Microbiome recovery in adult females with uncomplicated urinary tract infections in a randomised phase 2A trial of the novel antibiotic gepotidacin (GSK140944).

BACKGROUND: With increasing concerns about the impact of frequent antibiotic usage on the human microbiome, it is important to characterize the potential for such effects in early antibiotic drug development clinical trials. In a randomised Phase 2a clinical trial study that evaluated the pharmacokinetics of repeated oral doses of gepotidacin, a first-in-chemical-class triazaacenaphthylene antibiotic with a distinct mechanism of action, in adult females with uncomplicated urinary tract infections for gepotidacin (GSK2140944) we evaluated the potential changes in microbiome composition across multiple time points and body-sites ( ClinicalTrials.gov : NCT03568942). RESULTS: Samples of gastrointestinal tract (GIT), pharyngeal cavity and vaginal microbiota were collected with consent from 22 patients at three time points relative to the gepotidacin dosing regimen; Day 1 (pre-dose), Day 5 (end of dosing) and Follow-up (Day 28 ± 3 days). Microbiota composition was determined by DNA sequencing of 16S rRNA gene variable region 4 amplicons. By Day 5, significant changes were observed in the microbiome diversity relative to pre-dose across the tested body-sites. However, by the Follow-up visit, microbiome diversity changes were reverted to compositions comparable to Day 1. The greatest range of microbiome changes by body-site were GIT followed by the pharyngeal cavity then vagina. In Follow-up visit samples we found no statistically significant occurrences of pathogenic taxa. CONCLUSION: Our findings suggest that gepotidacin alteration of the human microbiome after 5 days of dosing is temporary and rebound to pre-dosing states is evident within the first month post-treatment. We recommend that future antibiotic drug trials include similar exploratory investigations into the duration and context of microbiome modification and recovery. TRIAL REGISTRATION: NCT03568942 . Registered 26 June 2018.

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 + 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.

Preliminary study of two antiviral agents for hepatitis C genotype 1.

BACKGROUND: Patients with chronic hepatitis C virus (HCV) infection who have not had a response to therapy with peginterferon and ribavirin may benefit from the addition of multiple direct-acting antiviral agents to their treatment regimen. METHODS: This open-label, phase 2a study included an exploratory cohort of 21 patients with chronic HCV genotype 1 infection who had not had a response to previous therapy (i.e., had not had ≥2 log(10) decline in HCV RNA after ≥12 weeks of treatment with peginterferon and ribavirin). We randomly assigned patients to receive the NS5A replication complex inhibitor daclatasvir (60 mg once daily) and the NS3 protease inhibitor asunaprevir (600 mg twice daily) alone (group A, 11 patients) or in combination with peginterferon alfa-2a and ribavirin (group B, 10 patients) for 24 weeks. The primary end point was the percentage of patients with a sustained virologic response 12 weeks after the end of the treatment period. RESULTS: A total of 4 patients in group A (36%; 2 of 9 with HCV genotype 1a and 2 of 2 with genotype 1b) had a sustained virologic response at 12 weeks after treatment and also at 24 weeks after treatment.. Six patients (all with HCV genotype 1a) had viral breakthrough while receiving therapy, and resistance mutations to both antiviral agents were found in all cases; 1 patient had a viral response at the end of treatment but had a relapse after the treatment period. All 10 patients in group B had a sustained virologic response at 12 weeks after treatment, and 9 had a sustained virologic response at 24 weeks after treatment. Diarrhea was the most common adverse event in both groups. Six patients had transient elevations of alanine aminotransferase levels to more than 3 times the upper limit of the normal range. CONCLUSIONS: This preliminary study involving patients with HCV genotype 1 infection who had not had a response to prior therapy showed that a sustained virologic response can be achieved with two direct-acting antiviral agents only. In addition, a high rate of sustained virologic response was achieved when the two direct-acting antiviral agents were combined with peginterferon alfa-2a and ribavirin. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT01012895.).

Efficacy of an interferon- and ribavirin-free regimen of daclatasvir, asunaprevir, and BMS-791325 in treatment-naive patients with HCV genotype 1 infection.

