Indian regulator rejects Sputnik V’s phase-3 trial request due to inadequate data

Rejecting a proposal to conduct a direct phase-3 clinical trial of the Russian Sputnik V coronavirus vaccine, Indian drug regulator has advised the promoters of the vaccine to carry out a phase-2 trial on Indian subjects first to check the vaccine’s immune response before going ahead with a larger phase-3 study.

This is because the number of people, who had received the vaccine for an initial (phase-1/2) trial in Russia was too small, the Central Drug Standards Control Organisation informed pharmaceutical firm Dr Reddy’s Laboratory, which had tied up with the Russian authorities for clinical trial and subsequent distribution of the vaccine in India, if the trials succeeded.

The CDSCO rejection may hamper the central government’s plan of a quick roll-out of a coronavirus vaccine with the Union Health Minister Harsh Vardhan setting up a target of “receiving and utilising” 400-500 million doses to cover 20-25 crore people by July 2021.

The company presented the phase-3 clinical trial protocol before the regulator along with overseas phase 1/2 clinical trial and non-clinical toxicity data. After perusing the data, the CDSCO panel concluded that the safety and immunogenicity data in overseas studies was small and there was no data available on Indian subjects.

“After detailed deliberation, the committee recommended that the firm should follow the regulatory requirements and conduct Phase 2/3 clinical trials in the country with proper monitoring for humoral and cell-mediated immune response,” the regulator wrote in the minutes of the meeting that took place on October 5.

Accordingly, DRL has been advised by the regulator to submit the protocol for consideration of the committee. The firm has also been asked to submit the stability data.

Results from the early-phase trials of Sputnik V in a total of 76 people - published in the Lancet last month – demonstrated that two formulations of the two-part vaccine exhibited a good safety profile with no serious adverse events detected over 42 days, and induce antibody responses in all participants within 21 days.

A larger trial with more participants has been approved in Russia. “The phase 3 clinical trial of our vaccine was approved on August 26, 2020. It is planned to include 40,000 volunteers from different age and risk groups, and will be undertaken with constant monitoring of volunteers through an online application," Alexander Gintsburg, lead researcher at the N F Gamaleya National Research Centre for Epidemiology and Microbiology, Russia, which developed the vaccine was quoted in a Lancet statement a month ago.