After the pandemic: perspectives on the future trajectory of COVID-19.

There is a realistic expectation that the global effort in vaccination will bring the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) under control. Nonetheless, uncertainties remain about the type of long-term association that the virus will establish with the human population and, in particular, whether coronavirus disease 2019 (COVID-19) will become an endemic disease. Although the trajectory is difficult to predict, the conditions, concepts and variables that influence this transition can be anticipated. Persistence of SARS-CoV-2 as an endemic virus, perhaps with seasonal epidemic peaks, may be fuelled by pockets of susceptible individuals and waning immunity after infection or vaccination, changes in the virus through antigenic drift that diminish protection and re-entries from zoonotic reservoirs. Here we review relevant observations from previous epidemics and discuss the potential evolution of SARS-CoV-2 as it adapts during persistent transmission in the presence of a level of population immunity. Lack of effective surveillance or adequate response could enable the emergence of new epidemic or pandemic patterns from an endemic infection of SARS-CoV-2. There are key pieces of data that are urgently needed in order to make good decisions; we outline these and propose a way forward.

A Randomized, Placebo-Controlled Trial to Evaluate the Safety and Efficacy of VIR-2482 in Healthy Adults for Prevention of Influenza A Illness (PENINSULA).

BACKGROUND: Influenza A results in significant morbidity and mortality. VIR-2482, an engineered human monoclonal antibody with extended half-life, targets a highly conserved epitope on the stem region of influenza A hemagglutinin and may protect against seasonal and pandemic influenza. METHODS: This double-blind, randomized, placebo-controlled, phase 2 study examined the safety and efficacy of VIR-2482 for seasonal influenza A illness prevention in unvaccinated healthy adults. Participants (N = 2977) were randomized 1:1:1 to receive VIR-2482 450 mg, VIR-2482 1200 mg, or placebo via intramuscular injection. Primary and secondary efficacy endpoints were the proportions of participants with reverse transcriptase-polymerase chain reaction-confirmed influenza A infection and either protocol-defined influenza-like illness (ILI) and Centers for Disease Control and Prevention-defined ILI or World Health Organization-defined ILI, respectively. RESULTS: VIR-2482 450 mg and 1200 mg prophylaxis did not reduce the risk of protocol-defined ILI with reverse transcriptase-polymerase chain reaction-confirmed influenza A versus placebo (relative risk reduction, 3.8% [95% confidence interval (CI), -67.3 to 44.6] and 15.9% [95% CI, -49.3 to 52.3], respectively). At the 1200-mg dose, the relative risk reductions in influenza A illness were 57.2% (95% CI: -2.5 to 82.2) using Centers for Disease Control and Prevention ILI and 44.1% (95% CI: -50.5 to 79.3) using World Health Organization ILI definitions, respectively. Serum VIR-2482 levels were similar regardless of influenza status; variants with reduced VIR-2482 susceptibility were not detected. Local injection site reactions were mild and similar across groups. CONCLUSIONS: VIR-2482 1200 mg intramuscular was well tolerated but did not significantly prevent protocol-defined ILI. Secondary endpoint analyses suggest this dose may have reduced influenza A illness. Trial registration: ClinicalTrials.gov identifier, NCT05567783.

Early Treatment for Covid-19 with SARS-CoV-2 Neutralizing Antibody Sotrovimab.

BACKGROUND: Coronavirus disease 2019 (Covid-19) disproportionately results in hospitalization or death in older patients and those with underlying conditions. Sotrovimab is a pan-sarbecovirus monoclonal antibody that was designed to prevent progression of Covid-19 in high-risk patients early in the course of disease. METHODS: In this ongoing, multicenter, double-blind, phase 3 trial, we randomly assigned, in a 1:1 ratio, nonhospitalized patients with symptomatic Covid-19 (≤5 days after the onset of symptoms) and at least one risk factor for disease progression to receive a single infusion of sotrovimab at a dose of 500 mg or placebo. The primary efficacy outcome was hospitalization (for >24 hours) for any cause or death within 29 days after randomization. RESULTS: In this prespecified interim analysis, which included an intention-to-treat population of 583 patients (291 in the sotrovimab group and 292 in the placebo group), 3 patients (1%) in the sotrovimab group, as compared with 21 patients (7%) in the placebo group, had disease progression leading to hospitalization or death (relative risk reduction, 85%; 97.24% confidence interval, 44 to 96; P = 0.002). In the placebo group, 5 patients were admitted to the intensive care unit, including 1 who died by day 29. Safety was assessed in 868 patients (430 in the sotrovimab group and 438 in the placebo group). Adverse events were reported by 17% of the patients in the sotrovimab group and 19% of those in the placebo group; serious adverse events were less common with sotrovimab than with placebo (in 2% and 6% of the patients, respectively). CONCLUSIONS: Among high-risk patients with mild-to-moderate Covid-19, sotrovimab reduced the risk of disease progression. No safety signals were identified. (Funded by Vir Biotechnology and GlaxoSmithKline; COMET-ICE ClinicalTrials.gov number, NCT04545060.).

