COVID-19 vaccine with IPD nanoparticles meets Phase 1/2 trial goals

This report was written and translated into English by SK bioscience. (Image: SK bioscience)

SK bioscience (CEO Jae-yong Ahn) announced on November 4th that the company has confirmed a positive immune response and safety in the final analysis result of the phase I/II clinical trial of the COVID-19 vaccine candidate, ‘GBP510,’ co-developed with the Institute for Protein Design at the University of Washington in the U.S and adjuvanted with GlaxoSmithKline’s (GSK) pandemic adjuvant system.

SK bioscience enrolled 328 healthy adult participants to conduct the phase I/II clinical trial of GBP510 at 14 clinical institutions including Korea University Guro Hospital. As a result, the generation of the neutralizing antibodies against the COVID-19 virus has been confirmed in all participants receiving the adjuvanted vaccine, demonstrating a 99% seroconversion rate.

The observed neutralizing antibody titer after two weeks from the injection was about 6 times higher in a pseudovirion-based neutralization assay of the entire subject and about 3.6 times higher in a plaque reduction neutralization test of the subset compared to the serum panel of recovered COVID-19 patients. GBP510, which demonstrated a high level of neutralizing antibody induction in the phase I/II clinical trial, which included those over 65 years old whose antibody response rate is usually low, indicated a similar or higher level of immunogenicity compared to the current COVID-19 vaccines.

The result has been acquired by standardized analysis using international standard material and analytic methods established by the World Health Organization and the UK’s National Institute for Biological Standards and Control. The convalescent sera control is inclusive of the lowest to the highest levels of neutralizing antibody formation rates.

In terms of safety, no serious adverse events following immunization were detected in relation to GBP510 injection, demonstrating sufficient tolerability.

SK bioscience will submit the positive data of the phase I/II clinical trial to domestic and international regulatory agencies and plan to further accelerate the development of GBP510 based on the results.

SK bioscience is currently planning to initiate the global phase III clinical trial across the regions including Europe and Southeast Asia, followed by Vietnam where the trial is being already conducted, with the International Vaccine Institute this month. In South Korea, 14 clinical institutions including Korea University Guro Hospital are conducting the phase III clinical trial for GBP510 since August with enrolling about 500 participants, 5 times more population than originally planned.

The protein-based nanoparticle vaccine is studded with 60 copies of the SARS-CoV-2 Spike protein’s receptor-binding domain. Image: IPD

Based on the data from the global phase III clinical trial targeting about 4,000 participants, SK bioscience will prepare to acquire an approval from South Korea’s Ministry of Food and Drug Safety. Also, the company plans to receive WHO Pre-qualification certification and emergency use authorization by individual countries based on the result of the phase III clinical trial.

GBP510 was the first COVID-19 vaccine candidate selected as a part of Wave 2, a project initiated by Coalition for Epidemic Preparedness Innovations (CEPI) in 2020 to support promising vaccine candidates. Following continued positive progress and market authorization, GBP510 will be made available to the COVAX Facility for procurement and equitable allocation worldwide. In addition, SK bioscience will supply GBP510 to the world, including Korea, by establishing its own distribution plans to individual countries through their approval process.

According to Our World in Data, a statistical site developed by a research team at Oxford University in the UK, only about 50% of the world’s population has received at least one dose of a COVID-19 vaccine, and the vaccination rate in low-income countries is only 3.7%, so the demand for vaccinations for COVID-19 is still high.

The synthetic antigen vaccine platform applied to the development of GBP510 allows it to be stored in normal refrigeration conditions under 2 to 8 degrees Celsius, so it can be distributed through the current vaccine logistics network and stored for a long time, securing wider accessibility.

SK bioscience CEO Jaeyong Ahn said, “We were able to successfully manage the phase I/II clinical trial with close cooperation of public health officials including the COVID-19 Pan-government Support Committee, MOHW, MFDS, and the KDCA, as well as global civil and public entities, such as CEPI, Bill and Melinda Gate Foundation, IVI, and GSK. As the phase 3 clinical trial is proceeding smoothly, we will develop GBP510 as quickly as possible to contribute to overcoming the pandemic and securing the right to human health.”