Impact of Preexisting Hepatitis C Virus Genotype 6 NS3, NS5A, and NS5B Polymorphisms on the In Vitro Potency of Direct-Acting Antiviral Agents.

HCV genotype 6 (GT-6) is found predominantly in East and Southeast Asia. Clinical studies have focused on patients infected with hepatitis C virus (HCV) GT-6a, where high sustained virologic response (SVR) rates to direct-acting antivirals (DAAs) have been achieved. However, GT-6 is highly diverse, with 29 reported subtypes. We explored the diversity of GT-6 polymorphisms at residues associated with DAA resistance, their impact on DAA in vitro potency when evaluated in a GT-6a consensus replicon, and their association with specific GT-6 subtypes. GT-6 sequences from 25 patient-derived samples and 105 sequences from the U.S. HCV database were compared, and substitutions at resistance-associated residue positions were phenotyped against different DAAs. Preexisting resistance-associated substitutions (RASs) to NS3 protease (A156V and D168E) and NS5B nucleotide (L159F and S282C) inhibitors were rare (<4%). Preexisting RASs to NS5A inhibitors were common, especially at L28 (A/F/G/M/T/V) and R30 (E/N/S). In vitro susceptibilities of NS5A-L28A and -L28T were dramatically reduced against all tested NS5A drugs (90% effective concentration [EC90] range, 119 to 2,032 nM) compared with susceptibilities against a GT-6a consensus replicon (EC90 range, 0.1 to 19 nM). These L28 RASs preexisted in combination with R30S (EC90 [L28A-R30S] of ≥720 nM or EC90 [L28T-R30S] of ≥128 nM against tested DAAs) or as L28T-L31I (EC90 [tested DAAs] of >5,000 nM) and were detected in evaluated GT-6b and -6f sequences. NS5A-L28A-R30A, observed in GT-6r, did not replicate. In conclusion, HCV GT-6b, GT-6f, and GT-6r sequences harbored highly resistant RASs to all evaluated NS5A drugs. Therefore, monitoring SVR in patients infected with these GT-6 subtypes treated with NS5A drug-containing regimens is suggested to confirm any association between noted NS5A polymorphisms and treatment failure.

Daclatasvir plus Sofosbuvir for HCV in Patients Coinfected with HIV-1.

BACKGROUND: The combination of daclatasvir, a hepatitis C virus (HCV) NS5A inhibitor, and the NS5B inhibitor sofosbuvir has shown efficacy in patients with HCV monoinfection. Data are lacking on the efficacy and safety of this combination in patients coinfected with human immunodeficiency virus type 1 (HIV-1). METHODS: This was an open-label study involving 151 patients who had not received HCV treatment and 52 previously treated patients, all of whom were coinfected with HIV-1. Previously untreated patients were randomly assigned in a 2:1 ratio to receive either 12 weeks or 8 weeks of daclatasvir at a standard dose of 60 mg daily (with dose adjustment for concomitant antiretroviral medications) plus 400 mg of sofosbuvir daily. Previously treated patients were assigned to undergo 12 weeks of therapy at the same doses. The primary end point was a sustained virologic response at week 12 after the end of therapy among previously untreated patients with HCV genotype 1 who were treated for 12 weeks. RESULTS: Patients had HCV genotypes 1 through 4 (83% with genotype 1), and 14% had compensated cirrhosis; 98% were receiving antiretroviral therapy. Among patients with genotype 1, a sustained virologic response was reported in 96.4% (95% confidence interval [CI], 89.8 to 99.2) who were treated for 12 weeks and in 75.6% (95% CI, 59.7 to 87.6) who were treated for 8 weeks among previously untreated patients and in 97.7% (95% CI, 88.0 to 99.9) who were treated for 12 weeks among previously treated patients. Rates of sustained virologic response across all genotypes were 97.0% (95% CI, 91.6 to 99.4), 76.0% (95% CI, 61.8 to 86.9), and 98.1% (95% CI, 89.7 to 100), respectively. The most common adverse events were fatigue, nausea, and headache. There were no study-drug discontinuations because of adverse events. HIV-1 suppression was not compromised. CONCLUSIONS: Among previously untreated HIV-HCV coinfected patients receiving daclatasvir plus sofosbuvir for HCV infection, the rate of sustained virologic response across all genotypes was 97.0% after 12 weeks of treatment and 76.0% after 8 weeks. (Funded by Bristol-Myers Squibb; ALLY-2 ClinicalTrials.gov number, NCT02032888.).

