KGF-1

Binds FGFR2b (the KGF receptor), which is exclusively expressed on epithelial cells — providing tissue-specific action without mesenchymal effects. Activates RAS/MAPK and PI3K/Akt to promote keratinocyte proliferation and migration. Extends the anagen phase of the hair growth cycle.

KGF-1 (keratinocyte growth factor 1; FGF-7) is a member of the fibroblast growth factor family that signals exclusively through the FGFR2b splice variant expressed on epithelial cells, where it acts as a potent mitogen and cytoprotective factor for keratinocytes and mucosal epithelial cells; uniquely paracrine in nature, KGF-1 is produced by stromal cells to maintain adjacent epithelial layer integrity and support mucosal healing. KGF-1 activates FGFR2b to drive epithelial cell proliferation, migration, and differentiation, and to protect mucosal surfaces from damage caused by cytotoxic therapies; this cytoprotective mechanism forms the basis of its clinical application in preventing chemotherapy- and radiation-induced breakdown of the gastrointestinal epithelium, where FGFR2b is highly expressed. A landmark randomized controlled trial published in the New England Journal of Medicine (2004) demonstrated that palifermin — recombinant human KGF-1 (Kepivance, Amgen) — significantly reduced the incidence and duration of severe oral mucositis in hematologic malignancy patients undergoing myelotoxic conditioning for stem cell transplant; this pivotal Phase 3 study established the evidence base for FDA approval in 2004. Palifermin (Kepivance) is FDA-approved and requires a prescription for prevention of severe oral mucositis in patients with hematologic malignancies receiving myelotoxic therapy; it is not approved for cosmetic applications, general wound healing, or skin rejuvenation, and the KGF-1 evidence base is specific to chemotherapy-conditioning mucosal protection in oncology settings.