundred eighty-one patients were evaluated; 56 with HCV GT5 and 125 with HCV GT6. The majority were treatment-naïve (88%) and non-cirrhotic (85%). Overall SVR12 rate with 8- or 12-week G/P treatment was 98% (178/181). Eight-week treatment with G/P yielded SVR12 rates of 95% (21/22) in HCV GT5- and 99% (69/70) in HCV GT6-infected non-cirrhotic patients. Eight- and 12-week treatment of patients with compensated cirrhosis achieved SVR12 rates of 100% (10/10) and 94% (17/18) respectively. The G/P regimen was well-tolerated; 3% (6/181) Grade 3 or higher adverse events, and no serious adverse events were attributed to G/P or led to study drug discontinuation. CONCLUSIONS: This integrated dataset demonstrates a high SVR12 rate following 8-week G/P treatment in patients with HCV GT5 (96%) or GT6 (99%) infection without cirrhosis or with compensated cirrhosis.

Ombitasvir/paritaprevir/ritonavir and dasabuvir±ribavirin for chronic HCV infection in US veterans with psychiatric disorders.

Hepatitis C virus (HCV) infections are more common among US veterans receiving care through Veterans Affairs (VA) Medical Centers than among the general population. Historically, HCV therapies had lower efficacy rates in VA patients, possibly due to common comorbidities such as psychiatric disorders and substance abuse. The direct-acting antivirals ombitasvir/paritaprevir/ritonavir and dasabuvir (OBV/PTV/r+DSV)±ribavirin (RBV) are approved in the US for HCV genotype 1 (GT1)-infected adults with or without cirrhosis. This study prospectively evaluated the safety and efficacy of OBV/PTV/r+DSV±RBV in VA patients with HCV GT1 infection. TOPAZ-VA was a phase 3b, open-label trial. Adult US veterans with HCV GT1 infection, without cirrhosis or with compensated cirrhosis, were eligible for enrollment. Patients with GT1a infection received OBV/PTV/r +DSV+RBV for 12 weeks or 24 weeks (for those with cirrhosis); GT1b-infected patients without cirrhosis received OBV/PTV/r +DSV for 12 weeks; those with cirrhosis received OBV/PTV/r +DSV with RBV. The primary endpoint was sustained virologic response at posttreatment week 12 (SVR12); safety was also assessed. Ninety-nine patients were enrolled at 10 sites from May through November 2015. The majority were male (96%), white (60%), and with GT1a infection (68%); 49% reported ongoing psychiatric disorders. Overall, 94% (93/99) achieved SVR12; three patients had a virologic failure. The most common AEs were fatigue (28%), headache (20%), and nausea (15%); six patients discontinued treatment due to AEs. In US veterans with HCV GT1 infection, OBV/PTV/r +DSV±RBV yielded a 94% overall SVR12 rate and was well tolerated. The presence of psychiatric disorders and/or injection drug use did not impact efficacy.

Efficacy and safety of glecaprevir/pibrentasvir in renally impaired patients with chronic HCV infection.

BACKGROUND AND AIMS: Chronic hepatitis C virus (HCV) infection increases the risk of incident chronic kidney disease (CKD) and progression to end-stage renal disease (ESRD). Previously available direct-acting antiviral regimens are not approved for patients with advanced CKD across all HCV genotypes. METHODS: EXPEDITION-5 is a phase 3 study to evaluate efficacy and safety of the fixed-dose combination of glecaprevir and pibrentasvir (G/P) for chronic HCV infection (genotype 1 through 6) in adults without cirrhosis or with compensated cirrhosis and with stage 3b, 4 or 5 CKD. Patients received approved duration of G/P according to HCV genotype, cirrhosis status and prior HCV treatment experience. The primary efficacy endpoint was percentage of patients with sustained virologic response at 12 weeks post-treatment (SVR12). RESULTS: Among the 101 patients enrolled in the study, 24% had predialysis CKD and 76% were on dialysis. Eighty-four patients were treated with G/P for 8 weeks, 13 patients for 12 weeks and four patients for 16 weeks. Fifty-five per cent of patients had genotype 1, 27% had genotype 2, 15% had genotype 3 and 4% had genotype 4, and none had genotype 5 or 6 infection. The SVR12 rate was 97% (98/101, 95% confidence interval, 91.6-99.0). No patients experienced virologic failure. Adverse events (AEs) reported in at least 5% of the patients were pruritus, bronchitis, hypertension and generalized pruritus. Serious AEs were reported in 12% of patients; none related to study drug. CONCLUSIONS: G/P treatment yielded high SVR12 rates irrespective of the presence of stage 3b, 4 or 5 CKD. No safety signals were detected. CLINICALTRIALS. GOV IDENTIFIER: This Phase 3 clinical trial was funded by AbbVie and registered with clinicaltrials.gov as NCT03069365 (EXPEDITION-5).

