The trials in the first and second phases had led to promising results.
Drug developer Ocugen Inc said on Tuesday it had partnered with Bharat Biotech to co-develop the Hyderabad-based company's COVID-19 vaccine candidate for the US market.
The vaccine candidate, Covaxin, showed it was safe and triggered immune responses in an ongoing early-stage trial on Wednesday and is currently part of a late-stage trial in India.
Under the partnership terms, Ocugen said it would have US rights to the vaccine candidate and be responsible for clinical development, registration, and commercialization for the US market.
Bharat Biotech is developing Covaxin with the government-run Indian Council of Medical Research (ICMR) and has sought emergency-use authorization from the Indian drug regulator.
Shares of Ocugen surged 10 per cent to 32 cents in trading before the bell.