Domestic Vaccine Emerges... SK Bioscience Enters Phase 3 Evaluation

'GBP510' Officially on Trial
Aiming for Emergency Use Authorization in Early Next Year

In August, subject administration for the Phase 3 clinical trial of SK Bioscience's COVID-19 vaccine candidate 'GBP510' was conducted at Dong-A University Hospital in Busan. (Photo by SK Bioscience)

[Asia Economy Reporter Lee Chun-hee] SK Bioscience's synthetic antigen vaccine 'GBP510,' developed with the goal of becoming the first domestically produced COVID-19 vaccine, is entering a full-scale testing phase.

The Korea Disease Control and Prevention Agency's National Institute of Health announced on the 21st that it will begin efficacy evaluation (neutralizing antibody analysis) of specimens from the large-scale Phase 3 clinical trial of GBP510. To this end, serum specimens isolated from the blood of Phase 3 clinical trial participants were delivered to the National Institute of Health on the morning of the same day.

Efficacy evaluation is a process to determine how much neutralizing antibody, which neutralizes viral infection in the bodies of actual clinical subjects, is formed through vaccine administration, and it is an essential step in vaccine development and approval. A KDCA official explained, "While Phases 1 and 2, which were conducted earlier, were reviewed internally by the company, this Phase 3 clinical trial is large-scale, so the National Institute of Health and the International Vaccine Institute (IVI) have stepped in to support the review."

SK Bioscience's 'L House Vaccine Center' in Andong-si, Gyeongbuk (Photo by SK Bioscience)

GBP510 is a COVID-19 vaccine candidate jointly developed by SK Bioscience and the Institute for Protein Design (IPD) at the University of Washington School of Pharmacy, utilizing GlaxoSmithKline (GSK)'s adjuvant technology. Currently, a large-scale global Phase 3 clinical trial involving 3,990 participants is underway in South Korea, Vietnam, Ukraine, Thailand, New Zealand, and the Philippines. On this day, blood samples from about half of the immunogenicity evaluation participants were delivered to the National Institute of Health.

In the earlier Phases 1 and 2 clinical trials conducted on 328 healthy adults, neutralizing antibody formation that neutralizes the COVID-19 virus was confirmed in over 99% of the group administered the vaccine along with the adjuvant. The level of neutralizing antibody induction two weeks after completing vaccination was about six times higher in pseudovirus-based neutralization antibody (PBNA) analysis compared to the serum panel of COVID-19 convalescent patients in the overall clinical group analysis. In plaque reduction neutralization test (PRNT) analysis conducted on some groups, it was 3.6 times higher, and in enzyme-linked immunosorbent assay (ELISA) results, binding antibodies were about 13.3 times higher compared to the convalescent serum panel.

Currently, SK Bioscience aims to obtain approval from the Ministry of Food and Drug Safety in the first half of next year. The company plans to rapidly commercialize the vaccine by obtaining the World Health Organization (WHO)'s prequalification (PQ) certification and emergency use authorizations from various countries overseas. In this case, it is highly likely to be selected as a domestically produced COVID-19 vaccine for government-led advance purchase. The government plans to make advance purchases of domestically produced COVID-19 vaccines based on comprehensive consideration of efficacy and safety, assuming the interim results of Phase 2 and entry into Phase 3. A budget of 192 billion KRW has been allocated to the KDCA for this purpose next year.