Glecaprevir/pibrentasvir for 8 weeks in treatment-naïve patients with chronic HCV genotypes 1-6 and compensated cirrhosis: The EXPEDITION-8 trial.

BACKGROUND & AIMS: Eight-week glecaprevir/pibrentasvir leads to high rates of sustained virological response at post-treatment week 12 (SVR12) across HCV genotypes (GT) 1-6 in treatment-naïve patients without cirrhosis. We evaluated glecaprevir/pibrentasvir once daily for 8 weeks in treatment-naïve patients with compensated cirrhosis. METHODS: EXPEDITION-8 was a single-arm, multicenter, phase IIIb trial. The primary and key secondary efficacy analyses were to compare the lower bound of the 95% CI of the SVR12 rate in i) patients with GT1,2,4-6 in the per protocol (PP) population, ii) patients with GT1,2,4-6 in the intention-to-treat (ITT) population, iii) patients with GT1-6 in the PP population, and iv) patients with GT1-6 in the ITT population, to pre-defined efficacy thresholds based on historical SVR12 rates for 12 weeks of glecaprevir/pibrentasvir in the same populations. Safety was also assessed. RESULTS: A total of 343 patients were enrolled. Most patients were male (63%), white (83%), and had GT1 (67%). The SVR12 rate in patients with GT1-6 was 99.7% (n/N = 334/335; 95%CI 98.3-99.9) in the PP population and 97.7% (n/N = 335/343; 95% CI 96.1-99.3) in the ITT population. All primary and key secondary efficacy analyses were achieved. One patient (GT3a) experienced relapse (0.3%) at post-treatment week 4. Common adverse events (≥5%) were fatigue (9%), pruritus (8%), headache (8%), and nausea (6%). Serious adverse events (none related) occurred in 2% of patients. No adverse event led to study drug discontinuation. Clinically significant laboratory abnormalities were infrequent. CONCLUSIONS: Eight-week glecaprevir/pibrentasvir was well tolerated and led to a similarly high SVR12 rate as the 12-week regimen in treatment-naïve patients with chronic HCV GT1-6 infection and compensated cirrhosis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03089944. LAY SUMMARY: This study was the first to evaluate an 8-week direct-acting antiviral (DAA) regimen active against all major types of hepatitis C virus (HCV) in untreated patients with compensated cirrhosis. High virological cure rates were achieved with glecaprevir/pibrentasvir across HCV genotypes 1-6, and these high cure rates did not depend on any patient or viral characteristics present before treatment. This may simplify care and allow non-specialist healthcare professionals to treat these patients, contributing to global efforts to eliminate HCV.

Ombitasvir/paritaprevir/ritonavir plus ribavirin for 24 weeks in patients with HCV GT4 and compensated cirrhosis (AGATE-I Part II).

