Trifolium Bio (02197.HK) announced that in Phase I clinical trials, evaluating the adjuvant-free bivalent RSV PreF trimer subunit candidate vaccine SCB-1019 (developed based on Trifolium Bio's unique Trimer-Tag protein trimerization vaccine technology platform) head-to-head comparison with GSK's adjuvanted RSV vaccine AREXVY in elderly subjects yielded more positive immunogenicity and safety data.

Compared to GSK's adjuvanted RSV vaccine AREXVY (76.7%), the adjuvant-free SCB1019 (16.7%) had a significantly lower rate of local adverse events (AEs).

Overall, SCB-1019 demonstrated good tolerability. Both local and systemic adverse events (AEs) of SCB-1019 were generally milder compared to the saline placebo group.

No vaccine-related serious adverse events (SAEs), adverse events of special interest (AESIs), or adverse events (AEs) leading to discontinuation were observed.

Based on the positive Phase I clinical trial results mentioned above, the company plans to initiate clinical trials in 2025 to evaluate SCB-1019 (adjuvant-free bivalent RSV-A/B candidate vaccine) for repeat administration of RSV vaccines and combined respiratory vaccines.