Activity of Galidesivir in a Hamster Model of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) has claimed the lives of millions of people worldwide since it first emerged. The impact of the COVID-19 pandemic on public health and the global economy has highlighted the medical need for the development of broadly acting interventions against emerging viral threats. Galidesivir is a broad-spectrum antiviral compound with demonstrated in vitro and in vivo efficacy against several RNA viruses of public health concern, including those causing yellow fever, Ebola, Marburg, and Rift Valley fever. In vitro studies have shown that the antiviral activity of galidesivir also extends to coronaviruses. Herein, we describe the efficacy of galidesivir in the Syrian golden hamster model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Treatment with galidesivir reduced lung pathology in infected animals compared with untreated controls when treatment was initiated 24 h prior to infection. These results add to the evidence of the applicability of galidesivir as a potential medical intervention for a range of acute viral illnesses, including coronaviruses.

Efficacy and safety of sofosbuvir plus daclatasvir or ravidasvir in patients with COVID-19: A randomized controlled trial.

Only a few treatments are approved for coronavirus disease-2019 (COVID-19) infections, with continuous debate about their clinical impact. Repurposing antiviral treatments might prove the fastest way to identify effective therapy. This trial aimed to evaluate the efficacy and safety of sofosbuvir (SOF) plus daclatasvir (DCV) or ravidasvir (RDV) added to standard care (SOC) for patients with moderate and severe COVID-19 infection. Multicentre parallel randomized controlled open-label trial. One hundred and twenty eligible patients with moderate and severe COVID-19 infection were randomized to one of the study arms. Ten days of treatment with SOF plus DCV or RDV in addition to the standard of care compared to SOC. Follow up in 7 days. Sum of the counted symptoms at 7 and 10 days, mean change in oxygen saturation level, viral negativity, and rate of intensive care unit (ICU) admission. Compared to SOC, the SOF-DCV group experienced a significantly lower sum of the counted symptoms (fever, headache, generalized aches, or respiratory distress) combined with no evidence of deterioration (ICU admission and mechanical ventilation) on Days 7 and 10 of treatment. Oxygen saturation also significantly improved among the SOF-DCV group compared to SOC starting from Day 4. The study also showed positive trends regarding the efficacy of SOF-DCV with a lower incidence of mortality. On the other hand, adding SOF-RDV to SOC did not show significant improvements in endpoints. The results support the efficacy and safety of SOF-DCV as an add-on to SOC for the treatment of moderate to severe COVID-19 infections.

Postinfection treatment with a protease inhibitor increases survival of mice with a fatal SARS-CoV-2 infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues to be a serious global public health threat. The 3C-like protease (3CLpro) is a virus protease encoded by SARS-CoV-2, which is essential for virus replication. We have previously reported a series of small-molecule 3CLpro inhibitors effective for inhibiting replication of human coronaviruses including SARS-CoV-2 in cell culture and in animal models. Here we generated a series of deuterated variants of a 3CLpro inhibitor, GC376, and evaluated the antiviral effect against SARS-CoV-2. The deuterated GC376 displayed potent inhibitory activity against SARS-CoV-2 in the enzyme- and the cell-based assays. The K18-hACE2 mice develop mild to lethal infection commensurate with SARS-CoV-2 challenge doses and were proposed as a model for efficacy testing of antiviral agents. We treated lethally infected mice with a deuterated derivative of GC376. Treatment of K18-hACE2 mice at 24 h postinfection with a derivative (compound 2) resulted in increased survival of mice compared to vehicle-treated mice. Lung virus titers were decreased, and histopathological changes were ameliorated in compound 2-treated mice compared to vehicle-treated mice. Structural investigation using high-resolution crystallography illuminated binding interactions of 3CLpro of SARS-CoV-2 and SARS-CoV with deuterated variants of GC376. Taken together, deuterated GC376 variants have excellent potential as antiviral agents against SARS-CoV-2.

Efficacy of combined Sofosbuvir and Daclatasvir in the treatment of COVID-19 patients with pneumonia: a multicenter Egyptian study.

BACKGROUND: Limited experimental and clinical evidence suggests a potential role for sofosbuvir/daclatasvir in treating COVID19. We aim to evaluate the efficacy of generic sofosbuvir/daclatasvir in treating COVID-19 patients with pneumonia. RESEARCH DESIGN AND METHODS: This multicenter prospective study involved 174 patients with COVID-19. Patients were randomized into two groups. Group A (96 patients) received sofosbuvir (400 mg)/daclatasvir (60 mg) for 14 days in combination with conventional therapy. Group B (78 patients) received conventional therapy alone. Clinical, laboratory, and radiological data were collected at baseline, after 7, 14, and 28 days of therapy. Primary endpoint was rate of clinical/virological cure. RESULTS: A lower mortality rate was observed in group (A) (14% vs 21%, P = 0.07). After 1 month of therapy, no differences were found in rates of ICU admission, oxygen therapy, or ventilation. Additionally, a statistically significant shorter duration of hospital stay (9% vs 12%, P < 0.01) and a faster achievement of PCR negativity at day 14 (84% versus 47%, P < 0.01) were noticed in group (A). CONCLUSION: Adding sofosbuvir/daclatasvir to conventional therapy of COVID-19 is promising. Their use is associated with shorter hospital stay, faster PCR negativity and may be reduced mortality.

Clinical efficacy of antiviral agents against coronavirus disease 2019: A systematic review of randomized controlled trials.

