CpG-adjuvanted Clostridioides difficile toxoid vaccine

CpG-adjuvanted Clostridioides difficile toxoid vaccine (PF-07831694) is an investigational bivalent protein subunit vaccine developed by Pfizer for the prevention of Clostridioides difficile infection (CDI). It is a second-generation, updated formulation of Pfizer's previous C. difficile vaccine candidate, PF-06425090, which failed to meet its primary endpoint in the Phase 3 CLOVER trial despite showing efficacy in reducing disease severity and duration. PF-07831694 consists of genetically and chemically inactivated C. difficile toxoids A and B (TcdA and TcdB) adjuvanted with CpG 24555, a synthetic B-class CpG oligodeoxynucleotide (ODN) that acts as a Toll-like receptor 9 (TLR9) agonist. The addition of the CpG adjuvant is designed to enhance the vaccine's immunogenicity, particularly in older adults, and enable a more potent and durable immune response using a 2-dose regimen. The vaccine is currently in Phase 3 clinical development (BEETHOVEN trial, NCT07282665) for the prevention of primary CDI in adults aged 65 years and older.

Other names

C. difficile adjuvanted vaccineClostridioides difficile adjuvanted vaccineClostridioides difficile vaccine (updated formulation)CpG-adjuvanted C. difficile vaccinePF-07831694 toxoidPF07831694 toxoidPF 07831694 toxoid