Evaluation of RNAi therapeutics VIR-2218 and ALN-HBV for chronic hepatitis B: Results from randomized clinical trials.

BACKGROUND & AIMS: Current therapy for chronic hepatitis B virus (cHBV) infection involves lifelong treatment. New treatments that enable HBV functional cure would represent a clinically meaningful advance. ALN-HBV and VIR-2218 are investigational RNA interference therapeutics that target all major HBV transcripts. METHODS: We report on: i) the safety of single doses of VIR-2218 (modified from ALN-HBV by enhanced stabilization chemistry plus technology to reduce off-target, seed-mediated binding while maintaining on-target antiviral activity) and ALN-HBV in humanized mice; ii) a cross-study comparison of the safety of single doses of VIR-2218 and ALN-HBV in healthy human volunteers (n = 24 and n = 49, respectively); and iii) the antiviral activity of two doses of 20, 50, 100, 200 mg of VIR-2218 (total n = 24) vs. placebo (n = 8), given 4 weeks apart, in participants with cHBV infection. RESULTS: In humanized mice, alanine aminotransferase (ALT) levels were markedly lower following administration of VIR-2218 compared with ALN-HBV. In healthy volunteers, post-treatment ALT elevations occurred in 28% of participants receiving ALN-HBV compared with none in those receiving VIR-2218. In participants with cHBV infection, VIR-2218 was associated with dose-dependent reductions in hepatitis B surface antigen (HBsAg). The greatest mean reduction of HBsAg at Week 20 in participants receiving 200 mg was 1.65 log IU/ml. The HBsAg reduction was maintained at 0.87 log IU/ml at Week 48. No participants had serum HBsAg loss or hepatitis B surface antibody seroconversion. CONCLUSIONS: VIR-2218 demonstrated an encouraging hepatic safety profile in preclinical and clinical studies as well as dose-dependent HBsAg reductions in patients with cHBV infection. These data support future studies with VIR-2218 as part of combination regimens with a goal of HBV functional cure. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT02826018 and NCT03672188. IMPACT AND IMPLICATIONS: A significant unmet need exists for therapies for chronic HBV (cHBV) infection that achieve functional cure. We report clinical and non-clinical data on two investigational small-interfering RNAs that target HBx, ALN-HBV and VIR-2218, demonstrating that incorporation of enhanced stabilization chemistry plus technology in VIR-2218 reduces its propensity to cause ALT elevations relative to its parent compound, ALN-HBV. We also show that VIR-2218 reduces hepatitis B surface antigen levels in a dose-dependent manner in participants with cHBV infection. These studies support the continued development of VIR-2218 as part of therapeutic regimens for cHBV infection, with the goal of a functional cure, and are important for HBV researchers and physicians.

Ledipasvir and Sofosbuvir for HCV in Patients Coinfected with HIV-1.

BACKGROUND: Effective treatment for hepatitis C virus (HCV) in patients coinfected with human immunodeficiency virus type 1 (HIV-1) remains an unmet medical need. METHODS: We conducted a multicenter, single-group, open-label study involving patients coinfected with HIV-1 and genotype 1 or 4 HCV receiving an antiretroviral regimen of tenofovir and emtricitabine with efavirenz, rilpivirine, or raltegravir. All patients received ledipasvir, an NS5A inhibitor, and sofosbuvir, a nucleotide polymerase inhibitor, as a single fixed-dose combination for 12 weeks. The primary end point was a sustained virologic response at 12 weeks after the end of therapy. RESULTS: Of the 335 patients enrolled, 34% were black, 55% had been previously treated for HCV, and 20% had cirrhosis. Overall, 322 patients (96%) had a sustained virologic response at 12 weeks after the end of therapy (95% confidence interval [CI], 93 to 98), including rates of 96% (95% CI, 93 to 98) in patients with HCV genotype 1a, 96% (95% CI, 89 to 99) in those with HCV genotype 1b, and 100% (95% CI, 63 to 100) in those with HCV genotype 4. Rates of sustained virologic response were similar regardless of previous treatment or the presence of cirrhosis. Of the 13 patients who did not have a sustained virologic response, 10 had a relapse after the end of treatment. No patient had confirmed HIV-1 virologic rebound. The most common adverse events were headache (25%), fatigue (21%), and diarrhea (11%). No patient discontinued treatment because of adverse events. CONCLUSIONS: Ledipasvir and sofosbuvir for 12 weeks provided high rates of sustained virologic response in patients coinfected with HIV-1 and HCV genotype 1 or 4. (Funded by Gilead Sciences; ION-4 ClinicalTrials.gov number, NCT02073656.).

Ledipasvir and sofosbuvir for untreated HCV genotype 1 infection.

