Favipiravir is a generic version of Avigan, which was earlier developed in Japan to treat influenza.Strides Pharma shares zoomed more than 10 per cent on the BSE on Thursday, extending its gains in the previous session, after the company said that it has developed and commercialized Favipiravir antiviral tablets for the treatment of Covid-19, and had applied to Indian drug authorities to start trials.At 10:00 am, the shares were trading at Rs 479, higher by Rs 30 or 6.6 per cent, on the BSE.

The shares opened at Rs 503 and have touched an intra-day high of Rs 506 and a low of Rs 464 thus far.

In the previous session, the stock was locked at the upper circuit on the BSE.Favipiravir is a generic version of Avigan, which was earlier developed in Japan to treat influenza."Favipiravir is an antiviral medication that was initially developed to treat influenza in Japan.

In February 2020, post the outbreak of Novel Coronavirus (Covid-19), Favipiravir was studied in China and several other countries as an experimental treatment of Covid-19," the company said in a filing to the BSE."The drug has demonstrated positive outcomes, including a reduction in the duration of COVID-19 and improved lung conditions for the patients," it added.Many Indian pharma companies such as Zydus Cadila, Cipla and Glenmark are working on developing antivirals.The BSE Sensex had gained 984 points or 3 per cent at 33,702 and the NSE Nifty had added 284 points or 2.89 per cent at the time.