Favipiravir is now the first oral COVID-19 treatment approved in India: All you need to know

The Drug Controller General of India (DCGI) has approved a new treatment for COVID-19 as of 19 June, in India. The drug favipiravir has been okayed for emergency medical use under the fast-tracked approval process. Glenmark Pharmaceuticals, the drug’s manufacturer, was given the permission to make and market favipiravir (200 mg) in a tablet form. As per a statement by Glenmark, the drug will be launched commercially by next week, to treat mild to moderate COVID-19 cases. Favipiravir is now the first oral approved medication in India for the treatment of COVID-19 and will be sold under the name FabiFlu. It will likely be made available across chemist outlets in the country to those with a prescription by the end of the month, priced at Rs 103 per tablet, according to a statement by Glenmark. “FabiFlu® has demonstrated an encouraging response in mild to moderate COVID-19 patients during clinical trials,” Glenn Saldanha, Chairman and Managing Director of Glenmark said. “Glenmark will work closely with the government and medical community to make FabiFlu® quickly accessible to patients across the country.” [caption id=“attachment_8511051” align=“alignnone” width=“1280”] Favipiravir tablets. Image: Reuters/ISSEI KATO[/caption]

What is Favipiravir?

Favipiravir is an antiviral medication that was developed in Japan and got approval for treating people with influenza. It reportedly showed anti-viral activity against all subtypes of influenza virus strains. Not only does it inhibit replication of influenza A and B, the drug has also shown promise in the treatment of avian influenza, and as an alternative to treat influenza strains resistant to the first choice of treatment. The flexibility that favipiravir shows in its ability to act on multiple different influenza viruses has led to other countries using the drug to explore treatments for novel (emerging) viruses including Ebola and most recently, COVID-19. However, outside of its effectiveness in treating the influenza virus, evidence in support of this drug is still scant and preliminary. Favipiravir is among the many  **drugs currently being trialled**  to treat COVID-19 (alongside Ebola drug **Remdesivir** , the HIV drug combination **lopinavir/ritonavir** , and a combination of lopinavir/ritonavir with **Interferon beta** , and **others** ). Favipiravir was being studied in China as an experimental treatment for COVID-19 by February 2020. Trials are now also underway in Italy, Japan, the USA, the UK and India. Favipiravir was given approval for the treatment of COVID-19 in hospital settings in Russia on 29 May 2020, after a randomized clinical trial that recruited 60 subjects on the drug. The 390 subject-strong trial is still underway and expected to end by 31 December 2020 according to a Russian government registry. On 19 June, the Indian government, too, approved the drug, manufactured by Glenmark Pharmaceuticals under the brand name FabiFlu®, to treat mild to moderate cases of COVID-19 in the country. “Favipiravir can be used in COVID-19 patients with co-morbid conditions such as diabetes and heart disease with mild to moderate COVID-19 symptoms,” a Glenmark statement published Saturday, read. “It offers rapid reduction in viral load within 4 days and provides faster symptomatic and radiological improvement. Of most importance, favipiravir has shown clinical improvement of up to 88 percent in mild to moderate COVID-19 cases.” The drug has been indicated by Glenmark for the treatment of novel influenza strains (which cause more severe disease), and not the seasonal flu-causing influenza strains.

How does Favipiravir work?

One of the key factors that distinguish a virus is the kind of genetic material it is made of – they are either DNA-based or RNA-based viruses. Favipiravir works exclusively on RNA viruses. It has a rather unique mechanism of action compared to other known influenza antivirals, which primarily stop a virus from either entering or exiting a living cell. Favipiravir prevents the virus from making copies of itself once it gets inside a host cell. It does this by targetting a key protein enzyme that the virus uses to multiply its genetic material (RNA) inside the body, called RNA polymerase. This unique mode of action has made favipiravir a potentially promising drug to treat particularly untreatable RNA viral infections, where all other interventions appear to have failed. A  study on 80 subjects found that favipiravir, compared to lopinavir/ritonavir, showed quicker clearance of the virus. The results showed that 91 percent of the participants had better CT scans after treatment. The results showed promise, barring a few side effects. And while the results were encouraging, the study was limited by design – it wasn’t the randomized, double-blinded, placebo-controlled trial format required to make a strong argument for the drug’s effectiveness. Favipiravir has been reported as risky in pregnancy. It is cited in some studies as a “teratogen” which can cause abnormalities in a fetus after it is exposed during pregnancy, potentially toxic to a growing embryo. According to the Canadian Drugbank, toxicity information regarding favipiravir in humans is not readily available. Glenmark is also conducting clinical trials to evaluate the efficacy of two antivirals Favipiravir and Umifenovir as a combination therapy to treat moderate COVID-19 cases in adults in India.