Long-term follow-up of clinical trial patients treated for chronic HCV infection with daclatasvir-based regimens.

BACKGROUND & AIMS: Daclatasvir has achieved high sustained virologic response (SVR) rates in diverse hepatitis C virus (HCV) populations. This study evaluated the long-term efficacy and safety of daclatasvir-based regimens administered during clinical studies. METHODS: Patients enrolled within 6 months of parent study completion or protocol availability at the study sites. The primary objective was durability of SVR at follow-up Week 12 (SVR12). Secondary objectives included analysing HCV sequences in non-responders or responders who relapsed, and characterization of liver disease progression. RESULTS: Between 24 February 2012 and 17 July 2015, this study enrolled and began following 1503 recipients of daclatasvir-based regimens (follow-up cut-off, 13 October 2015); 60% were male, 18% aged ≥65 years, 87% had genotype-1a (42%) or -1b (45%) infection, and 18% had cirrhosis. Median follow-up from parent study follow-up Week 12 was 111 (range, 11-246) weeks. 1329/1489 evaluable patients were SVR12 responders; 1316/1329 maintained SVR until their latest visit. Twelve responders relapsed by (n = 9) or after (n = 3) parent study follow-up Week 24; one was reinfected. Relapse occurred in 3/842 (0.4%) and 9/487 (2%) responders treated with interferon-free or interferon-containing regimens, respectively. Hepatic disease progression and new hepatocellular carcinoma were diagnosed in 15 and 23 patients, respectively. Among non-responders, emergent non-structural protein-5A (NS5A) and -3 (NS3) substitutions were replaced by wild-type sequences in 27/157 (17%) and 35/47 (74%) patients, respectively. CONCLUSIONS: SVR12 was durable in 99% of recipients of daclatasvir-based regimens. Hepatic disease progression and new hepatocellular carcinoma were infrequent. Emergent NS5A substitutions persisted longer than NS3 substitutions among non-responders.

The discovery and optimization of naphthalene-linked P2-P4 Macrocycles as inhibitors of HCV NS3 protease.

Naphthalene-linked P2-P4 macrocycles within a tri-peptide-based acyl sulfonamide chemotype have been synthesized and found to inhibit HCV NS3 proteases representing genotypes 1a and 1b with single digit nanomolar potency. The pharmacokinetic profile of compounds in this series was optimized through structural modifications along the macrocycle tether as well as the P1 subsite. Ultimately a compound with oral bioavailability of 100% in rat, and a long half-life in plasma was obtained. However, compounds in this macrocyclic series exhibited cardiac effects in an isolated rabbit heart model and for this reason further optimization efforts were discontinued.

P3-P4 ureas and reverse carbamates as potent HCV NS3 protease inhibitors: Effective transposition of the P4 hydrogen bond donor.

A series of tripeptidic acylsulfonamide inhibitors of HCV NS3 protease were prepared that explored structure-activity relationships (SARs) at the P4 position, and their in vitro and in vivo properties were evaluated. Enhanced potency was observed in a series of P4 ureas; however, the PK profiles of these analogues were less than optimal. In an effort to overcome the PK shortcomings, modifications to the P3-P4 junction were made. This included a strategy in which one of the two urea N-H groups was either N-methylated or replaced with an oxygen atom. The former approach provided a series of regioisomeric N-methylated ureas while the latter gave rise to P4 reverse carbamates, both of which retained potent NS3 inhibitory properties while relying upon an alternative H-bond donor topology. Details of the SARs and PK profiles of these analogues are provided.

Daclatasvir plus sofosbuvir for previously treated or untreated chronic HCV infection.

