Mixed dosing of Covaxin, nasal vaccine trials get panel nod

The subject expert committee (SEC) on Covid-19 under the country’s apex drug regulator approved vaccine maker Bharat Biotech’s plan to experiment a mixed-dosing of two of its vaccines – the intramuscularly administered Covaxin and an nasal inoculation based on a different vector.

Covaxin, based on an inactivated virus platform, is widely in use in India’s coronavirus immunisation while the second vaccine, based on an adenovirus vector, is in phase II clinical trials.

“The committee recommended for grant of permission for conduct of the proposed clinical trial removing the word “interchageability” from the study title. Accordingly, the firm should submit revised clinical trial protocol to CDSCO for approval,” the minutes of the meeting read.

After the SEC makes its recommendations, the final nod is given by the Central Drugs Standard Control Organisation (CDSCO).

The decision was taken by the committee in its meeting on Thursday when it also approved another mixed-dose trial for two of the vaccines already in use in India: Covaxin and Covishield. This will be carried out by a team from Christian Medical College-Vellore.

The meeting also discussed the decision by another coronavirus vaccine maker, Johnson and Johnson, to withdraw its proposal for a phase III bridging trial in India. “The firm has informed that they are withdrawing their proposal,” the minutes of the meeting read. The vaccine may still be brought to India since the drug regulator in April opened another route for foreign vaccine makers such as J&J, which have been approved by some western medical regulators, to be eligible for approval in India without the need for a bridging study.

The application for emergency use authorisation by Gujarat-based Cadila healthcare for its vaccine was not reviewed in Thursday’s meeting. It is the world’s first DNA vaccine for Covid-19 in large scale trials. The company has already submitted interim results of its three-dose vaccine to the drug regulator.

The protein subunit vaccine by BiologicalE also applied for a phase II/III clinical trial in children between the ages of 5 and 17 years. The proposal has been put on hold by the SEC stating that the decision will be taken only after complete safety and immunogenicity data from Phase II in adults is submitted.

The CSIR-Central Drug Research Institute also submitted phase III clinical trial data for antiviral medicine Umifenovir. The committee noted that the results in moderate Covid-19 patients was not statistically significant and recommended that a phase III trial with mild Covid-19 patients be conducted.

“The committee observed that results in moderate Covid-19 cases were not statistically significant. But, the sample size of mild patients was not adequate for considering emergency approval of the drug… the committee recommended that the applicant should conduct a large Phase III Clinical trial in statistically significant number of mild Covid-19 patients,” the minutes read.