Glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection: The TARGET3D study.

Background & Aims: Short duration treatment may aid HCV elimination among key populations. This study evaluated the efficacy of glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection. Methods: In this single-arm multicentre international trial, adults with recent HCV (duration of infection <12 months) received glecaprevir-pibrentasvir 300 mg-120 mg daily for 4 weeks. Primary infection was defined as a first positive anti-HCV antibody and/or HCV RNA measurement within 6 months of enrolment and either acute clinical hepatitis within 12 months (symptomatic illness or alanine aminotransferase >10x the upper limit of normal) or antibody seroconversion within 18 months. Reinfection was defined as new positive HCV RNA within 6 months and prior clearance (spontaneous or treatment). The primary endpoint was sustained virological response at 12 weeks post-treatment (SVR12) in the intention-to-treat (ITT) and per-protocol (PP) populations. Results: Twenty-three participants (96% men, 70% HIV, 57% ever injected drugs) received treatment, of whom 74% had genotype 1a infection and 35% recent reinfection. At baseline, median duration of infection was 17 weeks (IQR 11-29) and HCV RNA was 5.8 log10IU/ml (IQR 5.2-6.9). SVR12 was achieved by 78% (18/23; 95% CI 56-93%) and 82% (18/22; 95% CI 60-95%) of the ITT and PP populations, respectively, and in 100% (12/12; 95% CI 74-100%) of participants with baseline HCV RNA ≤6 log10. There were four cases of virological failure (relapse); three received retreatment with 12 weeks sofosbuvir-velpatasvir or grazoprevir-elbasvir (SVR, n = 2; loss to follow-up, n = 1). No serious adverse events were reported. Conclusion: While most achieved SVR, the efficacy of a 4-week regimen of glecaprevir-pibrentasvir was lower than observed with longer treatment durations (≥6 weeks) among people with recent HCV. Trial Registration: Clinicaltrials.gov Identifier: NCT02634008. Impact and implications: Short duration treatment may aid HCV elimination among key populations. This investigator-initiated single-arm multicentre international pilot trial demonstrated that efficacy of glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection was sub-optimal (SVR12 78% ITT, 82% PP). Baseline HCV RNA appeared to impact response, with higher efficacy among participants with lower baseline HCV RNA (≤6 log10; SVR12 100% ITT, 12/12). While most achieved SVR, the efficacy of 4 weeks of glecaprevir-pibrentasvir was below that seen with longer treatment durations (≥6 weeks).

Sexual and drug use risk behaviour trajectories among people treated for recent HCV infection: the REACT study.

INTRODUCTION: Exploration of sexual and drug use behaviours following treatment for recent hepatitis C virus (HCV) is limited. This analysis modelled behavioural trajectories following treatment for recent HCV and assessed reinfection. METHODS: Participants treated for recent HCV in an international trial (enrolled 2017-2019) were followed at 3-monthly intervals for up to 2 years to assess longitudinal behaviours. Population-averaged changes were assessed using generalized estimating equations. Distinct behavioural trajectories were identified using group-based trajectory modelling. HCV reinfection incidence was calculated using person-years (PY) of observation. RESULTS: During the follow-up of 212 participants (84% gay and bisexual men [GBM]; 69% HIV; 26% current injecting drug use [IDU]), behavioural trajectories for IDU and stimulant use (past month) did not change. However, population-averaged decreases in the likelihood of daily IDU (adjusted odds ratio [AOR] 0.83; 95% CI 0.72, 0.95) and opioid use (AOR 0.84; 95% CI 0.75, 0.93) were observed. Among GBM, behavioural trajectories for chemsex did not change. Population-averaged decreases in condomless anal intercourse with casual male partners (CAI-CMP) (AOR 0.95; 95% CI 0.90, 0.99) and group-sex (AOR 0.86; 95% CI 0.80, 0.93) were observed, but masked distinct trajectories. While a proportion had a decreased probability of CAI-CMP (23%) and group-sex (59%) post-treatment, a substantial proportion retained a high probability of these behaviours. High HCV reinfection incidence was observed for the sustained high probability IDU (33.0/100 PY; 95% CI 17.7, 61.3) and chemsex (23.3/100 PY; 95% CI 14.5, 37.5) trajectories. CONCLUSIONS: Limited sexual and drug use behavioural change was observed following treatment for recent HCV, supporting access to surveillance and (re)treatment.

Reinfection incidence and risk among people treated for recent hepatitis C virus infection.