BACKGROUND & AIMS: The combination of peginterferon and ribavirin with telaprevir or boceprevir is the standard treatment of hepatitis C virus (HCV) genotype 1 infection. However, these drugs are not well tolerated because of their side effects and suboptimal virologic responses. In a phase 2a, open-label study, we examined the safety and efficacy of an interferon-free, ribavirin-free regimen of direct-acting antivirals, comprising daclatasvir (an NS5A replication complex inhibitor), asunaprevir (an NS3 protease inhibitor), and BMS-791325 (a non-nucleoside NS5B inhibitor), in patients with chronic HCV infection. METHODS: We analyzed data from 66 treatment-naive patients with HCV genotype 1 infection without cirrhosis who were assigned randomly to groups given daclatasvir (60 mg, once daily), asunaprevir (200 mg, twice daily), and BMS-791325 (75 or 150 mg, twice daily) for 12 or 24 weeks. The primary end point was an HCV-RNA level less than 25 IU/mL at 12 weeks after treatment (sustained virologic response at 12 weeks [SVR12]). RESULTS: In 64 patients, HCV-RNA levels were less than 25 IU/mL by week 4 of treatment (including 48 of 49 patients with HCV genotype 1a infection and 45 of 46 patients with the non-CC interleukin 28B genotype). Sixty-one patients (92%) achieved SVR12, based on a modified intention-to-treat analysis. Virologic responses were similar between 12 and 24 weeks of treatment. During the study, 2 patients experienced viral breakthrough and 1 patient relapsed. There were no grade 3-4 increases in levels of alanine or aspartate aminotransferases or bilirubin; there were no deaths or discontinuations resulting from serious adverse events or adverse events related to the treatment regimen. The most common adverse events were headache, asthenia, and gastrointestinal symptoms. CONCLUSIONS: In a phase 2a study, the all-oral, interferon-free, and ribavirin-free regimen of daclatasvir, asunaprevir, and BMS-791325 was well tolerated and achieved high rates of SVR12 in patients with HCV genotype 1 infection. Further studies of this regimen are warranted. ClinicalTrials.gov, number NCT01455090.

Randomized trial of daclatasvir and asunaprevir with or without PegIFN/RBV for hepatitis C virus genotype 1 null responders.

BACKGROUND & AIMS: Patients with chronic hepatitis C virus (HCV) infection and prior null response (<2 log HCV RNA decline after ⩾ 12 weeks of PegIFN/RBV) have limited options. We evaluated daclatasvir plus once- or twice-daily asunaprevir in non-cirrhotic genotype 1 null responders. METHODS: In this randomized, phase 2a, open-label, 24-week treatment study, 101 patients received daclatasvir (60 mg) once-daily. In addition, 38 genotype 1b patients received asunaprevir (200mg) twice- (DUAL A1) or once-daily (DUAL A2); 36 genotype 1a and 5 genotype 1b patients received asunaprevir twice- (QUAD B1) or once-daily (QUAD B2) plus PegIFN/RBV; and 18 genotype 1a and 4 genotype 1b patients received asunaprevir twice-daily plus ribavirin (TRIPLE B3). The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (sustained virologic response, SVR12). RESULTS: Across all groups, mean HCV RNA was ⩾ 6 log IU/ml, and 99% of patients had a non-CC IL28B genotype. SVR12 rates were 78% (A1), 65% (A2), 95% (B1), and 95% (B2). In B3, most genotype 1a patients experienced virologic breakthrough. The most common adverse events were headache, diarrhea, and asthenia. Grade 3-4 aminotransferase elevations were infrequent and not treatment-limiting. CONCLUSIONS: In genotype 1 null responders, daclatasvir plus twice-daily asunaprevir DUAL therapy is effective for most genotype 1b patients, and daclatasvir, asunaprevir, and PegIFN/RBV QUAD therapy is effective for nearly all genotype 1a and 1b patients; but neither DUAL nor TRIPLE therapy is effective for genotype 1a patients. Interferon-free regimens including daclatasvir and twice-daily asunaprevir for genotype 1 null responders should be tailored to subtype.

Modelling the concentration of anti-SARS-CoV-2 immunoglobulin G in intravenous immunoglobulin product batches.

BACKGROUND: Plasma-derived intravenous immunoglobulin (IVIg) products contain a dynamic spectrum of immunoglobulin (Ig) G reactivities reflective of the donor population from which they are derived. We sought to model the concentration of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG which could be expected in future plasma pool and final-product batches of CSL Behring's immunoglobulin product Privigen. STUDY DESIGN AND METHODS: Data was extracted from accessible databases, including the incidence of coronavirus disease 2019 and SARS-CoV-2 vaccination status, antibody titre in convalescent and vaccinated groups and antibody half-life. Together, these parameters were used to create an integrated mathematical model that could be used to predict anti-SARS-CoV-2 antibody levels in future IVIg preparations. RESULTS: We predict that anti-SARS-CoV-2 IgG concentration will peak in batches produced in mid-October 2021, containing levels in the vicinity of 190-fold that of the mean convalescent (unvaccinated) plasma concentration. An elevated concentration (approximately 35-fold convalescent plasma) is anticipated to be retained in batches produced well into 2022. Measurement of several Privigen batches using the Phadia™ EliA™ SARS-CoV-2-Sp1 IgG binding assay confirmed the early phase of this model. CONCLUSION: The work presented in this paper may have important implications for physicians and patients who use Privigen for indicated diseases.

