- Head-to-head clinical results indicate a potential best-in-class combined efficacy & safety profile of non-adjuvanted bivalent RSV vaccine candidate (SCB-1019) --

-- RSV neutralizing antibodies for Clover's non-adjuvanted SCB-1019 matched GSK's AS01_E-adjuvanted AREXVY in older adults, while demonstrating significantly better tolerability compared to AREXVY --

-- Clover plans to initiate clinical trials in 2025 evaluating SCB-1019 in an RSV re-vaccination setting and as part of a respiratory combination vaccine --

Clover Biopharmaceuticals, Ltd.  a global commercial-stage biotechnology company committed to unleashing the power of innovative vaccines to save lives and improve health around the world, announced positive additional immunogenicity and safety data in older adult & elderly subjects from its Phase Ⅰ trial evaluating SCB-1019 – the company's non-adjuvanted bivalent RSV prefusion-stabilized F (PreF)-Trimer subunit vaccine candidate based on Clover's Trimer-Tag vaccine technology platform – compared head-to-head with GSK's AS01_E-adjuvanted RSV vaccine (AREXVY).

"We are pleased to announce positive head-to-head clinical data for our non-adjuvanted SCB-1019 RSV vaccine candidate compared to AS01_E-adjuvanted AREXVY, indicating our potential best-in-class combined efficacy & safety profile," said Joshua Liang, Chief Executive Officer & Board Director of Clover. "While currently approved protein-based RSV vaccines are safe & effective when given as an initial dose, the ability to re-vaccinate effectively when protection against RSV disease wanes and the prevention of respiratory disease caused by other viruses related to RSV both remain unaddressed & high unmet needs globally. We look forward to evaluating SCB-1019 in an RSV re-vaccination setting and as part of a respiratory combination vaccine in clinical trials in 2025."  

In the ongoing Phase Ⅰ trial, 70 older adult & elderly subjects were enrolled and received either Clover's SCB-1019, GSK's AREXVY or saline placebo. Preliminary results for immunogenicity and safety for SCB-1019 are summarized below:

Immunogenicity Results

• RSV Neutralizing Antibodies (nAbs): Non-adjuvanted SCB-1019 induced geometric mean titers (GMTs) in RSV-A and RSV-B nAbs that were comparable to AS01_E-adjuvanted AREXVY at Day 28, with no statistically significant differences observed.
  • RSV-A nAbs: SCB-1019 induced GMTs in RSV-A nAbs of approximately 30,500 IU/mL, compared to approximately 26,700 IU/mL for AREXVY and approximately 3,300 IU/mL for placebo at Day 28.
  • RSV-B nAbs: SCB-1019 induced GMTs in RSV-B nAbs of approximately 32,000 IU/mL, compared to approximately 37,700 IU/mL for AREXVY and approximately 2,900 IU/mL for placebo at Day 28.
• RSV-B Specific Antibodies: SCB-1019 (bivalent RSV-A/B) included an approximately 1.5-fold higher trend in antibodies (Geometric Mean Ratio [GMR]) against a potent RSV-B specific neutralization epitope in Site V compared to AREXVY (monovalent RSV-A), based on an exploratory competitive-ELISA assay, indicating the potential for greater and more sustained immunological breadth upon re-vaccination if confirmed in subsequent studies.

Safety & Reactogenicity Results

• Significantly lower rates of local adverse events (AEs) were observed for non-adjuvanted SCB-1019 (16.7%) compared to AS01_E-adjuvanted AREXVY (76.7%).
• SCB-1019 was generally well-tolerated. Local and systemic AEs were generally mild for SCB-1019 and were comparable to saline placebo.
• No vaccine related serious adverse events (SAEs), adverse events of special interest (AESIs), or AEs leading to discontinuation were observed.

Based on these positive Phase Ⅰ trial results, Clover plans to initiate clinical trials in 2025 evaluating SCB-1019 (non-adjuvanted bivalent RSV-A/B vaccine candidate) utilized in an RSV re-vaccination setting and as part of a respiratory combination vaccine.