BACKGROUND: In phase 2 studies, treatment with the all-oral combination of the nucleotide polymerase inhibitor sofosbuvir and the NS5A inhibitor ledipasvir resulted in high rates of sustained virologic response among previously untreated patients with hepatitis C virus (HCV) genotype 1 infection. METHODS: We conducted a phase 3, open-label study involving previously untreated patients with chronic HCV genotype 1 infection. Patients were randomly assigned in a 1:1:1:1 ratio to receive ledipasvir and sofosbuvir in a fixed-dose combination tablet once daily for 12 weeks, ledipasvir-sofosbuvir plus ribavirin for 12 weeks, ledipasvir-sofosbuvir for 24 weeks, or ledipasvir-sofosbuvir plus ribavirin for 24 weeks. The primary end point was a sustained virologic response at 12 weeks after the end of therapy. RESULTS: Of the 865 patients who underwent randomization and were treated, 16% had cirrhosis, 12% were black, and 67% had HCV genotype 1a infection. The rates of sustained virologic response were 99% (95% confidence interval [CI], 96 to 100) in the group that received 12 weeks of ledipasvir-sofosbuvir; 97% (95% CI, 94 to 99) in the group that received 12 weeks of ledipasvir-sofosbuvir plus ribavirin; 98% (95% CI, 95 to 99) in the group that received 24 weeks of ledipasvir-sofosbuvir; and 99% (95% CI, 97 to 100) in the group that received 24 weeks of ledipasvir-sofosbuvir plus ribavirin. No patient in either 12-week group discontinued ledipasvir-sofosbuvir owing to an adverse event. The most common adverse events were fatigue, headache, insomnia, and nausea. CONCLUSIONS: Once-daily ledipasvir-sofosbuvir with or without ribavirin for 12 or 24 weeks was highly effective in previously untreated patients with HCV genotype 1 infection. (Funded by Gilead Sciences; ION-1 ClinicalTrials.gov number NCT01701401.).

Ledipasvir and sofosbuvir for previously treated HCV genotype 1 infection.

BACKGROUND: Effective treatment for hepatitis C virus (HCV) genotype 1 infection in patients who have not had a sustained virologic response to prior interferon-based therapy represents an unmet medical need. METHODS: We conducted a phase 3, randomized, open-label study involving patients infected with HCV genotype 1 who had not had a sustained virologic response after treatment with peginterferon and ribavirin, with or without a protease inhibitor. Patients were randomly assigned to receive the NS5A inhibitor ledipasvir and the nucleotide polymerase inhibitor sofosbuvir in a once-daily, fixed-dose combination tablet for 12 weeks, ledipasvir-sofosbuvir plus ribavirin for 12 weeks, ledipasvir-sofosbuvir for 24 weeks, or ledipasvir-sofosbuvir plus ribavirin for 24 weeks. The primary end point was a sustained virologic response at 12 weeks after the end of therapy. RESULTS: Among the 440 patients who underwent randomization and were treated, 20% had cirrhosis and 79% had HCV genotype 1a infection. The rates of sustained virologic response were high in all treatment groups: 94% (95% confidence interval [CI], 87 to 97) in the group that received 12 weeks of ledipasvir-sofosbuvir; 96% (95% CI, 91 to 99) in the group that received 12 weeks of ledipasvir-sofosbuvir and ribavirin; 99% (95% CI, 95 to 100) in the group that received 24 weeks of ledipasvir-sofosbuvir; and 99% (95% CI, 95 to 100) in the group that received 24 weeks of ledipasvir-sofosbuvir and ribavirin. No patient discontinued treatment owing to an adverse event. The most common adverse events were fatigue, headache, and nausea. CONCLUSIONS: Treatment with a once-daily, single-tablet regimen of ledipasvir and sofosbuvir resulted in high rates of sustained virologic response among patients with HCV genotype 1 infection who had not had a sustained virologic response to prior interferon-based treatment. (Funded by Gilead Sciences; ION-2 ClinicalTrials.gov number, NCT01768286.).

Ledipasvir and sofosbuvir for 8 or 12 weeks for chronic HCV without cirrhosis.

