PTD-DBM

PTD-DBM is a synthetic peptide consisting of a protein transduction domain (PTD, a short cationic peptide that allows passage across cell membranes) fused to the Dvl-binding motif (DBM) of the CXXC5 protein. CXXC5 is a negative-feedback inhibitor of Wnt/β-catenin signaling in hair follicles that becomes upregulated during the catagen phase and contributes to hair-cycle slowdown. By introducing the CXXC5-mimetic DBM peptide into follicle cells (via the PTD-driven membrane crossing), PTD-DBM competitively displaces CXXC5 from Dishevelled (Dvl), restoring Wnt signaling and reactivating the anagen growth phase.

Preclinical work from Kang-Yell Choi's group at Yonsei University in South Korea — the same lab that originally characterized CXXC5's role in hair-cycle regulation — has shown that topical PTD-DBM in combination with valproic acid (another Wnt-pathway activator) produced substantial hair regrowth in mouse models. A Phase 1/2 clinical trial of a related Wnt-pathway combination has been conducted, though regulatory approval has not been achieved.

PTD-DBM is a topical investigational ingredient with a novel and well-characterized mechanism. Research-chemical vendors sell the peptide for cosmetic formulators interested in hair-loss applications. Clinical efficacy in human androgenetic alopecia outside of investigator-sponsored research is not established.

CXXC5 was identified as a negative regulator of Wnt-induced hair cycling by Kang-Yell Choi's group at Yonsei University in research published from 2014 onward. The PTD-DBM peptide therapeutic concept emerged from that same line of work, with the peptide being designed specifically to disrupt the CXXC5-Dvl interaction in hair follicles. The technology was spun out as the basis of a clinical development program by the Korean biotech CK Regeon.