A Trial of Favipiravir and Hydroxychloroquine combination in Adults Hospitalized with moderate and severe Covid-19: A structured summary of a study protocol for a randomised controlled trial

A Peek into Pandora’s Box: COVID-19 and Neurodegeneration

Ever since it was first reported in Wuhan, China, the coronavirus-induced disease of 2019 (COVID-19) has become an enigma of sorts with ever expanding reports of direct and indirect effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on almost all the vital organ systems. Along with inciting acute pulmonary complications, the virus attacks the cardiac, renal, hepatic, and gastrointestinal systems as well as the central nervous system (CNS). The person-to-person variability in susceptibility of individuals to disease severity still remains a puzzle, although the comorbidities and the age/gender of a person are believed to play a key role. SARS-CoV-2 needs angiotensin-converting enzyme 2 (ACE2) receptor for its infectivity, and the association between SARS-CoV-2 and ACE2 leads to a decline in ACE2 activity and its neuroprotective effects. Acute respiratory distress may also induce hypoxia, leading to increased oxidative stress and neurodegeneration. Infection of the neurons along with peripheral leukocytes’ activation results in proinflammatory cytokine release, rendering the brain more susceptible to neurodegenerative changes. Due to the advancement in molecular biology techniques and vaccine development programs, the world now has hope to relatively quickly study and combat the deadly virus. On the other side, however, the virus seems to be still evolving with new variants being discovered periodically. In keeping up with the pace of this virus, there has been an avalanche of studies. This review provides an update on the recent progress in adjudicating the CNS-related mechanisms of SARS-CoV-2 infection and its potential to incite or accelerate neurodegeneration in surviving patients. Current as well as emerging therapeutic opportunities and biomarker development are highlighted.

Structure genomics of SARS-CoV-2 and its Omicron variant: drug design templates for COVID-19

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has brought an unprecedented public health crisis and persistently threatens to humanity. With tireless efforts from scientists around the world, understanding of the biology of coronavirus has been greatly enhanced over the past 2 years. Structural biology has demonstrated its powerful impact on uncovering structures and functions for the vast majority of SARS-CoV-2 proteins and guided the development of drugs and vaccines against COVID-19. In this review, we summarize current progress in the structural biology of SARS-CoV-2 and discuss important biological issues that remain to be addressed. We present the examples of structure-based design of Pfizer’s novel anti-SARS-CoV-2 drug PF-07321332 (Paxlovid), Merck’s nucleotide inhibitor molnupiravir (Lagevrio), and VV116, an oral drug candidate for COVID-19. These examples highlight the importance of structure in drug discovery to combat COVID-19. We also discussed the recent variants of Omicron and its implication in immunity escape from existing vaccines and antibody therapies.

Efficacy of favipiravir in adults with mild COVID-19: a randomized, double-blind, multicenter, placebo-controlled trial clinical trial

Objective

To evaluate whether favipiravir reduces the time to viral clearance as documented by negative RT-PCR results for severe acute respiratory syndrome coronavirus 2 in mild cases of coronavirus disease 2019 (COVID-19) compared to placebo.

Methods

In this randomized, double-blinded, multicentre, and placebo-controlled trial, adults with PCR-confirmed mild COVID-19 were recruited in an outpatient setting at seven medical facilities across Saudi Arabia. Participants were randomized in a 1:1 ratio to receive either favipiravir 1800 mg by mouth twice daily on day 1 followed by 800 mg twice daily (n = 112) or a matching placebo (n = 119) for a total of 5 to 7 days. The primary outcome was the effect of favipiravir on reducing the time to viral clearance (by PCR test) within 15 days of starting the treatment compared to the placebo group. The trial included the following secondary outcomes: symptom resolution, hospitalization, intensive care unit admissions, adverse events, and 28-day mortality.

Results

Two hundred thirty-one patients were randomized and began the study (median age, 37 years; interquartile range (IQR): 32–44 years; 155 [67%] male), and 112 (48.5%) were assigned to the treatment group and 119 (51.5%) into the placebo group. The data and safety monitoring board recommended stopping enrolment because of futility at the interim analysis. The median time to viral clearance was 10 days (IQR: 6–12 days) in the favipiravir group and 8 days (IQR: 6–12 days) in the placebo group, with a hazard ratio of 0.87 for the favipiravir group (95% CI 0.571–1.326; p = 0.51). The median time to clinical recovery was 7 days (IQR: 4–11 days) in the favipiravir group and 7 days (IQR: 5–10 days) in the placebo group. There was no difference between the two groups in the secondary outcome of hospital admission. There were no drug-related severe adverse events.

