The Phase 3 clinical trial will evaluate SK’s vaccine candidate GBP510 against the AstraZeneca/Oxford Covid-19 vaccine


SK, GSK to jointly study adjuvanted Covid-19 vaccine. (Credit: SK bioscience.)

SK bioscience has teamed up with GSK to initiate a Phase 3 clinical study of its Covid-19 vaccine candidate, GBP510, in combination with GSK’s pandemic adjuvant.

The Phase 3 trial, which follows a positive interim Phase ½ trial, is designed to enrol nearly 4,000 participants from different countries.

The randomised, active-controlled global trial will evaluate the safety and immunogenicity of GBP510 compared to the active comparator AstraZeneca/Oxford Covid-19 vaccine.

Phase 3 GBP510 study is one of the first global trials comparing two different Covid-19 vaccine candidates, and its results are expected in the first half of 2022.

SK bioscience CEO Jaeyong Ahn said: “We are grateful that we were able to advance to the Phase 3 study with the unprecedented support of global initiatives, including GSK, Coalition for Epidemic Preparedness Initiative (CEPI), and the Bill & Melinda Gates Foundation (BMGF).

“Taking this important step towards overcoming the global pandemic situation, SK and GSK will bring our technical expertise together for the development of an adjuvanted protein-based vaccine candidate, GBP510.”

The positive interim Phase 1/2 data showed that the adjuvanted vaccine candidate developed strong neutralising antibody responses, with a 100% seroconversion rate.

In the ongoing study, neutralizing antibody titres were five to eight times higher compared to sera from people recovered from Covid-19, with no safety concerns identified to date.

GBP510 is a self-assembled nanoparticle vaccine candidate that targets the receptor binding domain of the SARS-CoV-2 Spike protein, combined with GSK’s pandemic adjuvant.

SK is developing the vaccine antigen in collaboration with the Institute for Protein Design (IPD) at the University of Washington with support from BMGF and CEPI.

The vaccine is expected to be supplied at scale worldwide through the COVAX facility, subject to positive results and regulatory approval.

GSK chief global health officer Thomas Breuer said: “While many countries have made good progress with vaccination, there remains a need for accessible and affordable Covid-19 vaccines to ensure equitable access and to protect people across the world.

“We are pleased to contribute with GSK’s pandemic adjuvant and to be working with SK to deliver the vaccine at scale via COVAX if it is approved.”