BACKGROUND: High rates of sustained virologic response were observed among patients with hepatitis C virus (HCV) infection who received 12 weeks of treatment with the nucleotide polymerase inhibitor sofosbuvir combined with the NS5A inhibitor ledipasvir. This study examined 8 weeks of treatment with this regimen. METHODS: In this phase 3, open-label study, we randomly assigned 647 previously untreated patients with HCV genotype 1 infection without cirrhosis to receive ledipasvir and sofosbuvir (ledipasvir-sofosbuvir) for 8 weeks, ledipasvir-sofosbuvir plus ribavirin for 8 weeks, or ledipasvir-sofosbuvir for 12 weeks. The primary end point was sustained virologic response at 12 weeks after the end of therapy. RESULTS: The rate of sustained virologic response was 94% (95% confidence interval [CI], 90 to 97) with 8 weeks of ledipasvir-sofosbuvir, 93% (95% CI, 89 to 96) with 8 weeks of ledipasvir-sofosbuvir plus ribavirin, and 95% (95% CI, 92 to 98) with 12 weeks of ledipasvir-sofosbuvir. As compared with the rate of sustained virologic response in the group that received 8 weeks of ledipasvir-sofosbuvir, the rate in the 12-week group was 1 percentage point higher (97.5% CI, -4 to 6) and the rate in the group that received 8 weeks of ledipasvir-sofosbuvir with ribavirin was 1 percentage point lower (95% CI, -6 to 4); these results indicated noninferiority of the 8-week ledipasvir-sofosbuvir regimen, on the basis of a noninferiority margin of 12 percentage points. Adverse events were more common in the group that received ribavirin than in the other two groups. No patient who received 8 weeks of only ledipasvir-sofosbuvir discontinued treatment owing to adverse events. CONCLUSIONS: Ledipasvir-sofosbuvir for 8 weeks was associated with a high rate of sustained virologic response among previously untreated patients with HCV genotype 1 infection without cirrhosis. No additional benefit was associated with the inclusion of ribavirin in the regimen or with extension of the duration of treatment to 12 weeks. (Funded by Gilead Sciences; ION-3 ClinicalTrials.gov number, NCT01851330.).

Prevalence of Resistance-Associated Substitutions in HCV NS5A, NS5B, or NS3 and Outcomes of Treatment With Ledipasvir and Sofosbuvir.

BACKGROUND & AIMS: We evaluated the effects of baseline hepatitis C virus (HCV) NS5A, NS5B, and NS3 resistance-associated substitutions (RASs) on response to the combination of ledipasvir and sofosbuvir, with or without ribavirin, in patients with HCV genotype 1 infection. METHODS: We analyzed data from 2144 participants in phase 2 and 3 studies of patients with HCV genotype 1a or b infection who received the combination of ledipasvir (90 mg) and sofosbuvir (400 mg) (ledipasvir/sofosbuvir) once daily, with or without ribavirin twice daily. Population and/or deep sequence analyses of the HCV NS3, NS5A, and NS5B genes were performed on blood samples collected at baseline. RESULTS: Overall, 16.0% of patients had detectable baseline RASs in NS5A. Among patients with HCV genotype 1b infection, there was no significant effect of baseline RASs in NS5A on sustained viral response 12 weeks after the end of treatment (SVR12) with ledipasvir/sofosbuvir and only a small effect in patients with HCV genotype 1a infection. RASs in NS5A that increased the half-maximal effective concentration to ledipasvir by more than 100-fold reduced the rate of SVR12 in treatment-naive patients given ledipasvir/sofosbuvir for 8 weeks (P = .011), but not for 12 weeks. These same baseline NS5A RASs reduced the percentage of treatment-experienced patients who achieved an SVR12 to 12 weeks (but not 24 weeks) ledipasvir/sofosbuvir (P < .001). These RASs had a small effect in patients given ledipasvir/sofosbuvir in combination with ribavirin for 12 weeks. Overall, 2.5% of patients had baseline NS5B nucleotide inhibitor RASs (L159F, N142T, S282G, or L320S) and all achieved an SVR12. Of patients previously treated with protease inhibitors, 53.7% had RASs in NS3 and 96.5% achieved an SVR12. CONCLUSIONS: Baseline RASs in NS5A have minimal effects on patient responses to ledipasvir/sofosbuvir therapy. When these RASs do have effects, they could be largely overcome by extending treatment duration or through treatment intensification.

Ledipasvir plus sofosbuvir for 12 weeks in patients with hepatitis C genotype 4 infection.

UNLABELLED: Genotype 4 hepatitis C virus (HCV) was considered difficult to treat in the era of pegylated interferon-alpha (Peg-IFN-α) and ribavirin regimens. We evaluated the efficacy and safety of therapy with the nonstructural (NS) 5A inhibitor, ledipasvir, combined with the NS5B polymerase inhibitor, sofosbuvir, in patients with HCV genotype 4. In this phase 2, open-label study, 44 patients (22 treatment naïve and 22 treatment experienced) received a fixed-dose combination tablet of 90 mg of ledipasvir and 400 mg of sofosbuvir orally once-daily for 12 weeks. The primary endpoint was the percentage of patients with HCV RNA <15 IU/mL 12 weeks after stopping therapy (SVR12). Among study participants, HCV genotype 4 subtypes were well represented (4a, n = 25; 4d, n = 10; other subtypes, n = 9). Ten patients (23%) had compensated cirrhosis. Of the 22 treatment-experienced patients, 21 (95%) had a non-CC IL-28B genotype. All 44 patients completed the full 12 weeks of dosing. The SVR12 rate was 93% (41 of 44; 95% confidence interval, 81-99). SVR12 rates were similar between treatment-naïve (95%; 21 of 22) and treatment-experienced (91%; 20 of 22) patients. All 3 patients who did not achieve SVR12 had virological relapse within 4 weeks of the end of treatment; all 3 had baseline HCV RNA ≥800,000 IU/mL, a non-CC IL-28B genotype, and pretreatment NS5A resistance-associated variants. None of the patients who relapsed had cirrhosis. The most common adverse events were asthenia, headache, and fatigue. No patients experienced a serious adverse event. CONCLUSION: The all-oral regimen of ledipasvir and sofosbuvir is an effective and safe treatment for a wide range of HCV 4 subtypes in both treatment-naïve and -experienced patients, including those with compensated cirrhosis. (EudraCT number: 2013-003978-27; Clinicaltrials.gov NCT02081079) (Hepatology 2016;64:1049-1056).