Conclusion

In this clinical trial, favipiravir therapy in mild COVID-19 patients did not reduce the time to viral clearance within 15 days of starting the treatment.

Treatment adherence of COVID-19 patients getting medication at home

Introduction: Turkey has adopted outpatient treatment of COVID-19 since the beginning of the pandemic. In the outpatient treatment of COVID-19 in Turkey, only hydroxychloroquine was initially used, favipiravir was added to the treatment, and finally, hydroxychloroquine was removed from the treatment and only favipiravir was used. Our study aims to examine the adherence to the recommended treatment of people diagnosed with COVID-19 who have received outpatient treatment without hospitalization and their attitudes and declared behaviors towards using the medications they were given free of charge. Methods: This follow-up study was conducted between February 15, 2021, and May 15, 2021, by telephone survey method in the Lüleburgaz District of Kırklareli City. The study participants were 4368 people who were diagnosed with COVID-19 with a positive PCR test in Lüleburgaz District between February 15 and May 15, 2021, and were given hydroxychloroquine and/or favipiravir drugs for home use after being deemed suitable for outpatient treatment according to the guidelines of the Republic of Turkey Ministry of Health. Results: 88.1% (n = 3849) of the survey respondents reported using the given medications regularly, while 11.9% (n = 519) did not use them regularly. The most important socio demographic factor affecting the regular use was age, and the patient-centered factor was the sense of trust. Conclusion: In the fight against COVID-19, measures to increase the sense of trust of patients who are expected to adhere to the treatments should be considered a priority.

Favipiravir and Hydroxychloroquine Combination Therapy in Patients with Moderate to Severe COVID-19 (FACCT Trial): An Open-Label, Multicenter, Randomized, Controlled Trial

Introduction

Antiviral drugs have shown limited effectiveness in treating patients with coronavirus disease 2019 (COVID-19). We aimed to assess the effects of a favipiravir and hydroxychloroquine combination on treating moderate-to-severe COVID-19 patients.

Methods

An investigator-initiated, multicenter, open-label, randomized trial at nine hospitals. Eligible patients were adults with moderate-to-severe COVID-19 defined as oxygen saturation (SaO₂) of ≤ 94% while breathing ambient air or significant clinical symptoms with chest x-ray changes requiring hospital admission. Randomization was in a 1:1 ratio to receive standard care (control group) or standard care plus favipiravir and hydroxychloroquine. The primary outcome was time to clinical improvement of two points (from the status at randomization) on a seven-category ordinal scale or live discharge from the hospital within 14 days. Analyses were done in an intention-to-treat population.

Results

From May 2020 to Jan 2021, 254 patients were enrolled; 129 were assigned to standard of care and 125 to the treatment. The mean age was 52 (± 13) years, and 103 (41%) were women. At randomization, six patients were on invasive mechanical ventilation, 229 (90.15%) were requiring supplemental oxygen only (with or without non-invasive ventilation), and 19 (7.48%) were receiving neither. The time to clinical improvement was not significantly different between the groups: median of 9 days in the treatment group and 7 days in the control group (HR: 0.845; 95% CI 0.617–1.157; p-value = 0.29). The 28-day mortality was not significantly different between the groups (7.63% treatment) vs. (10.32% control); p-value = 0.45. The most prevalent adverse events were headache, elevation in ALT, and the prolonged QTc interval in the treatment group.

Conclusion

The combination of favipiravir and hydroxychloroquine did not result in a statistically significant clinical benefit in patients with moderate-to-severe COVID-19.

Clinical Trial Registration

ClinicalTrials.gov (NCT04392973).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00496-6.

