Clover announces positive clinical data for RSV Vaccine candidate SCB-1019 compared head-to-Head Versus GSK's AREXVY

-- 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 --

SHANGHAI, Oct. 29, 2024 /PRNewswire/ -- Clover Biopharmaceuticals, Ltd. (Clover; HKEX: 02197), a global commercial-stage biotechnology company committed to unleashing the power of innovative vaccines to save lives and improve health around the world, today 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.