Safety and efficacy of ledipasvir-sofosbuvir in black patients with hepatitis C virus infection: A retrospective analysis of phase 3 data.

UNLABELLED: Black patients chronically infected with genotype 1 hepatitis C virus (HCV) have historically had lower rates of response to interferon-based treatment than patients of other races. In the phase 3 ION program, the single-tablet regimen of the NS5A inhibitor ledipasvir and NS5B nucleotide polymerase inhibitor sofosbuvir was shown to be safe and highly effective in the general population. The aim of this study was to evaluate the safety and efficacy of ledipasvir/sofosbuvir in black patients using data from the three open-label ION clinical trials, which evaluated the safety and efficacy of 8, 12, and 24 weeks of ledipasvir/sofosbuvir with or without ribavirin for the treatment of treatment-naïve and treatment-experienced patients with genotype 1 HCV, including those with compensated cirrhosis. The primary endpoint was sustained virologic response at 12 weeks after the end of therapy (SVR12). For our analysis, rates of SVR12, treatment-emergent adverse events, and graded laboratory abnormalities were analyzed in black versus non-black patients. Of the 1949 patients evaluated, 308 (16%) were black. On average, black patients were older, had higher body mass index, were more likely to be IL28B non-CC, and had a lower serum alanine aminotransferase at baseline than non-black patients. Overall, 95% of black and 97% of non-black patients achieved SVR12. The rate of relapse was 3% in black patients as compared with 2% in non-black patients. The most common adverse events included fatigue, headache, nausea, and insomnia. The majority of adverse events occurred more frequently in the ribavirin-containing arms of the studies. No differences were observed in overall safety by race. CONCLUSION: A once-daily dosage of ledipasvir/sofosbuvir was similarly effective in black and non-black patients with genotype 1 HCV infection. The addition of ribavirin did not appear to increase SVR12 but was associated with higher rates of adverse events.

Successful Re-treatment of Hepatitis C Virus in Patients Coinfected With HIV Who Relapsed After 12 Weeks of Ledipasvir/Sofosbuvir.

UNLABELLED: We assessed the efficacy and safety of ledipasvir/sofosbuvir plus ribavirin for 24 weeks in 9 human immunodeficiency virus/hepatitis C virus-coinfected patients who relapsed after receiving 12 weeks of treatment with ledipasvir/sofosbuvir. Eight of 9 (89%) achieved sustained virologic response 12 weeks after the end of treatment. One patient relapsed at posttreatment week 4. These results suggest an effective salvage therapy for patients for whom direct-acting antiviral treatment has failed. CLINICAL TRIALS REGISTRATION: NCT02073656.

Successful Retreatment of Chronic HCV Genotype-1 Infection With Ledipasvir and Sofosbuvir After Initial Short Course Therapy With Direct-Acting Antiviral Regimens.

BACKGROUND: The optimal retreatment strategy for chronic hepatitis C virus (HCV) patients who fail directly-acting antiviral agent (DAA)-based treatment is unknown. In this study, we assessed the efficacy and safety of ledipasvir (LDV) and sofosbuvir (SOF) for 12 weeks in HCV genotype-1 (GT-1) patients who failed LDV/SOF-containing therapy. METHODS: In this single-center, open-label, phase 2a trial, 34 participants with HCV (GT-1) and early-stage liver fibrosis who previously failed 4-6 weeks of LDV/SOF with GS-9669 and/or GS-9451 received LDV/SOF for 12 weeks. The primary endpoint was HCV viral load below the lower limit of quantification 12 weeks after completion of therapy (sustained virological response [SVR]12). Deep sequencing of the NS3, NS5A, and NS5B regions were performed at baseline, at initial relapse, prior to retreatment, and at second relapse with Illumina next-generation sequencing technology. RESULTS: Thirty-two of 34 enrolled participants completed therapy. Two patients withdrew after day 0. Participants were predominantly male and black, with median baseline HCV viral load of 1.3 × 10(6) IU/mL and Metavir fibrosis stage 1 and genotype-1a. Median time from relapse to retreatment was 22 weeks. Prior to retreatment, 29 patients (85%) had NS5A-resistant variants. The SVR12 rate was 91% (31/34; intention to treat, ITT) after retreatment. One patient relapsed. CONCLUSIONS: In patients who previously failed short-course combination DAA therapy, we demonstrate a high SVR rate in response to 12 weeks of LDV/SOF, even for patients with NS5A resistance-associated variants. CLINICAL TRIALS REGISTRATION: NCT01805882.

