An expert committee set up under India’s top drug regulatory body has directed Dr Reddy’s Laboratories (DRL), Bharat Biotech and Biological E (Bio E) to revise their proposals to conduct human trials of their Covid-19 vaccine candidates — a move that may see at least one of the firms revise the number of volunteers they would require for clinical trials of their vaccine candidates.
While DRL had sought permission to conduct late stage trials of the Russian candidate, Sputnik V, Bio E had submitted an application to conduct early stage trials for the vaccine candidate it was developing with Houston’s Baylor College of Medicine. Bharat Biotech, which has been testing its inactivated vaccine Covaxin, is also seeking permission to move to late stage trials.
The Subject Expert Committee (SEC) studying these requests this week said that the safety and immunogenicity data in the overseas trials of Sputnik V are “small” and that there is “no data available on Indian subjects”.
It has recommended that DRL revise its proposal for a phase 3 trial and instead conduct phase 2/3 trials, according to minutes of the SEC meeting on the proposals held on October 5.
“They have to submit a revised protocol now, which means the details of the number of participants and sites would also have to change,” said a senior government official close to the development, on condition of anonymity.
In Bharat Biotech’s case, the SEC said that the design of the phase 3 trials for Covaxin were satisfactory “in principle”, except for their clarification on certain definitions like “asymptomatic” participants.
“However, the study should be initiated with appropriate dose identified from the phase 2 safety and immunogenicity data,” stated the SEC in the minutes, adding that the firm should submit this data from the second phase of its trial “for consideration”.
The expert panel has told Bio E to conduct animal challenge studies in parallel to its phase 1/2 trials — testing that includes dosing an animal and later “challenging” it with the virus to test the effectiveness of the vaccine in providing immunity. It has also directed Bio E to submit “complete” non-clinical toxicity data from testing the vaccine on rabbits.
“Firm should carry out ascending dose safety study starting with 15 mcg dose, 25 mcg dose and 50 mcg dose before proceeding to Phase II study,” the minutes read.
This means Bio E’s safety testing on humans may include different groups of participants being injected with different doses of the vaccine to narrow down an appropriate dosage when moving to the next stage.
“Once we receive the NOC (no objection certificate) from the government (to conduct the trials), the details of the trials, the sites and the size (number of volunteers) and everything will be available publicly on their website,” Bio E managing director Mahima Datla told The Indian Express.
According to her, the changes required to the company’s proposal are “minor” and the firm is expecting to complete the first two phases of the trials by the end of this year.
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