Favipiravir vs Hydroxychloroquine vs Control in COVID -19

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2/2019-nCoV) and has developed into a pandemic with serious global public health and economic sequelae. As of June 30, 2020 over 10,000,000 cases have been confirmed worldwide leading to over 500,000 deaths (https://coronavirus.jhu.edu/map.html). Currently no vaccine exists, however chloroquine and hydroxychloroquine have been documented as potentially having antiviral properties with efficacy against COVID-19 disease. Chloroquine is used in the treatment of malaria and amebiasis and is still used in the prophylaxis of malaria. Hydroxychloroquine sulfate is a derivative of Chloroquine that has been demonstrated to be much less (~40%) toxic than Chloroquine in animals. Hydroxychloroquine is widely used to treat autoimmune diseases, due to its immunomodulatory properties, such as systemic lupus erythematosus and rheumatoid arthritis, with an excellent safety profile. In vitro studies have suggested that their mode of action in COVID-19 disease is blockade of SARS-CoV-2 transport from endosomes to endolysosomes, which appears to be a requirement to release the viral genome. Clinical investigation has found that high concentrations of cytokines are detectable in the plasma of critically ill patients infected with SARS-CoV-2, suggesting that cytokine storm is associated with disease severity; therefore, Chloroquine/ hydroxychloroquine may reduce this response by acting as anti-inflammatory agents in accord with their use in autoimmune disease, where their reduction in cytokine response has been extensively researched and demonstrated.

Favipiravir is an antiviral drug developed in Japan (as noted in the data sheets) that it is a pyrazinecarboxamide derivative with activity against influenza viruses, west nile virus, yellow fever virus, foot and mouth disease virus as well as against flaviviruses (i.e. arenaviruses, bunyaviruses and alphaviruses). Its mode of action is through inhibition of viral RNA-dependent RNA polymerase. In February the drug was used for COVID-19 disease in China and was declared effective in treatment, and a report published (in press) comparing Favipiravir with Lopinavir /ritonavir suggested that Favipiravir was superior for prevention of disease progression and viral clearance.

"The Solidarity Trial" is a global pragmatic clinical trial being undertaken by WHO that aims to explore the efficacy of different treatment modalities for SARS-CoV-2. An application for Bahrain to join the study for collaboration has been made. In "The Solidarity Study" there will be four treatment modalities investigated, including chloroquine phosphate alone, remdesivir, lopinarvir with ritonavir or lopinarvir with ritonavir plus interferon. Favipiravir is not included, and therefore this study will not be replicating features of "The Solidarity Trial" but instead will provide additional and novel findings on favipiravir efficacy.

Inclusion criteria

• Admitted COVID-19 patients being treated as an in-patient at a hospital facility.
• COVID-19 diagnosis confirmed by PCR nasopharyngeal swab.
• Study participants must be symptomatic with any COVID-19 symptoms defined by the Bahrain National Protocol
• Onset of symptoms must be within 10 days prior to enrolment.
• Study participants must have the ability to give informed consent.
• Participants must be at minimum 21 years of age.
• Mild to Moderate COVID-19 disease defined as saturation equals to or more than 93% on room air or PaO2:FiO2 ratio more than 300 on enrolment.

Exclusion criteria

• Severe COVID-19 disease: defined as presence of SpO₂ less than 93% on room air or a PaO₂ to FiO₂ ratio of 300 or lower.
• Patients on ventilatory support.
• Cardiac dysfunction that would preclude treatment with hydroxychloroquine:

• Patients on medication known to prolong QT segment.
• Known history of LQT syndrome.
• Acquired QT prolongation at baseline >500ms.
• AV block.
• Bundle Branch Block.
• Known history of Cardiomyopathy, Pulmonary Hypertension, or Sick Sinus Syndrome.
• History of ventricular tachyarrhythmia.
• Patients with implantable cardioverter-defibrillator (ICD).
• Patients with a baseline bradycardia of less than 50 beats per minute.
• Renal dysfunction (estimated glomerular filtration rate less than 30ml/min).
• Hepatic dysfunction defined as:

• Transaminitis more than three times the upper limit of normal or
• Chronic liver disease of Child Pugh Class B or higher.
• Gout or a history of gout
• Patients that are pregnant or breastfeeding.
• Patients with a known allergy to an intervention medication.
• Patients who receive any of the study medications prior to randomization
• Patient with G6PD
• Readmission due to COVID19 disease.
• Participants in any other COVID-19 disease trial.
• Patients on immunosuppressants, HIV patients, cancer patients who received chemotherapy within the past 6 months, or who are on chronic oral steroids.
• Patients unable to give informed consent.