Virological response after 6 week triple-drug regimens for hepatitis C: a proof-of-concept phase 2A cohort study.

BACKGROUND: Direct-acting antiviral drugs have a high cure rate and favourable tolerability for patients with hepatitis C virus (HCV). Shorter courses could improve affordability and adherence. Sofosbuvir and ledipasvir with ribavirin have high efficacy when taken for 8 weeks but not for 6 weeks. We assessed whether the addition of a third direct-acting antiviral drug to sofosbuvir and ledipasvir would allow a shorter treatment duration. METHODS: In this single-centre, open-label, phase 2A trial, we sequentially enrolled treatment-naive patients with HCV genotype 1 infection into three treatment groups: 12 weeks of sofosbuvir and ledipasvir; 6 weeks of sofosbuvir, ledipasvir, and GS-9669; or 6 weeks of sofosbuvir, ledipasvir, and GS-9451. Patients and investigators were not masked to treatment assignment. The primary endpoint was the propotion of patients with sustained viral response at 12 weeks after treatment completion (SVR12), assessed by serum HCV RNA concentrations lower than 43 IU/mL (the lower limit of quantification). We did an intention-to-treat analysis for the primary endpoint and adverse events. This study is registered with ClinicalTrials.gov, number NCT01805882. FINDINGS: Between Jan 11, 2013, and Dec 17, 2013, we enrolled 60 patients, and sequentially assigned them into three groups of 20. We noted an SVR12 in all 20 patients (100%, 95% CI 83-100) allocated to sofosbuvir and ledipasvir for 12 weeks; in 19 (95%, 75-100) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (one patient relapsed 2 weeks after completion of treatment); and in 19 (95%, 75-100%) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (one patient was lost to follow-up after reaching sustained viral response at 4 weeks). Most adverse events were mild and no patients discontinued treatment. Two serious adverse events occurred (pain after a post-treatment liver biopsy and vertigo), both unrelated to study drugs. INTERPRETATION: In this small proof-of-concept study, two different three-drug regimens that were given for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Addition of a third potent direct-acting antiviral drug can reduce the duration of treatment required to achieve sustained viral response in patients with chronic HCV genotype 1 infection without cirrhosis. FUNDING: National Institute of Allergy and Infectious Diseases (NIAID), National Cancer Institute and Clinical Center Intramural Program, German Research Foundation, National Institutes of Health, Gilead Sciences.

Efficacy of ledipasvir and sofosbuvir, with or without ribavirin, for 12 weeks in patients with HCV genotype 3 or 6 infection.

BACKGROUND & AIMS: We performed a phase 2 clinical trial to evaluate the efficacy and safety of ledipasvir and sofosbuvir, with or without ribavirin, in patients infected with hepatitis C virus (HCV) genotype 3 or 6. METHODS: We performed an open-label study of 126 patients with HCV genotype 3 or 6 infections at 2 centers in New Zealand from April 2013 through October 2014. Subjects were assigned 1 of 4 groups that received 12 weeks of treatment. Previously untreated patients with HCV genotype 3 were randomly assigned to groups given fixed-dose combination tablet of ledipasvir and sofosbuvir (n = 25) or ledipasvir and sofosbuvir along with ribavirin (n = 26). Treatment-experienced patients with HCV genotype 3 (n = 50) received ledipasvir and sofosbuvir and ribavirin. Treatment-naïve or treatment-experienced patients with HCV genotype 6 (n = 25) received ledipasvir and sofosbuvir. The primary end point was the percentage of patients with HCV RNA ≤15 IU/mL 12 weeks after stopping therapy (sustained virologic response at 12 weeks [SVR12]). RESULTS: Among treatment-naïve genotype 3 patients, 16 of 25 (64%) receiving ledipasvir and sofosbuvir alone achieved SVR12 compared with all 26 patients (100%) receiving ledipasvir and sofosbuvir and ribavirin. Among treatment-experienced patients with HCV genotype 3, forty-one of fifty achieved an SVR12 (82%). Among patients with HCV genotype 6, the rate of SVR12 was 96% (24 of 25 patients). The most common adverse events were headache, upper respiratory infection, and fatigue. One patient with HCV genotype 3 discontinued ledipasvir and sofosbuvir because of an adverse event (diverticular perforation), which was not considered treatment related. CONCLUSIONS: In an uncontrolled, open-label trial, high rates of SVR12 were achieved by patients with HCV genotype 3 infection who received 12 weeks of ledipasvir and sofosbuvir plus ribavirin, and by patients with HCV genotype 6 infection who received 12 weeks of sofosbuvir and ledipasvir without ribavirin. Current guidelines do not recommend the use of ledipasvir and sofosbuvir, with or without ribavirin, in patients with HCV genotype 3 infection. ClinicalTrials.gov Number: NCT01826981.