Despite aggressive efforts on containment measures for the coronavirus disease 2019 (COVID-19) pandemic around the world, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously spreading. Therefore, there is an urgent need for an effective antiviral agent. To date, considerable research has been conducted to develop different approaches to COVID-19 therapy. In addition to early observational studies, which could be limited by study design, small sample size, non-randomized design, or different timings of treatment, an increasing number of randomized controlled trials (RCTs) investigating the clinical efficacy and safety of antiviral agents are being carried out. This study reviews the updated findings of RCTs regarding the clinical efficacy of eight antiviral agents against COVID-19, including remdesivir, lopinavir/ritonavir, favipiravir, sofosbuvir/daclatasvir, sofosbuvir/ledipasvir, baloxavir, umifenovir, darunavir/cobicistat, and their combinations. Treatment with remdesivir could accelerate clinical improvement; however, it lacked additional survival benefits. Moreover, 5-day regimen of remdesivir might show adequate effectiveness in patients with mild to moderate COVID-19. Favipiravir was only marginally effective regarding clinical improvement and virological assessment based on the results of small RCTs. The present evidence suggests that sofosbuvir/daclatasvir may improve survival and clinical outcomes in patients with COVID-19. However, the sample sizes for analysis were relatively small, and all studies were exclusively conducted in Iran. Further larger RCTs in other countries are warranted to support these findings. In contrast, the present findings of limited RCTs did not indicate the use of lopinavir/ritonavir, sofosbuvir/ledipasvir, baloxavir, umifenovir, and darunavir/cobicistat in the treatment of patients hospitalized for COVID-19.

Treatment of severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and coronavirus disease 2019 (COVID-19): a systematic review of in vitro, in vivo, and clinical trials.

Rationale: Coronavirus disease 2019 (COVID-19) has spread worldwide and poses a threat to humanity. However, no specific therapy has been established for this disease yet. We conducted a systematic review to highlight therapeutic agents that might be effective in treating COVID-19. Methods: We searched Medline, Medrxiv.org, and reference lists of relevant publications to identify articles of in vitro, in vivo, and clinical studies on treatments for severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and COVID-19 published in English until the last update on October 11, 2020. Results: We included 36 studies on SARS, 30 studies on MERS, and 10 meta-analyses on SARS and MERS in this study. Through 12,200 title and 830 full-text screenings for COVID-19, eight in vitro studies, 46 randomized controlled trials (RCTs) on 6,886 patients, and 29 meta-analyses were obtained and investigated. There was no therapeutic agent that consistently resulted in positive outcomes across SARS, MERS, and COVID-19. Remdesivir showed a therapeutic effect for COVID-19 in two RCTs involving the largest number of total participants (n = 1,461). Other therapies that showed an effect in at least two RCTs for COVID-19 were sofosbuvir/daclatasvir (n = 114), colchicine (n = 140), IFN-ß1b (n = 193), and convalescent plasma therapy (n = 126). Conclusions: This review provides information to help establish treatment and research directions for COVID-19 based on currently available evidence. Further RCTs are required.

Sofosbuvir/daclatasvir regimens for the treatment of COVID-19: an individual patient data meta-analysis.

BACKGROUND: The combination of sofosbuvir and daclatasvir has a well-established safety profile and improves clinical outcomes in HCV patients. In silico and in vitro studies suggest that sofosbuvir/daclatasvir may show antiviral activity against SARS-CoV-2. METHODS: Three clinical trials comparing sofosbuvir/daclatasvir-based regimens with a comparator in hospitalized COVID-19 patients were combined in a meta-analysis. The primary outcomes measured were clinical recovery within 14 days of randomization, time to clinical recovery and all-cause mortality. A two-step approach was used to analyse individual-level patient data. The individual trial statistics were pooled using the random-effects inverse-variance model. RESULTS: Our search identified eight studies of which three met the inclusion criteria (n = 176 patients); two studies were randomized and one was non-randomized. Baseline characteristics were similar across treatment arms. Clinical recovery within 14 days of randomization was higher in the sofosbuvir/daclatasvir arms compared with control arms [risk ratio = 1.34 (95% CI = 1.05-1.71), P = 0.020]. Sofosbuvir/daclatasvir improves time to clinical recovery [HR = 2.04 (95% CI = 1.25-3.32), P = 0.004]. The pooled risk of all-cause mortality was significantly lower in the sofosbuvir/daclatasvir arms compared with control arms [risk ratio = 0.31 (95% CI = 0.12-0.78), P = 0.013]. CONCLUSIONS: Available evidence suggests that sofosbuvir/daclatasvir improves survival and clinical recovery in patients with moderate to severe COVID-19. However, the sample size for analysis was relatively small, one of the trials was not randomized and the designs were not standardized. These results need to be confirmed in larger randomized controlled trials.

Feline Infectious Peritonitis: Update on Pathogenesis, Diagnostics, and Treatment.

Feline infectious peritonitis (FIP) is a mysterious and lethal disease of cats. The causative agent, feline coronavirus (FCoV), is ubiquitous in most feline populations, yet the disease is sporadic in nature. Mutations in the infecting virus combined with an inappropriate immune response to the FCoV contribute to the development of FIP. Diagnosis can be challenging because signs may be vague, clinical pathology parameters are nonspecific, and the gold standard for diagnosis is invasive: histopathology of affected tissue. This article discusses the developments in the understanding of this disease as well as the progress in diagnosis and treatment.