OBJECTIVE: Reinfection poses a challenge to hepatitis C virus (HCV) elimination. This analysis assessed incidence of, and factors associated with reinfection among people treated for recent HCV (duration of infection <12 months). METHODS: Participants treated for recent HCV (primary infection or reinfection) in an international randomized trial were followed at 3-monthly intervals for up to 2 years to assess for reinfection. Reinfection incidence was calculated using person-time of observation. Factors associated with HCV reinfection were assessed using Cox proportional hazards regression analysis. RESULTS: Of 222 participants treated for recent HCV, 196 (62% primary infection, 38% reinfection) were included in the cohort at risk for reinfection, of whom 87% identified as gay or bisexual men, 71% had HIV and 20% injected drugs in the month prior to enrolment. During 198 person-years of follow-up, 28 cases of HCV reinfection were identified among 27 participants, for an incidence of 14.2 per 100 person-years [95% confidence interval (CI) 9.8-20.5]. Reinfection was associated with prior HCV reinfection [adjusted hazards ratio (aHR) 2.42; 95% CI 1.08-5.38], injection drug use posttreatment (aHR 2.53; 95% CI 1.14-5.59), condomless anal intercourse with casual male partners (aHR 3.32; 95% CI 1.14-9.65) and geographic region (United Kingdom, aHR 0.21; 95% CI 0.06-0.75). Among gay and bisexual men (GBM), reinfection was also associated with sexualized drug use involving injecting posttreatment (aHR 2.97; 95% CI 1.10-8.02). CONCLUSION: High reinfection incidence following treatment for recent HCV among people with ongoing sexual and drug use risk behaviour highlights the need for posttreatment surveillance, rapid retreatment of reinfection and targeted harm reduction strategies.

Short-Duration Pan-Genotypic Therapy With Glecaprevir/Pibrentasvir for 6 Weeks Among People With Recent Hepatitis C Viral Infection.

BACKGROUND AND AIMS: Among treatment-naive individuals with chronic hepatitis C viral (HCV) infection and without cirrhosis, glecaprevir/pibrentasvir for 8 weeks is recommended. The aim of this analysis was to evaluate the efficacy of glecaprevir/pibrentasvir for 6 weeks in people with acute and recent HCV infection. APPROACH AND RESULTS: In this open-label, single-arm, multicenter, international pilot study, adults with recent HCV (duration of infection < 12 months) received glecaprevir/pibrentasvir 300/120 mg daily for 6 weeks. Primary infection was defined by first positive anti-HCV antibody and/or HCV RNA within 6 months of enrollment and either acute clinical hepatitis within the past 12 months (symptomatic seroconversion illness or alanine aminotransferase > 10 × upper limit of normal) or anti-HCV antibody seroconversion within 18 months. Reinfection was defined as new positive HCV RNA within 6 months of enrollment and evidence of prior spontaneous or treatment-induced clearance. The primary endpoint was sustained virologic response at 12 weeks posttreatment (SVR12). Thirty men (median age 43 years, 90% men who have sex with men) received treatment, of whom 77% (n = 23) were human immunodeficiency virus-positive, 47% (n = 14) had ever injected drugs, and 13% (n = 4) had HCV reinfection. The majority had HCV genotype 1 (83%, n = 25), followed by genotype 4 (10%, n = 3) and genotype 3 (7%, n = 2). At baseline, median estimated duration of infection was 29 weeks (range 13, 52) and median HCV RNA was 6.2 log10 IU/mL (range 0.9, 7.7). SVR12 in the intention-to-treat and per-protocol populations was achieved in 90% (27/30) and 96% (27/28), respectively. There was one case of relapse, and there were two cases of nonvirological failure (death, n = 1; loss to follow-up, n = 1). No treatment-related serious adverse events were seen. CONCLUSIONS: Glecaprevir/pibrentasvir for 6 weeks was highly effective among people with acute and recent HCV infection, supporting further evaluation of shortened-duration pan-genotypic therapy in this setting.

Maraviroc, as a Switch Option, in HIV-1-infected Individuals With Stable, Well-controlled HIV Replication and R5-tropic Virus on Their First Nucleoside/Nucleotide Reverse Transcriptase Inhibitor Plus Ritonavir-boosted Protease Inhibitor Regimen: Week 48 Results of the Randomized, Multicenter MARCH Study.