Phosphatidylinositol 4,5-bisphosphate is an HCV NS5A ligand and mediates replication of the viral genome.

BACKGROUND & AIMS: Phosphoinositides (PIs) bind and regulate localization of proteins via a variety of structural motifs. PI 4,5-bisphosphate (PI[4,5]P2) interacts with and modulates the function of several proteins involved in intracellular vesicular membrane trafficking. We investigated interactions between PI(4,5)P2 and hepatitis C virus (HCV) nonstructural protein 5A (NS5A) and effects on the viral life cycle. METHODS: We used a combination of quartz crystal microbalance, circular dichroism, molecular genetics, and immunofluorescence to study specific binding of PI(4,5)P2 by the HCV NS5A protein. We evaluated the effects of PI(4,5)P2 on the function of NS5A by expressing wild-type or mutant forms of Bart79I or FL-J6/JFH-5'C19Rluc2AUbi21 RNA in Huh7 cells. We also studied the effects of strategies designed to inhibit PI(4,5)P2 on HCV replication in these cells. RESULTS: The N-terminal amphipathic helix of NS5A bound specifically to PI(4,5)P2, inducing a conformational change that stabilized the interaction between NS5A and TBC1D20, which is required for HCV replication. A pair of positively charged residues within the amphipathic helix (the basic amino acid PI(4,5)P2 pincer domain) was required for PI(4,5)P2 binding and replication of the HCV-RNA genome. A similar motif was found to be conserved across all HCV isolates, as well as amphipathic helices of many pathogens and apolipoproteins. CONCLUSIONS: PI(4,5)P2 binds to HCV NS5A to promote replication of the viral RNA genome in hepatocytes. Strategies to disrupt this interaction might be developed to inhibit replication of HCV and other viruses.

Ledipasvir and Sofosbuvir Plus Ribavirin for Treatment of HCV Infection in Patients With Advanced Liver Disease.

BACKGROUND & AIMS: There are no effective and safe treatments for chronic hepatitis C virus (HCV) infection of patients who have advanced liver disease. METHODS: In this phase 2, open-label study, we assessed treatment with the NS5A inhibitor ledipasvir, the nucleotide polymerase inhibitor sofosbuvir, and ribavirin in patients infected with HCV genotypes 1 or 4. Cohort A enrolled patients with cirrhosis and moderate or severe hepatic impairment who had not undergone liver transplantation. Cohort B enrolled patients who had undergone liver transplantation: those without cirrhosis; those with cirrhosis and mild, moderate, or severe hepatic impairment; and those with fibrosing cholestatic hepatitis. Patients were assigned randomly (1:1) to receive 12 or 24 weeks of a fixed-dose combination tablet containing ledipasvir and sofosbuvir, once daily, plus ribavirin. The primary end point was sustained virologic response at 12 weeks after the end of treatment (SVR12). RESULTS: We enrolled 337 patients, 332 (99%) with HCV genotype 1 infection and 5 (1%) with HCV genotype 4 infection. In cohort A (nontransplant), SVR12 was achieved by 86%-89% of patients. In cohort B (transplant recipients), SVR12 was achieved by 96%-98% of patients without cirrhosis or with compensated cirrhosis, by 85%-88% of patients with moderate hepatic impairment, by 60%-75% of patients with severe hepatic impairment, and by all 6 patients with fibrosing cholestatic hepatitis. Response rates in the 12- and 24-week groups were similar. Thirteen patients (4%) discontinued the ledipasvir and sofosbuvir combination prematurely because of adverse events; 10 patients died, mainly from complications related to hepatic decompensation. CONCLUSION: The combination of ledipasvir, sofosbuvir, and ribavirin for 12 weeks produced high rates of SVR12 in patients with advanced liver disease, including those with decompensated cirrhosis before and after liver transplantation. ClinTrials.gov: NCT01938430.

Ledipasvir-sofosbuvir plus ribavirin for patients with genotype 1 hepatitis C virus previously treated in clinical trials of sofosbuvir regimens.