BACKGROUND: All-oral combination therapy is desirable for patients with chronic hepatitis C virus (HCV) infection. We evaluated daclatasvir (an HCV NS5A replication complex inhibitor) plus sofosbuvir (a nucleotide analogue HCV NS5B polymerase inhibitor) in patients infected with HCV genotype 1, 2, or 3. METHODS: In this open-label study, we initially randomly assigned 44 previously untreated patients with HCV genotype 1 infection and 44 patients infected with HCV genotype 2 or 3 to daclatasvir at a dose of 60 mg orally once daily plus sofosbuvir at a dose of 400 mg orally once daily, with or without ribavirin, for 24 weeks. The study was expanded to include 123 additional patients with genotype 1 infection who were randomly assigned to daclatasvir plus sofosbuvir, with or without ribavirin, for 12 weeks (82 previously untreated patients) or 24 weeks (41 patients who had previous virologic failure with telaprevir or boceprevir plus peginterferon alfa-ribavirin). The primary end point was a sustained virologic response (an HCV RNA level of <25 IU per milliliter) at week 12 after the end of therapy. RESULTS: Overall, 211 patients received treatment. Among patients with genotype 1 infection, 98% of 126 previously untreated patients and 98% of 41 patients who did not have a sustained virologic response with HCV protease inhibitors had a sustained virologic response at week 12 after the end of therapy. A total of 92% of 26 patients with genotype 2 infection and 89% of 18 patients with genotype 3 infection had a sustained virologic response at week 12. High rates of sustained virologic response at week 12 were observed among patients with HCV subtypes 1a and 1b (98% and 100%, respectively) and those with CC and non-CC IL28B genotypes (93% and 98%, respectively), as well as among patients who received ribavirin and those who did not (94% and 98%, respectively). The most common adverse events were fatigue, headache, and nausea. CONCLUSIONS: Once-daily oral daclatasvir plus sofosbuvir was associated with high rates of sustained virologic response among patients infected with HCV genotype 1, 2, or 3, including patients with no response to prior therapy with telaprevir or boceprevir. (Funded by Bristol-Myers Squibb and Pharmasset (Gilead); A1444040 ClinicalTrials.gov number, NCT01359644.).

Daclatasvir with sofosbuvir and ribavirin for hepatitis C virus infection with advanced cirrhosis or post-liver transplantation recurrence.

UNLABELLED: Chronic hepatitis C virus (HCV) infection with advanced cirrhosis or post-liver transplantation recurrence represents a high unmet medical need with no approved therapies effective across all HCV genotypes. The open-label ALLY-1 study assessed the safety and efficacy of a 60-mg once-daily dosage of daclatasvir (pan-genotypic NS5A inhibitor) in combination with sofosbuvir at 400 mg once daily (NS5B inhibitor) and ribavirin at 600 mg/day for 12 weeks with a 24-week follow-up in two cohorts of patients with chronic HCV infection of any genotype and either compensated/decompensated cirrhosis or posttransplantation recurrence. Patients with on-treatment transplantation were eligible to receive 12 additional weeks of treatment immediately after transplantation. The primary efficacy measure was sustained virologic response at posttreatment week 12 (SVR12) in patients with a genotype 1 infection in each cohort. Sixty patients with advanced cirrhosis and 53 with posttransplantation recurrence were enrolled; HCV genotypes 1 (76%), 2, 3, 4, and 6 were represented. Child-Pugh classifications in the advanced cirrhosis cohort were 20% A, 53% B, and 27% C. In patients with cirrhosis, 82% (95% confidence interval [CI], 67.9%-92.0%) with genotype 1 infection achieved SVR12, whereas the corresponding rates in those with genotypes 2, 3, and 4 were 80%, 83%, and 100%, respectively; SVR12 rates were higher in patients with Child-Pugh class A or B, 93%, versus class C, 56%. In transplant recipients, SVR12 was achieved by 95% (95% CI, 83.5%-99.4%) and 91% of patients with genotype 1 and 3 infection, respectively. Three patients received peritransplantation treatment with minimal dose interruption and achieved SVR12. There were no treatment-related serious adverse events. CONCLUSION: The pan-genotypic combination of daclatasvir, sofosbuvir, and ribavirin was safe and well tolerated. High SVR rates across multiple HCV genotypes were achieved by patients with post-liver transplantation recurrence or advanced cirrhosis.

Daclatasvir, sofosbuvir, and ribavirin for hepatitis C virus genotype 3 and advanced liver disease: A randomized phase III study (ALLY-3+).