Pharmacokinetics, Safety, and Tolerability Evaluation of Single and Multiple Doses of GSK3342830 in Healthy Volunteers.

This was a first-time-in-human randomized, double-blind, single-center, placebo-controlled dose-escalation study to determine the safety, tolerability, and pharmacokinetic (PK) profiles of GSK3342830 after single and repeat intravenous doses in healthy adult subjects (NCT0271424). Sixty-two subjects were enrolled: 48 subjects in part 1 (single dose) and 14 subjects in part 2 (multiple doses). Following single intravenous infusions, total systemic exposure of GSK3342830 was dose proportional over the 250- to 6000-mg dose range evaluated, whereas peak exposure was approximately dose proportional over the dose range. Following repeat intravenous infusions 3 times a day, GSK3342830 showed time invariance with no drug accumulation. Steady state was reached before day 3, and approximately 90% of GSK3342830 was excreted unchanged in urine. All 48 subjects in part 1 (100.0%) completed the study. In part 2, 9 subjects (64.3%) completed the study, and 5 subjects, all receiving GSK3342830, discontinued early (35.7%), 4 after experiencing fever, headache, and malaise, whereas 1 subject met predefined criteria for drug discontinuation because of transaminitis. GSK3342830 demonstrated PK consistent with other cephalosporin-class antibiotics but poor tolerability following multiple doses in healthy volunteers.

CD40L-containing virus-like particle as a candidate HIV-1 vaccine targeting dendritic cells.

The central role of dendritic cell (DC) in mounting an immune response to a novel antigen is now well established. We sought to demonstrate the use of a particular vaccine strategy based on directing HIV-1 Gag proteins to DCs in conjunction with an activation signal. CD40L was expressed on the surface of virus-like particles (VLPs) to target HIV-1 Gag antigens to the CD40 receptor on DCs, whereas CD40L-CD40 interaction would also result in cellular activation. Multiple CD40L VLP constructs were made and evaluated in vitro and in vivo. Indeed, one VLP that expressed CD40L to the highest level showed greatest capacity to activate DCs in vitro. Correspondingly, this CD40L-VLP also proved to be most immunogenic in mice in raising both humoral and cellular responses to HIV-1 Gag. Confirmatory studies were performed to demonstrate the increased immunogenicity of CD40L-VLP is no longer observed when tested in CD40-/- mice. Our findings lend support to the belief that vaccine strategies that both target and activate DCs could yield a superior immune response.

In vivo electroporation enhances the immunogenicity of an HIV-1 DNA vaccine candidate in healthy volunteers.

BACKGROUND: DNA-based vaccines have been safe but weakly immunogenic in humans to date. METHODS AND FINDINGS: We sought to determine the safety, tolerability, and immunogenicity of ADVAX, a multigenic HIV-1 DNA vaccine candidate, injected intramuscularly by in vivo electroporation (EP) in a Phase-1, double-blind, randomized placebo-controlled trial in healthy volunteers. Eight volunteers each received 0.2 mg, 1 mg, or 4 mg ADVAX or saline placebo via EP, or 4 mg ADVAX via standard intramuscular injection at weeks 0 and 8. A third vaccination was administered to eleven volunteers at week 36. EP was safe, well-tolerated and considered acceptable for a prophylactic vaccine. EP delivery of ADVAX increased the magnitude of HIV-1-specific cell mediated immunity by up to 70-fold over IM injection, as measured by gamma interferon ELISpot. The number of antigens to which the response was detected improved with EP and increasing dosage. Intracellular cytokine staining analysis of ELISpot responders revealed both CD4+ and CD8+ T cell responses, with co-secretion of multiple cytokines. CONCLUSIONS: This is the first demonstration in healthy volunteers that EP is safe, tolerable, and effective in improving the magnitude, breadth and durability of cellular immune responses to a DNA vaccine candidate. TRIAL REGISTRATION: ClinicalTrials.gov NCT00545987.

Phase 1 safety and immunogenicity evaluation of ADMVA, a multigenic, modified vaccinia Ankara-HIV-1 B'/C candidate vaccine.