Classical Xanthinuria in Nine Israeli Families and Two Isolated Cases from Germany: Molecular, Biochemical and Population Genetics Aspects

Classical xanthinuria is a rare autosomal recessive metabolic disorder caused by variants in the XDH (type I) or MOCOS (type II) genes. Thirteen Israeli kindred (five Jewish and eight Arab) and two isolated cases from Germany were studied between the years 1997 and 2013. Four and a branch of a fifth of these families were previously described. Here, we reported the demographic, clinical, molecular and biochemical characterizations of the remaining cases. Seven out of 20 affected individuals (35%) presented with xanthinuria-related symptoms of varied severity. Among the 10 distinct variants identified, six were novel: c.449G>T (p.(Cys150Phe)), c.1434G>A (p.(Trp478*)), c.1871C>G (p.(Ser624*)) and c.913del (p.(Leu305fs*1)) in the XDH gene and c.1046C>T (p.(Thr349Ileu)) and c.1771C>T (p.(Pro591Ser)) in the MOCOS gene. Heterologous protein expression studies revealed that the p.Cys150Phe variant within the Fe/S-I cluster-binding site impairs XDH biogenesis, the p.Thr349Ileu variant in the NifS-like domain of MOCOS affects protein stability and cysteine desulfurase activity, while the p.Pro591Ser and a previously described p.Arg776Cys variant in the C-terminal domain affect Molybdenum cofactor binding. Based on the results of haplotype analyses and historical genealogy findings, the potential dispersion of the identified variants is discussed. As far as we are aware, this is the largest cohort of xanthinuria cases described so far, substantially expanding the repertoire of pathogenic variants, characterizing structurally and functionally essential amino acid residues in the XDH and MOCOS proteins and addressing the population genetic aspects of classical xanthinuria.

Safety and efficacy of favipiravir versus hydroxychloroquine in management of COVID-19: A randomised controlled trial

Favipiravir is considered a potential treatment for COVID-19 due its efficacy against different viral infections. We aimed to explore the safety and efficacy of favipiravir in treatment of COVID-19 mild and moderate cases. It was randomized-controlled open-label interventional phase 3 clinical trial [NCT04349241]. 100 patients were recruited from 18th April till 18th May. 50 patients received favipiravir 3200 mg at day 1 followed by 600 mg twice (day 2-day 10). 50 patients received hydroxychloroquine 800 mg at day 1 followed by 200 mg twice (day 2-10) and oral oseltamivir 75 mg/12 h/day for 10 days. Patients were enrolled from Ain Shams University Hospital and Assiut University Hospital. Both arms were comparable as regards demographic characteristics and comorbidities. The average onset of SARS-CoV-2 PCR negativity was 8.1 and 8.3 days in HCQ-arm and favipiravir-arm respectively. 55.1% of those on HCQ-arm turned PCR negative at/or before 7th day from diagnosis compared to 48% in favipiravir-arm (p = 0.7). 4 patients in FVP arm developed transient transaminitis on the other hand heartburn and nausea were reported in about 20 patients in HCQ-arm. Only one patient in HCQ-arm died after developing acute myocarditis resulted in acute heart failure. Favipiravir is a safe effective alternative for hydroxychloroquine in mild or moderate COVID-19 infected patients.

Understanding the clinical utility of favipiravir (T-705) in coronavirus disease of 2019: a review

The coronavirus disease of 2019 (COVID-19) has caused significant morbidity and mortality among infected individuals across the world. High transmissibility rate of the causative virus - Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) - has led to immense strain and bottlenecking of the health care system. While noteworthy advances in vaccine development have been made amid the current global pandemic, most therapeutic agents are repurposed from use in other viral infections and are being evaluated for efficacy in COVID-19. Favipiravir, an orally administered drug originally developed in Japan against emerging influenza viral strains, has been shown to have widespread application and safety across multiple ribonucleic acid (RNA) viral infections. With a strong affinity toward the viral RNA-dependent RNA polymerase (RdRp), favipiravir could be a promising therapy against SARS-CoV-2, by targeting downstream viral RNA replication. Initial trials for usage in COVID-19 have suggested that favipiravir administration during initial infection stages, in individuals with mild to moderate infection, has a strong potential to improve clinical outcomes. However, additional well-designed clinical trials are required to closely examine ideal timing of drug administration, dosage, and duration, to assess the role of favipiravir in COVID-19 therapy. This review provides evidence-based insights and throws light on the current clinical trials examining the efficacy of favipiravir in tackling COVID-19, including its mechanism, pharmacodynamics, and pharmacokinetics.