UNLABELLED: Patients with hepatitis C virus (HCV) genotype 3 infection, especially those with advanced liver disease, are a challenging population in urgent need of optimally effective therapies. The combination of daclatasvir (DCV; pangenotypic nonstructural protein 5A inhibitor) and sofosbuvir (SOF; nucleotide nonstructural protein 5B inhibitor) for 12 weeks previously showed high efficacy (96%) in noncirrhotic genotype 3 infection. The phase III ALLY-3+ study (N = 50) evaluated DCV-SOF with ribavirin (RBV) in treatment-naïve (n = 13) or treatment-experienced (n = 37) genotype 3-infected patients with advanced fibrosis (n = 14) or compensated cirrhosis (n = 36). Patients were randomized 1:1 to receive open-label DCV-SOF (60 + 400 mg daily) with weight-based RBV for 12 or 16 weeks. The primary endpoint was sustained virological response at post-treatment week 12 (SVR12). SVR12 (intention-to-treat) was 90% overall (45 of 50): 88% (21 of 24) in the 12-week (91% observed) and 92% (24 of 26) in the 16-week group. All patients with advanced fibrosis achieved SVR12. SVR12 in patients with cirrhosis was 86% overall (31 of 36): 83% (15 of 18) in the 12-week (88% observed) and 89% (16 of 18) in the 16-week group; for treatment-experienced patients with cirrhosis, these values were 87% (26 of 30), 88% (14 of 16; 93% observed), and 86% (12 of 14), respectively. One patient (12-week group) did not enter post-treatment follow-up (death unrelated to treatment). There were 4 relapses (2 per group) and no virological breakthroughs. The most common adverse events (AEs) were insomnia, fatigue, and headache. There were no discontinuations for AEs and no treatment-related serious AEs. CONCLUSION: The all-oral regimen of DCV-SOF-RBV was well tolerated and resulted in high and similar SVR12 after 12 or 16 weeks of treatment among genotype 3-infected patients with advanced liver disease, irrespective of past HCV treatment experience.

Short-duration treatment for chronic hepatitis C virus with daclatasvir, asunaprevir, beclabuvir and sofosbuvir (FOURward study).

BACKGROUND & AIMS: The phase 2, FOURward study (NCT02175966) investigated short-duration therapy (4/6 weeks) with four direct-acting antivirals (DAAs) with distinct mechanisms of action in patients infected with hepatitis C virus (HCV) genotype-1. METHODS: Non-cirrhotic patients were randomized 1:1 to DCV-TRIO (fixed-dose daclatasvir 30 mg, asunaprevir 200 mg and beclabuvir 75 mg) twice-daily + sofosbuvir 400 mg once-daily for 4 or 6 weeks. The primary endpoint was sustained virological response at post-treatment Week 12 (SVR12). Patients without SVR12 were offered retreatment based on the DAA resistance profile at failure; patients with resistance to ≤1 DCV-TRIO component received DCV-TRIO + RBV for 12 weeks. RESULTS: Twenty-eight patients with HCV genotype-1 were enrolled; 79% had genotype-1a infection and median baseline HCV-RNA levels were high (9 × 106  IU/mL). Most patients had undetectable HCV-RNA at end of treatment (96% [n=27/28]); however, relapse occurred in 77% (n=10/13) and 43% (n=6/14) treated for 4 and 6 weeks, leading to SVR12 rates of 29% (n=4/14) and 57% (n=8/14) respectively. SVR12 was higher in patients with lower baseline HCV-RNA (<2 million IU/mL, 71% [n=5/7]; ≥2 million IU/mL, 33% [n=7/21]). None of the 16 non-SVR12 patients had NS3 or NS5B resistance-associated substitutions (RAS) detected at failure. All 15 patients retreated with DCV-TRIO + RBV for 12 weeks achieved SVR12. All regimens were well tolerated. CONCLUSIONS: Short-duration treatment with four DAAs with distinct mechanisms of action was insufficient for most patients with genotype-1 infection and high baseline viraemia. Non-SVR12 was not associated with emergence of NS3 or NS5B RAS and retreatment with DCV-TRIO + RBV for 12 weeks led to SVR in all patients.

Structure-activity relationships of 4-hydroxy-4-biaryl-proline acylsulfonamide tripeptides: A series of potent NS3 protease inhibitors for the treatment of hepatitis C virus.

The design and synthesis of a series of tripeptide acylsulfonamides as potent inhibitors of the HCV NS3/4A serine protease is described. These analogues house a C4 aryl, C4 hydroxy-proline at the S2 position of the tripeptide scaffold. Information relating to structure-activity relationships as well as the pharmacokinetic and cardiovascular profiles of these analogues is provided.

Daclatasvir/asunaprevir/beclabuvir, all-oral, fixed-dose combination for patients with chronic hepatitis C virus genotype 1.

