Favipiravir is a ribonucleoside analogue that has been explored as a therapeutic for the treatment of Ebola Virus Disease (EVD). Promising data from rodent models has informed nonhuman primate ...trials, as well as evaluation in patients during the 2013–2016 West African EVD outbreak of favipiravir treatment. However, mixed results from these studies hindered regulatory approval of favipiravir for the indication of EVD. This study examined the influence of route of administration, duration of treatment, and treatment schedule of favipiravir in immune competent mouse and guinea pig models using rodent-adapted Zaire ebolavirus (EBOV). A dose of 300 mg/kg/day of favipiravir with an 8-day treatment was found to be fully effective at preventing lethal EVD-like disease in BALB/c mice regardless of route of administration (oral, intraperitoneal, or subcutaneous) or whether it was provided as a once-daily dose or a twice-daily split dose. Preclinical data generated in guinea pigs demonstrates that an 8-day treatment of 300 mg/kg/day of favipiravir reduces mortality following EBOV challenge regardless of route of treatment or duration of treatments for 8, 11, or 15 days. This work supports the future translational development of favipiravir as an EVD therapeutic.
The recent epidemic of Ebola has intensified the need for the development of novel antiviral therapeutics that prolong and improve survival against deadly viral diseases. We sought to determine ...whether ranpirnase, an endoribonuclease from Rana pipiens with a demonstrated human safety profile in phase III oncology trials, can reduce titers of Ebola virus (EBOV) in infected cells, protect mice against mouse-adapted EBOV challenge, and reduce virus levels in infected mice. Our results demonstrate that 0.50 μg/ml ranpirnase is potently effective at reducing EBOV Zaire Kikwit infection in cultured Vero E6 cells (Selectivity Index 47.8–70.2). In a prophylactic study, a single intravenous dose of 0.1 mg/kg ranpirnase protected 70% of mice from progressive infection. Additionally, in a post-exposure prophylactic study, 100% of female mice survived infection after intraperitoneal administration of 0.1 mg/kg ranpirnase for ten days beginning 1 h post challenge. Most of the male counterparts were sacrificed due to weight loss by Study Day 8 or 9; however, the Clinical Activity/Behavior scores of these mice remained low and no significant microscopic pathologies could be detected in the kidneys, livers or spleens. Furthermore, live virus could not be detected in the sera of ranpirnase-treated mice by Study Day 8 or in the kidneys, livers or spleens by Study Day 12, and viral RNA levels declined exponentially by Study Day 12. Because ranpirnase is exceptionally stable and has a long track record of safe intravenous administration to humans, this drug provides a promising new candidate for clinical consideration in the treatment of Ebola virus disease alone or in combination with other therapeutics.
•Ranpirnase is an RNAse from Rana pipiens with a proven safety profile in phase III oncology trials.•We show that ranpirnase eliminates Ebola virus (EBOV) in cultures of Vero E6 cells, with selectivity indexes of 47.8–70.2•Ranpirnase was protective against EBOV in most mice when administered prophylactically or post-exposure prophylactically.•Mice that survived EBOV after ranpirnase treatment regained lost weight and had exponentially reduced viral loads.•These findings suggest that ranpirnase is a suitable candidate for non-human primate studies.
When a nebulizer is evaluated by the Andersen Cascade Impactor (ACI), the flow rate is generally maintained at 28.3 L min, as recommended by the manufacturer. However, the nebulizer flow rate that a ...patient inhales is only around 18 L min. Because the drive flow of a nebulizer is approximately 6-8 L min, the nebulized drug is mixed with outside air when delivered. Evaluating impactor performance at the 28.3 L min flow rate is less than ideal because an additional 10 L min of outside air is mixed with the drug, thereby affecting the drug size distribution and dose before inhalation and deposition in the human lung. In this study we operated the ACI at an 18.0 L min flow rate to test whether the effect of the changing ambient humidity was being exaggerated by the 28.3 L min flow rate. The study was carried out at three different relative humidity levels and two different impactor flow rates with four commercially available nebulizers. The mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD) of the droplets were found to increase when the impactor was operated at a flow rate of 18 L min compared to that of 28.3 L min. The higher MMAD and GSD could cause the patient to inhale less of the drug than expected if the nebulizer was evaluated by the ACI at the operating flow rate of 28.3 L min.
In September 2012, the United States Department of Health and Human Services Food and Drug Administration's (FDA) Office of Counterterrorism and Emerging Threats and the University of Texas Medical ...Branch at Galveston entered into a collaborative educational partnership for the academic development of a robust training program for good laboratory practices in high-biocontainment environments. The implementation of problem-based learning techniques encouraged researchers and regulators to cross-educate each other on the challenges related to the conduct of regulated studies in biological safety level 4 (BSL-4) laboratories and identified solutions that were acceptable from scientific and regulatory perspectives. The result was the development of a face-to-face course entitled Achieving Data Quality and Integrity in Maximum Containment Laboratories and an additional online companion course covering the FDA regulation, Good Laboratory Practice for Nonclinical Laboratory Studies (21 CFR Part 58). The course offers a unique opportunity for members of the regulatory and scientific communities to solve complex issues in an interactive educational environment, especially for the advancement of medical countermeasures (MCMs) via the FDA Animal Rule (21 CFR Parts 314 and 601 (2002)). The program occurs annually and is expanding in 2019 to include a course addressing data quality and integrity in clinical trials involving the evaluation of MCMs for high-consequence pathogens. To date, 311 individuals have attended the course. Based on attendance numbers, diversity of participation (by affiliation and area of expertise), and self-reported evaluation results, course attendees indicate that the training program addresses a knowledge gap and that they will implement knowledge gained.
