Although several antiviral agents have become available for coronavirus disease 2019 (COVID-19) treatment, oral drugs are still limited. Camostat mesylate, an orally bioavailable serine protease inhibitor, has been used to treat chronic pancreatitis in South Korea, and it has an in vitro inhibitory potential against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study was a double-blind, randomized, placebo-controlled, multicenter, phase 2 clinical trial in mild to moderate COVID-19 patients. We randomly assigned patients to receive either camostat mesylate (DWJ1248) or placebo orally for 14 days. The primary endpoint was time to clinical improvement of subject symptoms within 14 days, measured using a subjective 4-point Likert scale. Three hundred forty-two patients were randomized. The primary endpoint was nonsignificant, where the median times to clinical improvement were 7 and 8 days in the camostat mesylate group and the placebo group, respectively (hazard ratio [HR] = 1.09; 95% confidence interval [CI], 0.84 to 1.43; P = 0.50). A post hoc analysis showed that the difference was greatest at day 7, without reaching significance. In the high-risk group, the proportions of patients with clinical improvement up to 7 days were 45.8% (50/109) in the camostat group and 38.4% (40/104) in the placebo group (odds ratio [OR] = 1.33; 95% CI, 0.77 to 2.31; P = 0.31); the ordinal scale score at day 7 improved in 20.0% (18/90) of the camostat group and 13.3% (12/90) of the placebo group (OR = 1.68; 95% CI, 0.75 to 3.78; P = 0.21). Adverse events were similar in the two groups. Camostat mesylate was safe in the treatment of COVID-19. Although this study did not show clinical benefit in patients with mild to moderate COVID-19, further clinical studies for high-risk patients are needed. (This trial was registered with ClinicalTrials.gov under registration no. NCT04521296).

BACKGROUND: The scientific researches on COVID-19 pandemic topics are headed to an explosion of scientific literature. Despite these global efforts, the efficient treatment of patients is an in-progress challenge. Based on a meta-study of published shreds of evidence about compounds and their botanic sources in the last six decades, a novel multiple-indication herbal compound (Saliravira®) has been developed. Based on the antiviral, anti-inflammatory, and immune-enhancing properties of its ingredients, we hypothesized that Saliravira® has the potential to act as an antiviral agent, accelerate treatment, and reduce undesirable effects of COVID-19.
METHODS: In this randomized, controlled, open-label clinical trial, COVID-19 outpatients were included by RT-PCR test or diagnosis of physicians according to the symptoms. Participants were randomly divided into intervention and control groups to receive Saliravira® package plus routine treatments of COVID-19 or routine treatments of COVID-19 alone, respectively. Saliravira® package includes tablets, nasal-sinuses spray, oral-pharynx spray, and inhaler drops. The treatment was for 10 days and followed up till 23 days after admission.
RESULTS: On the 8th day, the \"mean reduction rates\" of viral load of the patients in the intervention group was 50% lower compared to the control group with a p-value < 0.05. The improvement of 10 out of 14 COVID-19 symptoms in the intervention group was significantly accelerated. The mean treatment duration of patients in the intervention group was 4.9 days less than the control group. In addition, no patients in the intervention group were hospitalized compared to 28% of the control group needed to be hospitalized.

There are dozens of approved, investigational and experimental antiviral agents. Many of these agents cause serious side effects, which can only be revealed after drug administration. Identification of the side effects prior to drug administration is challenging. Here we describe an ex vivo approach for studying immuno- and neuro-modulatory properties of antiviral agents, which may be associated with potential side effects of these therapeutics. The current approach combines drug toxicity/efficacy tests and transcriptomics, which is followed by mRNA, cytokine and metabolite profiling. We demonstrated the utility of this approach with several examples of antiviral agents. We also showed that the approach can utilize different immune stimuli and cell types. It can also include other omics techniques, such as genomics and epigenomics, to allow identification of individual markers associated with adverse reactions to antivirals with immuno- and neuro-modulatory properties.

Host cell infection with HIV-1 requires fusion of viral and cell membranes. Sifuvirtide (SFT) is a peptide-based HIV-1 fusion inhibitor approved for phase III clinical trials in China. Here, we focused on characterizing HIV-1 variants highly resistant to SFT to gain insight into the molecular resistance mechanism. Three primary substitutions (V38A, A47I, and Q52R) located at the inhibitor-binding site of HIV-1\'s envelope protein (Env) and one secondary substitution (N126K) located at the C-terminal heptad repeat region of the viral protein gp41, which is part of the envelope, conferred high SFT resistance and cross-resistance to the anti-HIV-1 drug T20 and the template peptide C34. Interestingly, SFT\'s resistance profile could be dramatically improved with an M-T hook structure-modified SFT (MTSFT) and with short-peptide inhibitors that mainly target the gp41 pocket (2P23 and its lipid derivative LP-19). We found that the V38A and Q52R substitutions reduce the binding stabilities of SFT, C34, and MTSFT, but they had no effect on the binding of 2P23 and LP-19; in sharp contrast, the A47I substitution enhanced fusion inhibitor binding. Furthermore, the primary resistance substitutions impaired Env-mediated membrane fusion and cell entry and changed the conformation of the gp41 core structure. Importantly, whereas the V38A and Q52R substitutions disrupted the N-terminal helix of gp41, a single A47I substitution greatly enhanced its thermostability. Taken together, our results provide crucial structural insights into the mechanism of HIV-1 resistance to gp41-dependent fusion inhibitors, which may inform the development of additional anti-HIV drugs.

OBJECTIVE: Treatment for hepatitis B virus infection reduces the risk of hepatocellular carcinoma (HCC). However, the long-term protective effects for subgroups of patients with chronic hepatitis B are unclear.
METHODS: We conducted a retrospective nationwide cohort study using data from Taiwan\'s National Health Insurance Research Database (from January 1, 1997, through December 31, 2010). Cumulative incidences were calculated and multivariable analyses were carried out after adjusting for competing mortality. Propensity scores were used to match 21,595 patients with chronic hepatitis B who received nucleoside analogue therapy for at least 90 days (treated cohort) with 21,595 untreated patients with chronic hepatitis B (controls), who received hepatoprotectants for at least 90 days. Data were collected from the treated cohort for a mean period of 3.46 years and from controls for 5.24 years.
RESULTS: The treated cohort had a significantly lower 7-year incidence of HCC (7.32%; 95% confidence interval [CI], 6.77%-7.87%) than controls (22.7%; 95% CI, 22.1%-23.3%; P < .001). After adjusting for competing mortality and other confounders, nucleos(t)ide analogue treatment was associated with a reduced risk of HCC, with an adjusted hazard ratio of 0.37 (95% CI, 0.34-0.39; P < .001). Sensitivity analyses confirmed the association between nucleos(t)ide analogue treatment and reduced risk of HCC. Age, sex, cirrhosis, and diabetes mellitus modified this association.
CONCLUSIONS: Based on a retrospective, nationwide study in Taiwan, nucleoside analogue therapy use is associated with reduced risk of HCC in patients with chronic hepatitis B virus infection.