BACKGROUND AND AIM: This multinational (Taiwan, South Korea, Russia) phase 3 study evaluated the all-oral, ribavirin-free, fixed-dose combination (DCV-TRIO) of daclatasvir (NS5A inhibitor) 30 mg, asunaprevir (NS3 inhibitor) 200 mg, and beclabuvir (NS5B inhibitor) 75 mg, in patients with chronic hepatitis C virus genotype-1 infection, with or without compensated cirrhosis. METHODS: UNITY-4 (NCT02170727) was an open-label, two-cohort study in which 169 patients, treatment-naive (n = 138) or treatment-experienced (n = 31), received twice-daily DCV-TRIO for 12 weeks with 24 weeks of post-treatment follow-up. The primary efficacy end point was sustained virologic response at post-treatment week 12 (SVR12) in treatment-naive patients. RESULTS: Eighty-eight (52%) patients were men, 81 (48%) Taiwanese, 78 (46%) Korean, and 10 (6%) Russian; 23 (14%) had compensated cirrhosis, and 52 (31%) were IL28B (rs1297860) non-CC genotype. Baseline resistance-associated NS5A polymorphisms (L31 and/or Y93) were detected in 25/165 (15%) patients with available genotype-1 sequencing data. SVR12 was achieved by 98.6% (136/138; 95% confidence interval: 94.9-99.8%) of treatment-naive and 100% (31/31; 95% confidence interval: 88.8-100%) of treatment-experienced patients. Both virologic failures were found to be infected with hepatitis C virus genotype-6g; 100% SVR12 was observed for genotype-1a (n = 8) and genotype-1b (n = 157). Two patients experienced serious adverse events. Eight (5%) patients experienced reversible grade 3/4 alanine aminotransferase or aspartate aminotransferase elevations, leading to discontinuation in four (2%); all achieved SVR12. There were no grade 3/4 total bilirubin increases and no deaths. CONCLUSIONS: Twelve weeks of DCV-TRIO was well tolerated and provided 100% SVR12 in treatment-naive and treatment-experienced patients with genotype-1 infection, with or without cirrhosis, including those with baseline NS5A-L31 or NS5A-Y93 resistance-associated substitutions.

NS5A Sequence Heterogeneity and Mechanisms of Daclatasvir Resistance in Hepatitis C Virus Genotype 4 Infection.

BACKGROUND: Daclatasvir is an NS5A inhibitor approved for treatment of infection due to hepatitis C virus (HCV) genotypes (GTs) 1-4. To support daclatasvir use in HCV genotype 4 infection, we examined a diverse genotype 4-infected population for HCV genotype 4 subtype prevalence, NS5A polymorphisms at residues associated with daclatasvir resistance (positions 28, 30, 31, or 93), and their effects on daclatasvir activity in vitro and clinically. METHODS: We performed phylogenetic analysis of genotype 4 NS5A sequences from 186 clinical trial patients and 43 sequences from the European HCV database, and susceptibility analyses of NS5A polymorphisms and patient-derived NS5A sequences by using genotype 4 NS5A hybrid genotype 2a replicons. RESULTS: The clinical trial patients represented 14 genotype 4 subtypes; most prevalent were genotype 4a (55%) and genotype 4d (27%). Daclatasvir 50% effective concentrations for 10 patient-derived NS5A sequences representing diverse phylogenetic clusters were ≤0.080 nM. Most baseline sequences had ≥1 NS5A polymorphism at residues associated with daclatasvir resistance; however, only 3 patients (1.6%) had polymorphisms conferring ≥1000-fold daclatasvir resistance in vitro. Among 46 patients enrolled in daclatasvir trials, all 20 with baseline resistance polymorphisms achieved a sustained virologic response. CONCLUSIONS: Circulating genotype 4 subtypes are genetically diverse. Polymorphisms conferring high-level daclatasvir resistance in vitro are uncommon before therapy, and clinical data suggest that genotype 4 subtype and baseline polymorphisms have minimal impact on responses to daclatasvir-containing regimens.

Daclatasvir plus simeprevir with or without ribavirin for the treatment of chronic hepatitis C virus genotype 1 infection.