BACKGROUND AND AIMS: AGATE-I Part I previously reported high sustained virologic response rates in hepatitis C genotype 4 patients with cirrhosis, with 12 and 16 weeks' treatment with a combination of two direct-acting antivirals, ombitasvir and paritaprevir (codosed with ritonavir), plus ribavirin. Part II, reported here, extended the trial to include a 24-week treatment arm to fully assess treatment duration in patients with chronic hepatitis C genotype 4 infection and compensated cirrhosis. METHODS: Enrollment took place between June and November of 2015. Treatment-naive and interferon-experienced patients with chronic hepatitis C genotype 4 infection and compensated cirrhosis were enrolled into Arm C; patients previously treated with a sofosbuvir-based regimen were enrolled into Arm D. All patients received a 24-week treatment with ombitasvir, paritaprevir, and ritonavir plus ribavirin. The primary outcome was the proportion of patients with a sustained virologic response (hepatitis C virus RNA < 25 IU/mL) at posttreatment week 12 in the intention-to-treat population. The safety population included all patients who received at least one dose of study drug. RESULTS: In total, 64 patients were enrolled into AGATE-I Part II. Sustained virologic response at posttreatment week 12 was achieved in 57 of 61 patients (93.4%; 97.5% confidence interval, 92.6-97.7) in Arm C and 3 of 3 patients (100%) in Arm D. Two patients were missing SVR12 data, and two prematurely discontinued treatment. The most common adverse events for Arm C were fatigue (16 [26%]) and asthenia (15 [25%]). Results were comparable with those reported in Part I. CONCLUSIONS: AGATE-I Part II indicates that extending treatment beyond 12 weeks in genotype 4-infected patients with compensated cirrhosis does not offer additional benefit.

Efficacy and safety of glecaprevir/pibrentasvir in patients with chronic hepatitis C virus genotype 5 or 6 infection (ENDURANCE-5,6): an open-label, multicentre, phase 3b trial.

BACKGROUND: The pangenotypic direct-acting antiviral regimen of glecaprevir coformulated with pibrentasvir is approved to treat chronic hepatitis C virus (HCV) genotype 1-6 infection in adults. In registrational studies, 84 (99%) of 85 patients with HCV genotype 5 or 6 infection achieved a sustained virological response (SVR) with glecaprevir/pibrentasvir, with no virological failures. To increase the body of data for these less prevalent genotypes, ENDURANCE-5,6 evaluated the efficacy and safety of glecaprevir/pibrentasvir exclusively in patients infected with HCV genotype 5 or 6. METHODS: ENDURANCE-5,6 was a phase 3b, single-arm, open-label, multicentre trial done in 24 hospitals or clinics in Europe, Oceania, North America, South Africa, and southeast Asia. Adults with chronic HCV genotype 5 or 6 infection who were previously untreated or treatment-experienced were eligible to be enrolled. Glecaprevir/pibrentasvir (300 mg/120 mg) was given orally once daily for 8 weeks (for patients without cirrhosis) or 12 weeks (for patients with compensated cirrhosis). The primary efficacy endpoint was SVR12 (ie, HCV RNA <15 IU/mL at 12 weeks post-treatment), assessed within each HCV genotype, and analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02966795. FINDINGS: Between Feb 9, 2017, and Aug 28, 2018, 84 patients were enrolled: 23 with genotype 5 infection and 61 with genotype 6 infection. Overall, 82 (97·6%, 95% CI 94·4-100·0) of the 84 patients achieved SVR12. 22 (95·7%, 95% CI 87·3-100·0) of 23 patients with genotype 5 infection achieved SVR12, as did 60 (98·4%, CI 95·2-100·0) of 61 with genotype 6 infection. One patient with an HCV genotype 6f infection and cirrhosis had on-treatment virological failure at treatment week 12, and one patient with HCV genotype 5a without cirrhosis who had achieved SVR at post-treatment week 4 relapsed at post-treatment week 12. Five (6%) patients had serious adverse events, none of which were deemed related to glecaprevir/pibrentsavir or led to discontinuation. Fatigue (11 [13%] patients) and headache (11 [13%]) were the only adverse events that occurred in 10% or more of patients. No post-baseline grade 3 or higher increases in aminotransferase concentrations were reported. INTERPRETATION: Glecaprevir/pibrentasvir achieved high SVR12 rates, comparable with data reported in registrational studies, and was well tolerated in patients with HCV genotype 5 or 6 infection with compensated liver disease. FUNDING: AbbVie.

