SK bioscience : Material Business Matters Related to Investment Decisions (Announcement of the key results of Phase III clinical of COVID-19 vaccine GBP510)

Material Business Matters Related to Investment Decisions

1. Title	Announcement of the key results of Phase III clinical of COVID-19 vaccine GBP510
2. Details	※ Other references useful for making invest decisions The probability that a drug in a clinical trial will be finally approved as a finished drug product is known to be statistically around 10%. In the process of clinical trials and product approval, results may not meet expectations, and there is a possibility that the company may change or abandon its commercialization plan. Investors are encouraged to invest carefully, taking into account the above and the investment risks disclosed in the business report. 1. Title of Clinical Trial - Multicenter, parallel comparison, observer-blind, active control, randomized, Phase III clinical trials to evaluate the immunogenicity and safety of SARS-CoV-2 recombinant protein nanoparticle vaccine (GBP510) in adults 18 years or older 2. Phase of the clinical trial - Phase III clinical trial 3. Target disease (indications) - Prevention of COVID-19 disease caused by SARS-CoV-2 infection 4. Clinical trial application date and approval institution - Application date: June 28, 2021 - Approval date: August 10, 2021 - Clinical trial approval institution: Ministry of Food and Drug Safety (MFDS) - Clinical trial institution: Korea University Guro Hospital and 15 other institutions in and outside the country 5. Clinical trial registration number - NCT05007951 (https://www.clinicaltrials.gov) 6. Clinical trial method - This phase 3 study aimed to assesss the immunogenicity and safety of GBP510 25μg adjuvanted with AS03 in adults aged 18 years and older. The first subject was enrolled on 30th Aug 2021 and the enrollment of a total of 4,037 subjects was completed on 14th Jan 2022. As the primary endpoints, superiority and non-inferiority of immune responses in neutralizing antibodies were demonstrated after primary vaccination (2 doses at 4 weeks interval) compared to Vaxzevria which is a COVID-19 vaccine developed by AstraZeneca. 7. Clinical trial results ① Immunogenicity: - Superiority was assessed based on the post-GMT ratio of neutralizing antibodies (GBP510/Vaxzevria) 2 weeks after primary vaccination, and the superiority was decared since the superiority criterion was met and the hypothesis was satisfied. - Non-inferiority was assessed based on the difference of seroconversion rates (≥4-fold increase of neutralizing antibodies from baseline) between GBP510 and Vaxzevria 2 weeks after primary vaccination, and the non-inferiority was decared since the non-inferiority margin was met and the hypothesis was satisfied. ② Safety: - Details will be disclosed later. 8. Expected effect - All immunobridging criteria were fulfulled by the sufficient immune responses after primary vaccination of GBP510, therefore, a comparable or even better vaccine efficacy may be inferred by immunobridging from that of Vaxzevria, AstraZeneca. 9. Future Plans - Safety data will be further obtained and then BLAs will be submitted in Korea and other countries for the indication of prevention of COVID-19 in adults
3. Date of board resolution (decision date) or confirmation date	2022-04-22
- Attendance of outside directors	Present(No.)	-
Absent(No.)	-
- Attendance of auditors (members of Audit Committee who are not outside directors)	-
4. Other matters to be factored into investment decisions
- "3.Date of board resolution (decision date) or confirmation date" is the date when SKBS received the topline data of the Phase 3 clinical trial from the CRO.
※ Related disclosure	2021-08-10 투자판단 관련 주요경영사항 2021-06-28 투자판단 관련 주요경영사항