Favipiravir shows significant improvement in time to clinical cure for mild to moderate COVID-19

The oral antiviral medication Favipiravir, that prevents the replication phase of the virus life-cycle, leads to significant improvement in clinical cure in patients with mild to moderate COVID-19. These findings were observed in a randomized, controlled Phase 3 clinical study conducted by Glenmark Pharma, and the results are now published online in The International Journal of Infectious Diseases (IJID). The IJID is a globally peer-reviewed, pubmed indexed, open access journal published monthly by the International Society for Infectious Diseases, USA. The published findings will also appear in the print edition of the journal in the coming weeks.

The publication on the study titled “Efficacy and Safety of Favipiravir, an Oral RNA-Dependent RNA Polymerase Inhibitor, in Mild-to-Moderate COVID-19:  A Randomized, Comparative, Open-Label, Multicenter, Phase 3 Clinical Trial” was authored by Dr Zarir F Udwadia and other co-authors.

The Phase 3 study with antiviral drug Favipiravir, brand name FabiFlu, was conducted in 150 patients as part of a randomised, open-label, multicentre, Phase 3 study. The study aimed to evaluate the efficacy and safety of Favipiravir plus standard supportive care (Favipiravir treatment arm), versus standard supportive care alone (control arm), in mild to moderate patients, randomised within a 48-hour window of testing RT-PCR positive for COVID-19.

Favipiravir was found to provide multiple treatment benefits, demonstrated by faster time to clinical cure, and significantly delayed the need for supportive oxygen therapy. Additionally, patients of confirmed COVID-19 with moderate symptoms were discharged from hospital earlier than those patients that did not receive Favipiravir, with the median time to clinical cure reduced by 2.5 days compared with the control group.

Dr Zarir F Udwadia, Breach Candy Hospital, Mumbai commented “Every claim for the efficacy of a new drug in COVID-19 must be backed by evidence from a clinical trial. Glenmark has done just that with Favipiravir. Their well-designed trial in 150 patients showed Favipiravir resulted in a significantly improved time to clinical cure and rapid viral clearance. Based on this I would consider the use of this anti-viral drug in symptomatic patients with mild to moderate COVID-19. I eagerly await the results of similar trials presently being conducted in Boston and at Stanford”.

Favipiravir is an antiviral medication that works by inhibiting a viral enzyme called RdRP (RNA dependent RNA polymerase), thereby halting the virus’s replication cycle. This helps control the multiplication of the virus and prevents its spread in the patient. This mechanism of action of Favipiravir is novel compared to most antivirals that primarily prevent entry and exit of the virus from cells. Several published reports are now available of the drug’s effectiveness against COVID-19.

Robert Crockart, Chief Commercial Officer Glenmark Pharma said, “From the first reported case of COVID-19, our every effort was to bring a viable, safe and effective treatment option to patients in a timely manner. It is encouraging to see our trial results now published in a reputed global medical journal, which we hope will support other countries in their fight against this disease.”

Patients in the Glenmark clinical trial received Favipiravir tablets 3,600 mg (1,800 mg BID) (Day 1) + 1,600 mg (800 mg BID) (Day 2 or later) for up to maximum of 14 days, along with standard supportive care. Randomization was stratified based on disease severity into mild and moderate. Favipiravir was well tolerated with no serious adverse events (SAEs) or deaths in the Favipiravir treated arm.

The pre-specified primary endpoint, time from randomisation to cessation of oral shedding of the SARS-CoV-2 virus, demonstrated a 2 day earlier virological cure in the Favipiravir treatment group, though not statistically significant. However, significant improvement in time to clinical cure and other secondary end-points suggest Favipiravir may be beneficial in the treatment of mild-to-moderate COVID-19.

In June 2020, Glenmark received manufacturing and marketing approval from India’s drug regulator for Favipiravir (FabiFlu), making it the first oral approved medication in India for the treatment of mild to moderate COVID-19. The manufacturing and marketing approval was granted as part of an accelerated approval process, considering the emergency situation of the COVID-19 outbreak in India. The approval’s restricted use entails responsible medication use where every patient must have signed informed consent before treatment initiation.