BACKGROUND & AIMS: We evaluated the combination of daclatasvir (pan-genotypic NS5A inhibitor) and simeprevir (NS3/4A protease inhibitor), with or without ribavirin, in hepatitis C virus genotype 1-infected patients. METHODS: This phase II, open-label study enrolled treatment-naive patients or prior null responders with genotype 1b (n=147) or 1a (n=21) infection. Genotype 1b-infected patients were randomized 1:1 to receive daclatasvir 30mg plus simeprevir 150mg once daily with or without ribavirin; those who completed the initial 12-week treatment were re-randomized 1:1 to stop treatment or continue treatment through to week 24. Genotype 1a-infected patients received daclatasvir plus simeprevir with ribavirin for 24weeks. The primary endpoint was the proportion of patients with sustained virologic response at posttreatment week 12 (SVR12). RESULTS: For genotype 1b, 84.9% (45/53) and 74.5% (38/51) of treatment-naive patients and 69.6% (16/23) and 95.0% (19/20) of prior null responders to peginterferon and ribavirin achieved SVR12 with daclatasvir plus simeprevir alone and with ribavirin, respectively. Treatment duration did not have a well-defined impact on response. For genotype 1a, daclatasvir plus simeprevir with ribavirin provided a 66.7% (8/12) response rate in treatment-naive patients and was not effective in prior null responders. Data suggest that baseline resistance polymorphisms influenced SVR12 rates. Daclatasvir plus simeprevir was well tolerated with or without ribavirin with low incidences of serious adverse events and adverse events leading to discontinuation. CONCLUSIONS: Daclatasvir plus simeprevir, with or without ribavirin, was effective with a 12- or 24-week duration in genotype 1b-infected patients and was well tolerated. ClinicalTrials.gov identifier: NCT01628692.

Daclatasvir plus peginterferon and ribavirin is noninferior to peginterferon and ribavirin alone, and reduces the duration of treatment for HCV genotype 2 or 3 infection.

BACKGROUND & AIMS: Twenty-four weeks of treatment with peginterferon and ribavirin for chronic hepatitis C virus (HCV) genotype 2 or 3 infection produces a sustained virologic response (SVR) in 70%-80% of patients. We performed a randomized, double-blind, phase 2b study to assess whether adding daclatasvir, a nonstructural protein 5A (NS5A) inhibitor that is active against these genotypes, improves efficacy and shortens therapy. METHODS: Patients with HCV genotype 2 or 3 infection (n = 151), enrolled at research centers in North America, Europe, or Australia, were assigned randomly to groups given 12 or 16 weeks of daclatasvir (60 mg once daily), or 24 weeks of placebo, each combined with peginterferon alfa-2a and ribavirin. Treatment was extended to 24 weeks for recipients of daclatasvir who did not meet the criteria for early virologic response. The primary end point was SVR at 24 weeks after treatment (SVR24). RESULTS: Baseline characteristics were similar among patients within each HCV genotype group. However, the 80 patients with HCV genotype 3, compared with the 71 patients with HCV genotype 2, were younger (mean age, 45 vs 53 y, respectively), and a larger proportion had cirrhosis (23% vs 1%, respectively). Among patients with HCV genotype 2 infection, an SVR24 was achieved by 83%, 83%, and 63% of those in the daclatasvir 12-week group, the daclatasvir 16-week group, or the placebo group, respectively; among patients with HCV genotype 3 infection, an SVR24 was achieved by 69%, 67%, and 59% of patients in these groups, respectively. Differences between genotypes largely were attributable to the higher frequency of post-treatment relapse among patients infected with HCV genotype 3. In both daclatasvir arms for both HCV genotypes, the lower bound of the 80% confidence interval of the difference in SVR24 rates between the daclatasvir and placebo arms was above -20%, establishing noninferiority. Safety findings were similar among groups, and were typical of those expected from peginterferon alfa and ribavirin therapy. CONCLUSIONS: Twelve or 16 weeks of treatment with daclatasvir, in combination with peginterferon alfa-2a and ribavirin, is a well tolerated and effective therapy for patients with HCV genotype 2 or 3 infections. Daclatasvir-containing regimens could reduce the duration of therapy for these patients. Clinicaltrials.gov number: NCT01257204.

IFN-λ-mediated IL-12 production in macrophages induces IFN-γ production in human NK cells.

With increasing interest in alternative options to interferon-alpha-based treatments, IFN-λ has shown therapeutic promise in a variety of diseases. Although the antiviral activity of IFN-λ has been extensively studied, there is limited knowledge regarding the immunological functions of IFN-λ and how these differ from those of other classes of IFNs. In this study, we investigated the effects of IFN-λ on primary human NK cells, both in a direct and indirect capacity. We demonstrate that in contrast to interferon-alpha, IFN-λ is unable to directly stimulate NK cells, due to the absence of IFN-λ receptor chain 1 (IFN-λR1) on NK cells. However, IFN-λ, in combination with TLR4 challenge, is able to induce the production of select members of the IL-12 family of cytokines in monocyte-derived macrophages. We further show that through macrophage-mediated IL-12 production, IFN-λ is able to indirectly affect NK cells and ultimately induce IFN-γ production.

