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 IND clearance by U.S. FDA and that enrollment of the first participants has been completed in a Phase I revaccination clinical 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.

"We are pleased to announce the U.S. IND clearance and revaccination clinical trial initiation, which supports the differentiated global opportunity of Clover's RSV PreF vaccine (SCB-1019) utilizing our validated Trimer-Tag platform," 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, critical gaps persist globally: (1) suboptimal boostability for revaccination when protection against RSV disease wanes, and (2) inability to prevent respiratory disease caused by other viruses related to RSV such as hMPV and PIV3. Thus, we look forward to the clinical trial results for SCB-1019 in an RSV re-vaccination setting and as part of a respiratory combination vaccine (RSV + hMPV ± PIV3)." 

In October 2024, Clover announced Phase I results in 70 older adults (60-85 years) who were RSV vaccine-naïve, and results indicated a potential best-in-class combined immunogenicity & tolerability profile of non-adjuvanted SCB-1019 compared head-to-head to GSK's AS01_E-adjuvanted RSV vaccine (AREXVY).

The ongoing Phase I revaccination trial in the U.S. is enrolling up to 160 older adults (60-85 years) who previously received an initial dose of GSK's RSV vaccine (AREXVY) at least 2 seasons prior, and participants will be randomized to receive either a heterologous revaccination dose of SCB-1019, a homologous AREXVY revaccination dose or saline placebo. The study will assess safety, reactogenicity and immunogenicity.

Furthermore, evaluation of SCB-1019 as part of a respiratory combination Trimer-Tagged PreF vaccine (RSV + hMPV ± PIV3) is also on track for Phase I clinical trial initiation in 2025.