BACKGROUND: Alternative combination antiretroviral therapies in virologically suppressed human immunodeficiency virus (HIV)-infected patients experiencing side effects and/or at ongoing risk of important comorbidities from current therapy are needed. Maraviroc (MVC), a chemokine receptor 5 antagonist, is a potential alternative component of therapy in those with R5-tropic virus. METHODS: The Maraviroc Switch Study is a randomized, multicenter, 96-week, open-label switch study in HIV type 1-infected adults with R5-tropic virus, virologically suppressed on a ritonavir-boosted protease inhibitor (PI/r) plus double nucleoside/nucleotide reverse transcriptase inhibitor (2 N(t)RTI) backbone. Participants were randomized 1:2:2 to current combination antiretroviral therapy (control), or replacing the protease inhibitor (MVC + 2 N(t)RTI arm) or the nucleoside reverse transcriptase inhibitor backbone (MVC + PI/r arm) with twice-daily MVC. The primary endpoint was the difference (switch minus control) in proportion with plasma viral load (VL) <200 copies/mL at 48 weeks. The switch arms were judged noninferior if the lower limit of the 95% confidence interval (CI) for the difference in the primary endpoint was < -12% in the intention-to-treat (ITT) population. RESULTS: The ITT population comprised 395 participants (control, n = 82; MVC + 2 N(t)RTI, n = 156; MVC + PI/r, n = 157). Baseline characteristics were well matched. At week 48, noninferior rates of virological suppression were observed in those switching away from a PI/r (93.6% [95% CI, -9.0% to 2.2%] and 91.7% [95% CI, -9.6% to 3.8%] with VL <200 and <50 copies/mL, respectively) compared to the control arm (97.6% and 95.1% with VL <200 and <50 copies/mL, respectively). In contrast, MVC + PI/r did not meet noninferiority bounds and was significantly inferior (84.1% [95% CI, -19.8% to -5.8%] and 77.7% [95% CI, -24.9% to -8.4%] with VL <200 and <50 copies/mL, respectively) to the control arm in the ITT analysis. CONCLUSIONS: These data support MVC as a switch option for ritonavir-boosted PIs when partnered with a 2-N(t)RTI backbone, but not as part of N(t)RTI-sparing regimens comprising MVC with PI/r. CLINICAL TRIALS REGISTRATION: NCT01384682.

Results of external quality assessment for proviral DNA testing of HIV tropism in the Maraviroc Switch collaborative study.

The Maraviroc Switch collaborative study (MARCH) is a study in aviremic patients on stable antiretroviral therapy and utilizes population-based sequencing of proviral DNA to determine HIV tropism and susceptibility to maraviroc. An external quality assessment (EQA) program was implemented to ensure competency in assessing the tropism of clinical samples conducted by MARCH laboratories (n = 14). The MARCH EQA has three prestudy phases assessing V3 loop sequencing and tropism determination using the bioinformatic algorithm geno2pheno, which generates a false-positive rate (FPR). DNA sequences with low FPRs are more likely to be from CXCR4-using (X4) viruses. Phase 1 of the EQA involved chromatogram interpretation. Phases 2, 2/3, and 3 involved patient and clonal samples. Clinical samples used in these phases were from treatment-experienced HIV-infected volunteers; 18/20 had viral loads of <50 copies/ml, and 10/15 were CXCR4-tropic on prior phenotyping. All samples were tested in triplicate, and any replicate with a geno2pheno FPR of <10% was designated X4. Performance was deemed adequate if ≤2 R5 and ≤1 X4 specimens were miscalled. For several clinical samples in the EQA, triplicate testing revealed marked DNA variability (FPR range, 0 to 96.7%). Therefore, a consensus-based approach was employed for each sample, i.e., a median FPR across laboratories was used to define sample tropism. Further sequencing analysis showed mixed viral populations in the clinical samples, explaining the differences in tropism predictions. All laboratories passed the EQA after achieving predefined competence thresholds in either of the phase 2 rounds. The use of clinical samples from patients resembling those who were likely to be screened in the MARCH, coupled with triplicate testing, revealed inherent DNA variability that might have been missed if single or duplicate testing and/or clonal samples alone were used. These data highlight the importance of intensive EQA of tropism laboratories before embarking on clinical studies. (This study has been registered at ClinicalTrials.gov under registration no. NCT01384682 [http://www.clinicaltrials.gov/ct2/show/study/NCT01384682?term=NCT01384682&rank=1].).

Norovirus GII.4 variant 2006b caused epidemics of acute gastroenteritis in Australia during 2007 and 2008.