Characterization of NS5A polymorphisms and their impact on response rates in patients with HCV genotype 2 treated with daclatasvir-based regimens.

OBJECTIVE: Daclatasvir (DCV) is a pan-genotypic non-structural protein 5A (NS5A) inhibitor that is approved for treatment of hepatitis C virus (HCV) genotype (GT)1 and GT3 in the USA and GT1, GT3 and GT4 in Europe. We set out to examine the impact of daclatasvir-based regimens on the sustained virologic response (SVR) in patients with GT2 infection with respect to GT2 subtype and NS5A polymorphisms at amino acid positions associated with daclatasvir resistance. METHODS: Analyses were performed on 283 GT2 NS5A sequences from five daclatasvir regimen-based clinical trials (ClinicalTrials.gov: NCT-01257204, NCT-01359644, NCT-02032875, NCT-02032888 and NCT-01616524) and 143 NS5A sequences from the Los Alamos HCV database. Susceptibility analyses of substitutions at amino acid positions associated with daclatasvir resistance and patient-derived NS5A sequences were performed using an in vitro HCV replication assay. RESULTS: Of 13 GT2 subtypes identified from 426 NS5A sequences, the most prevalent were GT2a (32%), GT2b (48%) and GT2c (10%). The most prevalent NS5A polymorphism was L31M (GT2a = 88%; GT2b = 59%; GT2c = 10%). Substitutions identified in 96% of GT2 NS5A sequences exhibited daclatasvir EC50 values ranging from 0.005 to 20 nM when tested in vitro. A similar range in daclatasvir EC50 values was observed for 16 diverse GT2 patient-derived NS5A sequences (EC50 = 0.005-60 nM). Depending on the daclatasvir-based regimen studied (daclatasvir/interferon-based or daclatasvir/sofosbuvir-based), SVR rates ranged from 90% to 100% in GT2 patients with the most prevalent baseline NS5A-L31M polymorphism, compared with from 96% to 100% without this polymorphism. CONCLUSIONS: High SVR rates were achieved in patients infected with GT2 treated with daclatasvir-based regimens irrespective of GT2 subtype or baseline NS5A polymorphisms.

Hepatitis C virus drug resistance-associated substitutions: State of the art summary.

UNLABELLED: Hepatitis C virus (HCV) drug development has resulted in treatment regimens composed of interferon-free, all-oral combinations of direct-acting antivirals. While the new regimens are potent and highly efficacious, the full clinical impact of HCV drug resistance, its implications for retreatment, and the potential role of baseline resistance testing remain critical research and clinical questions. In this report, we discuss the viral proteins targeted by HCV direct-acting antivirals and summarize clinically relevant resistance data for compounds that have been approved or are currently in phase 3 clinical trials. CONCLUSION: This report provides a comprehensive, systematic review of all resistance information available from sponsors' trials as a tool to inform the HCV drug development field.

All-oral 12-week treatment with daclatasvir plus sofosbuvir in patients with hepatitis C virus genotype 3 infection: ALLY-3 phase III study.

UNLABELLED: Treatment options for patients with hepatitis C virus (HCV) genotype 3 infection are limited, with the currently approved all-oral regimens requiring 24-week treatment and the addition of ribavirin (RBV). This phase III study (ALLY-3; ClinicalTrials.gov: NCT02032901) evaluated the 12-week regimen of daclatasvir (DCV; pangenotypic nonstructural protein [NS]5A inhibitor) plus sofosbuvir (SOF; pangenotypic NS5B inhibitor) in patients infected with genotype 3. Patients were either treatment naïve (n = 101) or treatment experienced (n = 51) and received DCV 60 mg plus SOF 400 mg once-daily for 12 weeks. Coprimary endpoints were the proportions of treatment-naïve and treatment-experienced patients achieving a sustained virological response (SVR) at post-treatment week 12 (SVR12). SVR12 rates were 90% (91 of 101) and 86% (44 of 51) in treatment-naïve and treatment-experienced patients, respectively; no virological breakthrough was observed, and ≥99% of patients had a virological response (VR) at the end of treatment. SVR12 rates were higher in patients without cirrhosis (96%; 105 of 109) than in those with cirrhosis (63%; 20 of 32). Five of seven patients who previously failed treatment with an SOF-containing regimen and 2 of 2 who previously failed treatment with an alisporivir-containing regimen achieved SVR12. Baseline characteristics, including gender, age, HCV-RNA levels, and interleukin-28B genotype, did not impact virological outcome. DCV plus SOF was well tolerated; there were no adverse events (AEs) leading to discontinuation and only 1 serious AE on-treatment, which was unrelated to study medications. The few treatment-emergent grade 3/4 laboratory abnormalities that were observed were transient. CONCLUSION: A 12-week regimen of DCV plus SOF achieved SVR12 in 96% of patients with genotype 3 infection without cirrhosis and was well tolerated. Additional evaluation to optimize efficacy in genotype 3-infected patients with cirrhosis is underway.

