Shionogi has commenced Phase I/II/III and Phase III additional dose clinical trials of its vaccine, S-268019, in paediatric subjects in Japan against Covid-19.

The Japanese Phase I/II/III trial will be carried out in paediatric subjects aged five to 11 years and comprises two parts.

The first part was conducted for assessing the tolerability and safety of a primary series of the S-268019 vaccine.

Part 2 has commenced now, based on the favourable results obtained from Part 1.

This part of the Phase I/II/III trial comprises the primary vaccination and the booster vaccination section.

Immunogenicity after receiving a primary series of S-268019 in children will be compared to that after a primary S-268019 series in the primary vaccination part, to subjects aged 20 years or above in the Phase III active control, neutralising antibody comparative clinical trial.

The trial will be conducted in a blinded control group with a primary series of Comirnaty.

In the booster vaccination portion of the trial, immunogenicity after receiving a third S-268019 dose will be compared to immunogenicity after a primary series of the vaccine.

In the Japanese Phase III additional dose trial, the company will compare immunogenicity of an additional dose of the vaccine or Comirnaty in paediatric subjects, five months or more after they receive a primary Comirnaty series, to the immunogenicity of an additional S-268019 dose in 20 years or above aged subjects.

Shionogi has submitted an application for the manufacturing and sales approval of S-268019 to be used in priming and booster doses for Covid-19.

The Phase III double-blind, randomised, active controlled clinical trial will evaluate the neutralising antibody titer following the primary series of Vaxzevria or S-268019 in 1,000 adult and elderly subjects.

In April this year, Shionogi reported late-breaking data from two clinical trials of oral Covid-19 antiviral, S-217622, which concluded in Asia.