BACKGROUND: Over the last decade, four epidemics of norovirus-associated gastroenteritis have been reported in Australia. These epidemics were characterized by numerous outbreaks in institutional settings such as hospitals and nursing homes, as well as increases in requests for NoV testing in diagnostic centers. During 2007 and 2008, widespread outbreaks of acute gastroenteritis were once again seen across Australia, peaking during the winter months. OBJECTIVES: The primary objective of this study was to characterize two winter epidemics of NoV-associated gastroenteritis in 2007 and 2008 in Australia. Following this, we aimed to determine if these epidemics were caused by a new GII.4 variant or a previously circulating NoV strain. STUDY DESIGN: NoV-positive fecal samples (n=219) were collected over a 2-year period, December 2006 to December 2008, from cases of acute gastroenteritis in Australia. NoV RNA was amplified from these samples using a nested RT-PCR approach targeting the 5' end of the capsid gene, termed region C. Further, characterization was performed by sequence analysis of the RdRp and capsid genes and recombination was identified using SimPlot. RESULTS: From 2004 to 2008, peaks in the numbers of NoV-positive EIA tests from the Prince of Wales Hospital Laboratory correlated with the overall number of gastroenteritis outbreaks reported to NSW Health, thereby supporting recent studies showing that NoV is the major cause of outbreak gastroenteritis. The predominant NoV GII variant identified during the 2007-2008 period was the GII.4 pandemic variant, 2006b (71.51%, 128/179), which replaced the 2006a variant identified in the previous Australian epidemic of 2006. Four novel GII variants were also identified including the three GII.4 variants: NoV 2008, NoV Osaka 2007 and NoV Cairo 2007, and one novel recombinant NoV designated GII.e/GII.12. CONCLUSION: The increase in acute gastroenteritis outbreaks in 2007 and 2008 were associated with the spread of the NoV GII.4 variant 2006b.

Acute hepatitis C infection with evidence of heterosexual transmission.

A 62-year-old woman acquired acute hepatitis C virus (HCV) infection after heterosexual contact with a known HCV positive former injecting drug user. There were no known sexual or other risk factors for HCV acquisition. Phylogenetic analysis confirmed the case and index were infected with identical genotype 3a strains, consistent with heterosexual transmission in the absence of specific risk factors.

Norovirus excretion in an aged-care setting.

Norovirus genogroup II excretion during an outbreak of gastroenteritis was investigated in an aged-care facility. Viral shedding peaked in the acute stage of illness and continued for an average of 28.7 days. The viral decay rate was 0.76 per day, which corresponds to a viral half-life of 2.5 days.

Epidemics of gastroenteritis during 2006 were associated with the spread of norovirus GII.4 variants 2006a and 2006b.

BACKGROUND: Acute gastroenteritis is commonly associated with norovirus genogroup II (GII) infection. Norovirus GII has 17 classified genotypes (GII.1-GII.17), but only 1 norovirus genotype (GII.4) is associated with global epidemics of gastroenteritis. In 2006, an increase in global norovirus activity was observed. METHODS: During the period from December 2005 through August 2006, a total of 231 fecal samples were obtained from patients with acute gastroenteritis from Australia and New Zealand. Norovirus RNA was amplified and sequenced to determine norovirus genotype and relatedness to known epidemic norovirus GII.4 variants. RESULTS: Two GII.4 variants, designated 2006a and 2006b, were identified in 61.8% and 11.3%, respectively, of the 186 cases investigated. Norovirus 2006a and 2006b have also been implicated as the predominant causes of norovirus-associated gastroenteritis across Europe in 2006. CONCLUSIONS: The global increase in norovirus-associated gastroenteritis in 2006 was linked to the emergence of 2 novel GII.4 variants, 2006a and 2006b.

Genetic diversity of Sapovirus in children, Australia.

Sapovirus was detected in 7 of 95 stool specimens from children with gastroenteritis of unknown etiology in Sydney, Australia, from August 2001 to August 2002 and from February 2004 to August 2004, by using reverse transcription-polymerase chain reaction. Sequence analysis of the N-terminal capsid region showed all human sapovirus genogroups.

Emergence of a new norovirus genotype II.4 variant associated with global outbreaks of gastroenteritis.

Norovirus (NoV) is highly infectious and is the major cause of outbreak gastroenteritis in adults, with pandemic spread of the virus being reported in 1995 and 2002. The NoV genome is genetically diverse, which has hampered development of sensitive molecular biology-based methods. In this study we report on a nested reverse transcriptase PCR (nRT-PCR) that was designed to amplify the highly conserved 3' end of the polymerase region and the 5' end of the capsid gene of NoV genogroup II (GII). The nRT-PCR was validated with strains isolated from sporadic and outbreak cases between 1997 and 2004 in New South Wales, Australia. Phylogenetic analysis identified six genotypes circulating in New South Wales, GII.1, GII.3, GII.4, GII.6, GII.7, and GII.10, with GII.4 being the predominant genotype. In 2004, there was a marked increase in NoV GII activity in Australia, with a novel GII.4 variant being identified as the etiological agent in 18 outbreaks investigated. This novel GII.4 variant, termed Hunter virus, differed by more than 5% at the amino acid level across the capsid from any other NoV strain in the GenBank and EMBL databases. The Hunter virus was subsequently identified as the etiological agent in large epidemics of gastroenteritis in The Netherlands, Japan, and Taiwan in 2004 and 2005.