Daclatasvir + asunaprevir + beclabuvir ± ribavirin for chronic HCV genotype 1-infected treatment-naive patients.

BACKGROUND AND AIMS: This phase-2b study examined the safety and efficacy of an all-oral, interferon-free combination of the NS5A replication complex inhibitor daclatasvir (DCV), the NS3 protease inhibitor asunaprevir (ASV), and the nonnucleoside NS5B polymerase inhibitor beclabuvir (BCV) with or without ribavirin in patients with HCV genotype (GT) 1 infection. METHODS: A total of 187 patients received 12 weeks of DCV 30 mg BID plus ASV 200 mg BID and BCV 150 mg BID (n = 86) or 75 mg BID with (n = 21) or without (n = 80) weight-based ribavirin BID. The primary endpoint was HCV RNA <25 IU/ml at post-treatment week 12 (SVR12). RESULTS: Overall, 90% of patients (169/187) in the combined treatment groups achieved SVR on or after post-treatment week 12. SVR rates were similar across subgroups (by mITT analysis), i.e. patients with cirrhosis (88%, 14/16), HCV GT-1a (90%, 137/155), and IL28B non-CC genotype (90%, 115/128). There were no drug-related serious AEs or grade 4 AEs. The most frequently reported AEs were headache, diarrhoea, fatigue and nausea. Addition of ribavirin to DCV+ASV+BCV was associated with decreased haemoglobin, compared with DCV+ASV+BCV alone. There were six grade 3/4 laboratory abnormalities noted, all unrelated to the study drugs. Viral breakthrough occurred in 2.5-4.8% of patients across groups and appeared unrelated to BCV dose or ribavirin inclusion. CONCLUSIONS: Results support phase 3 evaluation of a twice-daily, fixed-dose formulation of this DCV+ASV+BCV regimen with or without ribavirin in HCV GT-1-infected patients.

Randomized comparison of daclatasvir + asunaprevir versus telaprevir + peginterferon/ribavirin in Japanese hepatitis C virus patients.

BACKGROUND AND AIM: Daclatasvir combined with asunaprevir is the first all-oral, ribavirin-free treatment of hepatitis C virus genotype 1b infection in Japan. This study compared the efficacy and safety of daclatasvir plus asunaprevir versus telaprevir plus peginterferon/ribavirin in Japanese treatment-naive patients infected with hepatitis C virus genotype 1b. METHODS: Treatment-naive patients (20-70 years; baseline viral load, ≥ 100,000 IU/mL) were randomly assigned (stratified by IL28B rs8099917 TT/non-TT status) to receive either daclatasvir 60 mg tablets once daily and asunaprevir 100 mg softgel capsules twice daily for 24 weeks or telaprevir 750 mg (3 × 250 mg tablets) three times daily for 12 weeks and peginterferon/ribavirin per Japanese prescribing information for 24 weeks. A cohort of prior relapsers to peginterferon/ribavirin (20-75 years; baseline viral load, ≥ 100,000 IU/mL) received daclatasvir plus asunaprevir. RESULTS: In treatment-naive patients, sustained virologic response at post-treatment week 12 in daclatasvir plus asunaprevir recipients was non-inferior (treatment difference, +25.8% in favor of daclatasvir plus asunaprevir) and higher (89.1%, 106/119) than telaprevir plus peginterferon/ribavirin recipients (62.2%, 69/111); sustained viral response was achieved in 95.5% (n = 21/22) of relapsers. Numerically, fewer patients receiving daclatasvir plus asunaprevir compared with telaprevir plus peginterferon/ribavirin experienced serious adverse events (4.2% vs. 5.4%), adverse events leading to discontinuation of any drug (5.0% vs. 62.2%), grade 3/4 treatment-related adverse events (14.3% vs. 72.1%), rash-related events (0% vs. 13.5%), or anemia (0% vs. 47.7%). CONCLUSION: Marked differences were observed in the efficacy and safety profile of daclatasvir in combination with asunaprevir, compared with telaprevir plus peginterferon/ribavirin.