Zydus Cadila has reported positive interim results from the Phase III clinical trial of its plasmid DNA Covid-19 vaccine candidate, ZyCoV-D.
Based on these data, the company is seeking emergency use authorization (EUA) from the Drug Controller General of India (DCGI) for the vaccine.
On administration, ZyCoV-D generates the SARS-CoV-2 spike protein and triggers cellular and humoral immune responses. It is a three-dose vaccine to be given intradermally using the PharmaJet needle-free applicator.
Performed at more than 50 centres to date, the Phase III trial is considered the largest Covid-19 vaccine study in India.
It is also the first to evaluate a Covid-19 vaccine in adolescent subjects aged 12-18 years in the country.
With 1,000 participants recruited in this age group, ZyCoV-D was safe and well-tolerated. The interim data also showed a tolerability profile similar to that observed in adults.
The primary efficacy of the vaccine was 66.6% in symptomatic patients who tested positive using reverse transcription-polymerase chain reaction (RT-PCR).
Furthermore, the trial did not report any moderate Covid-19 cases in the vaccine group after the third dose, indicating 100% effectiveness against moderate disease.
No Covid-19-related severe cases or deaths were seen following the second dose of ZyCoV-D.
In previous adaptive Phase I/II trials, the vaccine demonstrated strong immunogenicity and tolerability and safety profile. The Phase I/II and Phase III trials were reviewed by an independent Data Safety Monitoring Board (DSMB).
Cadila Healthcare managing director Dr Sharvil Patel said: “As the first-ever plasmid DNA vaccine for human use, ZyCoV-D has proven its safety and efficacy profile in our fight against Covid-19.
“The vaccine when approved will help not only adults but also adolescents in the 12 to 18 years age group.”
The company expects to produce 100 to 120 million doses of its Covid-19 vaccine a year.
Separately, Zydus assessed a two-dose regimen of ZyCoV-D with a 3mg dose administered per visit.
Data showed an immunogenicity equivalent to the three-dose regimen, the company said. This can decrease the full course vaccination duration.
In May 2021, Zydus sought regulatory approval to conduct Phase I/III trials of its drug candidate, ZRC-3308 (Covimabs), for the treatment of mild Covid-19.