SK Bioscience's Covid vaccine going into final trials

An SK Bioscience researcher conducts tests to develop a Covid-19 vaccine at the company's lab. [SK BIOSCIENCE]

SK Bioscience’s Covid-19 vaccine candidate GBP510 won approval to start Phase 3 clinical trials, the company said Tuesday.

It is the first domestic Covid-19 vaccine candidate to get the nod to start Phase 3 clinical trials — the last round required for a vaccine.

According to the vaccine unit of SK Group, the trials will be conducted by comparing the candidate with AstraZeneca vaccines. In late May, the Ministry of Food and Drug Safety designed new comparative-style clinical trials, which compare the immunogenicity of an already authorized vaccine with a candidate under development in order to prove its efficacy. That was supposed to help local companies speed up development of Covid-19 vaccines without having to go through clinical trials that require large control groups.

GBP510's Phase 3 clinical trials will be conducted on 3,990 people aged 18 or older. 3,000 people will be injected with SK Bioscience’s GBP510 while 990 will get AstraZeneca vaccines. They will receive two doses of 0.5 milliliters (0.017 ounces) at four-week intervals.

SK Bioscience’s GBP510 is a recombinant vaccine that uses protein antigens. It is the result of recombinant DNA technology, which involves inserting an antigen onto the surface of a protein. Inside the body, that antigen stimulates an immune response that creates antibodies to fight off the virus in case of infection.

The Phase 3 trials will take place in multiple countries including Korea and Southeast Asian and European countries. The company aims to release the interim results of the Phase 3 clinical trials by the first quarter of next year and, if the results are good, commercialize the vaccine within the first half.

On Tuesday, SK Bioscience also revealed that the Phase 1 and 2 clinical trials of the vaccine candidate have produced results confirming its efficacy and safety.

The vaccine is currently undergoing Phase 2 clinical trials. Originally, only companies that had successfully ended Phase 2 trials could start Phase 3 trials. But the Ministry of Food and Drug Safety gave the company approval to start the last stage based on an analysis that “results of Phase 1 clinical trials have proved enough safety and immunogenicity.”

According to the company, a total of 80 people between the ages of 19 and 55 participated in Phase 1 clinical trials and all induced antibodies to fight the Covid-19 virus. In terms of safety, no special symptoms were reported excluding some common symptoms like fatigue and headache.

For the Phase 2 trials, SK Bioscience completed injections of the second dose in a total of 247 participants in June, which also included older people. The company is currently observing the participants and no safety issues have been reported so far.

The development of GBP510 has been funded by the Bill & Melinda Gates Foundation and the Coalition for Epidemic Preparedness Innovations, an international foundation that promotes equal worldwide distribution of pandemic vaccines. Of $213.7 million the company received, about $173 million will be used for research and development expenses, which includes conducting the Phase 3 clinical trials, developing mass production methods and doing further studies on Covid-19 variants.

“The results SK Bioscience have had so far were only possible with the close cooperation of local health authorities including the Ministry of Health and Welfare, the Ministry of Food and Drug Safety and the Korea Disease Control and Prevention Agency, as well as many global organizations,” said SK Bioscience CEO Ahn Jae-yong. “SK Bioscience will contribute to the world’s continuous efforts to fight the Covid-19 pandemic by quickly developing an efficient and safe vaccine of our own.”

SK Bioscience shares closed at a record high of 301,500 won ($262.3) Tuesday, up 29.68 percent from the previous trading session, after the news of getting approval to start the last stage of clinical trials. Shares rose as high as 302,000 won, the maximum ceiling of 30 percent, during intraday trading.

BY SARAH CHEA [chea.sarah@joongang.co.kr]