The ability of a non-propagating microbial transport medium to maintain the viability of clinically relevant viruses was compared to a similar commercial medium to establish performance equivalence. ...Two dilutions of stock of test viruses, namely adenovirus (AdV), cytomegalovirus (CMV), echovirus Type 30 (EV), herpes simplex virus (HSV) types 1 and 2, influenza A, parainfluenza 3 (PIV), respiratory syncytial virus (RSV), and varicella zoster virus (VZV), were spiked into Puritan registered Medical Products Company Universal Transport System (UniTranz-RT(TM)) and BD super(TM) Universal Viral Transport System (UVT) and incubated at 4 degree C and room temperature (RT) for up to 72hr. Post incubation assessment of recovery of AdV, EV, HSV-2, PIV, and VZV from UniTranz-RT(TM) and UVT using shell vial assays followed by immunofluorescence staining demonstrated statistically significant differences between both transport media. In general, significantly higher recoveries of AdV, EV, and VZV were found from UniTranz-RT(TM) than UVT whereas HSV-2 and PIV were recovered better from UVT than UniTranz-RT(TM), under specific test conditions. The recovery of HSV-1, influenza A, PIV, and RSV showed no significant differences between transport media. Sulforhodamine B-based assay analysis of UniTranz-RT(TM) lots prior to and at expiration exhibited no cytotoxicity. The overall results of the study validate the full performance of UniTranz-RT(TM) as a viral transport medium and establish its effectiveness on par with the UVT. J. Med. Virol. 87:1796-1805, 2015.
Inhalational anthrax is caused by inhalation of Bacillus anthracis spores. The ability of B. anthracis to cause anthrax is attributed to the plasmid-encoded A/B-type toxins, edema toxin (edema ...factor and protective antigen) and lethal toxin (lethal factor and protective antigen), and a poly- d -glutamic acid capsule. To better understand the contribution of these toxins to the disease pathophysiology in vivo , we used B. anthracis Ames strain and isogenic toxin deletion mutants derived from the Ames strain to examine the role of lethal toxin and edema toxin after pulmonary spore challenge of cynomolgus macaques. Lethal toxin, but not edema toxin, was required to induce sustained bacteremia and death after pulmonary challenge with spores delivered via bronchoscopy. After intravenous challenge with bacilli to model the systemic phase of infection, lethal toxin contributed to bacterial proliferation and subsequent host death to a greater extent than edema toxin. Deletion of protective antigen resulted in greater loss of virulence after intravenous challenge with bacilli than deletion of lethal toxin or edema toxin alone. These findings are consistent with the ability of anti–protective antigen antibodies to prevent anthrax and suggest that lethal factor is the dominant toxin that contributes to the escape of significant numbers of bacilli from the thoracic cavity to cause anthrax after inhalation challenge with spores.
Melioidosis is an endemic disease caused by the bacterium Burkholderia pseudomallei. Concerns exist regarding B. pseudomallei use as a potential bio-threat agent causing persistent infections and ...typically manifesting as severe pneumonia capable of causing fatal bacteremia. Development of suitable therapeutics against melioidosis is complicated due to high degree of genetic and phenotypic variability among B. pseudomallei isolates and lack of data establishing commonly accepted strains for comparative studies. Further, the impact of strain variation on virulence, disease presentation, and mortality is not well understood. Therefore, this study evaluate and compare the virulence and disease progression of B. pseudomallei strains K96243 and HBPUB10303a, following aerosol challenge in a standardized BALB/c mouse model of infection. The natural history analysis of disease progression monitored conditions such as weight, body temperature, appearance, activity, bacteremia, organ and tissue colonization (pathological and histological analysis) and immunological responses. This study provides a detailed, direct comparison of infection with different B. pseudomallei strains and set up the basis for a standardized model useful to test different medical countermeasures against Burkholderia species. Further, this protocol serves as a guideline to standardize other bacterial aerosol models of infection or to define biomarkers of infectious processes caused by other intracellular pathogens.
The unprecedented magnitude of the 2013-2016 Ebola virus (EBOV) epidemic in West Africa resulted in over 11 000 deaths and spurred an international public health emergency. A second outbreak in ...2018-2020 in DRC resulted in an additional >3400 cases and nearly 2300 deaths (WHO, 2020). These large outbreaks across geographically diverse regions highlight the need for the development of effective oral therapeutic agents that can be easily distributed for self-administration to populations with active disease or at risk of infection. Herein, we report the in vivo efficacy of N
-hydroxycytidine (EIDD-1931), a broadly active ribonucleoside analog and the active metabolite of the prodrug EIDD-2801 (molnupiravir), in murine models of lethal EBOV infection. Twice daily oral dosing with EIDD-1931 at 200 mg/kg for 7 days, initiated either with a prophylactic dose 2 h before infection, or as therapeutic treatment starting 6 h post-infection, resulted in 92-100% survival of mice challenged with lethal doses of EBOV, reduced clinical signs of Ebola virus disease (EVD), reduced serum virus titers, and facilitated weight loss recovery. These results support further investigation of molnupiravir as a potential therapeutic or prophylactic treatment for EVD.
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