Clover Biopharmaceuticals, Ltd.? announced positive preliminary immunogenicity and safety data in the older adult & elderly cohort from its Phase ? trial evaluating SCB-1019 ?

the company's bivalent RSV prefusion-stabilized F (PreF)-Trimer subunit vaccine candidate ? which is based on Clover's Trimer-Tag vaccine technology platform. These preliminary results in older adults & elderly cohort (aged 60-85) are consistent with the positive results in younger adults (aged 18-59) announced earlier this year.

  In the ongoing Phase ? trial, 48 subjects were enrolled in the older adult & elderly cohort and received either SCB-1019 or saline placebo. Preliminary results for RSV neutralizing antibodies (nAbs) and safety for SCB-1019 at the selected dose-level are summarized below: Immunogenicity Results RSV-A nAbs: SCB-1019 induced geometric mean titers (GMTs) in RSV-A nAbs of up to 7,906 IU/mL compared to 1,078 IU/mL for placebo at Day 28.

RSV-B nAbs: SCB-1019 induced geometric mean titers (GMTs) in RSV-B neutralizing antibody titers (nAbs) of up to 46,674 IU/mL compared to 12,185 IU/mL for placebo at Day 28. Geometric Mean Fold Rise (GMFR): High baseline nAb titers at Day 0 (pre-vaccination), especially to RSV-B, were observed, potentially reflecting recent outbreaks near the clinical trial sites. Thus, sub-analysis in subjects with the lowest quartile baseline nAb titers was performed: GMFRs for SCB-1019 were up to 8-fold for RSV-A nAbs and 11-fold for RSV-B nAbs at Day 28 compared to Day 0 (pre-vaccination).

No increases in RSV-A or RSV-B nAbs were observed for placebo at Day 28. nAb results across both RSV-A and RSV-B appear to be in-line or potentially favorable compared to other protein subunit RSV PreF vaccines1, 2, 3 and continue to be supportive of Clover's bivalent RSV-A/B approach, given that other monovalent RSV-A vaccines have previously observed lower immune responses and/or efficacy against RSV-B 1, 4, 5. Results further confirm that Clover's PreF antigens in SCB-1019 are in the stabilized prefusion and trimeric form, additionally supported by exploratory immunogenicity results demonstrating significant increases in Site Ø and Site V nAb-competitive titers. Safety & Reactogenicity Results SCB-1019 was generally well-tolerated.

Local and systemic adverse events (AEs) were generally mild for SCB-1019 and were comparable to saline placebo. No serious adverse events (SAEs), adverse events of special interest (AESIs), or AEs leading to discontinuation were observed. Results indicate that SCB-1019 could potentially have a differentiated and favorable safety & reactogenicity profile compared to currently-approved oil-in-water adjuvanted4 and/or mRNA5-based RSV vaccines.

The Phase ? clinical trial in Australia is a randomized, placebo-controlled study to assess the safety, reactogenicity and immunogenicity of SCB-1019 at multiple dose levels and in different formulations in young and older adults. Full safety and immunogenicity results in the Phase ?

clinical trial are expected by the end of 2024 to support further development and strengthen the company's potentially differentiated profile for markets globally.