UNLABELLED: Patients who fail to achieve sustained virological response (SVR) after treatment with sofosbuvir (SOF) plus ribavirin (RBV) with or without pegylated interferon (Peg-IFN) do not have established retreatment options. We conducted an open-label trial to assess the efficacy and safety of ledipasvir (LDV)-SOF plus RBV in patients with genotype 1 hepatitis C virus (HCV) who did not achieve SVR after treatment in phase II and III trials of SOF regimens. We enrolled 51 patients at 24 sites in the United States. All patients received the fixed-dose combination tablet of LDV-SOF once-daily plus weight-based RBV (1,000 or 1,200 mg/day) for 12 weeks. The efficacy endpoint was the proportion of patients with SVR 12 weeks after discontinuation of therapy (SVR12). Of the 51 patients enrolled, 25 (49%) had previously received SOF plus Peg-IFN-RBV, 20 (39%) had received SOF-RBV, 5 (10%) had received SOF placebo plus Peg-IFN-RBV, and 1 (2%) received GS-0938 monotherapy. Fourteen (27%) had compensated cirrhosis at baseline, and 47 (92%) had non-CC interleukin-28B genotypes. SVR12 was achieved by 50 of the 51 patients (98%) treated. Among the 45 patients who received SOF in earlier treatment, 44 (98%) achieved SVR12. The only patient who did not achieve SVR12 was a patient with genotype 3a HCV who had been incorrectly genotyped as 1a in the previous study. Given the high rates of SVR12, no differences among patient subgroups were discernible. Of 51 patients, 41 (80%) experienced at least one adverse event (AE), but most events were mild to moderate in severity. The most common AEs were fatigue, headache, and diarrhea. One patient discontinued treatment because of an unrelated AE (bipolar disorder). CONCLUSION: Twelve weeks of LDV-SOF plus RBV was an effective and safe treatment for patients who have not achieved SVR with earlier regimens that included SOF.

Safety and tolerability of ledipasvir/sofosbuvir with and without ribavirin in patients with chronic hepatitis C virus genotype 1 infection: Analysis of phase III ION trials.

UNLABELLED: In phase III studies, treatment with the once-daily fixed-dose combination tablet of ledipasvir/sofosbuvir (LDV/SOF) with and without ribavirin (RBV) resulted in high rates of sustained virological response (SVR) in patients chronically infected with genotype 1 hepatitis C virus, including those with compensated cirrhosis. We conducted an analysis of data from these trials to compare the safety and tolerability profile of LDV-SOF with and without RBV. We analyzed treatment-emergent adverse events (AEs) and laboratory abnormalities in patients who were randomized to 8, 12, and 24 weeks of LDV/SOF with or without RBV. In total, data from 1,952 patients (of whom 872 received LDV/SOF with RBV and 1,080 received LDV/SOF alone) were analyzed. Overall, 308 patients (16%) were African American, 224 (11%) had compensated cirrhosis, 501 (26%) had a body mass index ≥30 kg/m(2) , and 440 (23%) were treatment experienced. Treatment-related AEs occurred in 71% and 45% of patients treated with and without RBV, respectively, including fatigue, insomnia, irritability, and rash/pruritus. Patients receiving RBV with LDV/SOF were more likely to require dose modification, interruptions of treatment resulting from AEs, or require the use of concomitant medications than those receiving LDV/SOF alone. Rates of treatment-related serious AEs and discontinuations resulting from AEs were similarly low (<1%) in both groups. The rate of SVR in those receiving RBV and those not receiving RBV was the same (97%). CONCLUSION: LDV/SOF plus RBV was associated with a greater incidence of AEs as well as concomitant medication use than LDV/SOF alone. Use of RBV did not impact the efficacy of LDV/SOF regimens in the ION phase III studies.

Ledipasvir/sofosbuvir fixed-dose combination tablet in Taiwanese patients with chronic genotype 1 hepatitis C virus.

BACKGROUND AND AIM: Pegylated-interferon-alpha plus ribavirin is the current standard-of-care regimen for treating chronic hepatitis C virus (HCV) infection in Taiwan; however, interferon-based regimens can be poorly tolerated. The interferon-free, two-drug, fixed-dose combination tablet ledipasvir/sofosbuvir is approved in Europe, the USA, and Japan for treating chronic genotype 1 HCV infection. Little is known about its efficacy/safety in Taiwanese patients. METHODS: In this multicenter, open-label, phase 3b (NCT02021656) study, 85 Taiwanese patients (n = 42, treatment-naïve; n = 43, treatment-experienced) with chronic genotype 1 HCV infection (±compensated cirrhosis) received 12 weeks of ledipasvir/sofosbuvir fixed-dose combination tablet. The primary efficacy end point was the proportion of patients with sustained virologic response 12 weeks after treatment discontinuation (SVR12). Safety and pharmacokinetic data were collected. RESULTS: The overall SVR12 rate was 98% (83/85), with 100% (42/42) and 95% (41/43) of treatment-naïve and treatment-experienced patients, respectively, achieving SVR12. There were no on-treatment virologic failures. One patient relapsed after treatment discontinuation; one patient withdrew consent on day 2. The most common treatment-emergent adverse event (AE) was headache (14%, 12/85). There was one grade 3 AE (small cell lung cancer unrelated to ledipasvir/sofosbuvir), no grade 4 AEs, and four grade 3-4 laboratory abnormalities. Only the patient with small cell lung cancer prematurely discontinued treatment. Two patients reported three serious AEs; none was considered related to ledipasvir/sofosbuvir. CONCLUSIONS: Data from this phase 3b study suggest that 12 weeks of once-daily treatment with the interferon-free, ribavirin-free regimen ledipasvir/sofosbuvir is effective and well-tolerated in Taiwanese patients with chronic genotype 1 HCV infection, irrespective of treatment history.