A novel product candidate, referred to as “C16G2″, was designed as a specifically targeted antimicrobial peptide (STAMP) with specificity for Streptococcus mutans. The C16G2 peptide consists of two functional regions: an S. mutans-selective ‘targeting region’ comprised of a fragment of the S. mutans competence stimulating peptide (CSP); and a broad-spectrum antimicrobial peptide (G2). Our research has shown that C16G2 is bactericidal via a membrane disruption mechanism similar to other antimicrobial peptides. The very fast kinetics of C16G2’s bactericidal activity against S. mutans confers its antimicrobial specificity (Kaplan, Sim et al. 2011) and provides for convenient administration by routes currently employed in dental practices. C16G2 is also bactericidal against early-stage and mature S. mutans biofilms and demonstrates selectivity for S. mutans in planktonic and biofilm-associated mixed culture systems (Eckert, He et al. 2006). Multi-species biofilms from which S. mutans has been eliminated by C16G2 resist re-colonization by S. mutans, thus demonstrating the distinguishing feature of this drug candidate: a protective colonization effect in vitro (Li, Guo et al. 2010). This product profile of C16G2 supports the rationale for it to be administered as a topical oral product to selectively kill S. mutans while not affecting the other species in the oral biofilm.
C16G2 has been investigated in Phase 2 Clinical trials under a U.S. FDA IND application. Studies conducted to date have showed an acceptable safety and tolerability profile of the drug while demonstrating a selective reduction of S. mutans in the oral cavity.
To complement our S. mutans therapeutic we have developed a polymerase chain reaction (PCR) based diagnostic assay. This assay has been extensively used during the course of our C16G2 clinical program to provide data on the antimicrobial efficacy of C16G2 against S. mutans and will aid in the diagnosis of subjects’ S. mutans levels for entrance to therapy and monitoring the effect of treatment.