BACKGROUND: We conducted a Phase I dose-escalation trial of ADMVA, a Clade-B'/C-based HIV-1 candidate vaccine expressing env, gag, pol, nef, and tat in a modified vaccinia Ankara viral vector. Sequences were derived from a prevalent circulating HIV-1 recombinant form in Yunnan, China, an area of high HIV incidence. The objective was to evaluate the safety and immunogenicity of ADMVA in human volunteers. METHODOLOGY/PRINCIPAL FINDINGS: ADMVA or placebo was administered intramuscularly at months 0, 1 and 6 to 50 healthy adult volunteers not at high risk for HIV-1. In each dosage group [1x10(7) (low), 5x10(7) (mid), or 2.5x10(8) pfu (high)] volunteers were randomized in a 3:1 ratio to receive ADMVA or placebo in a double-blinded design. Subjects were followed for local and systemic reactogenicity, adverse events including cardiac adverse events, and clinical laboratory parameters. Study follow up was 18 months. Humoral immunogenicity was evaluated by anti-gp120 binding ELISA, immunoflourescent staining, and HIV-1 neutralization. Cellular immunogenicity was assessed by a validated IFNgamma ELISpot assay and intracellular cytokine staining. Anti-vaccinia binding titers were measured by ELISA. ADMVA was generally well-tolerated, with no vaccine-related serious adverse events or cardiac adverse events. Local or systemic reactogenicity events were reported by 77% and 78% of volunteers, respectively. The majority of events were of mild intensity. The IFNgamma ELISpot response rate to any HIV antigen was 0/12 (0%) in the placebo group, 3/12 (25%) in the low dosage group, 6/12 (50%) in the mid dosage group, and 8/13 (62%) in the high dosage group. Responses were often multigenic and occasionally persisted up to one year post vaccination. Antibodies to gp120 were detected in 0/12 (0%), 8/13 (62%), 6/12 (50%) and 10/13 (77%) in the placebo, low, mid, and high dosage groups, respectively. Antibodies persisted up to 12 months after vaccination, with a trend toward agreement with the ability to neutralize HIV-1 SF162 in vitro. Two volunteers mounted antibodies that were able to neutralize clade-matched viruses. CONCLUSIONS/SIGNIFICANCE: ADMVA was well-tolerated and elicited durable humoral and cellular immune responses. TRIAL REGISTRATION: Clinicaltrials.gov NCT00252148.

A DNA vaccine targeting the receptor-binding domain of Clostridium difficile toxin A.

Clostridium difficile is a pathogen with increasing severity for which host antibody responses provide protection from disease. DNA vaccination has several advantages compared to traditional vaccine methods, however no study has examined this platform against C. difficile toxins. A synthetic gene was created encoding the receptor-binding domain (RBD) of C. difficile toxin A, optimized for expression in human cells. Gene expression was examined in vitro. Mice were inoculated and then challenged with parenteral toxin A. Vaccination provided high titer antibodies and protected mice from death. This represents the first report of DNA vaccine inducing neutralizing antibodies to C. difficile toxin A.

Design, construction, and characterization of a dual-promoter multigenic DNA vaccine directed against an HIV-1 subtype C/B' recombinant.

An effective vaccine against HIV-1 is generally considered the best hope for controlling the raging AIDS pandemic. As a part of our AIDS vaccine development effort, we constructed a dual-promoter plasmid capable of high-level expression of 2 independent transgenes. HIV-1 gag, pol, env, nef, and tat from a primary subtype C/B' CCR5-tropic HIV-1 were "codon" optimized, modified to eliminate known functional activity, and assembled using an overlapping polymerase chain reaction into 2 plasmids: ADVAX-I (containing env and gag) and ADVAX-II (containing pol and nef-tat). These 2 dual-promoter candidate vaccines showed levels of HIV-1 gene expression comparable to those observed with single-gene plasmids in vitro. Importantly, immunization of mice with these vaccine constructs resulted in dose-dependent multigenic CD4 and CD8 T-cell responses equivalent to those provided by vaccination with single-gene plasmids. With input from the US Food and Drug Administration, ADVAX-I and ADVAX-II have since been combined as a single candidate DNA vaccine, ADVAX. A phase 1 clinical trial of this product has been successfully completed, and its use in prime-boost studies is now underway.

Multiple-site DNA vaccination enhances immune responses in mice.

Intramuscular delivery of plasmid DNA encoding vaccine antigens induces systemic immune responses in small animals but is less effective in inducing strong responses in larger animals species. We investigated if anatomic distribution of DNA could enhance responses to decreasing DNA doses. We show that anatomic distribution of low-dose DNA improves cell-mediated and humoral immune responses in mice. Anatomic distribution of low-dose DNA provided a dose-sparing effect for both cell-mediated immunity and humoral responses. Enhanced systemic responses correlate directly with recruitment of antigen-specific CD8+ T-cells in the regional lymph nodes. These results have implications for DNA vaccination in humans.