The Hyderabad-based pharmaceutical company had applied to the Drugs Controller General of India (DCGI) last week, seeking permission to conduct phase-3 human clinical trials of the Russian vaccine. The Subject Expert Committee (SEC) on Covid-19 at CDSCO, asked the firm to submit a revised protocol stating it will have to conduct phase 2 and phase 3 clinical trials in a combined manner, sources told PTI. "It means that Dr. Reddy's laboratories will have to submit a new application. According to the SEC, they have to conduct both phase-2 and phase-3 clinical trials and cannot directly hold phase-3 trial for the vaccine in India," a source said.