Efficacy and Safety of Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir With or Without Ribavirin in Patients With Chronic Hepatitis C Virus Genotype 1 Infection Receiving Opioid Substitution Therapy: A Post Hoc Analysis of 12 Clinical Trials.

BACKGROUND: We evaluated the impact of opioid substitution therapy (OST) on the completion, adherence, efficacy, and safety of the 3-direct-acting antiviral regimen of ombitasvir, paritaprevir (identified by AbbVie and Enanta) co-dosed with ritonavir, and dasabuvir ± ribavirin among patients infected with hepatitis C virus (HCV) genotype (GT) 1, with or without compensated cirrhosis. METHODS: Data were pooled from GT1-infected patients enrolled in 12 phase II/III/IIIb clinical trials and categorized by use of OST. Patients with ongoing drug use were excluded. HCV treatment completion, treatment adherence (≥90%), sustained virologic response at post-treatment week 12 (SVR12), and adverse events were assessed. RESULTS: Of 4747 patients, 3% (n = 149) received OST. Among patients receiving OST vs those not receiving OST, 82% (n = 122) vs 52% (n = 2409) had GT1a infection; 76% (n = 113) vs 61% (n = 2792) were treatment naïve; and 17% (n = 25) vs 18% (n = 830) had cirrhosis, respectively. The proportion of patients completing HCV treatment did not differ between those receiving and not receiving OST (97% [n = 144] vs 98% [n = 4510], respectively), whereas adherence to treatment was reduced in patients receiving vs those not receiving OST (88% [n = 105] vs 97% [n = 4057], respectively). SVR12 was similar between patients receiving and not receiving OST (94% [n = 140] vs 96% [n = 4405], respectively; P = .273). Treatment was well tolerated. CONCLUSIONS: Although treatment adherence was lower in patients receiving OST vs those not receiving OST, treatment completion and SVR12 were similar between groups. These data support the use of direct-acting antiviral therapies in patients receiving OST.

Hepatitis C virus genetic diversity by geographic region within genotype 1-6 subtypes among patients treated with glecaprevir and pibrentasvir.

Hepatitis C virus (HCV) is genetically diverse and includes 7 genotypes and 67 confirmed subtypes, and the global distribution of each HCV genotype (GT) varies by geographic region. In this report, we utilized a large dataset of NS3/4A and NS5A sequences isolated from 2348 HCV GT1-6-infected patients treated with the regimen containing glecaprevir/pibrentasvir (GLE/PIB) to assess genetic diversity within HCV subtypes by geographic region using phylogenetic analyses, and evaluated the prevalence of baseline amino acid polymorphisms in NS3 and NS5A by region/country and phylogenetic cluster. Among 2348 NS3/4A and NS5A sequences, phylogenetic analysis identified 6 genotypes and 44 subtypes, including 3 GT1, 8 GT2, 3 GT3, 13 GT4, 1 GT5, and 16 GT6 subtypes. Phylogenetic analysis of HCV subtype 1a confirmed the presence of two clades, which differed by geographic region distribution and NS3 Q80K prevalence. We detected phylogenetic clustering by country in HCV subtypes 1a, 1b, 2a, 2b, and 5a, suggesting that genetically distinct virus lineages are circulating in different countries. In addition, two clades were detected in HCV GT4a and GT6e, and NS5A amino acid polymorphisms were differentially distributed between the 2 clades in each subtype. The prevalence of NS3 and NS5A baseline polymorphisms varied substantially by genotype and subtype; therefore, we also determined the activity of GLE or PIB against replicons containing NS3/4A or NS5A from HCV GT1-6 clinical samples representing 6 genotypes and 21 subtypes overall. GLE and PIB retained activity against the majority of HCV replicons containing NS3/4A or NS5A from HCV GT1-6 clinical samples, with a median EC50 of 0.29 nM for GLE and 1.1 pM for PIB in a transient replicon assay. The data presented in this report expands the available data on HCV epidemiology, subtype diversity by geographic region, and NS3 and NS5A baseline polymorphism prevalence.

