Chinese biotechnology company Clover Biopharmaceuticals Ltd (HKEX:02197) announced on Sunday positive preliminary data from a Phase 2 clinical trial in older adults in Australia evaluating SCB-1022 (RSV + hMPV) and SCB-1033 (RSV + hMPV + PIV3) protein-based vaccine candidates based on prefusion-stabilised F (PreF)-Trimer subunit vaccine antigens utilising Clover's validated Trimer-Tag vaccine technology platform.

The ongoing Phase 2 trial for Clover's combination vaccine candidates is a randomised, observer-blinded, multi-centre study with 420 older adults (60-85 years) enrolled in Australia, with the participants randomised to receive either SCB-1022 (RSV + hMPV), SCB-1033 (RSV + hMPV + PIV3) or placebo.

Robust neutralising antibody responses were seen across RSV, hMPV and PIV3, demonstrating best-in-class breadth with no immune interference and no drop-off in responses in the oldest participants (75+ years).

Approximately 62% lower rate of respiratory tract infection was observed in the vaccine groups (SCB-1022 and SCB-1033) versus the placebo group within 28 days of vaccination based on adverse events reporting of any respiratory tract infections.

In parallel with the Phase 2 trial, Clover conducted commercial-scale 2,000L bioreactor scale-up production of multiple batches of Trimer-Tagged RSV, hMPV and PIV3 PreF antigen components of SCB-1022/1033.

Based on the positive Phase 2 results for the RSV + hMPV ± PIV3 combination vaccine candidates further validating the Trimer-Tag platform, Clover will continue to evaluate continued mid- and late-stage development plans, as well as potential global collaboration opportunities.