Pooled Resistance Analysis in Patients with Hepatitis C Virus Genotype 1 to 6 Infection Treated with Glecaprevir-Pibrentasvir in Phase 2 and 3 Clinical Trials.

Over 2,200 patients infected with hepatitis C virus (HCV) genotypes (GT) 1 to 6, with or without cirrhosis, who were treatment naive or experienced to interferon, ribavirin, and/or sofosbuvir were treated with glecaprevir/pibrentasvir for 8, 12, or 16 weeks in eight registrational phase 2 and 3 clinical studies. High rates of sustained virologic response at 12 weeks postdosing (SVR12) were achieved with a <1% virologic failure (VF) rate. The prevalence of baseline polymorphisms (BPs) in NS3 at amino acid position 155 or 168 was low (<3%) in patients infected with GT1, GT2, GT3, GT4, and GT6, while 41.9% of the GT5-infected patients had NS3-D168E; BPs were not detected at position 156 in NS3. The prevalence of NS5A-BPs was high across genotypes, driven by common polymorphisms at amino acid position 30 or 31 in GT2, 58 in GT4, and 28 in GT6. The prevalence of NS5A T/Y93 polymorphisms was 5.5% in GT1, 4.9% in GT3, and 12.5% in GT6. Consistent with the activity of glecaprevir and pibrentasvir against most amino acid polymorphisms in vitro, BPs in NS3 and/or NS5A did not have an impact on treatment outcome for patients infected with GT1 to GT6, with the exception of treatment-experienced GT3-infected patients treated for 12 weeks, for whom a 16-week regimen of glecaprevir/pibrentasvir was required to achieve SVR12 rates of ≥95%. Among the 22 patients experiencing VF, treatment-emergent substitutions were detected in NS3 in 50% of patients and in NS5A in 82% of patients, frequently as a combination of substitutions that conferred resistance to glecaprevir and/or pibrentasvir. The glecaprevir/pibrentasvir regimen, when the recommended durations are used, allows for a pan-genotypic treatment option without the need for baseline resistance testing.

Resistance Analysis of a 3-Day Monotherapy Study with Glecaprevir or Pibrentasvir in Patients with Chronic Hepatitis C Virus Genotype 1 Infection.

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.

Resistance characterization of hepatitis C virus genotype 2 from Japanese patients treated with ombitasvir and paritaprevir/ritonavir.

Treatment of HCV genotype (GT) 2-infected Japanese patients with paritaprevir (NS3/4A inhibitor boosted with ritonavir) and ombitasvir (NS5A inhibitor) without ribavirin for 12 weeks in the phase 2 study M12-536, and with ribavirin for 16 weeks in phase 3 study GIFT II resulted in SVR rates of 72.2% to 91.5%. Overall, 11 out of 125 patients with GT2a and 37 out of 79 patients with GT2b infection experienced virologic failure. The prevalence of baseline polymorphisms in NS3 and NS5A and their the impact on treatment outcome, as well as the development of viral resistance in GT2-infected patients experiencing virologic failure were evaluated by HCV NS3 and NS5A population and clonal sequence analyses. Baseline polymorphisms in NS3 that confer resistance to paritaprevir were rare in both GT2a- and GT2b-infected patients, while baseline polymorphisms in NS5A that confer resistance to ombitasvir were detected in 11.2% and 14.1% of the GT2a- and GT2b-infected patients, respectively. There was no significant impact of baseline polymorphisms on treatment outcome in Japanese patients. The most common treatment-emergent substitutions at the time of virologic failure occurred at amino acid positions 168 in NS3 and 28 in NS5A in both GT2a- and GT2b-infected patients. Although there was a higher rate of virologic failure in patients with GT2b infection, the resistance analyses presented in this report support the conclusion that testing for baseline resistance-associated polymorphisms is not warranted for HCV GT2-infected patients treated with a regimen of ombitasvir/paritaprevir/ritonavir + ribavirin for 16 weeks.